Z-axis Motor Broke? Pictures attached

[Angie Orfanedes]

Agree this is likely a classic case of a stress fracture from misalignment. The stepper shaft was flexing every rotation and finally gave up - like a paper clip or an airplane wing that bends one too many times.

[Joey Jarrard]

We*have*to*remember*the*job*application*and*motor* size that*we*are dealing with you*have*a*quarter*inch*shaft*and you are drilling*into*aluminum*over*and*over*again*I*have* seen*running*the*same*job*a vitec rebel's gantry flex from this same stress.*The rebel new was around 120K and your mc does not flex doing this job. The stress will go to the weakest link.
If*you*want*to*check*for allinment you*can*loosen*the*bolts*on*the*block*at*the*botto m*of*the*ball*screw*run*the*machine*down*allowing* the*machine*to line up if needed. Then just tighten*the*bolts*back*up*I*have*seen*in*shipping* things*get*misaligned*are*moved.*
Like Jim*said*it*would*be*a*good*idea*to*have*a*motor*o n*hand*this*would*be*great*piece*of*mine*for*about *$75

[Joey Jarrard]

Sorry about the "*" I used a dictation app on my I phone.

[Bryan Cowan]

Not sure if it's just the pictures, but the alignment looks way off. Shouldn't it be centered in the hole? I've seen a few of the chinese steppes with broken shafts, usually due to misalignment.

It kinda was. Grant it, when nothing is connected to the top of the ballscrew, it was leaning to one side. When I reinstalled the collar onto the broken spindle and then back onto the ballscrew, I did have to play/force it to line up. Nothing drastic, but maybe it's enough that over a 8 month period finally gave way.

[Bryan Cowan]

bryan i am in business with my router so downtime matters, i keep extra drives and motors on hand, i have fried my share

You think I cut aluminum for fun? It's business to me as well. However, I had the calmest attitude I've ever had when something broke yesterday. I was 2/3rds done drilling a full sheet when it gave up on me. I just shrugged my shoulders and began investigating knowing full well whatever the problem may be could cause my business downtime for an unknown amount of time. But luckily with the forums and CAMaster's customer service, it only cost me an hour or two of downtime, then it was back to business!

[Bryan Cowan]

also i see something i am not sure is a good idea, will report more tommorrow

jim

Received your email late last night. Looking forward to what you may be seeing in the images I posted. Not a fan of the mountain bikes in the first image?

[james mcgrew]

i was looking for the alignment adjustment and with out a mc near i asked first, it is in the base pillowblock, joey has already described this and how to realign it, if these ballscrews are out as much as to cause breakage the grinding and steploss would be real apparent.

turn the machine off, take your fingers and turn the nut (connecting) if it is reasonably smooth figuring the weight of your z head then alignment is not an issue, if it was out you would know right there, then loosen the bottom pillow block a tad and run the z up and down on the down retighten.


one of the largest reasons i bought camaster in the first place is the ability to have the calhoun fellows on the line quick and be able to under stand and work on the machine myself, i have really screwed up my machine more than i care to know and yet never lost more than a full work day of operation.

many who have visited my shop see two bit trays and two shelves of parts

one for the good and current stuff

the other for the burnt, broken motors and bits so i can constantly remind myself of what goes wrong!!!

i call it the "Shelf of Shame"

[james mcgrew]

ps, what mountain bikes?