For the punch gurus

I have a need, and it shouldn't be rocket science, but does have some interesting "possibilities and opportunities." I'm working in HO scale, buildings, and need a bunch of pieces with openings cut to fit small (tiny?) plastic moldings, windows and doors. One or two, I cut with an exacto knife, but I'm looking at making six or eight of the same thing now, each with four windows and four doors. The material is basswood, and I have an Electropress that I'm wanting to make a punch for the different openings. Doesn't need much accuracy, anything I can make that will come within .005" will be fine, but the problem comes with the sheeting I'm using. It's scribed to simulate boards, and that scribing is done on 1/32" sheet, so there isn't a lot of split resistance left. The scribing is nearly half of that depth, with the grain, 1/32" spacing. The moldings are made so they cover the front a little, a rough opening isn't going to show unless it's pretty bad.

Does anyone have any experience with making a hollow punch, maybe coming down around a drilled hole for something like this? Doors will be about 3/8" by 1", give or take a little, windows maybe 3/8" by

1/2". I'm guessing the press is somewhere in the 1/4 - 1/2 ton range, a dandy little finger smasher. (It's a big solenoid on a heavy frame.)

Greybeard

Reply to
Greybeard
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Since you have a master, why not just replicate it by making a silicone RTV mold, then casting either urethane or low-temp melt metal that looks exactly like steel and is solid at room temperature? The silicone mold will capture the smallest detail from your master. It's really incredible stuff. You can buy a kit with instructions and all you need from

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or do a bit of research and order from McMaster Carr... or a local urethane supplier.

Wayne in ChulaJuana

Reply to
Wayne Lundberg

Ummmm. on accountabecause I already have the plastic moldings, and they're cheaper than I could ever make them for. What I need is a punch that will punch the openings in the wood, and none of my buildings are plastic, they're all scratch built from scribed or other pattern of wood. IF you're suggesting that I make a mold and model the building in plastic, forget that, I like things to look halfway real, not like a cheap plastic imitation. As per, where the corner trim comes over the lap siding, I can see the slight gap, something I can't mold, and wouldn't anyhow. The same building can probably be molded in plastic, but there's a reason that people scratch from wood, and craftsman kits cost nearly four times as much as plastic, but people still buy and build them. It's a bloody hobby, there's no reason to settle for what I don't really want.

Greybeard

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Reply to
Greybeard

A mortising chisel came to mind right away, I'm just trying to figure how to make something that will work on the thin wood without splitting it all to hell. Trying to make all of the buildings look old and decrepit, so if a window isn't perfectly straight, it doesn't matter. Just the number of them that I'm contemplating, hand cutting works, but the time to make the winow openings looks excessive when I'm looking at that number of them.

Greybeard

Reply to
Greybeard

you do in fact need a hollow punch , and it needs to be surrounded by a very resilient [80-90] durometer urethane sleeve at least three times the diameter of the punch, the idea is the urethane is slightly longer than the punch and it touches first and holds the material tightly down on the cutting substrate [ uhmw] as the razor sharp punch cuts the material , I would suggest a steel rule die, that is what is used to make the precut model kits

good luck

Reply to
williamhenry

As the urethane compresses, is it going to put any outward force on the wood? Also, HO scale board and batten, the battens are not more than .005" above the rest, if that much. Wouldn't take too much for that to disappear.

Most commonly known as "Die crunched" or "Die smashed". ;^)) Don't know if basswood is going to smash as easily as balsa, and I've already figured that I'm going to have to finish the corners with a knife, but that's better than having to endure the "death of a thousand cuts" to get the opening through in the first place.

Looks like a little experimenting might be in order. If nothing else, I reduce the amount of scraps and leftover wood I have.

There are places that will laser cut them, but in multiples that I don't need, and I doubt anyone else is crazy enough to want anything similar.

Greybeard.

Reply to
Greybeard

Go take to your local awards and trophy shop. Find one that has a laser. They may be able to cut what you need for a reasonable price.

Howard R Garner a fellow modeler.

Reply to
Howard R Garner

Not what you want to hear, but the model airplane folks are big on laser cutting balsa parts these days -- you can make your outlines on a CAD program & take them to most laser cutting houses along with your wood. There's one or two pitfalls, but you get good, accurate cuts. The worst problem for the planes is the blackened edges that you need to either deal with or sand off; if you're using molding that's not going to be an issue for you at all.

Reply to
Tim Wescott

Why not a master router template and a router attachment for a Dremel ? Ken Cutt

Reply to
Ken Cutt

For little jobs like that I would use a sheet metal nibbler. They are fast, neat and cheap. I f you wnated to make 5,000, then a die would make sense. Bugs

Reply to
Bugs

Perhaps something on the lines of a mortising chisel may work. You could get an idea on design from here:

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Tom

Reply to
Tom

Perhaps if you incorporated a top clamping plate, that could eliminate the material splitting?

Tom

Reply to
Tom

Probably because I hadn't thought of it. Might be the best way though. Having to clean out the corners would beat cutting the whole thing by hand.

Greybeard

Reply to
Greybeard

Have you considered a steel rule die? These are steel knives set into a kerf in a piece of plywood. Cheap.

Reply to
Roger Shoaf

COnsidered, but not seriously. There are die cut kits available, and while it beats hand cutting, it still leaves a lot to be desired. The router/master is looking the best right now, and cheap really isn't a factor. There are four different window and door castings that I use, that would mean four masters, not really a big deal. The occasional odd ball that I use, one opening isn't a big thing, I've been doing it that way for 25 years. Just not liking it when I'm looking at bigger numbers. The basswood isn't bad to work with until you take the 1/32" sheet and scribe halfway through it, then it likes to split a little too easy. With the router, I might be able to stack sides together and do the whole lot at once. Or maybe I'm dreaming too.

Greybeard

Reply to
Greybeard

I suspect that you will be done and happy with the results in nothing flat ;-) . Luck Ken Cutt

Reply to
Ken Cutt

Greybeard wrote in news: snipped-for-privacy@4ax.com:

Try using either a "corner chisel" or a V-groove veining tool for the clean-out.

Reply to
Eregon

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