Building A Coining Press

[jimzim75]

Hi Marten Stoltz,
So, I bought a 50 ton bottle jack the other day and I have a rail track from a
switching yard. This is the biggest track they make, so I think it should hold up
under 100,000 pounds of pressure. I using half sheet for the sides and I'm
going to hold it together with one and quart in threaded. I might weld the base
but I want to keep the top open so I can raise it if needed.
Marten or anybody, does this sound likes it's enough.

The working surface will be 16 inches wide by 6 inches across.
Height will be around 20 inches.
The rail road track is the latter 6" by 7" tall.

I was going to use O1 oil hardening steel for the blanks. Do you use something
that isn't so dog gone tough to cut.

I was inspired by your Youtude video. Must be fun to work with the press
I saw in the video.

Talk to ya later,
Jim

 

[gtsport]

Coining press

Just a quick note before I'm off to sleepyland. I would recommend that if any bolts or rod is used, they should be parallel to the direction of force. I had a harbor freight 20 ton bottle jack in a frame held together with 3/4 inch grade 8 bolts and I snapped them off the first time I used it... and the second. My present framework is completely welded and although it may flex, it hasn't broken yet.

Joe Paonessa

 

[jimzim75]

Thanks Joe,
Haven't firmed up the design quite yet. It may be that it's going to have to be a solid frame.
Jim

 

[vanknife]

Coin press

Hi Jim,
I have seen a guy making coins with a drop hammer with the dies in a sand box and dropping a weight of about 30 KG from a height of I would guess 3 Meter and it worked perfect every time, the sand box is compacted just enough to eliminate rebound to prevent double stamping.

Just something to think about if You are interrested in some sketches i might be able to help with what i can remember.

Cheers

"VAN"

 

[jimzim75]

Thanks Van,
That I didn't know. I have access to Drop Hammers but they are kind of scary things.
I think I'll stick with the bottle jack.
Jim

 

[DanM]

I used a 60 ton bottle jack for a press for a number of years.You may want to look for heavier materials for the construction.Several of the knife working forums have a lot of discussion on materials,stress,and design.The pictured press is a 25 ton press made by Ron Claiborne .

 

[bartelfitzneel]

There was just a great discussion on this but....

I just made some dies out of 8620 steel and they were great. Plenty soft annealed and darn hard when quenched right. Polished up really bright. But then again I'm a novice. And I try to make medieval style coins, so there is a lot less relief and li,mited engraving.

 

[jimzim75]

Hi Dan,
I like the looks of your press. This is a small press that I made.
I very simple but will do what I have needed to do until now.
I'm usually the type of guy that walk around till I find something that
will work that I don't have to pay top dollar for.

It will hand my 12 ton and the twenty ton okay, but the 50 ton. All the steel started moving.
That was barely any pressure at all.

I was out to the local surplus steel yard. Everything's berried in the snow and ice. Lot of jumbo to slog though
also. So I think I'll be design this thing for another month and half.

So it looks like fun with welding this summer. At least I can sneak it past the wife in my lunch box a piece
at a time.

Hey Bart,
Thanks for the tip. I try to snag a piece of 8620 and give it a go.
Talk to ya later,
Jim

 

[autumnwinds44]

Now you have something new to do when snowed in other than drive you mrs nuts. Men and boys and the price and size of their toys.

 

[Martin Strolz]

Hello Jim,

Lately I haven’t looked up the forum each day so I discovered your post right now. I am sorry for the delayed answer. What we have in school is an old Sack & Kiesselbach hobbing press. The company still exists, here is the link:
http://www.sack-kiesselbach.de/english/e-einsenk.html
Our press was built in the fifties only needed new gaskets once. The main cylinder gasket is made of leather and should never dry out completely. They are leaking a little, that’s normal.
It is very well and extremely rigid constructed. When the school house was renovated, we didn’t move it out because of its weight. This machine then survived a construction environment for several years without any problems. If you plan buying a used one, you have to be lucky and quick. They are much sought after.
What I can offer is to take pictures and some important measurements, so you have a guideline for your home built press. Anyway, you will need a very heavy O-shaped frame and a big diameter cylinder.
A big steel tube with walls about 2 or more inches thick would make a fine frame.

Martin

 

[jimzim75]

Hi Martin,
Thanks for the reply. Interesting link. I think I'll have to wait a couple of weeks until the new large
capacity lunch box comes in for me to sneak it by the wife. I got a friend with a back end loader
that can dig the hole in the garage. I going to have to come up with a tall tail why I need the hole.
Maybe something about drainage. These thing aren't to noisy are they. Can I run it on AA batteries?

Seriously, I think it about a half million more than I wanted to spend. I don't plan on counterfeiting
Casino Tokens which is about the only way I could afford one. I'm extremely green with envy that you
get to play with one everyday. I'd like to see some more coins if you get a chance.
Talk to you later,
Jim

 

[quickcut07]

Don't know how far you want to go with this Jim. The unit I own and the ones I use at work are adjustable. The table moves up and down for height and held there by hardened pins 1'' to 1 1/2'' in diameter. Stop into Princess Auto in London or Sarnia next time your out and about. Look at what is available for hydraulics. You will be pleasently surprised on choices I believe. Good luck, the build is half the fun. E.
PS. Moving the table is easy with a cheap boat style winch, makes for lighter work.

 

[jimzim75]

Hi QC07,
I was probable looking at the same one you were in Sarnia. I like the 20 ton
but I don't think it handle the 50 ton jack I got. It was a good price at $375.00
The fifty ton was a model with hose hydraulics hooked up and would look real
sweat in the shop. It's big and so far I haven't need to bend a springs for
the car. I a cheap bugger and don't want to part with $1500.00 they're
asking.

I thought about beefing up the twenty ton they're selling. After thinking about
it I think I'll just sort of barrow the design. There's a place called Marten's
steel up by Clinton that sells odds and ends to the farmers. They have some
good part and 50 ton press that I'm going to incorporate some the design
form. They use a car coil spring as a piston retractor.

I'd snag Marten press in Austria if every one
would turn there backs for five minutes.
Oh well, fun with welding. I think to should be kinda fun.

Talk to ya later,
Jim