Smoke Lifters On A Challenger?

[robert.]

Sandwich it between 2 pieces of wood. Cut with hacksaw.

[bob turner]

What gauge of brass? I use Wiss #7 and get no distortion through .032.
Cutting windows I use Dremel cut-off discs and serious eye protection. Sometimes I trim edges of cabs that way.

[big bad jim]

Piercing saw and/or skrawker are both possibilities for cutting sheet brass. I'll see if I can find the info I was looking at before about those techniques.

[2railjon]

Thank you Jim. I don’t know what those tools are!

[2railjon]

Bob, this tool?

[Roy]

The problem with shearing is that it introduces residual stresses in the sheet. This often results in localized distortion. I'm with Bob, regarding the use of cut-off wheels. I've been using them since the time they were un-reinforced, and would shatter easily. The newer, reinforced wheels don't shatter so much, but they're thicker. I save them as they wear down, as the smaller diameter is useful in tighter quarters. Of course, smaller wheels need to be run at higher speed.

There's also sawing. I often use a small hobby hacksaw. You can also use a coping saw, or a jeweler's piercing saw. I have a jigsaw attachment for my Unimat, but never use it. I also use knife-edged jeweler's files, in some situations.

I haven't yet personally tried chemical etching, laser, and plasma cutting. Don't use home etching kits, because the chemicals cause cancer. Just make the resist masks yourself, then have a job shop do the actual etching.

[big bad jim]

Jon,
A piercing saw, also known as a jeweler's saw, is more or less a cross between a hacksaw and a coping saw. It has a deep frame, holding a thin profile metal cutting blade. As if you took a hacksaw and shortened it by half. Do a search on google and you'll see a bunch of examples as well as plenty of youtube videos on how to use them.

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A skrawker is really just a knife with a particular style of hooked tip. I think it's usually known as a laminate cutter or knife. You can buy them at big box home stores like Home Depot, or from hobby tool suppliers. I know Tamiya offers one in the modeler's realm, it's called a plastic scriber in their case, you could probably find one at MicroMark as well. For hardware type brands, I know that Olfa makes one. I tend to like Olfa knives, I have several, although no skrawkers! Yet.

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The idea with a skrawker is to use it as a scoring tool. Much as you would work on styrene sheet. I don't know why the blade tip shape is important, but apparently there's something about it that works. The nice thing about scoring on brass or nickel silver sheet is that you can form bends with clean corners. I don't think you need that for the smoke lifters. In your case, I think you would score, then bend back and forth, then snap off. You would need to file to de-burr and finish to the final size.

You can find videos on using skrawkers on youtube. Lot's of military modelers use them.

If you visit page 16 of this linked thread, you'll find some discussion about both tools in the context of cutting and forming brass sheet.

https://www.westernthunder.co.uk/index. ... ost-121881

Jim

[Roy]

Here's a small hobby hacksaw similar to mine. I've found blades, with a variety of teeth, at both hobby shops and tool dealers. I use it as a hand tool, and in the lathe. The blades are narrower than full-sized hacksaw blades, but much wider than coping or piercing saw blades.



Vendor: https://www.modelcrafttoolsusa.com/hobby-saws/426-modelcraft-junior-hacksaw-with-blade.html

[bob turner]

No, these:

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