[SugarFox5]

I am trying to reach optimum feeds and speeds for cutting acrylic. I work for a sign shop and I think I am running my machine much to slow with most plastics. I need to maintain a decent edge finish but I also want to decrease cut times. I have only been programming CNC machines for a year and any information about feeds/speeds and tooling would be GREATLY appreciated.

Thanks for reading!... and hopefully responding

[Bob La Londe]

I am trying to reach optimum feeds and speeds for cutting acrylic. I work for a sign shop and I think I am running my machine much to slow with most plastics. I need to maintain a decent edge finish but I also want to decrease cut times. I have only been programming CNC machines for a year and any information about feeds/speeds and tooling would be GREATLY appreciated.

Thanks for reading!... and hopefully responding

I haven't cut much plastic, but I have found it to be quite a challenge. If I try to go very fast I just melt it and make a mess.

You did not provide enough information to guess at your answers though. Depth of cut, width of cut, cutter diameter, speed of your machine, any form of coolant. Those are all necessary to get even a basic answer.

I have a Speed Feed ap on my Android Phone by Christopher Gay that does show Acrylic listed in the materials under thermoplastics. You might download it, plug in some numbers and cut up some scrap parts to see what you can do.

I think the ap name is just SandF.

I just checked ME Consultant Pro, and it only shows metals.

[grabberr]

The tool you are using makes a big difference. We generally use single flute cutters, and run approximately 16,000 RPM and 150 IPM with a 3/8" single flute cutter and 3/8" to 1/2" depth of cut, cutting full slot.

If its melting you may have to travel faster to peel a big enough chip to get the heat out.

[brian257]

Onsrud cutters are great and they have feed and speed calculations on their web site. LMT Onsrud | Router Bits, Cutting Tools & Drilling Tools, LMT Onsrud.

[SugarFox5]

I am cutting a lot of push through for signs. I generally do an island fill for the flange using 3/16" bit to hog out and an 1/8" bit for the fine pass. Final depth is .6". Running three passes at 4 ipm with spindle speed of 16000. Oh, I am using single flute "O" cutters... not sure if they are up or down cut or how to tell.

I am also having trouble with sharp edges matching up with rounded ones when I try to fit the push through into the face. I am using EnRoute 5 software and my client wants a very tight fit. I tried using the inline function (for the plastic) with rounded corners checked but still ran into issues with a tolerance of .02. Is there any other way to get such a tight tollerance to fit than to manually manipulate the txt to work with the bit diameter?

Thank you all for your help and suggestions!!

[SugarFox5]

thank you . Looks like I need to speed things up.

[CNCMad_Monkey87]

in the past I have used 1/2 in double O flute from onsrud those are the absolute best I run at 12000 rpm at 150 ipm for a depth of about .375 per hit, ramp in if your machine allows. after your multi pass rough cut you can do a climb cut finish with a 3 flute end mill I was using one from amana they are pretty cheep, do the final cut in one pass and that will give you the best edge quality same speeds and feeds just take off about .02 from the sides either using cutter comp, or an offset at the machine. if you want a glass-like edge try using a hydrogen oxygen torch and flame polish the sides after machining.
hope that helps I was making signs for over 2 yrs

[sofi1812]

university http://www.kstu.kz/ is studying this issue