Might try higher rpm and slower feed rate on a finish/spring pass (not removing much material) to see if that smooths things up. Just leave a little stock on the first run and create a second tool path with the new parakeets at the final size.
I saw a video of a shop using a 3 flute for a polished edge, but I don’t think we can get away with cutting with one of those.
I don’t know estlcam, but other software like fusion let’s you create a toolpath then pattern it out. In two directions to replicate as many as you need.
So far as I know, no abrasion or cutting tool is going to give you a see-through edge on acrylic. The only time I have seen that is laser cut.
Get the best finish you can. In this case that will mean a finishing pass. A sanding block might also be a good idea to get things even closer, then a very light flame polish should do the trick without dulling the edges.
I honestly do not know. I’ve set my Katsu to speed setting 2. According to this topic that’s 22k RPM without load. So I expect 19-20k during the milling process.
Thanks for the suggestion! I was already looking to a 1.5mm bit as alternative as the difference in radius will be negligible. These I can order easily with cutting length up to 9mm.
Regarding your suggested bit, have you tried this on on Acrylic too? It seems like a 3 flute bit, and I believe this might make it more difficult?
That’s a good idea, going to try that one!
No, not perse according to what I’ve read. However they suggest to use a hydrogen oxide torch, and I am using a regular one. That doesn’t seems to work out. It does it a bit, if doing multiple passes, thus loosing the sharp edge.
Example video:
Yup! I got this one from Germany. It’s rated 4 out of 5 for acrylic. I’d like to buy a dedicated Acrylic bit, but can only find them in the USA or UK, making it rather expensive with the import fees. If one has a link to an affordable shop in Europe I’d love to hear it!
I know my CNC knowledge is limited today, but after seeing these I believe it should be doable:
No, I haven’t tried them on acrylic, I think I just surprised myself that I haven’t managed to break one cutting wood (yet).
I think you’re correct, they do look like 3 flutes. They list plastics as one of their applications but I know all too well how different the promise can be from reality.
Happy to hear this!
will need to look for mapp gas then. Do you have an idea how sharp the edges remain after this polish?
I totally understand, still waiting for that moment to happen too
yeah, as most posts on the web point to a single flute, I believe that a 3 flute might work but is far from perfect. So will keep looking for dedicated Acrylic bits.
Does anyone have some insights on optimizing jobs in estlcam so I could put multiple squares next to each other in 1 job?
As I said, I haven’t really looked too deeply but if you’re cutting duplicate parts I’d guess you could adjust the spacing for one pass to cut the sides of two parts? Might be self defeating though if conventional vs. climb milling has a large affect on finish when cutting acrylic.
I get your idea but not sure if estlcam is able to just cut that side once. Because if I select parts, it will try to cut all sides. But will experiment with it.
This would mean that the one edge of the part would be “climb” milling, while the corresponding edge against another would be “conventional” milling, and Estlcam doesn’t like to mix those up. (Neither should we, as they have different characteristics in the finished piece.)
The reason for finishing passes is that the tool path isn’t precisely predictable under load. We could reduce the load via DOC and speed so that a finish pass isn’t necessary, but I think it would be a very rare event where you would end up with a faster cut sharing a side that way. The idea of the finishing pass is that the load on the tool is very low, so the tool path is precise and predictable and you end up with the best precision for the final part possible.
Even if you only need to cut 3 sides of a rectangle, the tool still needs to traverse the 4th side for every pass (See above for climb versus conventional milling) and while this might save a few seconds for a “rapid” pass versus a milling pass, it’s really not that much.
I’ve looked at trying to eliminate 1 or 2 sides for a job where I wanted to use the original material edge, and in the end, I ended up just taking a small amount of material off, because I wanted the accuracy, or else I did the interior features only and cut the outline on something else, like the table saw.
I totally understand, still waiting for that moment to happen too