Acrylic Speeds & Feeds for Shapeoko - #MaterialMonday

Some safe starting recipes for the Shapeoko 3 in acrylic (cast).

-----

TLDW:
With a 1/16” 2-flute square endmill, for pocketing I like:
18k RPM
72 IPM
0.045” DOC
1/32” Stepover

For an adaptive toolpath (and this is a conservative set of parameters) I’d start at:
18k RPM
90 IPM
1/16” DOC
0.01” Optimal load

In a slotting application, or full width of cut contour, I like to back off a little because of the increased wall contact and compromised chip evacuation.
18k RPM
54 IPM
1/32” DOC

With an 1/8" endmill, for pocketing I’d start at:
18k RPM,
72 IPM
0.08” DOC
50% stepover

Adaptive:
18k RPM,
108 IPM
0.125” DOC
0.013” OPT
Again, this is probably quite conservative, but it’s a safe place to start.

2D contours:
18k RPM
50 IPM
0.0625 DOC

And lastly, for a 1/4" endmill like our 201, for pocketing:
10k RPM
75 IPM
0.0625” DOC
0.125” Stepover

Adaptive:
10k RPM
105 IPM
0.15” DOC
0.05" OPT (tested to 0.0625" but that sounds a bit rougher)

And for contouring:
10k RPM
75 IPM
0.055” DOC

[billpackman]

Excellent video. Have been running big CNCs for years but first time cutting acrylic. Lots of shouting and frustration (and quite a few quid in broken bits) before I found this gem. Top work. Thanks.

[RC-Flight]

Thanks for including metric speeds and cut depths!

[ricknull]

Great video! I’m brand spanking new to CNC work and I even understood this… kind of.

[koos]

Oh! I recognize that waste board scar at 3:23, I too have had an up-cut bit auger itself into the spoil board and out of the chuck! I have been a bit more shy about my DOC since then.

[markadamarnold]

"Finding limits is an exercise left to youth..." I love this quote. Thanks for the laugh. Great info in this video. Definitely bookmarking for future reference.

[threeque]

You make the BEST cnc videos. Love them.

[miragerd]

You are a well of knowledge. Thanks for all the insights.

[Revvek]

Great video!

What 1/8” end mill did you use in that section?
Single flute?
We are trying to cut acrylic on somewhat upgraded xcarve, and though we got the 1/4 cuts working we seem to be having issues with 1/8 cuts with a single glue upcut.

[joe_fabricator]

Will try some of these toolpaths. Luckily, VCarve has ramping options which is great. Nice video.

[SerialPyro]

I'll have to give these a try, when i tried to run acrylic on Saturday i had alot of issues

[StephensCustomModels]

This was a very helpful starting point, thank you.

[FriedrichKegel]

Use air cooling to keep the tool cool for longer operations ;) And only use single flute endmills which are new/very sharp/only used for plastics!

[KalebQi]

So how do you adjust these parameters if you’re using a single flute or 4 flute cutter instead of a 2 flute cutter for example?

[piotrhasse]

Summary in description is nice but I miss same information in metric units as it is in video and lack of links to shop (like in previews videos was done).

[whyemmi]

How many flutes cuter are you using in this video?

[SolarBurrito]

What bit do you use to engrave tiny word labels into acrylic? Words about 1/4 tall

[flavianojose]

hey there, hope you are doing great, i have a 3018 cnc, and i bought now one flute from HQ Master, and still dont get the best settings to cut my acrylics, its always melting the acrylics, do you have better settings to recommend?

[buddyturner]

Good video, what are your recommendations for engraving acrylic and type of bits? I’m getting build up on my vbits which is marring the surface white, thanks!

[theguncouple]

any tips for avoiding build up on smaller bits? the build up is really bad that it ruins what im trying to drill/cut

[AllanScheSar]

2:26 it looks like a popcorn action :D