Supermax Ymc 30 X Table Removal. How To Start? ?

countryguy

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Hi folks- Is it time to admit that I need to take my Supermax YMC30 and dig into the bowels of thy'n beast.
Seems recently with my high than usual CNC jobs I now have X backlash in .003/4 range. Using Centroid I was able to compensate it out but it does not make me feel any better.

I have the YMC 30 maint. manual Nothing about how you take the Top X table off of this thing. I have the HF gantry positioned over / Chain fall ready to go.
Is this something along the lines of:
remove cranks, wheels, and Ball screw cover. carefully unbolt and record disassembly.
hoist it up?
Any good videos, or sites , point the way pls!
I wanted to also check the Ball-screw mechanics. I see a lot of posts about issues and how to check/resolve in there. Somwhere in there lies my issue, but a 80's YMC w/ .004 is not going to cut it!

The real solution IMO: As a CNC system for positional accuracy, Jim D. has sold me on Mag Tape scales vs the motor encoders I put in. His well documented and proven method to eliminate BL w/ Ditron /(Renishaw eqiuv) magnetic tape is in the works for this. I have my Ditron request in. But... I have seen some of the pictures of BPorts that at look horribly worn. I'll also clean or replace the oil dist. system if I'm in there.

Man... and I thought I was just about caught up w/ my Shop!
 
You should be able to get to the ball nut by sliding the table to the left. I suspect that you have a double nut system so should be able to preload it. If needed, once you get to the ball nut, you can unbolt it and pull it and the leadscrew out as a unit. It sounds like you have a good plan to support the table, so I think you're fine there. If you need to remove the table, it just slides off. I normally remove to the left, but I think it would go either way. Remove the gib before removing the table so you don't damage it.

One place that can cause backlash is the leadscrew support bearings. Normally one side is free floating, and the other side (normally right) controls the backlash.

On my machine I have about 0.004 backlash in my Y axis, the mag scales take care of most of it. But when pocketing a circular pocket, for a bearing as an example, I can count on it being slightly ovoid by about 0.001, with the major axis aligned at about 45° CCW from the Y axis. I need to fix that one of these days.

BTW, I sent an email to Ditron some time ago and haven't heard back from them. I'll try again.
 
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...and I was in the shop with flashlight at 5am today b4 work. I learned about tapered gibs and the fact they too have a contribution to BL. My hats off to Jumps4 and his great video. Very informative! I was dying to get out there and eliminate my problem with a simply gib adjustment. Right?... Nope. I can get it down to 003". But that is all no matter how loose the gib.

There is A stiff steel wrap around the ball screw. Somehow I need to get that off just to see in there. I really do not want to tear this down but like life I just need to see behind the curtain :).

I think it goes something like this? I have search for anything on ymc table removal. Getting blanks.
Remove the motor , housing and mounting. Left side.
Remove the handle and unbolt right side.
Swear a bit, Scratch a few things, look at the manual. Walk away to think.
Strap up the table to the gantry and see what I see as I slide to the left.
 
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