Cutting 1/4" Clear Acrylic Advice

[SirGariff (Gary Clark)]

I am wanting to cut out 1/4" clear acrylic for router templates for cutting boards, etc.

1. Is it possible with a CNC?
2. If so, any advice on bit for doing this?

Thanks!

[WillAdams (William Adams (Carbide 3D))]

1. Yes.
2. Use O-flute tools and source cast (not extruded) acrylic

See the videos at:

#MaterialMonday on YouTube

@wmoy has begin a series of YouTube videos on #MaterialMonday. For the full list: https://www.youtube.com/hashtag/materialmonday A central tenet of this series is an acknowledgement that the hobby CNC routers need different numbers for different sorts of paths. Thus far he has done: Aluminum: Shapeoko 3: [Aluminum Feeds and Speeds for the Shapeoko - #MaterialMonday] [Machining Aluminum with the 278-Z on the Shapeoko - #MaterialMonday] Nomad 883 Pro: [Sing…

[HeuristicBishop (Tyler Sowers)]

Absolutely possible with CNC, in fact I think it’s probably better than laser when it comes to thicker acrylics.

The most common failure mode is melting plastic, the somewhat counterintuitive solution to this is almost always to go faster. Folks tend to try and back off but that leaves your tool dwelling in one spot longer which builds heat which leads to more melting…and the cycle continues.

For bits, I’d recommend finding a plastic specific end mill if you have the funds for a material specific end mill. They tend to be razor sharp compared to non plastic-specific end mills and usually have different helix angles to facilitate chip clearing. The edge can be much sharper because tool life isn’t as much a concern in plastics, cutting edge doesn’t take a beating like metals.

I’ve been eyeing a single flute polished Datron end mill for plastics but haven’t pulled the trigger yet.

Super interested to see your results if/when you get around to it

(Oh also you’ll want to get cast acrylic for cnc. It machines much better than extruded. IIRC you can usually tell it’s cast if the paper on it is brown as opposed to thin plastic film…I think that’s just a rule of thumb though)

[Emmess (Matthias Solga)]

As William said: “O”-flute.
And: slow speed, and fast feed. 1. rub a little as possible → low speed, 2. get away from the place as fast as possible to leave no heat behind → fast feed. And always try to check for chips with your settings. As long as chips are produced the plastic does not melt. Use cast acrylic (has paper protection layers, never saw it in a hardware store like homedepot) because the melting temperature is slightly higher than from extruded acrylic.

Made the same with clear acrylic, don’t find the image.

[Graham (Graham Murray)]

I just cut two 55mm dia rings today at 4.5mm thick and I just use the 1/8 square end mill.Kept the speed down low and excellent chips and a very clean cut,The acrylic is the cast variety.