how to do a nice square opening for a window

[jkristia]

I just finished the foam core part of my first scratch builded building, and started cutting windows openings in the styrene sheet. But those !@#$ small openings are difficult to get nice and square. It’s not too difficult in a 0.020” plain styrene, but I’m using the 0.040” 'metal siding' styrene sheet, and I find it difficult to get a nice clean square hole. I just finished another 2 openings, but they took me about 40 minutes to do (but they are nice and square). Now my question. What is the best / fastest way to make those openings in thick styrene? I’m doing an N-scale building.

Thanks
Jesper

 

[60103]

Jesper: are you cutting from the pattern side or the plain side? Use the plain side.
Put the metal ruler so that you're cutting into the window opening if the knife slips.
Cut smaller than the opening and file to size.
Cover your slips with plastic angle to represent the window frame.
Use a fresh Knife blade.

 

[jkristia]

That's how I do it. I was just wondering if there is an easier/faster way to do it. I saw some time ago in MR a tool used to punch square holes, it was like a 90-degree angled chisel. Has anyone used that tool?

Jesper

 

[NYCentral]

I use a nibbler tool from Micro-Mark which works very well.
Here is the link
http://www.dxmarket.com/micromark/products/81477.html

 

[jkristia]

There it is. It was something like that I was looking for, and now when you pointed me to MicroMarks web, I found that other tool

http://www.dxmarket.com/micromark/products/82394.html

That was the one I saw in MR some time ago I think.
So that nibling cutter works by drilling a center hole and then "eat" it's way out, 3/32 (2.3mm) at a time correct ?, that means that I can also use it for N-scale window openings ?

Thanks for the link.

Jesper

 

[NYCentral]

yes you are correct. I have been using it for about 3 years now. I would practice on a scrap piece first, but it works very well.

 

[jkristia]

I just ordered that tool.
Thanks again for Info.
Jesper

 

[Vic]

Square Cuts In Styrene

Here's how to make square openings for windows, doors etc. in styrene.

1. Layout the opening size on the material to be cut.

2. Using a steel straight edge draw diagonal lines across the opening from corner to corner

3. Drill a small hole at the center point of the opening

4. Starting at the corners cut the diagonal lines first

5. Finally cut the outside lines of the opening

6. Dress the opening with a flat needle file if needed

When cutting styrene always start with a brand new sharp blade. No matter how thick or thin the work piece is you do not want to try to cut it in one or two cuts. Use gentle multiple cuts. Heavy pressure will cause your blade to "wander". Use a steel straight edge to assure proper alignment of your knife.

Larger pieces of styrene can be cut just like a sheet of glass. Simply score the sheet with two or three light passes of the knife and then apply pressure to both sides of the score (bend it at the score line) and it will break away cleanly.

 

[60103]

I'll offer this method that I saw written up; I HAVEN'T TRIED IT.

Score the vertical lines from top to bottom of the sheet, both sides of the window, then snap the plastic into 3 bits.
Score the horizontal lines and snap again.
Discard the bit where the window is going to be, and glue the rest of the bits back together.
If you have a line of windows, you can score them all at once. You can also reverse the horizontal and vertical sequence.
I just don't have the confidence that I could glue it back together seamlessly.
(you could try it while you wait for MicroMart to deliver.)

 

[Blake]

Use a pillar file to file out the openings. A pillar file is a triangular shaped file that is smooth on 2 of the 3 sides. This prevents you from getting a notch on the opposite side that you are filing.

 

[Bill Pontin]

Jesper, the best method I found for doors and windows is the method described in the book "Styrene Modeling". What they basically describe is to cut the wall into horizontal bands. The band or strip would be the height of your window openings. You then cut the band where your window or door opening would be, after which you weld the entire wall back together discarding the pieces where your openings will be. In your case, using a vertical type textured siding, the bands would be vertical and dimensioned for your window or door widths. When the pieces are welded back together they are almost invisable. On smooth type sheets of styrene they recommend letting it dry overnight and then lightly sanding to clean up any misalignments when gluing. Wished my scanner was functional, then I could post that page that shows this method. You might want to pick up a copy of the book, great tips and techniques for working with styrene. It is published for Evergreen, same size as your monthly train magazine and most hobby shops have a copy in their magazine section.

 

[jkristia]

I just received the tool I ordered, the 90 degree punch tool and the nibbling cutter, and both works well, except the nibbling tool requires a larger hole than I expexted, so it can't be used for 6 pane horizontal window from Grandt Line (N scale), but for larger windows it's perfect.

The "cutting the styrene into strips" method sounds like an interesting idea if you have a lot of windows on a wall. I might give that a try too.

Thanks again
Jesper

 

[tomfassett]

I have had a problem with this for longer than I care to admit. Vic's suggestion works fantastic as it allows the waste from the inside to flex without warping the styrene which causes non straight cuts. Thanks, Vic--but where were you when I needed this information 20 years ago?...

Tom F

 

[Vic]

Hey Tom, Glad it works...I can't for the life of me remember where I picked that up but then again...I can't remember what I had for supper either!!! Let's see....20 years ago....Duuuuuuuhhhhhh