Cutting openings in thick styrene?

[Ray Dunakin]

Does anyone know of an easier way to cut openings for windows and doors in thick (1/8") styrene? Cutting through it with an X-acto is difficult at best. I've been scoring the edges with the knife, then sort of grinding it out with a drill bit in a Dremel. That's a bit faster but I can never keep the edges straight or the corners square.

[mabloodhound]

First, why are you using such thick styrene?   Or is it a kitbash?

Something I have NOT tried but may work are the new vibrating saw tools.   The speed is slow enough that the plastic shouldn't melt and clog up.   The tool is very controllable BUT the item being cut MUST be held down firmly.  I've used these for cutting small areas out of oak flooring or trimming the bottom of door casing and such.   It seems most tool makers have these offered and some are battery powered.

Take a piece of styrene to Lowes with you and try it on their Dremel model.    Lowes usually has the Dremel tools out at the aisle for you to try.  http://www.lowes.com/pd_35904-353-6300-02L_0__?productId=1244425&Ntt=dremel+oscillating&pl=1&currentURL=%2Fpl__0__s%3FNtt%3Ddremel%2Boscillating&facetInfo=

They have a 3/4" wide blade that could even be ground down narrower.

[Design-HSB]

Hi Ray,
i've just come from the work area and have been working on the model of a mine shaft.
Since I have done my good old times again fretsaw (in German Laubsäge) well.
Currently I have indeed only cut wood with it, but go with the hacksaw or thick (1 / 4 ") or thicker styrene good sawing.
I also saw 2 vibration, which I use for straight cuts in wood, have not tested this only in styrene.

[greenie]

A jewellers saw works exceptionally well for this, use a courser toothed blade, to stop the teeth clogging up, a bit of candle wax works wonders for the cutting too.

Have a look at this page, the saw blades  with the teeth count are there, all you have to do is click on the blue word "more" and all will be revealed.
As a general guide to the blades, is that a  #2/0  blade is good for brass anywhere from 3 mm to 0.5 mm, but clogs up quickly if used in styrene.
So for what your trying to do,  a  #1 or #2 blade will be OK.


http://www.jewelrysupply.com/jewelry_making_supply_tools/saw_blades_frames.html

Buy them from where ever you want too, this site is only a reference guide. ( modified - don't buy the el-cheapo saw blades from the flea-bay dealers, these blades are from India and are absolute rubbish, buy the ones made in Europe, they have to make them to a standard, not the cheapest price )

regards  Graham

[mabloodhound]

The jewelers saw is a good recommendation,   However, I personally have never been able to cut a straight line with them.
I guess you could get close enough and file/sand down the rest.

[Ray Dunakin]

Yeah, I think a jeweler's saw will probably be my simplest and cheapest option. MicroMark has a nifty little scroll saw that looks like it would do the job pretty quick but it's not very cheap. Maybe someday when money's not so tight here.

[marklayton]

Ray -

There are two jewelers' saw options that will guarantee a vertical cut.  Both are made by Knew Concepts.
The manual die blanking saw runs about $385 and keeps the blade straight.  The electric saw is great if you have to cut a lot of windows, and have about $1,900 lying around.  Both are available from Rio Grande:
www.riogrande.com  Knew Concepts manufactures a line of quality jewelry making tooling.





Mark

[Design-HSB]

If there must be electric because, here the absolute reference, I could already tested successfully.

http://translate.google.com/translate?hl=de&sl=de&tl=en&u=http%3A%2F%2Fwww.hegner-gmbh.com%2Findex.cfm%3Fcontentid%3D18

But since I now have a CNC milling machine, I've made ​​the purchase back.

Even today, I suppose, but like my good old jigsaw and I need my free hand I hardly cuts rework.

[Younger]

Layout the openings to be cut. Using a drill or punch, remove most of the waste material, leaving a small amount close to the edges of the opening. Then, using a straight edge and sharp blade, trim to the lines. The rough opening allows the trimmed material to move with the cut.
-Younger

[fspg2]

Hi Ray,

To cut in 1/8" styrene (I think it is the same as we call in Germany Polystyrol) with a cutter it is certainly a little bit difficult!

I succeeded several times as follows:



1.  I pierce all four corners with a small drill bit (eg 1mm)

2.  then I put a ruler on the outer edges of two holes as a guide

3.  I carve with the cutter several times slightly from hole to hole along the ruler

4.  this I proceed with all outer sides of the window...
    I do it to the two diagonals equally.

5.  from the backside I repeated  step 2 + 3 + 4 in the same way

6.  in the cross of the two diagonals I drill a hole through the styrene

7.  now I saw with a fretsaw from this central hole diagonal up to the four corner holes

8. the four visible triangles should be pressed several times in both directions
   - until they break out. Sometimes the cutter helps a little.

Try it first with an old piece of styrene!

The corners can be easily cleaned with a square file.

Good luck!

[Ray Dunakin]

First, why are you using such thick styrene? 

I'm modeling in 1/24th scale, and the structure is going outdoors.

[greenie]

I'm modeling in 1/24th scale, and the structure is going outdoors.

Hmm, better keep the hot sun of it then, or it will definitely sag.

If you have a large sheet of styrene and it's not flat, just lay it on a piece of glass and set it outside in full sun, after a couple of hours in the sun, have a look and the styrene sheet will be down flat against the glass. Just mist the styrene with water and it will set hard and be flat again.

regards  Graham

[mabloodhound]

I'm modeling in 1/24th scale, and the structure is going outdoors.

Well, then that makes sense.   I would thing the 1/8" would be stable enough outside.   
I get caught up in this 1:48 world and forget there are larger scales.

I have done the drill, score and snap method but that to can be tedious.   I need to try the fret saw again.

[DaKra]

What I've done, pre laser days, is score the outline, then drill a whole bunch of holes a little inside of the outline, then cut from hole to hole with a jigsaw.  When the main chunk is out, I sneak up on the outline with a grinder, then a rasp, then a fine flat file.   When I did prototype work at a small, low tech toy company, I cut a lot of holes in a lot of heavy styrene that way. 

Filing a nice straight line is a test of skill with a file, very satisfying when a good job is done. You might also design your openings to have a pre-fabricated doorframe cover the opening, so you need not be as precise. 

Dave 

[finescalerr]

How about the old trick of not cutting openings at all? Instead build up the outer wall from rectangles, leave openings where appropriate, then brace the interior. That is, after all, pretty close to how we build full size walls. -- Russ