Cutting thin sheet metal (0.1-0.3mm)

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sky1911
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Cutting thin sheet metal (0.1-0.3mm)

Post by sky1911 »

Hi folks,

I have a question for you. For a long time I have been thinking of doing a 1/12 scale chassis from sheet metal (aluminium) and have a few of various thickness at the ready. However, I can't be bothered trying to cut them with a mini saw or scribing them until kingdom come. So my thought have been wandering off into the direction of these paper cut machines. There you normally align paper or cardboard stock towards a straight edge where the material is clamped down and then you push the handle with the blade down essentially cutting off the excess. Has anyone tried this with these thin metal sheets? 0.1mm should be do-able with most devices. However, 0.2 and even more so 0.3 are dimensions where this may not be feasible. Of course I am aware that those devices are not intended for this, but paper. Hence, why I am thinking about one such device that can handle thick stacks of paper / cardboard.
Why do I want to do that? Simple. My tries of using scissors or even scribing or using a cutter were never as precise as I would have wanted them to. Plus with scissors you usually deform the material around the cut a bit. With a device such as this, that should not be the case, as the part will be clamped down right at the edge and only the excess will be trimmed.

If anyone has done this, please let me know.

Token picture from the interwebs:
__1_584_438_dahle_hebel_schneidemaschine_modell_533.jpg
Cheers,
Roman
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Re: Cutting thin sheet metal (0.1-0.3mm)

Post by pstager »

Just curious, when you say scissors/cutter, are you referring to tin/aviation snips? They always seemed fairly precise, perhaps in combination with a little Dremeling to fully clean them up. I've never experimented with this myself, however. I'm curious if your method would work! Seems like a time saver.
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Re: Cutting thin sheet metal (0.1-0.3mm)

Post by sky1911 »

Nope actual scissors. I have some heavy duty scissors that are made for cutting sheet metal, but they're not really made for long straight cuts. I've done the scalpel along a metal ruler and file thing, but that is not for me. Considering a chassis like that photoetching may also be an option but that is even more work, optimum precise, but also considerably more expensive considering the tools and materials you need.
This is why I'm thinking down this road. It is relatively cheap, definitely fast and precise. Of course this is only true if you have a lot of straight cuts. As soon as angles and curves are coming into it, you're better of cutting the pieces into a rough shape and then filing the excess away.
Cheers,
Roman

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Re: Cutting thin sheet metal (0.1-0.3mm)

Post by robdebie »

Not an answer to your question, but did you consider having the parts photo-etched? You can quite easily incorporate folding lines and rivet holes. I've long wanted to do a Porsche 956 / 962 tub this way. I made a aprtial 3D CAD model years ago.

https://robdebie.home.xs4all.nl/models/images/956-05.jpgImage

Rob
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Re: Cutting thin sheet metal (0.1-0.3mm)

Post by steinietrabi »

I have such a paper cutter here and this evening I have to see what sheet metal I still have with me (aluminum / brass) and in what thickness.
Then I could try it tomorrow and add a few pictures.
Greetings Thomas
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Re: Cutting thin sheet metal (0.1-0.3mm)

Post by sky1911 »

steinietrabi wrote:I have such a paper cutter here and this evening I have to see what sheet metal I still have with me (aluminum / brass) and in what thickness.
Then I could try it tomorrow and add a few pictures.
Thomas, cool beans. Just please be aware you could dull the blade of your cutter that way. That's why they limit some of them to a certain thickness / paper weight. I just don't want you to mess up your cutter for this trial. Thank you.
robdebie wrote:Not an answer to your question, but did you consider having the parts photo-etched? You can quite easily incorporate folding lines and rivet holes. I've long wanted to do a Porsche 956 / 962 tub this way. I made a aprtial 3D CAD model years ago.
Rob
Rob, I have, see last post of mine. I actually have an A4 sized UV device but didn't get around to ordering the chemicals and the nickel-silver sheets etc. And of course you would need to print the etch layout to plastic sheets - or better have printed by a professional outfit. As said, PE is going to be considerably more expensive. Ultimately it would be the best solution - if cost is of no concern. Your plan reminds me of Michael's 956 project. I think he redid the aluminium tub of the 956 that very way. There is a started WIP around here. It's glorious.

Things like that are always my first idea - best possible solution. But then think of the work & cost involved - even if you are going to do everything yourself, much more when you have it done (printing, etching, ...). PE is relatively expensive for a reason.
Cheers,
Roman
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Re: Cutting thin sheet metal (0.1-0.3mm)

Post by PeteJ »

The problem that I have run into, trying all the above methods is the metal curls when you cut is and you wind up spending a lot of time straightening it. I got very frustrated some time ago and bought one of these. https://www.amazon.com/Scientific-Model ... 2502&psc=1
It is usable as both a shear and bending brake. I bought it because I was using nickel-silver because I could solder that and it is very hard to cut with anything. It works very well, and there are several companies importing them, including Micro Mark. They are not super expensive if you plan on doing a fair amount of this stuff. Only problem is shipping cost. The darned thing is very heavy cast metal.
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Re: Cutting thin sheet metal (0.1-0.3mm)

Post by CK »

Depending on the complexity of the piece, you can try scoring the sheet and then fold alone the score line a couple of times. The metal will break clean at the score line. It will be cleaner if you can score both side at the same place. All you need then is file down that sharp edge slightly. I have done this on aluminum, brass and mild steel sheets up to 0.5mm.

This method only work easily with straight lines. It will be quite difficult with curves.

If you have some scraps, try it out.
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Re: Cutting thin sheet metal (0.1-0.3mm)

Post by steinietrabi »

So I've tested it with 0.3mm aluminum and 0.2mm brass. It works very well for long and straight cuts - I'd say a perfect cut. One side is the original cut edge, the other side my cut edge - no difference can be seen!
The cut off area will curl up if it's not that wide, but I guess it doesn't matter to this thing.
How long the knife stays sharp is the question, but since it is a straight knife, it should also be sharpened by knife or scissors grinding shops.
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Re: Cutting thin sheet metal (0.1-0.3mm)

Post by sky1911 »

PeteJ wrote:The problem that I have run into, trying all the above methods is the metal curls when you cut is and you wind up spending a lot of time straightening it. I got very frustrated some time ago and bought one of these. https://www.amazon.com/Scientific-Model ... 2502&psc=1
It is usable as both a shear and bending brake. I bought it because I was using nickel-silver because I could solder that and it is very hard to cut with anything. It works very well, and there are several companies importing them, including Micro Mark. They are not super expensive if you plan on doing a fair amount of this stuff. Only problem is shipping cost. The darned thing is very heavy cast metal.
Hi Pete,
In the past I have looked into these things as well, as I also have some larger scale projects where I would need to bend the edges at 90° to rivet to another sheet. So it's again the old problem, go small for one application or go all the way. However, I'm not so sure if the heavy duty parts work as well for small delicate parts. But it is a good pointer. The bending of the parts ... well I can see it happening, because the same can be true when cutting paper in a similar manner. Usually it is the excess side (the part being cut off) that starts to curl. This is what Thomas describes below. The part in the machine should not be affected. But I guess that depends on if your machine has a flat mechanism to hold the part being cut in place (a simplified press if you will). With just a straight knife cutting along an edge I can see both pieces curling. With the hold down thing you have to orient your piece in such a way that only the excess is dangling free, maybe flip the part over and cut from the back so the excess will be hanging over. -- If that description makes sense? I sometimes flip parts around when I cut using scissors and have the actual part being cut off (hanging free) with the excess being held in place. That way I can see your part curling. Again, question of orientation, I beleive.
CK wrote:Depending on the complexity of the piece, you can try scoring the sheet and then fold alone the score line a couple of times. The metal will break clean at the score line. It will be cleaner if you can score both side at the same place. All you need then is file down that sharp edge slightly. I have done this on aluminum, brass and mild steel sheets up to 0.5mm.
This method only work easily with straight lines. It will be quite difficult with curves.
If you have some scraps, try it out.
Hi CK,
That's how I did it at first. I found this a bit unsatisfactory. For several reasons. As you said it works best for straight edges - which is what I'm looking at here anyway. However, I don't what I do wrong, but every once in a while the blade slips out of the groove and scores into other areas at which point you can almost forget about the part. Of course you can try to score in the other direction to deepen the actual groove, but meh. Plus you need to sand the edges afterwards. With the straight cut from the machine that step should not really be necessary - at least that is my hope :). My trials have been done with .3mm aluminium and i think even .15mm steel sheets (real pain in the ass).
steinietrabi wrote:So I've tested it with 0.3mm aluminum and 0.2mm brass. It works very well for long and straight cuts - I'd say a perfect cut. One side is the original cut edge, the other side my cut edge - no difference can be seen!
The cut off area will curl up if it's not that wide, but I guess it doesn't matter to this thing.
How long the knife stays sharp is the question, but since it is a straight knife, it should also be sharpened by knife or scissors grinding shops.
Hi Thomas,
great stuff. That sounds and looks great. Do you know they type / name of your device so I can try and find its specs? This sounds just like what I am looking for. On the plus side, I can also use it for some art projects involving folded coloured paper that I am working on at this time. And yes, it should be possible to have the blade re-sharpened, either by a shop or by the application of a grindstone yourself.
Thank you for this test run and verifying my "theory" :D
Cheers,
Roman
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