rock jaw-crusher, other rock crushers

[Richard Smith]

You have proved to be a remarkable font of knowledge.

Fancifully looking forward to tunnel-blasting rock (local is a very
hard granite) I looked to the "stemming". What you put put in the
collar of the drilled hole beyond the last charged blasting medium, to
effect a seal intensifying the blasting effect.

I know the one about if you try to press ceramic material down a hole
(or die or mould) it "bridges" and "locks". So I see "stemming" would
work in that way and is a good idea.
Then with a gravel stemming all that happens when it does "let go" is
a spray of grit - no heavy projectiles.

So that seemed a motivation to make a small jaw-crusher (best type of
crusher?) which can convert lumps of the granite into sharp gravel
about 4mm to 5mm size (?) to pack down the hole filling to the last
charge.

Whatever - it's a project.
I hear that a double-toggle crusher is best for very hard stone -
which this granite is. Giving a pure crushing action.
A single-toggle crusher with the eccentric shaft above the inlet for
the rock produces a combined crushing+shear as the moving jaw also has
up-and-down movement - which is reputed to increase throughput for
softer rocks but produce extra wear for no advantage on hard rocks.

Or does this not matter at small sizes?

I was thinking about 5"/125mm to 6"/150mm inlet capacity.
So quite a small machine.
Big rocks could be split with "feathers" - drill a socket, put in the
"feathers" and the wedge and split the rock.
We are not talking of huge quantities here.

Fanciful for sure. No-one at the mo. has a current blasting licence,
for a start...

But anyway - any experience?
I was thinking welded steel construction.
Apart from the jaws.
Cast very hard metal?
Cast "Hadfield Manganese Steel"?
Structural steel plate with welded hard-facing?

Regards,
Rich Smith

[Jim Wilkins]

"Richard Smith" wrote in message news:***@void.com...

You have proved to be a remarkable font of knowledge.

Fancifully looking forward to tunnel-blasting rock (local is a very
hard granite) I looked to the "stemming". What you put put in the
collar of the drilled hole beyond the last charged blasting medium, to
effect a seal intensifying the blasting effect.

I know the one about if you try to press ceramic material down a hole
(or die or mould) it "bridges" and "locks". So I see "stemming" would
work in that way and is a good idea.
Then with a gravel stemming all that happens when it does "let go" is
a spray of grit - no heavy projectiles.

So that seemed a motivation to make a small jaw-crusher (best type of
crusher?) which can convert lumps of the granite into sharp gravel
about 4mm to 5mm size (?) to pack down the hole filling to the last
charge.

[What protects the wires to the blasting cap?]

Big rocks could be split with "feathers" - drill a socket, put in the
"feathers" and the wedge and split the rock.
We are not talking of huge quantities here.

[Wedges and shims or "feathers" is what I use to cut away granite protruding
into the paths around my house, which was crammed into a rocky hillside.

I've watched large granite boulders at a blasting site being broken up for
fill with a hydraulic "pecker" which is an oscillating single point chisel
mounted on a tracked excavator in place of the bucket. They said the
vibrations damaged the excavator so they used an old worn one for this job.
A single point carbide-tipped chisel is recommended for manually carving
granite too.

Apparently "Excavator" is also the British term. In German it's "Bagger".]

Fanciful for sure. No-one at the mo. has a current blasting licence,
for a start...

But anyway - any experience?
I was thinking welded steel construction.
Apart from the jaws.
Cast very hard metal?
Cast "Hadfield Manganese Steel"?
Structural steel plate with welded hard-facing?

[Around here AR400 is commonly used for repairs and mods to construction
equipment.]
https://www.steelwarehouse.com/ar400/

[Richard Smith]

Current practice seems to be to use "Nonel" (non-electric) detonators.
Brilliant explanation at
YouTube channel
https://www.youtube.com/@mbmmllc

Video of "Opening My Gold Mine" series
"Opening My Gold Mine! Part 12: Last Drill & Blast"
go to about 23:39 / 36:20

* there's two delays - 0.3s at the clamp to pass on to the next shock tube
and 7s at the actual "blasting cap"

* the detonator goes to the bottom of the hole, so the blast propagation
is from deepest to near surface

* the "Nonel" tube conducting the shock/signal holds intact and does not
disturb the stemming or the blasting material it runs past

* the use of the delays is well explained in the video

Hope this is helpful


The "AR400" I think that is for excavator bucket lining and the like -
nothing like as hard as a rock crusher working face needs to be?

[Jim Wilkins]

"Richard Smith" wrote in message news:***@void.com...

The "AR400" I think that is for excavator bucket lining and the like -
nothing like as hard as a rock crusher working face needs to be?

----------------------------

It's a machinable high strength steel that I can obtain locally in small
cut-offs.
https://www.practicalmachinist.com/forum/threads/milling-ar-400-need-some-advice-please.239548/

Another is 5160 leaf spring stock, but it's limited in sizes. I made a D
step drill from O-1 drill rod to open a leaf spring shackle hole from 1/2"
to 5/8" that cut well enough after the second heat treating attempt. The kid
just had to lift his truck higher than his father's which was on a
commercial lift kit, so he had a higher lift kit fabricated and it came with
5/8" U bolts. As usual the answer was to call Jim for help.

If they are available wherever the H you are (Coober Pedy, Alice Springs?)
they might be strong plus tough enough for the toggle linkage and blade
bodies though not the cutting face which you suggested hardfacing.

[Jim Wilkins]

"Richard Smith" wrote in message news:***@void.com...

But anyway - any experience?
I was thinking welded steel construction.
Apart from the jaws.
Cast very hard metal?
Cast "Hadfield Manganese Steel"?
Structural steel plate with welded hard-facing?

--------------------
I bought proper material when building for paying customers, otherwise after
roughly estimating the demands I searched out what was available locally and
designed around it, usually in my head when I found it. This avoids minimum
ordering quantities and long waits. It helps a lot to pay attention to what
others have used to solve similar problems, and to own or have access to
machine shop equipment to modify stock shapes.

I depend on a medium sized vertical knee-type milling machine, a
thread-cutting lathe similar to a Myford, a 4"x6" horizontal metal-cutting
bandsaw and a pedestal grinder in addition to the welding equipment. The
mill serves as my drill press. For most jobs a good mill/drill would also
do. A larger bandsaw would be better, but what I have was enough to make a
hydraulic bucket loader attachment for my small tractor and a bandsaw lumber
mill, plus lab prototypes for aerospace projects and various custom
automotive tools. I have other equipment including a surface grinder, rotary
indexers and sheet metal shear/brake but those are the essentials. To
oversimplify the bandsaw and mill make the framework, the lathe makes the
moving parts.

To some extent the framework can be plate sawn or torched to shape and the
bolt and bearing holes done on a drill press, preferably after welding which
may shift nearby holes. Drilling two side plates clamped together makes the
hole locations identical if not exactly where intended. High tensile bolts
like US Grade 5 and 8 can serve as pivots though they aren't ideal for
diameter, length or surface finish. Machine tools give you many more options
and make putting bearing holes right where you want them and all parallel
(for the toggle linkage) much easier.

Here's a tungsten carbide hardface meant for rock impacts that can be
applied with acetylene:
https://tnfarriersupply.com/products/black-diamond-borium-rods

[Richard Smith]

Notes from yesterday "YouTube'ing"...

vvvvvvvv

Notes from yesterday "YouTube".
Various manufacturers talking.
[Came across the eccentric wheel crusher]

Jaw crushers are tough - the reality. For primary crushing cone /
gyrating crushers have the numbers for throughput and the crushing
performance - but not that toughness. Much more vulnerable to
"uncrushable" debris, etc. - where damage sends up cost.

Impact crushers are found in bigger sizes.
Anyone wants a "one pass" large initial to fine final size.
Yes for small sizes / small operations.
Scale-up - still "one pass" - but wear goes against them, compared to
large crushing crushers.

Small-scale - gold prospectors sometimes improvise a chain-flail
impact crusher where deliberately nothing leaves the chamber until it
leaves with a throughflow of air as dust...

^^^^^^^^

For stemming you want a definite size distribution - a coarse (~ 4mm to
5mm ?) sharp grit - so much of above not relevant. Many "ore
extraction" applications - finer is better (?).

Heard of a roll crusher which apparently gives a lot of the throughput
close to the aim size (???).

[Leon Fisk]

On Thu, 15 Feb 2024 04:43:51 +0000
Richard Smith <***@void.com> wrote:

<snip>

Post by Richard Smith
Heard of a roll crusher which apparently gives a lot of the throughput
close to the aim size (???).

There are several old texts, compilations on Mining and such at
Archive.com. If you have any spare time nowadays :) For instance:

https://archive.org/details/miningscientific96sanfuoft/page/154/mode/2up

Came across them awhile back while searching for some old info...

[Richard Smith]

Post by Leon Fisk
On Thu, 15 Feb 2024 04:43:51 +0000
<snip>

Post by Richard Smith
Heard of a roll crusher which apparently gives a lot of the throughput
close to the aim size (???).

There are several old texts, compilations on Mining and such at
https://archive.org/details/miningscientific96sanfuoft/page/154/mode/2up
Came across them awhile back while searching for some old info...

Thanks for that link.

At the mine yesterday someone told me

* he appreciated my links to YouTube videos on my webpage
http://www.weldsmith.co.uk/tech/minerals/240205_yt_goldmine/240205_yt_goldmine.html
"Opening My Gold Mine!" series
and had got up to 8 of the 17 of the series

* he and his father have a "hammer mill" - a high-speed (?) impact
crusher

* the output of that goes to some "California stamps" they made

* they have some 5% cassiterite (tin oxide) - ie. notably excellent -
ore to work which they obtained from a mine a few decades ago

So that's opened another conversation.

Rich Smith

[Jim Wilkins]

Post by Leon Fisk
On Thu, 15 Feb 2024 04:43:51 +0000
<snip>

Post by Richard Smith
Heard of a roll crusher which apparently gives a lot of the throughput
close to the aim size (???).

There are several old texts, compilations on Mining and such at
https://archive.org/details/miningscientific96sanfuoft/page/154/mode/2up
Came across them awhile back while searching for some old info...

Thanks for that link.

At the mine yesterday someone told me

* he appreciated my links to YouTube videos on my webpage
http://www.weldsmith.co.uk/tech/minerals/240205_yt_goldmine/240205_yt_goldmine.html
"Opening My Gold Mine!" series
and had got up to 8 of the 17 of the series

* he and his father have a "hammer mill" - a high-speed (?) impact
crusher

* the output of that goes to some "California stamps" they made

* they have some 5% cassiterite (tin oxide) - ie. notably excellent -
ore to work which they obtained from a mine a few decades ago

So that's opened another conversation.

Rich Smith
------------------------------------

My impression is that stamping mills have the advantage of being simple and
easily maintainable without needing a machine shop, perhaps only basic
blacksmithing equipment (or acetylene) suffices. When I study early 1800's
tech I look for what they needed to make it. Steam engines languished at a
primitive level for a century for lack of machine tools.

While not specific to mining, the forge that accompanied horse artillery is
a well described example of a self-sufficient portable metalworking
capability.
https://en.wikipedia.org/wiki/Traveling_forge
The original Army manual lists the equipment but not how it was used. In
addition to horseshoeing they had battle damage to their and other vehicles
to repair.

A modern version is the rather minimal gear blacksmiths carry to demonstrate
at fairs and festivals.

[Jim Wilkins]

"Richard Smith" wrote in message news:***@void.com...

Jaw crushers are tough - the reality. For primary crushing cone /
gyrating crushers have the numbers for throughput and the crushing
performance - but not that toughness. Much more vulnerable to
"uncrushable" debris, etc. - where damage sends up cost.

Impact crushers are found in bigger sizes.
Anyone wants a "one pass" large initial to fine final size.
Yes for small sizes / small operations.
Scale-up - still "one pass" - but wear goes against them, compared to
large crushing crushers.

Small-scale - gold prospectors sometimes improvise a chain-flail
impact crusher where deliberately nothing leaves the chamber until it
leaves with a throughflow of air as dust...

^^^^^^^^

For stemming you want a definite size distribution - a coarse (~ 4mm to
5mm ?) sharp grit - so much of above not relevant. Many "ore
extraction" applications - finer is better (?).

Heard of a roll crusher which apparently gives a lot of the throughput
close to the aim size (???).

----------------------------
I've been waiting for and researching the question of what you need to build
such machinery, and haven't found good answers because it depends so much on
what you want/need to do, and how much size capacity you are willing to buy
new or can find locally used. Metalworking can become an expensive hobby
depending on the size, power and complexity of your designs.

[Jim Wilkins]

"Jim Wilkins" wrote in message news:uqsrip$11g2t$***@dont-email.me...

I've been waiting for and researching the question of what you need to build
such machinery, and haven't found good answers because it depends so much on
what you want/need to do, and how much size capacity you are willing to buy
new or can find locally used. Metalworking can become an expensive hobby
depending on the size, power and complexity of your designs.

------------------------------

Here is a good example. Required horsepower and speed determine shaft
torque, and the dimensions of the appropriate shaft partly determine lathe
size, the spindle bore for long shafts and distance between centers for
short ones.
https://www.plantengineering.com/articles/relationship-of-torque-and-shaft-size/

Buying expensive new drive components can reduce or eliminate custom
machining, using salvaged ones increases it.

Likewise the distance between bearing bores that must be parallel determines
milling machine table size. Building larger with self-aligning pillow blocks
can bring fussy alignment issues and higher maintenance.

[Richard Smith]

Post by Jim Wilkins
I've been waiting for and researching the question of what you need to build
such machinery, and haven't found good answers because it depends so much on
what you want/need to do, and how much size capacity you are willing to buy
new or can find locally used. Metalworking can become an expensive hobby
depending on the size, power and complexity of your designs.
------------------------------
Here is a good example. Required horsepower and speed determine shaft
torque, and the dimensions of the appropriate shaft partly determine
lathe size, the spindle bore for long shafts and distance between
centers for short ones.
https://www.plantengineering.com/articles/relationship-of-torque-and-shaft-size/
Buying expensive new drive components can reduce or eliminate custom
machining, using salvaged ones increases it.
Likewise the distance between bearing bores that must be parallel
determines milling machine table size. Building larger with
self-aligning pillow blocks can bring fussy alignment issues and
higher maintenance.

I was thinking of a small device to start with.
Maybe opening to jaw area is very few inches wide and gap.
If objective is "grit" around 6mm / 1/4inch, the stroke of the jaws
could be small?
Limited throughput, but advantages?
Looking to get a sack of the coarse grit for "stemming"
(can go down into the mine in the skip down the shaft)

Haven't developed anything more at the moment.
Line-boring the bearings yes.
How to machine and eccentric - realise don't know how to do that.
Visualise having two centres each end for between-centres.
Challenge is their axis, offset being on the same radius (the radial
direction) and radial offset.
Must look-up how that is done...

[Snag]

Post by Richard Smith

Post by Jim Wilkins
I've been waiting for and researching the question of what you need to build
such machinery, and haven't found good answers because it depends so much on
what you want/need to do, and how much size capacity you are willing to buy
new or can find locally used. Metalworking can become an expensive hobby
depending on the size, power and complexity of your designs.
------------------------------
Here is a good example. Required horsepower and speed determine shaft
torque, and the dimensions of the appropriate shaft partly determine
lathe size, the spindle bore for long shafts and distance between
centers for short ones.
https://www.plantengineering.com/articles/relationship-of-torque-and-shaft-size/
Buying expensive new drive components can reduce or eliminate custom
machining, using salvaged ones increases it.
Likewise the distance between bearing bores that must be parallel
determines milling machine table size. Building larger with
self-aligning pillow blocks can bring fussy alignment issues and
higher maintenance.

I was thinking of a small device to start with.
Maybe opening to jaw area is very few inches wide and gap.
If objective is "grit" around 6mm / 1/4inch, the stroke of the jaws
could be small?
Limited throughput, but advantages?
Looking to get a sack of the coarse grit for "stemming"
(can go down into the mine in the skip down the shaft)
Haven't developed anything more at the moment.
Line-boring the bearings yes.
How to machine and eccentric - realise don't know how to do that.
Visualise having two centres each end for between-centres.
Challenge is their axis, offset being on the same radius (the radial
direction) and radial offset.
Must look-up how that is done...

When I've needed an eccentric I set my piece up in a 4 jaw chuck
offset the needed distance . If short , you can machine it without a
center on the open end . If you need length you have to be careful to
index your stock so the offset centers are aligned .

[Richard Smith]

Post by Snag

...

...

When I've needed an eccentric I set my piece up in a 4 jaw chuck
offset the needed distance . If short , you can machine it without a
center on the open end . If you need length you have to be careful
to index your stock so the offset centers are aligned .

Thanks Snag.
I can "see" that.
Presumably can wind the saddle of the lathe along with a
test-dial-indicator against the now offset shaft, checking by zero
deflection that the shaft is still on the same axis?
"Fiddle" until you find a perfect alignment then get machining?
For the longer shafts of the eccentric of a jaw-crusher you would drill
a small centre-taper and have the tailstock supporting?

[Snag]

Post by Richard Smith

Post by Snag

...

...

When I've needed an eccentric I set my piece up in a 4 jaw chuck
offset the needed distance . If short , you can machine it without a
center on the open end . If you need length you have to be careful
to index your stock so the offset centers are aligned .

Thanks Snag.
I can "see" that.
Presumably can wind the saddle of the lathe along with a
test-dial-indicator against the now offset shaft, checking by zero
deflection that the shaft is still on the same axis?

I was thinking more of an index line down the length of the stock
aligned with one of the chuck jaws as a reference , but a pass with the
DI would be a good way to insure the alignment .

Post by Richard Smith
"Fiddle" until you find a perfect alignment then get machining?
For the longer shafts of the eccentric of a jaw-crusher you would drill
a small centre-taper and have the tailstock supporting?

Actually holding the part on offset centers and using a drive dog would
work well too . But yes , you have the idea I was trying to convey .
I used the chuck to offset the cam on my home made QCTP but it's only
a couple of inches long .

[Jim Wilkins]

Post by Richard Smith

Post by Snag

...

...

When I've needed an eccentric I set my piece up in a 4 jaw chuck
offset the needed distance . If short , you can machine it without a
center on the open end . If you need length you have to be careful
to index your stock so the offset centers are aligned .

Thanks Snag.
I can "see" that.
Presumably can wind the saddle of the lathe along with a
test-dial-indicator against the now offset shaft, checking by zero
deflection that the shaft is still on the same axis?

I was thinking more of an index line down the length of the stock
aligned with one of the chuck jaws as a reference , but a pass with the
DI would be a good way to insure the alignment .

Post by Richard Smith
"Fiddle" until you find a perfect alignment then get machining?
For the longer shafts of the eccentric of a jaw-crusher you would drill
a small centre-taper and have the tailstock supporting?

Actually holding the part on offset centers and using a drive dog would
work well too . But yes , you have the idea I was trying to convey .
I used the chuck to offset the cam on my home made QCTP but it's only
a couple of inches long .
Snag
"They may take our lives but
they'll never take our freedom."
William Wallace

--------------------------------
That's in the class of problems I assume can be solved when making it, cross
that bridge... They don't hold up the design process, though I may make them
first to be sure. If someone else has done it there must be a way. The
solution may be having to make a locating fixture, as for machining a
crankshaft.
https://modelenginenews.org/techniques/crankshafts.html

I use 5C collets in square or hex blocks to accurately machine the ends of
round rods. Vee blocks on a mill would do for eccentric center holes in
fairly short shafts.

[Gerry]

Post by Richard Smith

Post by Snag

...

...

When I've needed an eccentric I set my piece up in a 4 jaw chuck
offset the needed distance . If short , you can machine it without a
center on the open end . If you need length you have to be careful
to index your stock so the offset centers are aligned .

Thanks Snag.
I can "see" that.
Presumably can wind the saddle of the lathe along with a
test-dial-indicator against the now offset shaft, checking by zero
deflection that the shaft is still on the same axis?
"Fiddle" until you find a perfect alignment then get machining?
For the longer shafts of the eccentric of a jaw-crusher you would drill
a small centre-taper and have the tailstock supporting?

IIRC that is how I made the eccentrics for my compost screen shaker. I
started with a short length of round stock offset in the four jaw,
centre drilled the right end, turned down the mid section; then
through drilled for the shaft and cut it in half andused the small
diameter in the fixed journals and the larger eccentrics in the screen
frame rails. The two sections are keyed to the driving shaft by set
screws in dimples in the shaft
Now that the City has institutrd a green bin program I will probably
transfer my screening plant to Junior who lives out of town.

[Jim Wilkins]

"Richard Smith" wrote in message news:***@void.com...

I was thinking of a small device to start with.
Maybe opening to jaw area is very few inches wide and gap.
If objective is "grit" around 6mm / 1/4inch, the stroke of the jaws
could be small?
Limited throughput, but advantages?
Looking to get a sack of the coarse grit for "stemming"
(can go down into the mine in the skip down the shaft)

Haven't developed anything more at the moment.
Line-boring the bearings yes.
How to machine and eccentric - realise don't know how to do that.
Visualise having two centres each end for between-centres.
Challenge is their axis, offset being on the same radius (the radial
direction) and radial offset.
Must look-up how that is done...

----------------------------

That's the sort of question we can help with. The simple way is to lightly
mark the centers on both sides, clamp it from turning on a flat surface and
scribe a horizontal line through both centers. Dividers can then scribe the
offset radius on both ends. Make a small punch mark at the intersection,
chuck the blank in a 4-jaw lathe chuck and adjust the jaws until a pointed
rod pushed against the offset center doesn't wiggle as the chuck is rotated.
Then the eccentric can be turned around its offset center.

Scribing and punching usually gets me within about 0.1mm of the intended
location.

This describes the methods and the necessary, often cheap used, equipment
required. It's mainly Euclidian geometry.
https://www.amazon.com/Accurate-Tool-Work-Clarence-Goodrich/dp/B004QZ9Y5M

[Richard Smith]

Post by Jim Wilkins

...

...

That's the sort of question we can help with. The simple way is to
lightly mark the centers on both sides, clamp it from turning on a
flat surface and scribe a horizontal line through both
centers. Dividers can then scribe the offset radius on both ends. Make
a small punch mark at the intersection, chuck the blank in a 4-jaw
lathe chuck and adjust the jaws until a pointed rod pushed against the
offset center doesn't wiggle as the chuck is rotated. Then the
eccentric can be turned around its offset center.
Scribing and punching usually gets me within about 0.1mm of the
intended location.
This describes the methods and the necessary, often cheap used,
equipment required. It's mainly Euclidian geometry.
https://www.amazon.com/Accurate-Tool-Work-Clarence-Goodrich/dp/B004QZ9Y5M

Right...
Yup seeing myself going around the local college and using a
surface-plate and the vertical gauge with the scribing edge.

[Jim Wilkins]

Post by Jim Wilkins

...

This describes the methods and the necessary, often cheap used,
equipment required. It's mainly Euclidian geometry.
https://www.amazon.com/Accurate-Tool-Work-Clarence-Goodrich/dp/B004QZ9Y5M

Right...
Yup seeing myself going around the local college and using a
surface-plate and the vertical gauge with the scribing edge.

---------------------------
I assembled a good set of layout equipment at low cost because CNC has made
it obsolete.

The old timers came up with many ways to do very accurate work using simpler
machine tools without digital readouts. The US watchmaking industry was
especially skilled at making very precise fixturing for rapid mass
production on hobbyist-sized lathes. Later the auto makers met the challenge
but their methods involved large custom machinery. I apprenticed at a
company that supplied them with custom equipment.

That company welded the framework and then we assemblers used manual methods
to locate and bolt on the components. The machines tested electronic
components for emission controls etc so they didn't have much mechanical
power transmission, except parts handlers. I have to use the old methods
when my projects are too large for my machine tools, like the center splice
on the 16 foot long, 200 lb gantry hoist track.

I just bought a 2000 Kg hanging scale for it, for $90, since the logs
waiting to become beams and boards weigh well over the 1000 Kg capacity of
my older scale. I consider the cost to be medical insurance, to avoid
accidents from overloads.

[Jim Wilkins]

"Richard Smith" wrote in message news:***@void.com...

Haven't developed anything more at the moment.
Line-boring the bearings yes.

----------------------------

Modern lathes aren't as easily set up for line boring or other milling-type
operations as older designs like the Myfords with tee slots for clamping
bolts on the flat top of the carriage.

Myford lathes seem as popular in Britain as old South Bends (like mine) are
in the USA. Perhaps Tony could help you with their capabilities and
limitations.

[David Billington]

Post by Richard Smith
Haven't developed anything more at the moment.
Line-boring the bearings yes.
----------------------------
Modern lathes aren't as easily set up for line boring or other
milling-type operations as older designs like the Myfords with tee
slots for clamping bolts on the flat top of the carriage.
Myford lathes seem as popular in Britain as old South Bends (like
mine) are in the USA. Perhaps Tony could help you with their
capabilities and limitations.

I'm not so sure about that, my Harrison M300 has a flat top cross slide
with a dovetail section to allow add ons such as rear tool posts to be
clamped to it. When I wanted to do some line boring I made a T slot
table to clamp to it and got on with the job. I think many modern lathes
do similar. That's a bit different to having T slots in the cross slide
as standard which my Kerry 1140 has 2 and an older lathe but the table
was an easy add on to make.

[Jim Wilkins]

"David Billington" wrote in message news:ur8mg6$53it$***@dont-email.me...
I'm not so sure about that, my Harrison M300 has a flat top cross slide
with a dovetail section to allow add ons such as rear tool posts to be
clamped to it. When I wanted to do some line boring I made a T slot
table to clamp to it and got on with the job. I think many modern lathes
do similar. That's a bit different to having T slots in the cross slide
as standard which my Kerry 1140 has 2 and an older lathe but the table
was an easy add on to make.

------------------------

My first student Bridgeport project was a dovetail base for a milling
attachment for the 6" lathe whose worn bed I had milled straight on a big
horizontal mill. The task wasn't too difficult and functioned as expected
though the project convinced me I needed a larger lathe, as that little one
was fine for brass and aluminum but could barely cut mild steel. I found the
10" South Bend and haven't regretted it. The little one turns much faster
and I put a 1/2" drill chuck on it for safety and use it for polishing and
drilling deep grease holes in axles.

It seems the 10" lathe was meant for one-offs and small batches for a tool
maker, inventor or model shop and companies doing higher volume commercial
work chose larger lathes, like 15". Likewise I've seen mill-drills and
smaller knee mills such as my Clausing only in shops that did little
milling, the Bridgeport size is standard. A smaller second-hand machine may
not have as much wear as one suited to production work.

[Richard Smith]

Thanks everyone for coming back on this one.
Not sure can take it anywhere at mo. - but appreciate knowing how I
would go about it...

[Jim Wilkins]

"Richard Smith" wrote in message news:***@void.com...

Thanks everyone for coming back on this one.
Not sure can take it anywhere at mo. - but appreciate knowing how I
would go about it...

------------------------------

The decisions break down to buy, build or find another interest. Build
involves an investment in space-consuming machinery that hopefully retains
or gains resale value (that's the excuse). For me the advantage of learning
machining was becoming able to take on all of a project instead of only the
electrical part. It might not have been done if it required assembling,
coordinating and paying a team.

On the better-run projects I've seen each member had a self-contained
portion of it that didn't need much interaction (disagreement) with others.
Dealing with the company machine shop required defining problems in their
terms, machine to these dimensions and tolerances, instead of expecting them
to come up with a solution to someone else's problem. That was usually my
job.

[Richard Smith]

There's been quite a lot of responses since "thanks" message.
That there is this article
https://modelenginenews.org/techniques/crankshafts.html
implies I have unwittingly stumbled on something which is a big subject.
Thanks all for inducting me.

[Jim Wilkins]

"Richard Smith" wrote in message news:***@void.com...

There's been quite a lot of responses since "thanks" message.
That there is this article
https://modelenginenews.org/techniques/crankshafts.html
implies I have unwittingly stumbled on something which is a big subject.
Thanks all for inducting me.

---------------------------------

Despite R.C.M being an interest group for hobby and small shop machinists I
tried to show you the substantial investment involved in building
useful-sized powered machinery, instead of luring you to join us. I had soon
banged into the limits of what I could build with a saw and drill press.
Several past posters here stubbornly resisted spending for a lathe and mill
and continually suffered the resulting frustration.

I was helping a non-machining inventor with the physics, chemistry and
engineering to copy the Rossi E-Cat and trying not to discourage him until I
found and showed him hard evidence it was either a scam or experimental
error.
https://en.wikipedia.org/wiki/Energy_Catalyzer

[Richard Smith]

Post by Richard Smith
There's been quite a lot of responses since "thanks" message.
That there is this article
https://modelenginenews.org/techniques/crankshafts.html
implies I have unwittingly stumbled on something which is a big subject.
Thanks all for inducting me.
---------------------------------
Despite R.C.M being an interest group for hobby and small shop
machinists I tried to show you the substantial investment involved in
building useful-sized powered machinery, instead of luring you to join
us. I had soon banged into the limits of what I could build with a saw
and drill press. Several past posters here stubbornly resisted
spending for a lathe and mill and continually suffered the resulting
frustration.
I was helping a non-machining inventor with the physics, chemistry and
engineering to copy the Rossi E-Cat and trying not to discourage him
until I found and showed him hard evidence it was either a scam or
experimental error.
https://en.wikipedia.org/wiki/Energy_Catalyzer

A physicist I knew explained it is actually quite readily achieved to
get fusions - over a period of hours you can produce a few atomic events
- at vast consumption of power running the device which causes them.
FWIW.

[Jim Wilkins]

"Richard Smith" wrote in message news:***@void.com...

A physicist I knew explained it is actually quite readily achieved to
get fusions - over a period of hours you can produce a few atomic events
- at vast consumption of power running the device which causes them.
FWIW.
-------------------------------------

Several thousand volts is enough to overcome proton repulsion. So far the
Farnsworth Fusor has not progressed past a very inefficient small scale lab
demo.
https://en.wikipedia.org/wiki/Fusor
https://makezine.com/projects/nuclear-fusor/
It's an example of what can be built with only a drill press.

Flying saucers powered by static electric ion repulsion are also possible,
on a small scale.

Rossi used a brazed copper water pipe reactor in which the hot hydrogen
could reduce the copper oxide scale inside to atoms and blow them into the
nickel. My first clue was that the copper found in the nickel had the
isotope ratios of the natural element. It should have been different if it
had been transmuted from nickel.

I had to be careful of which projects I agreed to work on. Some engineers
and inventors had inadequate training outside their specialty, or of the
practical aspects within it. Until I bought a house I was limited to what I
could make in my father's wood shop.

[Jim Wilkins]

"Jim Wilkins" wrote in message news:uri09o$2hfo3$***@dont-email.me...
"Richard Smith" wrote in message news:***@void.com...

https://en.wikipedia.org/wiki/Fusor

------------------------------

https://unitednuclear.com/chemicals-metals-c-69/deuterium-oxide-p-135.html

I've used Deuterium to tag molecules so they could be traced with MRI to
where in the body they were metabolized and disappeared.

[Bob La Londe]

Post by Richard Smith
You have proved to be a remarkable font of knowledge.
Fancifully looking forward to tunnel-blasting rock (local is a very
hard granite) I looked to the "stemming". What you put put in the
collar of the drilled hole beyond the last charged blasting medium, to
effect a seal intensifying the blasting effect.
I know the one about if you try to press ceramic material down a hole
(or die or mould) it "bridges" and "locks". So I see "stemming" would
work in that way and is a good idea.
Then with a gravel stemming all that happens when it does "let go" is
a spray of grit - no heavy projectiles.
So that seemed a motivation to make a small jaw-crusher (best type of
crusher?) which can convert lumps of the granite into sharp gravel
about 4mm to 5mm size (?) to pack down the hole filling to the last
charge.
Whatever - it's a project.
I hear that a double-toggle crusher is best for very hard stone -
which this granite is. Giving a pure crushing action.
A single-toggle crusher with the eccentric shaft above the inlet for
the rock produces a combined crushing+shear as the moving jaw also has
up-and-down movement - which is reputed to increase throughput for
softer rocks but produce extra wear for no advantage on hard rocks.
Or does this not matter at small sizes?
I was thinking about 5"/125mm to 6"/150mm inlet capacity.
So quite a small machine.
Big rocks could be split with "feathers" - drill a socket, put in the
"feathers" and the wedge and split the rock.
We are not talking of huge quantities here.
Fanciful for sure. No-one at the mo. has a current blasting licence,
for a start...
But anyway - any experience?
I was thinking welded steel construction.
Apart from the jaws.
Cast very hard metal?
Cast "Hadfield Manganese Steel"?
Structural steel plate with welded hard-facing?
Regards,
Rich Smith

I have not read this thread at all, but... I saw a few comments about
materials, and I was reminded of some "salvage" from rock boring
machines, and the teeth on the heads were some sort of carbide. Now,
wait. Before you lecture me that carbide is to fragile, bear in mind
that there are probably different forms of carbides. Just like there
are different forms of steel and even different forms of HSS steel.

Sorry, that's it. That's all I got. I wasn't that interested at the
time and flipped to another feed.

Yeah AR400 and AR500 are tough, but I seem to see a post in this thread
as I was clicking it read that dismissed those for this application.
Those would have been my first guess on the basic premise of this thread.

[Richard Smith]

Post by Bob La Londe
Yeah AR400 and AR500 are tough, but I seem to see a post in this
thread as I was clicking it read that dismissed those for this
application. Those would have been my first guess on the basic premise
of this thread.

I should have made it more of a question.
Many rock-crusher jaws seem to be made out of Hadfield manganese steel -
14%Mn. Intensely work-hardening. Guessing that as can be cast and get
the properties, enables the ridged surface which presumably helps the
breaking action.

Great hint about wear-resisting plates. IF took this anywhere, go see
if can blag offcuts. Don't put the cart before the horse - get a
working version going asap.

[Jim Wilkins]

"Richard Smith" wrote in message news:***@void.com...

Great hint about wear-resisting plates. IF took this anywhere, go see
if can blag offcuts. Don't put the cart before the horse - get a
working version going asap.

--------------------------

Perhaps a demo model with long pipes for handles, which allow measuring the
required force.

[Bob La Londe]

Great hint about wear-resisting plates.  IF took this anywhere, go see
if can blag offcuts.  Don't put the cart before the horse - get a
working version going asap.
--------------------------
Perhaps a demo model with long pipes for handles, which allow measuring
the required force.

In my dad's stuff is a chain cutter left over from his hardware store.
It's lever operated, and I seen have seen it cut through 3/8 grade 70
logging chain (along with other sizes and grades). We used to stock the
stuff in bulk. I don't think I could cut the same chain with my biggest
bolt cutters. Wouldn't it be nice to know what that chain cutter is
made of. It might not be suitable rock crushing, but it might make for
a good lead. I'd cut a piece off and let one of you guys send it out to
be x-rayed, but I have no idea how I would cut it. LOL. ;^) Well, and
someday it might be handy to have a chain cutter in the shop.

P.S. I haven't been ignoring you guys. I've been busy, and I haven't
had much to add.

[Jim Wilkins]

"Bob La Londe" wrote in message news:urijd1$2lpu7$***@dont-email.me...

In my dad's stuff is a chain cutter left over from his hardware store.
It's lever operated, and I seen have seen it cut through 3/8 grade 70
logging chain (along with other sizes and grades). We used to stock the
stuff in bulk. I don't think I could cut the same chain with my biggest
bolt cutters. Wouldn't it be nice to know what that chain cutter is
made of. It might not be suitable rock crushing, but it might make for
a good lead. I'd cut a piece off and let one of you guys send it out to
be x-rayed, but I have no idea how I would cut it. LOL. ;^) Well, and
someday it might be handy to have a chain cutter in the shop.

P.S. I haven't been ignoring you guys. I've been busy, and I haven't
had much to add.

Bob La Londe
CNC Molds N Stuff

--------------------------------
Spark test?

The discount store where I bought my Grade 43 and Grade 70 chain didn't want
to cut the 3/8" because they said it was wearing out their hydraulic chain
shear. I couldn't complain, a Gr70 3/8" x 20' length with hooks cost $2 per
foot, the 5/16" Grade 43 $1.50. I suspect they might have been barrels of
chain that failed proof test because it wasn't tagged but I won't load it
near its rating. My biggest crane scale and chainfall are 4000 Lbs.

[Richard Smith]

Post by Bob La Londe
...
Yeah AR400 and AR500 are tough, but I seem to see a post in this
thread as I was clicking it read that dismissed those for this
application. Those would have been my first guess on the basic premise
of this thread.

In the meantime, with needing to clear a small level accessed via couple
of risers of large rocks from previous blasting without using enough
blasting medium (as explained by ex-miner member), ordered
* "feathers"/splitting wedges - 14mm=9/16ths" yes, but also 10mm=3/8ths"
* smaller SDS battery / cordless SDS drill

The unusually small 10mm "feathers" - hopefully SDS drill can do 10mm
holes in the hard granite with cordless drill - whereas 14mm my instinct
says (and various online commentators say) that is a bit of an "ask".
Need is to break up blasted-out but not shattered boulders only inches
dimension apart from length up to 3ft - so can easily move to the raise
and lower down in cargo-net (tramming level below - cannot simply throw
down).

"Smaller" cordless SDS drill - needs to easily go into a bag which can
be carried down the ladders into the mine. Easy to put out-of-the-way
until needed. And cost - be something you could cope with loosing as
it's a bit of an envirnment down there.

Dust - instinct is to do bigger version of bottle used when mag-base
drill for steel in workshop. Use scriber pushed through cap of plastic
bottle like milk bottle, and spray enough water onto drill to make
drilled material into a slurry (as you also do with watering can when
using a gasoline "Stihl saw" to cut rock).

No idea how this will pan-out in reality.
Sometimes you have to lunge at something.
Whilst none of this is necessary, it leaves some of us lugging largish
boulders along the overhead level and lowering to tramming level.

Thanks everyone for hints.

[Jim Wilkins]

"Richard Smith" wrote in message news:***@void.com...

In the meantime, with needing to clear a small level accessed via couple
of risers of large rocks from previous blasting without using enough
blasting medium (as explained by ex-miner member), ordered
* "feathers"/splitting wedges - 14mm=9/16ths" yes, but also 10mm=3/8ths"
* smaller SDS battery / cordless SDS drill

The unusually small 10mm "feathers" - hopefully SDS drill can do 10mm
holes in the hard granite with cordless drill - whereas 14mm my instinct
says (and various online commentators say) that is a bit of an "ask".
Need is to break up blasted-out but not shattered boulders only inches
dimension apart from length up to 3ft - so can easily move to the raise
and lower down in cargo-net (tramming level below - cannot simply throw
down).

"Smaller" cordless SDS drill - needs to easily go into a bag which can
be carried down the ladders into the mine. Easy to put out-of-the-way
until needed. And cost - be something you could cope with loosing as
it's a bit of an envirnment down there.

Dust - instinct is to do bigger version of bottle used when mag-base
drill for steel in workshop. Use scriber pushed through cap of plastic
bottle like milk bottle, and spray enough water onto drill to make
drilled material into a slurry (as you also do with watering can when
using a gasoline "Stihl saw" to cut rock).

No idea how this will pan-out in reality.
Sometimes you have to lunge at something.
Whilst none of this is necessary, it leaves some of us lugging largish
boulders along the overhead level and lowering to tramming level.

Thanks everyone for hints.

------------------------------------------
https://trowandholden.com/wedge-shim-sets.html
https://trowandholden.com/client_media/files/T_H%20WedgesShims%20HowTo...pdf

I found that my Makita rock drill cut satisfactorily fast in NH granite with
a 1/2" bit and bought the splitting sets to match. An adjustable nozzle
spray bottle of water was enough to control the dust without wasting the
limited water supply, with a bit of soap added to make it wet the fine
powder better.

[Bob La Londe]

Post by Richard Smith

Post by Bob La Londe
...
Yeah AR400 and AR500 are tough, but I seem to see a post in this
thread as I was clicking it read that dismissed those for this
application. Those would have been my first guess on the basic premise
of this thread.

In the meantime, with needing to clear a small level accessed via couple
of risers of large rocks from previous blasting without using enough
blasting medium (as explained by ex-miner member), ordered
* "feathers"/splitting wedges - 14mm=9/16ths" yes, but also 10mm=3/8ths"
* smaller SDS battery / cordless SDS drill
The unusually small 10mm "feathers" - hopefully SDS drill can do 10mm
holes in the hard granite with cordless drill - whereas 14mm my instinct
says (and various online commentators say) that is a bit of an "ask".
Need is to break up blasted-out but not shattered boulders only inches
dimension apart from length up to 3ft - so can easily move to the raise
and lower down in cargo-net (tramming level below - cannot simply throw
down).
"Smaller" cordless SDS drill - needs to easily go into a bag which can
be carried down the ladders into the mine. Easy to put out-of-the-way
until needed. And cost - be something you could cope with loosing as
it's a bit of an envirnment down there.
Dust - instinct is to do bigger version of bottle used when mag-base
drill for steel in workshop. Use scriber pushed through cap of plastic
bottle like milk bottle, and spray enough water onto drill to make
drilled material into a slurry (as you also do with watering can when
using a gasoline "Stihl saw" to cut rock).
No idea how this will pan-out in reality.
Sometimes you have to lunge at something.
Whilst none of this is necessary, it leaves some of us lugging largish
boulders along the overhead level and lowering to tramming level.
Thanks everyone for hints.

I've got a couple SDS drills which are generally adequate for drilling
concrete, and with some patience the odd piece of rebar or rock in the
mix, but when I get to hard stuff I break out the 1 in Milwaukee spline
drive. I wouldn't want to carry that in a bag down a ladder deep into a
mine shaft.I don't like carrying it from the shop to the truck, but I
have carried it up and down a few ladders when it was the only tool that
would do the job. When I had to drill 60 year old well aged structural
concrete the SDS drills just didn't have the umph to push a big drill
very far very fast. That's why I bought the bigger 1" spline drive. I
was drilling conduit runs through two feet of structural concrete in an
old post office building built in the 1940s. I've never drilled
anything harder to drill. I think you are going to have to count on
fault lines to help if you plan to drill anything really hard with a
relatively easily bag toted "cheap" SDS drill.

[Bob La Londe]

Post by Bob La Londe

Post by Richard Smith

Post by Bob La Londe
...
Yeah AR400 and AR500 are tough, but I seem to see a post in this
thread as I was clicking it read that dismissed those for this
application. Those would have been my first guess on the basic premise
of this thread.

In the meantime, with needing to clear a small level accessed via couple
of risers of large rocks from previous blasting without using enough
blasting medium (as explained by ex-miner member), ordered
* "feathers"/splitting wedges - 14mm=9/16ths" yes, but also 10mm=3/8ths"
* smaller SDS battery / cordless SDS drill
The unusually small 10mm "feathers" - hopefully SDS drill can do 10mm
holes in the hard granite with cordless drill - whereas 14mm my instinct
says (and various online commentators say) that is a bit of an "ask".
Need is to break up blasted-out but not shattered boulders only inches
dimension apart from length up to 3ft - so can easily move to the raise
and lower down in cargo-net (tramming level below - cannot simply throw
down).
"Smaller" cordless SDS drill - needs to easily go into a bag which can
be carried down the ladders into the mine.  Easy to put out-of-the-way
until needed.  And cost - be something you could cope with loosing as
it's a bit of an envirnment down there.
Dust - instinct is to do bigger version of bottle used when mag-base
drill for steel in workshop.  Use scriber pushed through cap of plastic
bottle like milk bottle, and spray enough water onto drill to make
drilled material into a slurry (as you also do with watering can when
using a gasoline "Stihl saw" to cut rock).
No idea how this will pan-out in reality.
Sometimes you have to lunge at something.
Whilst none of this is necessary, it leaves some of us lugging largish
boulders along the overhead level and lowering to tramming level.
Thanks everyone for hints.

I've got a couple SDS drills which are generally adequate for drilling
concrete, and with some patience the odd piece of rebar or rock in the
mix, but when I get to hard stuff I break out the 1 in Milwaukee spline
drive.  I wouldn't want to carry that in a bag down a ladder deep into a
mine shaft.I don't like carrying it from the shop to the truck, but I
have carried it up and down a few ladders when it was the only tool that
would do the job.  When I had to drill 60 year old well aged structural
concrete the SDS drills just didn't have the umph to push a big drill
very far very fast.  That's why I bought the bigger 1" spline drive.  I
was drilling conduit runs through two feet of structural concrete in an
old post office building built in the 1940s.  I've never drilled
anything harder to drill.  I think you are going to have to count on
fault lines to help if you plan to drill anything really hard with a
relatively easily bag toted "cheap" SDS drill.

I never even considered a cordless rotary hammer. Is there one that
will actually do real work? I do have a couple cordless hammer drills,
and I've worn out many over the years, but a real rotary hammer? I am
prepared to be impressed when you post the video of one blasting through
rock.

[Jim Wilkins]

"Bob La Londe" wrote in message news:urik1i$2lufk$***@dont-email.me...

I never even considered a cordless rotary hammer. Is there one that
will actually do real work? I do have a couple cordless hammer drills,
and I've worn out many over the years, but a real rotary hammer? I am
prepared to be impressed when you post the video of one blasting through
rock.

Bob La Londe
CNC Molds N Stuff

--------------------------------

I bought an import corded hammer drill the size of a 1/2" wood drill and
found it useless in granite with 1/4" and 3/16" masonry bits. The 1" spline
drive Makita cuts faster with 1/2" bits.

[Richard Smith]

Should arrive tomorrow.
Will see what it will do.

[Richard Smith]

Thanks for the soap suggestion

[Richard Smith]

Wear resistant plate for excavator buckets, chutes, etc...
Late much-appreciated Randy Zimmerman showed me welding replacement
wear-resistant plates into large excavator bucket when visiting Canada
15 years ago.

[Jim Wilkins]

"Richard Smith" wrote in message news:***@void.com...

Cast "Hadfield Manganese Steel"?

-------------------------
https://en.wikipedia.org/wiki/Mangalloy
I'd never heard of it. From the description it sounds like an excellent
facing over a structure of more machinable steel that contains the bearings.

[David Billington]

Post by Richard Smith
Cast "Hadfield Manganese Steel"?
-------------------------
https://en.wikipedia.org/wiki/Mangalloy
I'd never heard of it. From the description it sounds like an
excellent facing over a structure of more machinable steel that
contains the bearings.

I wonder how well that would work, if you might have issues with
dissolution of the manganese into the substrate giving problems if in
the range quoted where it has very poor properties.

I may have a decent sized piece of this steel as some years ago while in
a scrap metal yard in Bristol UK getting some steel plate I spotted a
pile of what I was told were ore crusher knuckles, now I see them as
very worn hammer mill hammers. Pics I've seen show them with a
rectangular block working end where the one I bought looks like a
mushroom from wear, likely why they were in a scrap yard. I bought one
as a metal working stake.

[Jim Wilkins]

"David Billington" wrote in message news:urj7jq$2q4qb$***@dont-email.me...

I wonder how well that would work, if you might have issues with
dissolution of the manganese into the substrate giving problems if in
the range quoted where it has very poor properties.

-------------------------
This suggests it can be welded (to other steel?) with the proper procedure:
https://ajmarshall.com/manganese-steel-6-things-you-need-to-know/

[David Billington]

Post by David Billington
I wonder how well that would work, if you might have issues with
dissolution of the manganese into the substrate giving problems if in
the range quoted where it has very poor properties.
-------------------------
https://ajmarshall.com/manganese-steel-6-things-you-need-to-know/

Thanks for that, as with many things the devil is in the detail.

[Jim Wilkins]

Post by David Billington
I wonder how well that would work, if you might have issues with
dissolution of the manganese into the substrate giving problems if in the
range quoted where it has very poor properties.
-------------------------
https://ajmarshall.com/manganese-steel-6-things-you-need-to-know/

Thanks for that, as with many things the devil is in the detail.
--------------------------------
Your concern shows up when soldering to a gold-plated circuit board,
especially tacking a thin wire to an edge connector finger with thicker
plating. The solder needs to stay molten long enough to dissolve the gold,
otherwise a brittle lead-gold alloy forms and the joint can fall apart.

https://www.911metallurgist.com/blog/gold-alloys
"Gold alloys with a small percentage of lead is a hard, brittle, pale-yellow
substance, which can be crumbled with the fingers."

[Richard Smith]

Hi Jim, David, everyone

Hadfield Manganese Steel is something very unusual. Not sure there is
anything similar. It's "out on a limb" - no incremental connection to
anything else?

It is apparently very very very work-hardening.
It only works up its properties is subject to extreme "attack".
eg.
crushing *hard* rock (apparently it can wear quickly if used on soft
rocks)
railway / railroad junctions / points / switches (went from weeks to
decades service-life)

I have handled Hadfield Manganese steel at the Hadfield plant, but
didn't much find out its properties.
I did try that with a very sharp hacksaw blade and deliberate slow
forward cutting strokes with no drag on the backstroke that did some
cutting (never let it work-harden). If my memory serves me right.

[Jim Wilkins]

"Richard Smith" wrote in message news:***@void.com...

Hi Jim, David, everyone

Hadfield Manganese Steel is something very unusual. Not sure there is
anything similar. It's "out on a limb" - no incremental connection to
anything else?

It is apparently very very very work-hardening.
It only works up its properties is subject to extreme "attack".
eg.
crushing *hard* rock (apparently it can wear quickly if used on soft
rocks)
railway / railroad junctions / points / switches (went from weeks to
decades service-life)

I have handled Hadfield Manganese steel at the Hadfield plant, but
didn't much find out its properties.
I did try that with a very sharp hacksaw blade and deliberate slow
forward cutting strokes with no drag on the backstroke that did some
cutting (never let it work-harden). If my memory serves me right.

--------------------------------

I assume that with minimal equipment you could torch out rectangles and weld
drilled attachment lugs to the edges or back. Or copy a manufactured
crusher. Crushing one rock with the plates set up like a long handled
nutcracker could give you the forces to size the bearings and drive, with
one handle end on a bathroom scale and you and your gang on the other. It
might even crush enough to test your stemming concept.

The price of scales to measure large forces is decreasing. The 2000 Kg crane
scale cost me $89.99.

[Bob La Londe]

Post by Richard Smith
Hi Jim, David, everyone
Hadfield Manganese Steel is something very unusual. Not sure there is
anything similar. It's "out on a limb" - no incremental connection to
anything else?
It is apparently very very very work-hardening.
It only works up its properties is subject to extreme "attack".
eg.
crushing *hard* rock (apparently it can wear quickly if used on soft
rocks)
railway / railroad junctions / points / switches (went from weeks to
decades service-life)
I have handled Hadfield Manganese steel at the Hadfield plant, but
didn't much find out its properties.
I did try that with a very sharp hacksaw blade and deliberate slow
forward cutting strokes with no drag on the backstroke that did some
cutting (never let it work-harden). If my memory serves me right.

My first thought for a work hardening heavy load steel was railroad
track. Didn't bother to look it up though.

[Jim Wilkins]

"Bob La Londe" wrote in message news:url9c1$3be9d$***@dont-email.me...

My first thought for a work hardening heavy load steel was railroad
track. Didn't bother to look it up though.

[Gerry]

Post by Bob La Londe

Post by Richard Smith
Hi Jim, David, everyone
Hadfield Manganese Steel is something very unusual. Not sure there is
anything similar. It's "out on a limb" - no incremental connection to
anything else?
It is apparently very very very work-hardening.
It only works up its properties is subject to extreme "attack".
eg.
crushing *hard* rock (apparently it can wear quickly if used on soft
rocks)
railway / railroad junctions / points / switches (went from weeks to
decades service-life)
I have handled Hadfield Manganese steel at the Hadfield plant, but
didn't much find out its properties.
I did try that with a very sharp hacksaw blade and deliberate slow
forward cutting strokes with no drag on the backstroke that did some
cutting (never let it work-harden). If my memory serves me right.

My first thought for a work hardening heavy load steel was railroad
track. Didn't bother to look it up though.
--
Bob La Londe
CNC Molds N Stuff

I have no knowledge of the history of the two sections of rail in my
posession other than the fact that one came to our house with my
maternal grandfather - a blacksmith, who once worked for Henry Ford -
when he came to live with us in 1945; shortly thereafter he used a
hand hacksaw to cut it in half to gift a piece to a neighbour. The
other section came from a co-worker in 1972. this piece was taken to
work by second son where he used the band saw to slice off a couple of
paper weights for one of the office staff. Over the years I have
subjected both pieces to severe beatings with hammers up to six pounds
without noticeable dammage other than some cold chisel marks on the
older piece from cutting a section of expanded metal sheet.

[Richard Smith]

Post by Bob La Londe

Post by Richard Smith
Hi Jim, David, everyone
Hadfield Manganese Steel is something very unusual. Not sure there is
anything similar. It's "out on a limb" - no incremental connection to
anything else?
It is apparently very very very work-hardening.
It only works up its properties is subject to extreme "attack".
eg.
crushing *hard* rock (apparently it can wear quickly if used on soft
rocks)
railway / railroad junctions / points / switches (went from weeks to
decades service-life)
I have handled Hadfield Manganese steel at the Hadfield plant, but
didn't much find out its properties.
I did try that with a very sharp hacksaw blade and deliberate slow
forward cutting strokes with no drag on the backstroke that did some
cutting (never let it work-harden). If my memory serves me right.

My first thought for a work hardening heavy load steel was railroad
track. Didn't bother to look it up though.

Rails for railroads are simply hard.
Something like 0.6%C

Odd niche - last use of Bessemer converter in the UK was making rail
steels - the nitrogen introduced from blowing with air (20%Oxygen
80%Nitrogen) - which gives a for-free hardening increase without its
generally unacceptable deleterious effects being a problem in the
specific application of railroad rails.

In UK there was the realisation that with computer control you could
spray water on the head of the rail as it came off the mill, giving a
quench-hardening. Which presumably self-tempers as the heat from the
rest of the rail conducts up to the head of the rail.

Unforeseen problem - always be careful what you do and check it's all
for-real...

The rails didn't wear. Great...
Then we had a train crash where the rail shattered into many pieces on a
corner on a mainline out of London heading North.
Then it's found the entire network is riddled with cracks. Had to have
a national "go-slow" to keep stress off the rails and make any further
accidents low / survivable consequence.
Tawdry story emerges.
Railways have been "privatised". "Board" / Directors of private company
all financial types. No engineering representation.
The Ultrasonic Testing trains were picking up squillions of big cracks -
and there was a pause while they worked out what the problem was with
the U/T trains.
With no-one technical at the top of the company, no-one thought to take
a manual U/T set and a bucket of "goo" (couplant) to a few indicated
sites and see what / if anything is really there - as any technical
person would. "Schoolperson level" thought process.
The cracks were real and everywhere - the U/T trains were correct.

New phenomenon no-one had ever seen before or thought of - previously
the rails wore faster than they fatigued. No fatigue cracks.
New hardened rails - rate they fatigue is faster than they wear -
fatigue cracks.
Now we have to have rail-grinding trains - periodically grind the top of
the rails so any embyonic fatigue cracks are lost in the ginding swarf.

Orthodoxy says... That's way in the absence of anyone technical there
we inexorably went straight into a disaster despite indications
something was amiss.

Hope you enjoy the response.

[Jim Wilkins]

Post by Bob La Londe

Post by Richard Smith
Hi Jim, David, everyone
Hadfield Manganese Steel is something very unusual. Not sure there is
anything similar. It's "out on a limb" - no incremental connection to
anything else?
It is apparently very very very work-hardening.
It only works up its properties is subject to extreme "attack".
eg.
crushing *hard* rock (apparently it can wear quickly if used on soft
rocks)
railway / railroad junctions / points / switches (went from weeks to
decades service-life)
I have handled Hadfield Manganese steel at the Hadfield plant, but
didn't much find out its properties.
I did try that with a very sharp hacksaw blade and deliberate slow
forward cutting strokes with no drag on the backstroke that did some
cutting (never let it work-harden). If my memory serves me right.

My first thought for a work hardening heavy load steel was railroad
track. Didn't bother to look it up though.

Rails for railroads are simply hard.
Something like 0.6%C

Odd niche - last use of Bessemer converter in the UK was making rail
steels - the nitrogen introduced from blowing with air (20%Oxygen
80%Nitrogen) - which gives a for-free hardening increase without its
generally unacceptable deleterious effects being a problem in the
specific application of railroad rails.

In UK there was the realisation that with computer control you could
spray water on the head of the rail as it came off the mill, giving a
quench-hardening. Which presumably self-tempers as the heat from the
rest of the rail conducts up to the head of the rail.

Unforeseen problem - always be careful what you do and check it's all
for-real...

The rails didn't wear. Great...
Then we had a train crash where the rail shattered into many pieces on a
corner on a mainline out of London heading North.
Then it's found the entire network is riddled with cracks. Had to have
a national "go-slow" to keep stress off the rails and make any further
accidents low / survivable consequence.
Tawdry story emerges.
Railways have been "privatised". "Board" / Directors of private company
all financial types. No engineering representation.
The Ultrasonic Testing trains were picking up squillions of big cracks -
and there was a pause while they worked out what the problem was with
the U/T trains.
With no-one technical at the top of the company, no-one thought to take
a manual U/T set and a bucket of "goo" (couplant) to a few indicated
sites and see what / if anything is really there - as any technical
person would. "Schoolperson level" thought process.
The cracks were real and everywhere - the U/T trains were correct.

New phenomenon no-one had ever seen before or thought of - previously
the rails wore faster than they fatigued. No fatigue cracks.
New hardened rails - rate they fatigue is faster than they wear -
fatigue cracks.
Now we have to have rail-grinding trains - periodically grind the top of
the rails so any embyonic fatigue cracks are lost in the ginding swarf.

Orthodoxy says... That's way in the absence of anyone technical there
we inexorably went straight into a disaster despite indications
something was amiss.

Hope you enjoy the response.
------------------------------------
At least your trains won't hit icebergs or launch into space.

I mustn't tell tales of those I worked for, but engineers running a business
they created can be troublesome too. Almost every high tech company I worked
for dissolved somehow.

The problems remain hidden until they cause a disaster and public inquiry,
some of which I've studied to explore the decision process that allowed them
and the methods and instrumentation of failure analysis. Part of my career
was building custom instruments to measure something.

We also meander between private and public management of utilities. Both
have their inherent problems which I divide into efficiency vs fairness.
Here a citizens' cooperative is due to take over shopping for lowest
electric rates, though we can opt out. Initially they are $0.0018 below the
corporation's rate.