[okthierry]

Hello doers,

I am starting to experiment with creating thin wood and leather cutting die. What do you think I should use? Would aluminum do the job or should I go directly with copper or brass? 3D printed nylon works for leather so Aluminum should be fine, but what about thin soft wood cutting die? Steel would be best but it's too hard to mill. By thin wood I mean 8mm soft wood.

Wood cutting die
Attachment 272056
Attachment 272058
Attachment 272060

Leather punches
Attachment 272066
Attachment 272068

Cheers,
Thierry

[awerby]

If all you need to do is make shallow impressions on the leather, those materials will work to some degree. Harder is better, but bronze would probably be fine. But for cutting, you really want to use steel. Those other materials might make a few cuts, but they will go dull very quickly.

[okthierry]

Even for ultra-soft wood like this? What would be best to start with, Aluminum, Brass or Bronze?
Attachment 272164

Otherwise, would 316 Stainless Steel do the job? What grade would you recommend?
Poper feed and speed with a small diameter tool is advisable I guess.
I'm only having a 2.2kw spindle on a custom build machine.

[rowbare]

For cutting soft materials steel rule dies are typically used. That is basically what your second image shows. They are pretty straigtforward to make. A good source of material for DIY is the steel strapping they use for crates. Do a bit of research on them and you will get a good idea how to proceed at least for the cutting aspect.

A lot of the smaller dies are photochemically etched. Commercial leather stamps are most likely forged or cast. You might find this interesting, he is making punches from SS bolts: making my own Stamps - Leather Tools - Leatherworker.net

bob

[okthierry]

Thanks for the tips! Indeed leather punches are easy work. Some folks even 3D print some in Nylon and it works.
Steel rule die are cool when you have the proper machine to fold them. I keep reading.

However, there's quite a few different type of machined dies that, I am sure, can do a much better job for semi-soft material.
Have a look at these: CNC Cutting dies, Solid Milled Clicker Dies, Standard Clicker Dies, Steel Rule Dies, Punch dies, Mallet Handle Dies, Specialty Dies
Just need to find the proper alloyed, the right tools and voilà!

[rowbare]

That is pretty cool. While they mention milling, I would guess that the more complex ones are Wire EDMed from pre-hardened stock. As hobbyists, we would have to work with annealed stock then heat treat though we might be able to get away using 4140 pre-hard. I am not sure if that would require further heat treatment though. I tried making a paper cutting die from aluminum but that failed. That may be a design issue more than a material issue though

For cutting thin materials the most acdessible way to go is probably photochemical etching. I have been meaning to try it to make paper cutting dies but I am not sure if it would work for thicker material.

bob

[okthierry]

Nice Bob! 4140 pre-hard seems pretty cool. I'm new to milling steel so I have a lot of reading to do. Thanks for pointing me in the right direction. How hard is it to mill 4140 PH? Can a modest CNC machine / spindle do the job?

Thierry

[rowbare]

I have some pre-hard in the shop but haven't had a chance to work with it yet. It probably wants a pretty rigid setup though. I was watching one of Dan Gelbart's videos this morning and he was talking about materials. He talked about some air hardening stainless steels that sound like they might work well.

BTW you might find his series interesting: see https://www.youtube.com/user/dgelbart

The video on materials is # 9 in his series on Building Prototypes. The whole series is good though.

bob

[okthierry]

Which kind of tool are you using to mill steel?

[rowbare]

HSS and Carbide end mills. I don't do any heavy hogging but I can get pretty good finishes.

bob