How best to cut doors and windows?

Paul, Take a pin vice and drill a small hole right at each corner of your marked out doors or windows. Then just use your straight edge and knife to make the cut outs. This way you won't over run your cuts and its also very easy to nicely square off the corners if needed to fit your frames or castings. If you are using castings be sure to measure the back side of the casting that fits into the opening and use those dimensions to size your openings rather than those that may be on a plan or drawing. Bruce

Use a right angle cutter - See

items 81652 or

82394. Gives a precise, neat corner with much less effort than drilling and filing out or cutting to drawn lines. Limitations are that the material can't be too thick or so soft that it compresses as it is cut, and that the window or door opening must be no smaller than the cutter side dimension. An advantage is that a straight-edge can be taped or clamped to the material at the top and bottom of a row of windows to align the horizontal edge of the cutter, assuring a nice straight row. Gary Q

I have one of these, and it's a great little tool. But I'd never thought of using a straight-edge as Gary has suggested. What a great idea - thanks for sharing the tip! :-)

All the best,

Mark.

My problem is cutting some styrene windows with rounded corners as on a passenger car. I've tried to drill holes where the corners will be, but accurately locating these holes is the problem. Even by being off by the tinyest amount throws the geometry of the winder cutout off. Trying to file things straight just makes things worse!

Bob Boudreau

Using a corner chisel, as suggested, would still work if you first ground a suitable radius on the outer corner. Tho complete the job would also entail regrinding the inner beveled edges so a radius appeared there as well ... otherwise you'd just get two flat chisels at right angles, with a small gap in the corner between them.

A bench grinder would be the best tool for this modification, but you could do it with a motor tool (Dremel)or such. With more effort, you could do the whole thing with hand stones. In either case, you'll likely need to touch up the inner surfaces of the bevel with a fine stone or diamond hone. All this is a little tedious, but fairly cheap, and should make an effective tool. It would be a good investment if you need to male a bunch of the round corner windows, as for a passenger car.

Dan Mitchell ============

I've had some success using small diameter wad punches. To make even smaller radius corners, I ground/filed/machined edges into various small diameter tubes, and this also works well.

Those Micromark tools look nice--but they're over $20.00. Kind of spendy for something so specialized.

How about using a drafting program and printing out a template? Some white glue to hold the template in place on the styrene while drilling and cutting, then just soak it off in warm, soapy water.