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Milling UHMW Plastic
- Thread starter Todd3138
- Start date
So, working on the advice you guys provided, I decided to do this project largely on the table saw instead of the mill. My gosh, it was simple, though I did get a little gumming on my saw blade. It wasn't enough to make a big difference in performance and we made both parts, took them to the drill press to drill the 3 bolt holes, and then ran them on the mill to create a 45' bevel on the back of the thick side. I think they turned out really well and my buddy was happy with them.
Here is a pic of the original with the block cut down to overall gross dimensions.
This one shows the two pieces in comparison with the original prior to cutting the 5/16 channel in the bottom.
And here they are side by side after drilling and beveling. The original is on the right.
Interesting stuff to work with but made much easier with the great advice you guys provided - thanks again!
Todd
Here is a pic of the original with the block cut down to overall gross dimensions.
This one shows the two pieces in comparison with the original prior to cutting the 5/16 channel in the bottom.
And here they are side by side after drilling and beveling. The original is on the right.
Interesting stuff to work with but made much easier with the great advice you guys provided - thanks again!
Todd
Just got a look at the finished pieces. Nice job! When you get a a chance, practice making parts out of all sorts of plastic and plexiglass and Delrin. You will use the experience over and over again.
Thanks! I used the original piece as the template for every cut on the saw and just set the fence based on setting the original in the next orientation for the next cut then ran the two new pieces. The sizing ended up just a little larger than the original but my buddy assured me that these are not close fit tolerances and being off by a few thou wouldn't hurt.
It was definitely interesting to work this on the saw and see the long, wispy strands of plastic that were coming off of it and, to an extent, finding a home in my beard, compared to the chips that came off it on the mill when I added the 45* bevel. I suspect some of that may have been the fact that I used a countersink drill on the mill as opposed to an endmill, but it was interesting nonetheless to see how the plastic reacted differently.
So I assume there are some materials that respond better to milling than UHMW does. Is there a handy way to get an overview of that kind of a breakdown or is just asking here when a new material comes my way?
Todd
- Joined
- Sep 5, 2013
- Messages
- 3,668
I've always found this site to be quite comprehensive. I'm sure there are other resources, perhaps not quite so technical, but I still go to this one first. Machinability is rated on a 1-10 scale so once you have one or two to compare to it begins to hang together a bit more. Many plastic shops also have their own data sheets / tables for reference as well.
-frank
Research & Compare Plastics A - Z | Boedeker
www.boedeker.com
-frank
Best you can do is to get a scrap of different types of plastic and experiment. I just drilled a couple of hundred #41 holes 5/16" deep in two 1/4 " plexiglass plates with a picture sandwiched in between them. On a small size drill like that the normal speed in most materials would be a couple of thousand RPM. I found out around 400 rpm with medium down pressure resulted in perfect looking holes with nice shavings off the the drill bit. I also backed off the 1/4" 4 flute endmill speed. I could hog plenty of material in conventional cutting. Stop the mill and peel off the melted accumulation. Around .008 slow cut in climb mode gave me a glass like edge finish. More or less was not as pretty looking. Go figure.
Anytime you go to do something you have not before or on a new material or special circumstances, ask. Sort through the answers and adapt the best one.
Anytime you go to do something you have not before or on a new material or special circumstances, ask. Sort through the answers and adapt the best one.
Thanks. That makes sense and having scrap definitely allows for screw ups, er, learning!