Can the onefinity use 3/8” endmills?hi all!

Hi all!

I currently have a shapeoko and want to upgrade to the onefinity as the belts are a pain in the ass to deal with.

I was wondering if a time e has expierence citting with 3/8” endmills? I found a nice Amana one and the feeds are 200 ipm @18,000 rpm. Would the onefinity be able to handle such speeds and feeds? How is the deflection on the machine? When I cut a channel for wood to slot into, it usually comes up not wide enough and I can’t properly make nice pocket joints on the shapeoko due to its deflection.

Thank you!

You would need to use a spindle vs the router. Deflection shouldn’t be an issue but I’ve never used a 3/8" bit (just 1/2, 12mm, 1/4, and 1/8). I always use the default setting from Amana even if it’s not one of their bits. The only issue I’ve ever had was when I messed up a deep cut with a 1/4" bit and instead of doing it in steps I went full depth (3/4" in maple) and after I realized I should of stopped the cut but I figured I would let it go. After about 20 minutes I broke the bit but the cut up until that point was nice and smooth. When I went back and set up the job doing it in steps on that same piece of wood the bit followed the exact same line. SO I assume there was no deflection.

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Thanks for the response!

I already use a 65mm water cooled spindle on the shapeoko with 1/4” endmills. Im planning on getting a 80mm ER20 water cooled spindle. I thought I wouldn’t be able to use 1/2” endmills as that seems like there would be a crazy amount of cutting forces on the machine. Is the onefinity really able to handle these kinds of cutting forces? I think Amana says their 0.5” ones run at 200ipm which is crazy high!

The cutting forces are also related to the depth of cut too. The Onefinity is very stout, I have bent a 1/4" shank roundover bit at about 75 degree angle one time due to a improperly configured toolpath. Some deflection will occur in the frame, the mounting, the bit, the work holding etc - might only be .001" but there will be deflection, the question is what level of deflection is acceptable for your project?

Why would you be looking to run a 1/2" endmill, for faster clearing? In that case I’d typically use a finishing pass to avoid issues with deflection while clearing

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I need the machine to be accurate within +- 0.002 inches. If it can get down to 0.001” accuracy the. That is even better. I need larger endmills so I can remove more material faster to save on cutting time. Takes forever for a little 0.25” endmill to carve large speaker horns or speaker enclosure panels with pockets for wood to slot into. Because the shapeoko is belt driven, I have to take shallower passes which makes it take even longer! If I get the onefinity I’m sure I could cut my machining time in half or even by 60% using a 3/8” or 0.5” endmill. When I cut horn flares out of pine, it takes forever on the shapeoko to remove all the material before it does the contour. Some cuts take 1+ hours and the flare is made from 1” slices and it takes 4 slices ti make one flare so 4 hours of cutting for one flare of a horn. It’s ridiculous. I also wanna cut deeper on my roughing passes.

Just an FYI, you can get a 3/8 collet for the makita router.

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Ran the settings for a 3/8" bit in my app. I have a feature the calculates milling force. My OF machine model is a best guess value but I think it’s in the ballpark based on some data I got from the Millizer app. With a 50% depth cut your hitting 50% of the limit so you are good. I think a 1/2" but will push the limits though.