Re: Looking to pull the CNC conversion trigger
Good work. A couple of questions. Did you ever find the shims for the bearings? Mine have the same problem and its been years since I looked at them but I know the Z has a big problem with back lash, and a lot is in the bearings when I have the gibs tight (ballscrew moves up and down measurably).
Also on Z I see you used 2 ballnuts nuts. How are they preloaded / spaced? It looks like both are hard bolted to the ballnut adapter.
Mike
Re: Looking to pull the CNC conversion trigger
For the shims, I ended up making my own. I used disc cutters to punch out .003" stainless from a roll I bought from mcmaster. The OD turned out to be right around 1-1/4". The ID I made 7/8" to clear the inner race with room to spare. Turned out only the z axis bearings needed shims, as the x and y were a different brand and had proper spacing between the two bearings
http://uploads.tapatalk-cdn.com/2016...465e516979.jpg
http://uploads.tapatalk-cdn.com/2016...54028a5a20.jpg
For the z axis, and actually the others as well, I made the ballnut bearing blocks as close to the actual thicknesses I measured between flanges. Any preloading was done by being a hair under that thickness and if off too much then I used the .003" shim material again to fill the gap. This gave me a 0.000-.002 range of preloading.
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Re: Looking to pull the CNC conversion trigger
91TSiGuy,
Where did you procure the disc cutter from? I would like the exact same unit.
Live from downtown Burbank, home of the endless Cup-O-Joe.
JoeyB
Quote:
Originally Posted by
91TSiGuy
For the shims, I ended up making my own. I used disc cutters to punch out .003" stainless from a roll I bought from mcmaster. The OD turned out to be right around 1-1/4". The ID I made 7/8" to clear the inner race with room to spare. Turned out only the z axis bearings needed shims, as the x and y were a different brand and had proper spacing between the two bearings
http://uploads.tapatalk-cdn.com/2016...465e516979.jpg
http://uploads.tapatalk-cdn.com/2016...54028a5a20.jpg
For the z axis, and actually the others as well, I made the ballnut bearing blocks as close to the actual thicknesses I measured between flanges. Any preloading was done by being a hair under that thickness and if off too much then I used the .003" shim material again to fill the gap. This gave me a 0.000-.002 range of preloading.
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Re: Looking to pull the CNC conversion trigger
I bought the one pictured above from Amazon and used another one from work for the ID. There's a round model on there that includes both 7/8" and 1-1/4" which is what sizes I ended up needing to make the shims but I don't know how well it'll hold up as stainless cutting stainless.
SE JT-SP310 Locking Disc Cutter Set (10 Piece) https://www.amazon.com/dp/B00CPTXKCO..._WFLCxbMH9V87X
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Re: Looking to pull the CNC conversion trigger
91TSiGuy,
Thanks for the super fast reply, I could use one of our donut hole cutters but it might not be good for food service afterwards.
Live from downtown Burbank, home of the endless Cup-O-Joe.
JoeyB
Re: Looking to pull the CNC conversion trigger
Just a heads up, the shim material is about as thin as I'd go for these import disc cutters. Their side wall clearance is right at the point where the shim can become pulled between the cutter and hole. Using a sacrificial piece of sheet metal under the shim stock while cutting could help I believe ( perhaps above it--i can't recall what i read)
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Re: Looking to pull the CNC conversion trigger
Te sacrificial part is where I see a real use for MDF on one off parts.
Re: Looking to pull the CNC conversion trigger
Thanks for the answer, I need to get in and shim my Z now, and seeing a non spring loaded double ballnut gives me confidence to try my own perhaps (I think X is the easy 1st try for me).
Mike
Re: Looking to pull the CNC conversion trigger
$25 in materials, an hour of time, and I have some make-shift chip containment.
http://uploads.tapatalk-cdn.com/2016...e64c6a9c7f.jpg
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Re: Looking to pull the CNC conversion trigger
Limit/homing switches wired up. Each axis got it's own input on the breakout board.
http://uploads.tapatalk-cdn.com/2016...a22a14dcf1.jpg
http://uploads.tapatalk-cdn.com/2016...6c620b797e.jpg
Rear Y switch, ends up covered by the bellows.
http://uploads.tapatalk-cdn.com/2016...28f70aac6b.jpg
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Re: Looking to pull the CNC conversion trigger
Re: Looking to pull the CNC conversion trigger
The upper mount is a bit too wide to swing the head from 90* to upright after bolting it on so I had to drop the middle bolt and only use the side ones for attachment. I thought cutting off the corners of the bar would work but it wasn't enough. Oh well, the gas struts are on.
http://uploads.tapatalk-cdn.com/2016...761387ab2e.jpg
http://uploads.tapatalk-cdn.com/2016...54da6400ac.jpg
http://uploads.tapatalk-cdn.com/2016...0872078d2b.jpg
http://uploads.tapatalk-cdn.com/2016...7cdec8b2c2.jpg