Looking for suggestions on acrylic bits

1

Are O spiral bits the way to go? Should there be a different bit for a cutting out, drilling, and pocketing?

2

Freud 1/16" (Dia.) Double Flute… https://www.amazon.com/dp/B00004T7B2?ref=ppx_pop_mob_ap_share

I bought this and am really pleased, especially for the price. I’ve only done small shape and word cutouts (1" tall script) on 3mm ish cast acrylic.

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3

We used single flute, upcut endmills at my past workplace. Make sure you lead/ramp in as you cut.

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4

I use my ‘trusty’ 1/8" o flute on my acrylic projects, cuts like a dream. Used it to make a new base for my handy DeWalt palm router I use since it has that pesky pac-man shaped base.

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5

Nice job, you should flame polish the edges!

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6

I have had good luck with the Amana Tool 51515-K Spektra Coated SC Spiral Single Flute just purchased the Amana Tool 51405-K

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Thanks for the suggestion, I’ll have to look it up on how to do it.

8

A few notes on machining acrylic. First of all, the sharper the cutter, the cleaner the cut. Acrylic is brittle so you need to be careful when you enter and exit the material. It’s pretty common for the acrylic to chip when the cutter enters or exits the material. Also, always buy cast acrylic. The extruded is cheaper but whatever they add to make it extrudable causes it to melt while while cutting (and sanding) which will will leave you with a terrible surface.

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9

Thanks for the tip. Any suggestions on brand or where to purchase / order?

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Yes the the two Amana bits I referenced above. I like Tools Today. Fast shipping, easy website, great customer service, reasonably priced.

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11

Do you have any suggestions for feeds/speeds with acrylic?

12

I imported the Amana library into fusion and vectric and utilizes the defaults for my feeds and speeds.

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13

one other thing, High Speed steel is sharper then any carbide bit can be, the acrylic will not dull the bit much any way.

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14

I’m going to second what Knappwerks says about only using cast acrylic. It’s a wonderful material to work with and machines beautifully. Extruded acrylic on the other hand will almost invariably bring you to tears. The cut line will always( always!) heat up and close the kerf meaning you will need to pop the piece you’ve just cut out of the panel. This will always ( always!) chip the surface of your piece. It’s only really useable if it’s going to be put in a frame that covers the edges. While cast acrylic is astonishingly clear, extruded acrylic has a slight milky blueish haze to it. Not a problem at all if you are looking straight through 1/4" stuff but you can see clearly through an 8’ strip of 3/4" cast acrylic with no distortion. Love working with it, although I haven’t yet tried it on my CNC.

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15

I have had success with both - am currently machining some extruded parts as of this writing - although failures have left spectacular melted endmill blobs, or fused chips in narrow pockets. :grinning:
Some things that have worked for me…

  1. using single ‘O’ flute end mills
  2. using carbide - uncoated - just because I buy carbide
  3. using a strong air blast for most toolpaths, especially when there is little clearance ( I do not to use coolant, just my preference)
  4. using endmills dedicated to only machine acrylic
  5. using my favourite Datron 4 in 1 endmill
  6. staying close to CNC to fine-tune feed and RPM on the fly based on what is happening at the cut
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