Can't Win Some Days

I'm learning a lot... like you hardly need any torque on the thrust
bearing retaining nut on this KMB1. I learned how to make new tab lock
washers too since nobody stocks them, but several say they can get
them... eventually. I even learned what the X axis is supposed to sound
like with good thrust bearings. It never really had any problems, but
its sure sounds a lot smoother now. Obviously the bearings were bad.
With new thrust bearings on the Y-Axis its pretty smooth now too, but
only for about 7/10 of a turn. Then it pulses. Its actually a lot
worse than it was before. Before I could see a little flutter about
every 1000 steps or so on the scope, but the machine appeared to move
smoothly. I guess the Y-axis thrust bearings were so wore out that it
allowed it to move smoother. With new fresh bearings it pulses badly.
And no its not a matter of tuning. As near as I can tell the ballscrew
is bent and its binding as it turns. That would sure explain the
chatter I saw before. Now its unusable.
The bad part is I don't know how to remove the new bearings and save
them. The obvious way to pull the bearings pulls the rear bearing apart
when you take the housing and bearings off the shaft. So... even if I
find a good replacement ballscrew I'll wind up having to chase down
another set of bearings too.
Of course I have one piece to make to finish a job that is just a little
too big for the little mills.
DANG-IT!
Reply to
Bob La Londe
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I've got some much smaller cheap Chinese double nut ball screws on the shelf. I'm right at that point where I am tempted to make an adapter plate to mount the ball nut for one of those, and make my own bearing and motor mounting plate for the front of the machine. It probably wouldn't last long, but it should be reversible. I'd have to direct drive the screw which would leave the motor sticking out in the way in the front of the machine. Its not a pleasant solution. Atleast I could make all the parts on the little high speed machines, and then I might be able to finish my current job.
Reply to
Bob La Londe
If you're going to junk the old ballscrew anyway, just machine away enough to let you get the good bearings off.
Reply to
Robert Nichols
them. The obvious way to pull the bearings pulls the rear bearing apart when you take the housing and bearings off the shaft. So... even if I find a good replacement ballscrew I'll wind up having to chase down another set of bearings too.
enough to let you get the good bearings off.
That's not a bad idea. Although I also considered turning the bearing surface to a smaller more concentric OD and using a bushing. Probably would re-turn the whole end and make appropriate adjustments including a different size encoder disc though... or a whole bunch of bushings. LOL.
Reply to
Bob La Londe
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Yep. Lots of options. I'll look at some of the sources on the PM thread with more care in a bit.
Reply to
Bob La Londe
I'll post some info when I have time to pull that part of the machine apart again. Right now I have to get some jobs on the little machines and keep them going. Might not be until tonight or tomorrow when I some have time to disassemble.
Reply to
Bob La Londe
Basic Dimensions:
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More Pictures:
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Good news. I was able to get the ball screw out of the new bearings without pulling the bearings apart. I unbolted everything from the machine and took it out as an assembly. Without everything in a bind it came apart modestly easily.
If something wonderful doesn't present itself I'll have a go at turning the end of the shaft down and using a bushing or bushings to bring it back up to spec. Obviously I'd have to change threads and nuts, but that's not a huge problem I suspect.
Reply to
Bob La Londe
Nothing Huh? Ok, well I need the machine working. I can get a decent price on a metric screw with oversized balls new from Automation Overstock. (about 7 tenths backlash) I'll just go that way and make an adapter, because I need to get the machine going pretty quickly. its been down for three weeks, and while it doesn't do the bulk of my work its made me realize how much I do use it. There are somethings that are easier to do with horsepower than with high speed and feed.
Reply to
Bob La Londe
Well in the years we have interacted on-line this is the fifth time you haven't followed through on something you said you would do for me. The first time I think was before your stroke so call it 4 times. One in theory you might still be following thru on so still 3 times. As to the tolerance... well... if you had something better I could afford and followed through I'd have bought it. But go ahead and blink feigning astonishment and superiority. It doesn't matter to me how superior you think you are in everything you are or do or have. Does me no good without follow through. I just need to get my job done. With or without you.
I have seen others post about how you did something or sent them something so I just figured you didn't like me, and didn't mind wasting my time.
You do know the original claim of tolerance for this machine in the manual is only .003, although its always produced better than .001 for me. Its got a decent screw, but its still only a single nut ball nut.
So, why in the heck do you think I posted dimensions and images at your request if I had it all fixed.
Reply to
Bob La Londe
******************** Here ***********************
**** Apart without breaking doesn't mean fixed ****
**** Sure doesn't sound like fixed there either. Sounds like waiting and hoping for a better option ****
Don't worry about it. I didn't think you would come through anyway. I just gave you the benefit of the doubt one more time since it didn't really cost me anything, and I generated those pics for somebody else anyway.
Have a great life. I need to get back to work.
Reply to
Bob La Londe
From the cross posting hermaphragroupie. PLEASE crawl back under your rock. That stench wafting off of you is killing us.
Reply to
Bob La Londe
ME: FYI: I fixed that axis a long time ago
John Dookie: Bullshit!
Me: Ok. What you think isn't important to anybody anyway.
Reply to
Bob La Londe
This troll just can't get enough of itself...
Reply to
John Doe
No apparently you can't. You are the one who went trolling for an old thread to try to annoy me and then cross posted your tripe to a SPAM group.
I'd tell you your mom is calling, but if she was it would be for help because she was be afraid you were coming back.
Reply to
Bob La Londe
This asswipe thinks it owns USENET...
Reply to
John Doe
That is so weird. I never figured you would admit to that. You just don't have that much self awareness.
Reply to
Bob La Londe

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