Since I built my machine I have used it extensivily for cutting lexan, and the odd bit of aluminium.

Yesterday I cut a engine plate for a F15 ducted fan model I am building out of 1/4" ply.

I found that the dust was fairly dark and the finished edge was on the black side but not burnt as such. Would I be cutting it too slow regarding feed ? (8" min) or is my cutter too fast. (my router goes from 15000 to 35000) it was set about midway.

I never got round to building a bigger PSU for my machine so I am still running on a computor PSU with max speed about 12" min on my setup which has been ok for now.

Just wanted to check from experienced wood cutters !!

Would I be cutting it too slow regarding feed ? (8" min) or is my cutter too fast. (my router goes from 15000 to 35000) it was set about midway.


Both. If your moving as fast as you can, slow down the spindle speed. I'd slow it down in increments and test as you go, but you'll probably want to go as slow as possible. Keep in mind, though, that the slower the spindle, the bigger bite the tool takes, which can require more power. I don't think you'll have a problem at 8ipm, though.

and or switch to a carbide cutter....8 inches per minute....I would think that you're lingering too long in one place....rub a piece of ply long enough and it will turn black (well burn) on you.

At 8 ipm, carbide will burn up just as fast.

I just set up my cutting speed as I normally do at f200 I could try cutting at 12" min see what happens.

Hi

I’ve cut lots of ply with a cnc router and find it’s a balance between feed speed, rpm and cutting depths.
If your machine is at it’s limits where feed rate is concerned then it is as already said down to your rpm.
If power is a problem at low rpm then cutting depth will have to be reduced and more passes made.
One other point, use sharp cutters.

TCT cutter are your only choice as tooling goes but I’m guessing you already knew this.

Hope this helps, John

Try a new sharp bit, Lexan will dull bits. Clear Lexan I find is harder on them than colored Lexan.