Engraving Plastic Sign Material

[Dingo745]

I just had my first go at engraving some dual layer sign material, not sure of it's technical name.
I'm very new to cnc so I'm learning as I go.
First I should mention it was trialled on a cnc router, using a 30deg. conical engraving bit with a flat 0.1 end. The router I used has a minimum speed of 11,500 rpm. unloaded. Feed Rate was around 600 mm/min.

Anyhow as expected it was flop. The plastic quickly melted onto the cutting tip.
I couldn't slow the router any more so I tried a water/detergent spray on to the cutter to help cool it down, but also without success.

Can anyone offer some tips on engraving this type of material, or a link to a good source of relevant info.

Thanks.

[engraversman]

that type of plastic these using

[rustamd]

what about tring to use faster speed(mm/min)?

[John Klemmer]

Your feed rate is too slow. That's a good way to start a fire. Typically you need a tooth load greater than 0.001" (0.025mm) per tooth per revolution. Try feeding in the 2000 to 3000mm/min range. Slow down to improve finish or prevent breaking small diameter cutters.

[Dingo745]

At the moment the old girl won't do 2000mm/min feeds.
I'm upgrading to a coarser pitch ballscrew to improve speed and accuracy.
I'm also going to try another brand of router that has a minimum speed of 8000 rpm. which might help as well.
All part of the learning process I guess.

[kyfds]

can it be engraved by a laser engraving machine??

[Dingo745]

Yes it probably could be done with a laser, but I have a rotary machine.
I built myself a multi-purpose machine and was hoping to be able to some engraving on plastics and other materials.
It was my first effort, so it now needs some refinement of technique and machine.

[srmaietta]

maybe get a variable speed controller for your machine? run the motor at maximum and then use the variable speed control to slow it down, might work to get your rpms down.
Ive got some plastic on order, and cant wait to try it out.. now Im worried about melting!

(crossed fingers)
~Steve

[watkins8014]

I think thename of the plastic is Traffilite and when ordering you specify black white black or whatever colour preferencies you require

[tpworks]

Actually it is a co-extruded plastic for engraving. Traffilite might be a brand name.
http://www.artisan-es.com/Rowmark.htm

Tom

[watkins8014]

I Stand Corrected, Traffolite Is A Tradename Abit Like Delrin And Acetal

[tpworks]

There is a plastic designed for laser different from engraving type also here is a link addressing your problem.
http://www.talkshopbot.com/forum/mes...tml?1180131665