Bosch JsS470E plexiglass cutting speed

[Beebad]

I have the JS470E and the plexiglass blade.

 

My question is what speed 1-6 should I use for cutting plexiglass.

 

I am trimming a motorcycle windshield and I get once chance to mess this up!

 

Thanks

[ToolBane]

I’d suggest getting some spare scrap to play with a little bit so you can get a feel for it. If you’re able, it’s best to ascertain if it’s plexiglass vs polycarbonate just so you know the scrap you’re working with is exactly the same material.
 

Polycarbonate generally has better impact resistance for this purpose FYI, and is probably what you actually have if it’s either the original windshield itself or an aftermarket part specifically designed for this purpose. Not sure how you’re going about this but I would NOT buy plexiglass to make a windshield out of; it doesn’t have the impact resistance polycarbonate has. Anyway, if you haven’t already, chances are good you can find a plastic supply store that can sell you scrap for nicely discounted prices.

 

The melting point for these plastics isn’t terribly high. If cutting with a jigsaw, as the blade heats up during cutting, semi-melted plastic shavings can easily bond right back into the cut or on the surface of your workpiece as you proceed. If this is a stock sheet bought from a plastic supply store, you should leave the paper/plastic backing on the sheet while cutting to help counteract that problem. If that isn’t an option, using some sort of a blower to keep the blade from heating up too much as you go can also be very helpful.

 

I don’t have your specific jigsaw but in general I would just start off with medium cut speeds to get an initial feel. My general feeling is, pacing how fast you go through the material to avoid the blade heating up too much is more important than the speed setting of the jigsaw. So cut an inch or whatever, let the blade cool, then proceed another inch, etc.

 

Disclaimer: I have not cut anywhere near as much polycarbonate as I have plexiglass, and it’s been a while so I easily may be forgetting any nuances between how the materials cut if in fact you have polycarbonate and not plexiglass.

 

Hope this helps and best of luck!

[SetBuilder]

You will have a very hard time getting a clean line with a jig saw.  I'd rough cut it with a jig saw, then make a template out of 1/4" MDF and make the final cut with a router trim / pattern bit. Then round over the sharp edges.  You will probably have to swing a radius to make the template. I would try and double stick some MDF or other bendable material to the windscreen when cutting with a jig saw so the "bounce" of the saw doesn't crack it.  Also tape off the base or put felt on it, so you don't scratch the windscreen