Dust collection for plastics

[heftyh]

I know there is another thread running now for dust collection but I thought I would start a new one since I'm cutting polycarbonate and the chips are different than when I run wood. To be more specific, the 1/8" cutting bit generates rather large slivers, sometimes as long as 2mm. These chips don't compress and they "grind" their way into the rubber compression rollers causing a motor overload after about 4 minutes of cutting. I have to use a scotchbrite pad on the rollers to remove the chips. The polycarb does not generate "dust" like MDF or wood. For this machine to work, the chips need to be removed around the cutting area so they won't jam the rollers.
So- I've been staring at the machine all weekend and reading all the posts on dust collection and hopefully someone else is cutting polycarb like me.
I'm concerned that the downdraft system will not suck the chips (or enough of them) around the workpiece. There is a post which shows a rectangular channel added to the side of the machine to suck across the cutting surface on the top of the workpiece- this looks like it would have a better chance than the downdraft. But now I have my own idea, and would like the experts to shoot holes in it before I start cutting holes in my machine this week (I'm serious).
How well would this work: install a 4" port (for my Jet dust collector) on the rear cover plate of the machine. The area I'm refering to is where the keypad would be on the front plate- but on the rear plate which is empty. The only thing on the inside is the verticle screw. In addition, on the front plate, behind the keypad, install an air jet blowing towards the 4" port on the back side. I'm hoping that this will blow the chips back and they will be extracted out of the machine.
Thanks,
John

[JOHNB]

here's how i run mine. a vac on the side would be better. good place for a port.

[DocWheeler]

John,

I recall that someone had attached the collector as you describe. They said that although it worked, it didn't do as well as expected - but that was for wood.

Several people have installed a small tube to the Z truck that blows air across the cutting tip toward the back. I think you can see such a setup on Jeff Birt's site.

[Kenm810]

Hi John,

I’m one of the guys that’s always modifying my machine, and I do have an air jet that travels along with my machines “Z’ truck, cleaning the dust and wood chips out of the carving and off the surface of the project board. It also helps keep the rollers clean and holds most of the dust in suspension long enough for the down draft air flow to grab it and pull down and out of the bottom of the machine. Lately I’ve been carving quite a bit of SignFoam that sticks to everything inside the machine. I’m working on a 4 gang brass aquarium valve unit to add more stationary air jets to keep the plastic from building up on the rollers and board sensor.
I have read of some folks cutting into their machines on the far side away from the key pad for dust control, but before I would do that, I would remove that side of the machine and replace it with a 1/16” flexible sheet of lexon or pvc plastic. With a dust collector adapter attached to it. Something like the ones Rockler or the WoodCraft Store sells, just to see if it well do what I would want it to do. Just my thoughts

[TIMCOSBY]

when you open the front of the machine there is that 2" or so black flat area that collects dust going on into the nachine it drops down and has a 1/2" or so lip on it. i was thinking about making a wood port the width of the machine with a 1/4 slit along the bottom that sticks on with double stick tape at that 1/2" lip or for that matter on top of the 2" area. the slit would be an 1\8" above the board and would suck all the shavings before they get to the front roller. should work for raster but don't know about vector cuts.