HI after I cut cast acrylic at .0001 or any deep of cut at 75mm speed I am left with bits of acrylic that are in the grove of the cut. note (60degree v bit)
Not sure how to get around this problem? the small bits are very hard to remove. I have tried a soft brush but only helps a little.
I would try a heat gun (or hair dryer) it worked for me when I did some work on extruded acrylic.
tried a mini torch. no lunk. maybe I need to get a laser engraver?
It’s a symptom of melting the plastic instead of chipping. Increase your rate of travel or slow down your rpm.
I went through those pains when I learned not to use double bladed spiral bits in a single speed spindle (35K rpm).
I see you are using a v-bit… if you up your feed rate, maybe reduce your doc to offset the torque (load).
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I use these
http://www.harborfreight.com/pick-and-hook-set-7-pc-69592.html
but most of the time i use window cleaner when cutting to keep the plastic chips from getting hot and sticking. water with a lil soap in a spray bottle works to
Spray the acrylic with Windex as coolant and that should stop that build up. slow down the router rpm and increase the feel.
ok will try the windex and I have the dewalt router set as low at it will go. I will try speed of 90mm
So I spray the windex as it is cutting or just spray it on the acrylic beforehand?
If you have a deflector for the air from the router then just the beginning, if not spray often
Tried both ways did not help. Oh well.
Tried using 60 degree bit then reran the cut with 90 degree. It helped some
If you have a scrap piece of acrylic with a fairly sharp corner it works well as a scraper. Also if you do a finishing pass removing next to nothing with the same bit you can usually clean it off. You can use Windex as a lubricant on that finish pass. As far as preventing it in the future DamnitJim is correct its heat that is your enemy. A brand new quality bit will make a big difference. Other than that adjusting feeds and speeds till it goes away.
I have used window chauk to form a resevoar around the design and filled that with water.
I use the same set that Shane Bell mentioned above. I use a soft brush as Phil described first, then anything that doesn’t come out I hit with the pick. Just have to have slow controlled movements so it doesn’t go outside the line and scratch your work piece…
ok thank you
I’ve experienced this last summer with 3 signs of acrylic . Didn’t matter with number of flutes at all . Always used lowest speed on Dewalt Router . However , an upcut bit was always the best varying different pass depths .
just make sure you do not use isopropyl alcohol when cutting acrylic. Alcohol breaks down acrylic polymers and will cause cracks, sometimes nearly instantly depending on the stress of the joint.
Yeah this was done with a v carve bit. Do they make a v carve bit of some sort with up spiral cut?
No. But its not necessary with a V bit. Sharp quality carbide bit, low rpm, high feed rate. That’s it. I can’t give you exact numbers. If changing feeds and speeds don’t fix it your bit is dull. Also I’ve bought cheap bit that weren’t very sharp right out of the box.
Whenever I engrave acrylic I run the toolpath twice to clean out the grooves and it works perfectly.
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You can probably up the feedrate high as you are not cutting so much material on your second pass.