penny squashing machine plans?

[aboard_epsilon]

Originally Posted by Evan

A little coin press research says that you will need about 22 tons pressure to smash a regular copper coin.

so what do you need for a copper plated steel coin ..that link i posted seems to say that the whole world has changed to copper or bronze plated steel.

all the best.markj

[Evan]

I don't know but I have been doing some research on this because it seems a useful machine to have. The proper name for the penny press machine is a Jeweller's Mill. They are used to roll metal into sheets and to emboss material or roll wire. It is a common jewellery making accessory and they are extremely expensive to buy.

This is a very basic model:



This is an older but more capable machine:

[Too_Many_Tools]

Originally Posted by Evan

I don't know but I have been doing some research on this because it seems a useful machine to have. The proper name for the penny press machine is a Jeweller's Mill. They are used to roll metal into sheets and to emboss material or roll wire. It is a common jewellery making accessory and they are extremely expensive to buy.

This is a very basic model:



This is an older but more capable machine:

Could you discuss the more capabilities of the older machine?

They would seem to do the same thing.

THanks


TMT

[Evan]

I can only tell you what I can suss out looking at the machines and the few details I found on line. These machines seem to be a well kept secret.

The older unit has one major difference in that it is driven by compound gearing. That implies a much higher tonnage capacity. It also has two sets of rolls, one set is for wire forming and the other set is for sheet forming. This means that the width capacity is greater than the smaller combination machine that does both on the same rolls.

[dneufell]

Brian Rupnow!!!!! Draw us a squashing machine please! (with dims)
(slowly chanting) Brian....Brian....Brian.......

[Evan]

It should be a simple exercise to design one of these machines. The gearing is very basic and there are no particular accuracy requirements in that aspect. The main issue will be the rolls. They will need to be very concentric with the bearing blocks they ride on at both ends. They will need to be made from a good grade of steel such as 4140 and then heat treated to maximum hardness. I would expect the commercial rolls would be induction hardened to produce a strong inner core and a very hard surface.

Dies for impressing patterns can be made from etched or ground spring steel that is sandwiched with the work piece as it is fed through the roll.

[YukonHam]

Originally Posted by Evan

It's only illegal to deface coinage if the intent is to defraud.

Er ... not exactly, in Canada at least.

I've been a lurker for some time, but this has the potential to be bad [or at least, incomplete] legal advice, so felt compelled to register.

While many of the legal provisions concerning coin, slugs and counterfeit DO depend on a person having an intent to deceive or defraud, it is a specific criminal offence in Canada to deface a current coin, even if you have no fraudulent intent. Have a look at s. 456 of the Criminal Code.

It's a summary offence (comparable to what our American friends call a misdemeanor).

While it doesn't seem to be commonly known or enforced, it's there. Less of a concern for pennies I would guess, but for Canadian jewellers who might want to buy and melt down those lovely Canadian gold coins, could be asking for trouble.

In other posts I have seen it suggested one not deface or tamper with the currency of the country you are in... Might be safer that way.

And yes, I am a lawyer. (Home shop machining makes a very satisfying 'other life' though.)

[snowman]

Originally Posted by Evan

It should be a simple exercise to design one of these machines. The gearing is very basic and there are no particular accuracy requirements in that aspect. The main issue will be the rolls. They will need to be very concentric with the bearing blocks they ride on at both ends. They will need to be made from a good grade of steel such as 4140 and then heat treated to maximum hardness. I would expect the commercial rolls would be induction hardened to produce a strong inner core and a very hard surface.

I made one a few years back and it's just a slip roll with tighter tollerances. I think I used 4140, but it's just what I had lying around. Mine wasn't nearly as fancy with all the downward gearing, but that's easy to get around with a couple of feeler gauges. All I used it for was embossing and reducing sheet, mostly from a forged chunk to a flat plate trying to play with mokume gane.

The jewelers grade ones aren't really that much higher in quality than what I made. I've worked on professional ones. I just put a nice surface finish on mine, then sanded and polished the surface. Remember, jewelers aren't overly concerned about having wide sheets of perfectly flat plate, unless they are a refining factory. It's usually used more for quick reduction of annealed sheet or ingot. Plus, all of the metals used are usually quite soft in the annealed state.

You can buy a basic model at harbor freight.

[aostling]

Originally Posted by YukonHam

And yes, I am a lawyer. (Home shop machining makes a very satisfying 'other life' though.)

A lawyer, a machinist, and maybe a ham? You've come to the right place.

If you are writing from Whitehorse, I wouldn't mind trading places. It was 95ºF in Phoenix today (breaking a record set in 1931). I'm ready for winter.

[Evan]

Originally Posted by YukonHam

Er ... not exactly, in Canada at least.

True enough. However, my reference was to US law, with which I am also familiar being born and raised in the US.

Usually if I make a comment that applies to Canadian laws I will specifically say so.

At any rate welcome to the board.