[airbrush]

Hi,

I have an all aluminum machine (one of the early xzero machine kits from about 4 years ago...)
When I move the y axis (just by pushing it along, holding it at the bottom where the ballscrew is...there is a notice able wobble/shake to the gantry.

What would you say is the general cause for this...?
ballscrew no aligned properly?

How to diagnose/fix ...?

thx

[awerby]

It sounds like something is loose. Was it always like that, or did this just happen recently?

[airbrush]

Just assembling it ...will double check all the bolts and try again

[airbrush]

Tightened everything....sighting down the ball screw(am i referring to it wrong?? leadscrew?) while moving the gantry it looks like it's rotating slightly offset... Not centered perfect.
Not sure how I can fix that...
I would always need to move it slowly then? And precision would be slightly off .

Suggestions on what to do about it??

I suppose I would need a tool to measure run out on the ends? Not sure how likely it would be that the ballscrew is slightly out of whack?

[airbrush]

even moving it slowly I can feel a drag on every rotation...don't see how I can leave it like this.

What are my options...replacing the ballscrew(am i referring to it wrong?? leadscrew???

Where to get ballscrews in Canada?
How do I figure out what type of leadscrew it is? Looking around sites...there are alot of variations....what numbers do i need to know.
I basic measurement looked like .75" diameter by 35" long and 6 'threads' per inch...
If I post a clear picture of the leadscrew close up with a ruler next to it can anyone tell me what exactly I will need?

...newbie here, any help much appreciated.

[airbrush]

from what i've found so far...its looks like a minimum $400 fix to replace ballscrew/leadscrew...assuming i dont need new bearings on the ends and coupler and can re use those?.

I wonder if its possible to get a machinist to return the ends(that's if the leadscrew isn't out of whack?)...then i would need new bearings and couplers for sure, and possibly new end blocks to hold the bearings...so not even sure its worth it...might come out to the same amount with more hassle....

...either way...looks like I got screwed

the leadscrews i have, are threaded all the ways to the ends...the ones i've looked up so far all seem to have machined ends of a couple inches or so. My guess is that he just bought the leadscrews non machined and had someone cut and do the ends to save a few bucks....which is probably why they not correct....

[awerby]

If the ballscrew or leadscrew or whatever you've got isn't bent, it's probably possible to re-machine the ends to make it true, if you're right about this being the problem. Once you do that, you can either replace the bearings that hold it, or put a sleeve on it to bring it back up to the original size. If the screws are hardened, that would take a grinding machine, otherwise it could be done with a lathe.

[bhurts]

Have you contacted Xzero. He has a thread here on the zone he posts in regularly. If he can't get you going check out eBay or automation technologies/ keling to find a replacement setup. It is most likely a metric 2005 ballscrew if your measuring around 3/4".

Ben

[airbrush]

Will have to take it apart and find a machine shop to get it checked out.

If the ballscrew or leadscrew or whatever you've got isn't bent, it's probably possible to re-machine the ends to make it true, if you're right about this being the problem. Once you do that, you can either replace the bearings that hold it, or put a sleeve on it to bring it back up to the original size. If the screws are hardened, that would take a grinding machine, otherwise it could be done with a lathe.

[airbrush]

No intention of contacting him...was nothing but a hassle dealing with him way back then...

Have you contacted Xzero. He has a thread here on the zone he posts in regularly. If he can't get you going check out eBay or automation technologies/ keling to find a replacement setup. It is most likely a metric 2005 ballscrew if your measuring around 3/4".

Ben

[airbrush]

So I took the machine down to a local cnc machinist shop.
Basically what he told me is that the machine should have built with supported rails for the length that is and even if the ballscrew were out a bit that the rigidity of the rails will hold it in place.
machine is 36" long

so looks like i'll have to replace the rails and bearings and hopefull that will fix it .... Anyone know of suppliers in Toronto?? round rail supported(20mm) and open bearings.

...I tend to believe this guy...since shortly after those initial machine kits were offered he(xzero) switched everything to supported rails...

[airbrush]

Okay, so onto the next issue/question...

I've sourced parts and can get everything I need, my only concern is trying to reuse the endplate and gantry plates if I can??
For example the bearings that were attached had a 40mmx40mm mounting...the new ones have 35mmx35mm.
Is it possible to just fill those old holes with JB weld or something and re drill my new holes...the new holes would overlap where the old holes were slightly
Same would go for the endplates as I need to mount new extrusions but the holes would overlap just slightly on those as well.

here is how the mounting holes would look...
Attachment 257582

[airbrush]

replaced with supported rails. solved issue with bear blocks by simply cutting the existing ones and swapping out the cut bearings into them.
Wobble is fixed...now at least is useable.