Origional 883 Pro - Bad Spindle?

CNC Machines Nomad
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Hello,

I have on original 883 Pro. It has been sitting for several years. I finally had a project I could use it on and dusted it off last night. While using it I was noticing the spindle motor would randomly stop. So I reset everything and tried out the MDI as a diagnostic.

With the spindle off of the work piece after a couple seconds of starting up the spindle it would make a grinding noise and would stop and no further commands would re-activate short of a power cycle and restarting carbide motion. I was able to spin the spindle by hand and didnt notice any grittiness in the motion, though I could feel a bit of cogging, but I believe that is inherent to any stepper motor driven system. So in an effort to further diagnose I disconnected the drive belt and spun the motor and it was able to reach full speed and hold with no noise or stalling. Upon re-connecting the drive belt and running a test the noise was even worse. I can only assume the bearings in the spindle have gone bad even though they feel fine when spun by hand.

Is there a way to service the spindle, or are replacements available. I checked the store and didnt see replacement parts listed. Or is there something else you suggest I check before firing up the parts cannon?

Thanks

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Check in with support@carbide3d.com and we will work out how to handle this.

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As a general FYI, grease separates over time, so spindle bearings should be run-in veeeerrrrry carefully after any long period sitting.

I like to run at 10% speed for a half hour, then 20% for 15 minutes, then 30% for 15 minutes, etc. until getting to normal running speed.

This isn’t Nomad-specific advice, just comes from a lot of time working on high-speed bearing assemblies in the past. We had a custom machine just to run in new bearing cartridges.

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So I emailed support as WillAdams said and still havent heard anything back. I assume they took time off for the holidays so I’m not holding anything against them. But in the meantime I didnt want to sit still on this so I disassembled the spindle and replaced the bearings. This has not resolved the issue.

I tried doing a slow bed in process like nwilson suggested just to give the new bearings the best chance. I ran it at 10% but the rpm wasnt consistent. After about 40 minutes it started making a buzzing / grinding noise and stopped on its own before I could shut it down. After a reset I tried running it at 10% again but this time it only lasted about 10 minutes. Out of curiosity I tried a 3rd time to see if a pattern emerged and this time it only lasted about 15 seconds. I checked the motor but it wasnt even warm, so I dont believe heat to be a factor.

I gave up for the night in frustration and tried again the next day. It seemed to be back to the mostly functional state it was in for my 1st test, so this time I tried different speeds. It seems the higher the speed the quicker the buzz / grinding sets in. I managed to get a couple videos to show what I’m experiencing.

The first shows the inconsistent speed and the second shows the buzz / grinding. I probably should have mentioned that the inconsistent speed was also happening before I replaced the bearings so this isnt new, I just forgot to mention it in my original post. I’m now starting to suspect the motor controller.

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It wouldnt let me put both links into one post, so here is the second video

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I’m a bearing nerd, so forgive me…

That said, spindle bearings are precision instruments. I don’t know about these, specifically, (hmm, what were the part numbers?) but a typical spindle bearing will have precision to the nearest 5 microns or less.

When working on spindles, you need a cleanroom (yes, a real one, with MERV 15 filters or better), sterile tools, bearing heaters, and presses with adapters. A bearing that’s a press fit on a shaft should be pressed only on the inner ring, because pressing on the outer ring leads to little dents in the race where the force goes from the ring, into the ball, into the inner ring, which provides the drag on the shaft. These “Brinell” marks lead to rapid failures. Contamination (even stuff smaller than cigarette smoke) leads to stress risers which lead to rapid failures. Installing it a little bit crooked leads to uneven wear, which leads to rapid failures. Bearings are really picky when they’re going fast.

If you do another rebuild, do it in the kitchen (unless your shop is cleaner - mine is certainly not), and take lots of photos. The shaft should be spotless and cleaned with brake cleaner (preferably NOT in the kitchen) then bagged until you’re ready with the bearings. The bearings should be unpackaged at the least second, and can be carefully heated on a clean piece of aluminum foil, at 240 degrees F on your pancake griddle, to make them easier to slide on to the shaft. After the shaft/ bearing assembly has cooled a lot (not in the fridge; they’ll attract condensation when they come out, which wrecks the grease) so the bearings get back to the original size, you can put it in a slightly warmed housing (IDK, run your toaster over to 250, then turn it off, then put the housing in for a few minutes to let it up to 150F or so?) and they should slide in more easily.

Even I don’t do spindles at home. I know enough to know my shop is way too dirty, and my tools too cheap, to do anything more precise than a bicycle hub. But… sometimes you just need to get it running while you wait for a better spindle to come in the mail. I get it. Get bearings from someone reputable like Motion Industries or Purvis or Applied, not from Amazon or ebay (you’d be shocked how common counterfeit bearings are), and get good bearings. And best of luck - sometimes the stars align and you’ll get 20 years from a rush job. The extra care is usually worth it.

1 Like
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Well I heard back from support and they are sending a new motor controller board, but as far as the bearings go I’m just going to hope I get lucky since I already did several things you said not to do durring the reassemble process. I’m using SKF 608 2RSL from simply bearings. I did assemble it in the kitchen, but I put the bearings in the freezer and the housing in the oven. I didn’t have to use any force to get them together, and I was able to get the shaft into the bearings without any hammering so I don’t think I did any damage there. Though I did just put it back in as is without the brake clean treatment. At this point I think I’m just going to run it as is and if the bearings go bad I now know what not to do next time.

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Ok, not too bad then. I’m in the US so I can’t comment on whether Simply is authorized, but they seem legit? And it sounds like, as long as you kept the grease dry (hopefully your HVAC had your house dried out for winter) it’ll be in decent shape.

If you need to do another swap down the road, SKF’s site has mounting instructions on the product page. They’re good about sharing info, too - productselect.skf.com lets you check a lot of stuff, including some lubrication info.

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