cut acrylic crazing

[seanjournot]

After doing a bit of research it seems that acrylic, whether cast or extruded, becomes susceptible to crazing when joined after laser cutting. Since this effect is due to rapid localized heating I would imagine that this is also an issue with milled or sawed acrylic.

I am planning on making a acrylic sump and tank soon and wanted to know if the following feeds and speeds seem reasonable; I would prefer to maintain a 1500 psi continuous load rating on all of my parts. I will be using a palm router.

1/8" up cutting single flute square endmill, 10,000 RPM
hand safe dish washing soap (like dawn) and water for coolant

I have a lot of experience working with metals but not with plastics; the fact that acrylic will craze if continuously loaded well below it's ultimate tensile strength makes me a bit nervous about cutting it.

Here is a render of the sump I want to build. It's not finalized yet, waiting for a few plumbing parts to verify fit and will need to rework a few things to make it easier to fabricate. Factor of safety of about 5 at the moment (assuming 1500 psi limit). 20" X 20" foot print; 14.25" water height it the refugium section.

 

[lapin]

https://www.acrylite.co/tech-briefs/routing-extruded-acrylic.html
Having ref this here is what I do since i do not have a CNC machine
Rough cut the sheet on a table saw with a 90T Freud blade. I finish route the piece to size with a table mounted router. Spiral down cut bit. And the (no no) I do, is to run the piece between the router and a fence.

 

[seanjournot]

Thanks I had not run a crossed that reference yet. Looks like what I am planning will work fine and I may be able to run my spindle speeds higher without any issues.

 

[lapin]

Oh and howdy and welcome