i can measure the ball screws for you. Have them shipped in convenient lengths, ball screws are HARD to cut, turn and thread.
The x axis ball screw is captive on the right side, it has a radial and thrust bearing captive to the table and screw. the left side should have a RADIAL bearing and the ball screw MUST slip in it. As the temperature changes the the screw lengthens and the left side of the screw should be allowed to slip in and out as needed.
The y axis far end is free with no bearing as it is so short.
Z axis has a bearing on the top and bottom
Pics, drawings and video are coming for the z axis
ALL ball screws use 2 ball nuts
LOL on the dizzy thing. But thank you for adding the video and drawing or the Z, that makes sense now.
If you want to get a rough measurement of a ball screw, can you measure the one on your Z? I should be able to figure out the others.
Would it be better to have all the motors on a belt drive setup?
I was wondering what that cap screw was for, that's a good idea for a bearing retainer.
If I was to do it again I would go with larger x y steppers and direct drive them. I am running a 3:1 ratio on my belts. Look for stronger steppers and possibly a larger required power supply. Or you could belt drive the y axis and go with a larger direct drive x.
Do you think the 495 oz motor would be enough for direct drive?
What about the Z, think that would work with a direct drive? Assuming it could be mounted that way.
I think that will be enough, becaise of the shape of the table, the x needs a drirect drive. They y can do either.. the z needs belt drive to keep it compact. I would go with larger steppers on x y z just to be on the safe side. Remember of it skips you lose zero...
Ball screw length:
x 33 ( extra long on one side)
Since you keep saying about going with large stepper I'll plan on those 500+ oz ones since they're just five bucks more.
Thanks for the measurements, I think I'll get two three foot pieces so I'll have extra for the Z in case I need it.
The only reason I was thinking of doing all axis with belt drives is because other then yours I've seen four other machines like ours and they had all three axis belt drive, guess I'll have to rethink what I was thinking of doing. :D
I tried to join that CNCZone forum to try and see what others have done on theirs, but I haven't gotten the confirmation email yet
Got any links? I would like to see a belt drive setup for the x axis that doesnt force you to losea few inches of table movement. That is the main reason i say go direct drive.
Mostly I got a few pics I saved, I'll most likely have to put them in a couple posts, and a few videos I found on YouTube.
Remember I was just looking for mounting ideas.
Here's some links to videos.
This was the first one I found, it looks like it just hooks up to a stock machine.
Vulcan - Harbor Freight milling machine retrofit. Testings - YouTube
This guy did servo motors and a variable speed DC drive motor
CNC CONVERTED RONG FU DRILL MILL (DC SERVOS + MACH) - YouTube
This one mostly shows it cutting
RF30 RongFu milldrill converted to cnc - servos-MACH-GECKO - YouTube
First Cut with my CNC Converted Mill - YouTube
CNC home shop mill retrofit - YouTube
Now the pics
I like how this guy set his up. He kept the X mount thin so it will clear the base if the table moves far enough, but it does stick above the table a little.
His Z is a really nice setup but it's complicated looking with little margin for error.