Best way to make coin blanks??

[Defender92]

I don’t have any experience in manufacturing! I’m seriously considering purchasing a fiber laser engraving machine. One of the things I would be interested in doing is making basic challenge coins (I’m law enforcement and ex-military). I would like to make coin dies with the laser engraver and my lathe. Instead of buying coin blanks I would like to stamp out my own. I like being able to make everything. I would probably be making them out of brass, copper or aluminum. I also plan on getting a heat treating kiln, I’m sure the dies need to be hardened. What is the most economical way to make blanks??



I have a 20 shop press with a pneumatic jack. I considered making a punch die and using it on that. But I think it would be time consuming.



Another possibility I considered was buying a “punch press”. They pop up on Facebook marketplace often for cheap. Although I have never used one before they seem like they would be quicker than the shop press. Although I don’t even know if it would work for this.



Am I getting in over my head? Am I missing something? To make matters worse I’m limited on space and just picked up a Bridgeport.

 

[C-Bag]

I have worked for a couple of small manufacturers and what that has taught me is an eye for process. There seems to be a lot more than just punching out the blank, that’s just the first step. To get that raised edge then the knurling on the edge along with the mirror finish are all steps that I don’t know how they are done. But are crucial to the finished product. I would guess this is an investment in equipment that is far more specialized and therefore expensive than you can comprehend without a deep dive. There are a couple of guys here who might be able to shed some light and I hope they chime in here as I’m always interested in how things are made.

 

[pontiac428]

Search up @BGHansen's erector set parts punching threads, and @JimDawson's high speed punch press threads on this site for insight.

Here's 3 free fish:

https://www.hobby-machinist.com/threads/building-a-high-speed-punch-press.32063/

Erector set part number 'NU' parachute men punch and die

I’m a long time member of the A. C. Gilbert Heritage Society which is primarily a club of Erector set collectors. The ACGHS (www.ACGHS.org) hosts an annual National meeting which this year will be in Huntsville, Alabama. The club is a fairly tight-knit group and most members are known for...

www.hobby-machinist.com

Erector set part number 'ED' triple drum hoist

Here’s another thread of an Erector set part reproduction. This one is Gilbert Erector set part number ‘ED’, the triple drum hoist. First the obligatory history lesson . . . Gilbert introduced this part to the Erector set line in 1927 and included it in sets (just the largest two sets, size...

www.hobby-machinist.com

 

[Defender92]

Search up @BGHansen's erector set parts punching threads, and @JimDawson's high speed punch press threads on this site for insight.

Here's 3 free fish:

https://www.hobby-machinist.com/threads/building-a-high-speed-punch-press.32063/

Erector set part number 'NU' parachute men punch and die

I’m a long time member of the A. C. Gilbert Heritage Society which is primarily a club of Erector set collectors. The ACGHS (www.ACGHS.org) hosts an annual National meeting which this year will be in Huntsville, Alabama. The club is a fairly tight-knit group and most members are known for...

www.hobby-machinist.com

Erector set part number 'ED' triple drum hoist

Here’s another thread of an Erector set part reproduction. This one is Gilbert Erector set part number ‘ED’, the triple drum hoist. First the obligatory history lesson . . . Gilbert introduced this part to the Erector set line in 1927 and included it in sets (just the largest two sets, size...

www.hobby-machinist.com

Thank you! That’s helpful and makes me feel like I can actually do this.

 

[Defender92]

I have worked for a couple of small manufacturers and what that has taught me is an eye for process. There seems to be a lot more than just punching out the blank, that’s just the first step. To get that raised edge then the knurling on the edge along with the mirror finish are all steps that I don’t know how they are done. But are crucial to the finished product. I would guess this is an investment in equipment that is far more specialized and therefore expensive than you can comprehend without a deep dive. There are a couple of guys here who might be able to shed some light and I hope they chime in here as I’m always interested in how things are made.

I really just want a plain metal disc. The die can make the edge and I’m not concerned about knurling. That probably wasn’t the best example I could have used.

 

[vtcnc]

I just bought a small Benchmaster 4 ton press and am currently making some complicated (for me) dies. For what you want, I would buy a small punch press and find some standard Roper Whitney, Pexto, or Diacro die sets for challenge coins. Standard sizes and not too pricey. You will probably spend more finding the die shoes to mount the punch and die, but can usually find someone selling a set cheap on FB or eBay. One shoe set will work for multiple punch die combinations if you decide to make more than one size of a challenge coin.

That looks like a fun project and for a good reason! Keep us posted!


Sent from my iPhone using Tapatalk

 

[Defender92]

After a little more research I am thinking this is totally doable. And I found a YouTube video that’s encouraging. This guy is cutting steel and much thicker than the non ferrous metals I will be. I will stick with my 20 ton shop press for now.

 

[Winegrower]

I built a simple version of a punch and die for my small arbor press, as an experiment. The main issue to overcome is alignment of punch and die, otherwise it's simple. I made a punch holder to fit on the end of the press ram, and a sort of floating die holder that once you aligned it, it would stay that way. I'd like to do something for the HF 20T press, but there is a lot more flexibility there, and I can't quite see how to get past that yet. But ideas are always welcome.

 

[Firstram]

You could start with a C Frame Punch to hold the dies, tons of sizes to chose from.
https://www.ebay.com/itm/362388185590?hash=item546004e1f6:g:hGYAAOSwBrtjxpby

 

[BGHansen]

Sounds like a nice project! The biggest problem with off the shelf punches and dies is the purpose is generally to make the hole, the slug is scrap. So, the punches have either a prick and or rake built into them which damages the slug. Here's an example off eBay from a search for "Roper Whitney 1" punch":



You'll see what I mean about the rake on the punch. The rake (or whatever it's called) is done so the punch starts shearing the material as the punch advances. The high area goes through first, then shears its way around the perimeter. If there's no rake, your punch will shear the entire perimeter in one shot. That's not a problem with 1/2" or smaller punches, but when you get up to 3/4" or larger they generally have rake. If you are using a 12-ton or 20-ton press, all of the pressure is setting there waiting for the punch to bust through. When it does, all of that pressure is released at once. The punch with overtravel some through the die. Ask me how I know. . . The thread below is for an Erector set part I made that needed 1 3/4" diameter stainless steel disks. BIG BANG when the punch went through, so I ground a rake into the punch.

Erector set part number 'ED' triple drum hoist

Here’s another thread of an Erector set part reproduction. This one is Gilbert Erector set part number ‘ED’, the triple drum hoist. First the obligatory history lesson . . . Gilbert introduced this part to the Erector set line in 1927 and included it in sets (just the largest two sets, size...

www.hobby-machinist.com

If searching on eBay, try "Diacro punch" and your size also. I have a Roper Whitney #218 press that would take the punch/die in the ad above. You're looking at $500+ for a RW218 unless you score a great deal.

That ED triple-drum hoist thread also shows what's called a "die shoe". There's a small one from an eBay ad shown below. These let you align your punch and die and use a 12/20 ton press to do the heavy work. That lets you avoid finding a punch press if you already have a hydraulic press. You'll need to make an adapter plate of some sort to secure the punch and die. You'll also need to check the max height of the die shoe to ensure your die/punch and blank fit between the platens with it's fully open.



Or, check out the thread below. This is one for an Erector set part# BV chain bucket. I didn't know what a die shoe was at the time so I made my own. Yeah, $50 for the one above was a deal compared to all of the work I put into making one.

Draw die for making Erector set 'BV' large chain buckets

I usually document these types of projects in the POTD string but this one was a little more involved. A lot of my shop projects are reproductions of Erector set parts from the 1910’s through 1950’s. Latest part is a die set for making part number “BV” large chain buckets. These buckets were...

www.hobby-machinist.com

For stock, I'd look at aluminum in your final stock thickness (0.062"?). It's a ton cheaper than brass or copper. Aluminum is about $15 for a 12" x 12" x 1/16" piece. Brass is running about $80 and Copper is running about $70 for the same size sheet (both priced at Online Metals).

Bruce