# Ideas for cutting windows in thick plastic



## Pete Thornton (Jan 2, 2008)

I'm working on several coaches for the EBT using the Accucraft coach - all of which had windows in the ends as well as the sides. Which means I'll have to cut some square windows in the Accu coach ends. 4 windows / coach, and I have at least 2 coaches to do - maybe 3 or 4.










I can drill holes for the corners and connect them with a coping saw. Would a powered coping saw (i.e. a scroll saw) make it easier - I haven't tried one ? I believe they jam on plastic ?

Last time I used a roto-tool cutter, but it tends to wander and the Accu ends have tabs and things so it is tough to make them sit down flat and not move.

Any thoughts ?


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## docwatsonva (Jan 2, 2008)

Pete,

I would do it the first way you mentioned. I would drill holes in the corners and use a coping saw to cut them out. I have an old Dremel scroll saw that I've used to cut windows in both wood and plastic. It worked fine, but slow, careful cutting with a coping saw will give the most accurate results, in my opinion.

Here's a photo from my private car project.













Doc


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## Bruce Chandler (Jan 2, 2008)

Pete,

For plastic, I like to scribe and snap as you get such a nice straight edge. 


Of course the trick is to be able to snap! I drilled a hole and then used a miniature jigsaw to cut an "X" in the window opening, with the cuts going to each corner. Then I could just snap off the piece and get a nice clean edge.

This miniature saw from Micromark works great.


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## Pete Thornton (Jan 2, 2008)

This miniature saw from Micromark works great. 
Woow! Never saw a miniature jig-saw before! Thanks Bruce. Looks like a good solution. 

The other plan is to find a local laser cutter and have them do the cuts.


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## lownote (Jan 3, 2008)

I've been stumped by this for a while. Right angle windows are hard enough--what about round-topped windows. I've tried sawing them out, or using a dremel router bit--the plastic melts, the saw is too crude. Find a "local laser cutter"--can you do that? Can a laser cutter cut styrene? If you find one in annapolis, let me know!


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## Totalwrecker (Feb 26, 2009)

My old Dremel had the 3' flex shaft. Using that you can make your router cuts under water and not melt the plastic. A shallow pan and just enough to cover and help the chips flow away. Not so fast you foam the water. 

DO NOT stick your dremel in water! There wil be too much spray for that to be safe. 

I use a variable speed Foredom flexshaft and have used water for years. Oil after use. 

John


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## Michael Glavin (Jan 2, 2009)

If the car is assembled a Laser won't be able to load the car end to end so to speak, to deep, relatively flat stuff is no problem. Yes a Laser cuts styrene and most plastics I believe. 

How about this; make a jig sized to the window in question that can be positioned over the desired area and fixed with double sided tape or similar. Use a Dremel or the like with a small diameter router bit fitted with a roller bearing to guide the router bit along/against the jig. Using a low RPM setting together with a two flute cutter would likely be best. In any case practice will allow you to perfect the method on scraps. 

The jig could be made from 1/4”x1/4” scrap wood glued together to form whatever shape/size desired… Fix the jig in place, plunge cut into the material and drag the roller bearing along against the jig all the way around. Simple, quick and consistent results should be the end result. 

I’ve done this in the past and it works very well. I had to obtain the bearing at my local hobby shop; 1/8”x 1/4" will work (of course it depends on the shank size of the bit on hand). 

Michael


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## lownote (Jan 3, 2008)

Although I'm thinking if I make a template out of wood, why not just make the part out of wood? In my case I was thinking of a cab which was wood in the prototype. Maybe thin, high quality plywood.


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## sheepdog (Jan 2, 2008)

I use my Micro Mark table saw with the fine tooth, thin kerf blade to cut windows in acrylic. 

This was a test in sintra.

front









back











Craig


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## wchasr (Jan 2, 2008)

Depending on the laser cutter they MAY be able to do deep objects. We had 12 x 12 square tubing cut at a local laser cutter for a former employer. They had to disassemble some of the tabel to do it but they coudl a did do it for us. Runs of 100 at a time because the set up was time consuming. The problem with all of the local laser cutters I'm aware of is that none of them will cut plastics due to the fumes. They aren't set up to handle the fumes created by cutting plastic. 

Chas


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## Pete Thornton (Jan 2, 2008)

Great suggestions guys. Obviously I'm not the only person with this problem. 

I like the idea of using a router with a roller to guide it on the jig - under water sounds like fun! 

The problem with Accucraft coach ends is they have all these tabs and hinges, etc. Difficult to set it up on the table saw. 

Can a laser cutter cut styrene? 
The GAL coach sides (see the Combine I posted a while ago) are styrene, so yes, it can. However, I'm not sure the Accu coach is styrene - the plastic cement I was using (Testors Master Modeller stuff) didn't melt it and the GAL styrene wouldn't stick to it. Maybe ABS or similar. 

Chas - no need for a deep cutter - the ends can be taken off with a few screws. 

why not just make the part out of wood? 
Well, ALan at GAL keeps pointing out that he can make the ends of styrene on the laser just as easily. He's already done some fancy ones for a Business Car (stay tuned.) It's getting to the point that we hardly need the Accu coach!


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## Michael Glavin (Jan 2, 2009)

Posted By lownote on 05 Aug 2010 03:48 AM 
Although I'm thinking if I make a template out of wood, why not just make the part out of wood? In my case I was thinking of a cab which was wood in the prototype. Maybe thin, high quality plywood. 
Model Aircraft plywood and veneers would work nicely for manual efforts as well as Laser/Router work. In the past I have had a lot of various types of model aircraft wood supplies cut with a laser and a CNC router, for the most part it was all good. This approach is likely not viable for a small one off project in terms of expense, but in multiples it makes a lot of sense IMO. (On the other hand $50.00 for 30 minutes or so might be of interest to some, a laser can do a lot of work in 30 minutes). 

The fumes generated from Laser cutting plastic is a viable concern, I know a couple of small operations that specialize in styrene model stuff that can assist if interested use PM. 

Michael


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## kormsen (Oct 27, 2009)

i get the best results with the oldfashioned method of drilling, then cutting too small and filing to the desired size. 
the slowness of using handtools stands for strighter lines.


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## xo18thfa (Jan 2, 2008)

I think part of the answer is the type of plastic you use. I've had good luck with a product called Lexan (from GE), Home Depot (or maybe it was Lowe's) sells it as a glass substitute. It cuts easier then "plexiglass".


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## SE18 (Feb 21, 2008)

try a shop press and punch it out


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## Pete Thornton (Jan 2, 2008)

try a shop press and punch it out 
I'd like to do that, but the Accu coach end has a lot of protrusions so it would be difficult to get it flat and to support the edges. I suspect it would chip or crack the sides. 


best results with the oldfashioned method of drilling, then cutting too small and filing 
No argument that it can produce the bext results, but (a) this is fairly thick plastic and (b) I have to cut at least 2 windows in 4 ends - maybe more. I just hoped there was a better/easier way. 

If you find one in annapolis, 
I asked around at the local sign shop and a plastics supplier, and I did find a guy with a laser in Annapolis! He's just installing a new one, so we'll have to go and try it out next month.


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## denray (Jan 5, 2008)

I have mounted a sabersaw on the bottom side of a table, works great for when drilling a hole in the product, use a fine tooth blade and you can also get smaller scroll blades that work very well. 
Another switch with the cord plugged into it works best. Lock on the saws switch and use the remote switch, safer and easier. 
Dennis


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## Pete Thornton (Jan 2, 2008)

Dennis, 
Your sabre saw (or Bruce's mini-sabre-saw) both look like a good solution - I found my saw and a very small blade, so I might try it - if I can find some way to mount it in my tiny workspace. 

Alan (at GAL) was discussing it with me, and he suggested heat. Either a big window-size block heated with a torch and pressed rapidly through the plastic end, or a brass frame the right size heated by a soldering iron and pushed into the end. 

Anyone tried heat for this type of activity ? 

P.S. Bob (Sorenson) I sent you a 'message' via this site - did your spam filter capture it?


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## caferacer (Jul 22, 2010)

Hi guys when i was building model warships we found a few ways to cut plastic from my son in law whom builds 1/24 scale plastic cars/trucks for customers and it goes like this, you should try this out drill small hole clamp down object model etc and use sewing cotton to draw up and down along the door line of the model you end up with a very neat clean line so we tried it on a bigger scale plastic panel we used dacron black non stretch fishing line from tackle shop kmart etc drilled hole clamp down the panel and pulled the line up down in a sawing motion and it works a treat clean line seems the up down motion cuts the plastic and seals it off once cut,my son in law has car doors that open and shut with millermeters of gap . 
Some of my museum model ships have opening doors and hatchs that are both square and minor opening gaps ,so get apiece of plastic and give it a try sounds funny but it works a treat caferacer


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## SE18 (Feb 21, 2008)

ah, friction cutting. On a different note, I've seen people using dull bandsaw blades friction-cut steel; also, saw dental floss used to cut PVC


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