Making Accurate Stryrene Cuts

[chicken45]

The Chopper is made to cut strip stock. It's not designed to cut sheet material.

Yes, I should have clarified. I was cutting patches from thing flat strips to patch in coach windows and couldn't get square cuts. I also have trouble with the True Sander and smaller parts. How do you guys get so precise with your square edges on small thin parts?

[gary60s]

An old Architecture School trick is to run some masking tape along the underside of your straightedge.  It serves the same purpose as gluing sandpaper but won't damage the surfaces it is resting on.  Also, you can just peel it off.  Electrical tape works as well but us Architecture kids never had that stuff on us. 

scott lupia

"Damage the surface"??? You've got to be kidding. If you're going to use it to sand your surface sure, but this is just to keep the straightedge from slipping on styrene that can be slippery. If you glue the sandpaper to the straightedge with rubber cement, you can also easily peel it off.

[bbussey]

I believe he's referring to when the straightedge is placed on other surfaces when not being used to score the styrene, such as a desk or work table, or leaning against a wall or other furniture.

[bbussey]

Yes, I should have clarified. I was cutting patches from thing flat strips to patch in coach windows and couldn't get square cuts. I also have trouble with the True Sander and smaller parts. How do you guys get so precise with your square edges on small thin parts?

Milling machine for thicker styrene and diecast.  Chopper for thin styrene.  A good-quality old-style paper cutter also works, as DKS mentioned.

[wazzou]

I picked up one of those heavy 3' square paper cutters with the big brass guillotine handle from the school my wife was teaching at.
I got it because I was cutting large sheets of watercolor paper frequently but I have used it for styrene too.

[Scott Lupia]

Whoa, easy there I was just adding options not attacking any single idea.  No need for multiple question marks.  The sandpaper would most certainly mar the surface of clear styrene or anything with a "neat" finish to it.  I am not saying your approach is bad, nothing like that at all.  I was just adding to the conversation with what we used to do with our straightedges and what works well for me.  That is what the OP was looking for, ideas and suggestions rather than debates and flames.

Scott Lupia

[gary60s]

Whoa, easy there I was just adding options not attacking any single idea.  No need for multiple question marks.  The sandpaper would most certainly mar the surface of clear styrene or anything with a "neat" finish to it.  I am not saying your approach is bad, nothing like that at all.  I was just adding to the conversation with what we used to do with our straightedges and what works well for me.  That is what the OP was looking for, ideas and suggestions rather than debates and flames.

Scott Lupia

If you're a gorilla you're going to mar the surface, but if you're a gorilla you should look for a different hobby. Fine sandpaper glued to the bottom of a straightedge works just fine, and I haven't damaged any materials.

[Scott Lupia]

 

Scott Lupia

[Catt]

Gary,you got somethin againest Gorillas????? 

[peteski]

Gary,you got somethin againest Gorillas????? 

Um, I have feeling that Ms. Dee Rayle will have something to say about this. 

[Kisatchie]

Um, I have feeling that Ms. Dee Rayle will have something to say about this. 

Hmm... I'd better not
hear anything bad about
a fellow Great Ape...

[Noah Lane]

Never thought cutting styrene would be such a controversial topic...

One other thought--for long straight cuts, I often use a big old (guillotine-type) paper cutter. Once the styrene sheet is aligned, I tape it down and let 'er rip. If you have access to one, it's a useful tool.

If I could only get my hands on one of those. My Mom retired from teaching after 34 years (every grade K-8th) and now substitutes. But I think she's way too honest to "borrow" from la escuela.

As for the Testors Aircraft Grey. I bought one type yesterday at hobby lobby (i think it said "dark aircraft grey"), but it certainly didn't look the color of the roads on the James River Branch. It was more taupe. Do you know the paint number perchance?

Since you are using Unitrack, there are a couple of other solutions to this problem.  Kato has just introduced track set in slabs of concrete (20-014).  It may not be exactly the look you are shooting for, but they created it to be just that.  I got some to use as a station track, and it serves that purpose very well.  And if you are looking for track buried in pavement, you might look at their tram track (40-010) or continue with the Styrene cutting techniques.

Terry N
T-Kits.com

Yeah, that's not what I mean by tracks in a slab. I mean only the rails exposed, no ties. Similar to what you find at a grade crossing.

Place
kraft (or butcher) paper over the scene with a few pins (reinforce with mesh packing tape) to hold it firmly in place.  Rub a crayon lightly over the rails...

Funny, this is what I did to get my templates. Only it came out very inaccurate because I didn't have a crayon (used a carpenter's pencil shaved down), I used several 8.5x11" sheets taped together, and I didn't properly secure the paper down.

It was one of those situations where you're still thinking about methodology, but in the mean time you execute with D- effort.

[basementcalling]

The Chopper is made to cut strip stock. It's not designed to cut sheet material.

I found my  chopper was very out of square.

[nkalanaga]

For a straightedge with sandpaper, if one doesn't want to alter their expensive steel one, buy a strip of K&S brass.  1/16 inch by half to one inch works very nicely, is a foot long, and is cheap enough to "waste" on a single-purpose straightedge.  I've used one, without the sandpaper, for years.

Most of the strips I've seen are straight, but slightly curved across the strip, meaning that one surface is slightly convex, and the other concave.  Put the concave surface down, and the edges tend to grip the styrene, keeping it in place.  With the convex surface down, the strip rocks, and can easily pivot while cutting.  If the difference isn't easily visible, put a piece of sandpaper on a flat surface, and sand the strip.  The concave side will show sanding just along the edge, while the convex side sands in the middle, or clear across, depending on how straight one holds it.

[pnolan48]

I found my  chopper was very out of square.

Yes. Mine would not make a square vertical (up & down) cut until I shimmed the blade with a .01" strip. The blade now looks not vertical, but cuts vertical, especially in thicker stock.

The squareness to the fence has some wobble to it. That frustrates me, especially when cutting 10 or 12 mm strips. Cut them, flip them and put them back together. The joint will not be straight. I use a small square with an exacto knife instead.

I am having good luck cutting 2 mm strips about 10 inches (254 mm) long with vinyl cutters, using multiple passes and cutting most of the way through. Cutting all the way through causes the strips to curl and foul the cutter head. Depending on the blade and the hardness of the surface of the styrene, which varies a great deal, I can sometimes cut even 1 mm strips out of 0.5 mm styrene about 6 inches long, but that takes a lot of patience to separate the strips without curling them up like party streamers. The thinner strips are better cut from .015" (0.38 mm) or even cardstock.