Heard of a roll crusher which apparently gives a lot of the throughput
close to the aim size (???).
On Thu, 15 Feb 2024 04:43:51 +0000
Richard Smith <null@void.com> wrote:
<snip>
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...
"Jim Wilkins" wrote in message news:uqsrip$11g2t$1@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.
"Jim Wilkins" <muratlanne@gmail.com> writes:
"Jim Wilkins" wrote in message news:uqsrip$11g2t$1@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.
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...
"Richard Smith" wrote in message news:m1edd479wi.fsf@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.
......
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
......
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 .
Snag <Snag_one@msn.com> writes:
......
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 <Snag_one@msn.com> writes:IIRC that is how I made the eccentrics for my compost screen shaker. I
......
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?
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
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.
...
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" wrote in message news:m1frxhyn4v.fsf@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" wrote in message news:m1a5nn7ifb.fsf@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 <none@none.com99> writes:
...
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.
On 2/26/2024 1:30 AM, Richard Smith wrote:
Bob La Londe <none@none.com99> writes:
...
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.
"Richard Smith" wrote in message news:m14jecdcjc.fsf@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" wrote in message news:urj7jq$2q4qb$1@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/
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.
On 2/27/2024 2:48 AM, Richard Smith wrote:I have no knowledge of the history of the two sections of rail in my
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
On 2/27/2024 2:48 AM, Richard Smith wrote:
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.
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