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Discussion in 'CNC Mills/Routers' started by azarock, Nov 23, 2015.
Square shaped OX for doing general purpose engraving and cutting into wood, acrylic, and aluminum.
azarock published a new build:
Read more about this build...
Looks good, but why 3 layers of MDF on the work surface?
I can remove the top 2 sheets as needed for different thicknesses of material. At least that was the thought, I can always change it if I need to in the future.
Well done @azarock ! love the look in black V-Slot.
Thank you for the share my friend.
Thanks @Mark Carew
I have a better set of proper end mill bits on order as well as a Colt router to replace this old Rotozip. Should be able to cut much better after the upgrade.
Hey guys, can anyone tell me what is the best clear plastic for milling on a CNC? Acrylic or Plexiglass or something else? I'm designing a dust shoe for my machine and got some 1/4" clear plastic from work last week out of the scrap bin, but not sure if it's Acrylic or Plexiglass. It's just clear with a blue film over it. I was able to cut it, well I should say melt into small blobs anyways using my 1/4" 2 flute straight bit (sharpest bit I have), but it's more melting the plastic rather than cutting it. The cut edge finish wasn't terrible, but it was rough as hell an I'd like it better and don't like the blobs flying everywhere. I even tried hitting it with a torch when it was done, but didn't help much. My feeds were really slow @ 100mm/sec and ran the router at it's lowest setting (10k rpm I think) while misting water at the plastic, but it just kinda melted it as it cut throwing small blobs of crap all over my shop.
Any input on what material to use, and or feeds/speeds to try, or do I need a different cutting bit?
I'm pretty sure Plexiglass is a brand name for acrylic sheet. When I was looking the choices were acrylic or polycarbonate. I chose Acrylic in the end as it's a little cheaper here.
If it is acrylic I've had success cutting with a 1 flute lapped 3mm cutter which are designed for plastic; 20,000rpm and 400mm/min which is pretty much the equivalent of what you were doing I think.
I suppose the question is "How sharp was the sharpest bit" I've found I need to keep cutters I use just for acrylic as if I use them on mdf or wood first they aren't sharp enough and I get melting.
Yes, sorry my speeds were 100mm/minute not seconds, sorry brain fart. 100mm/seconds would cause havoc on my machine.
I'll try speeding up the feed rate to 400mm/min and see if that helps.
I have been using this bit on A LOT of mdf for prototyping over the past month so maybe it's not as sharp as I think it is (I'm using the finger test method). Might be time for a new bit or two.
@Teflon4 I think what I have is Polycarbonate, doesn't cut worth a crap even with a new 2 flute carbide bit a bought today from a local jobber, same results. Going to order some acrylic sheet tonight and see how that cuts in a few days. If I still have problems I'll look into a singe flute bit as you recommended.
i have cut both... without any trouble.
Both (or generally all) plastics need a high feed rate. Speed up your cut considerably..say another 4-6 times
That is one reason to use a single flute bit..in order to match feedrate to rpm. If your router or mill cannot take the speed try more shallow passes.
So for evaluation either half your rpm or double your feed in order to see the results you would get on a single flute bit...
Cooling does help heaps.. i used water highly dilluted with spirit(s? - the funny smelling variety for general cleaning purpose)
There is nothing to loose - just do straight cuts at different speeds on your already cut leftovers/cutoffs to compare...