Belt Replacement on Nova Comet II

[KMCloonan]

I need your help! I needed to replace the belt on my Nova Comet II lathe (left the spindle lock on a few too many times, created flat spots on belt....).

I watched a YouTube video on how to replace the belt - everything went ok with the disassembly (except for the double grub/set screw on the pulley that had me stumped until I read my manual...).

When I reassembled the spindle back into the bearings, I cannot seem to get it seated/inserted far enough to expose the snap ring channel, for me to reinstall the snap ring. It looks like I am about 1/16" of an inch shy. I have removed the spindle a second time, cleaned everything (in case it was crud that was preventing me from inserting the spindle the whole way)... I have tapped and tapped, using a block of wood and a variety of hammers, from a dead blow, to a claw hammer, to a sledge hammer, but nothing is budging for that final 1/16".

Any thoughts, suggestions?

Thanks,
Kevin

 

[duserart]

I need your help! I needed to replace the belt on my Nova Comet II lathe (left the spindle lock on a few too many times, created flat spots on belt....).

I watched a YouTube video on how to replace the belt - everything went ok with the disassembly (except for the double grub/set screw on the pulley that had me stumped until I read my manual...).

When I reassembled the spindle back into the bearings, I cannot seem to get it seated/inserted far enough to expose the snap ring channel, for me to reinstall the snap ring. It looks like I am about 1/16" of an inch shy. I have removed the spindle a second time, cleaned everything (in case it was crud that was preventing me from inserting the spindle the whole way)... I have tapped and tapped, using a block of wood and a variety of hammers, from a dead blow, to a claw hammer, to a sledge hammer, but nothing is budging for that final 1/16".

Any thoughts, suggestions?

Thanks,
Kevin

Hi,
I had the opposite problem getting mine apart to replace the belt and was ready to take it to Nova. I removed the headstock to make the trip easier. While I had it apart I decided to lay it on the bench with the shaft vertical and got a bit more aggressive, my problem was resolved, changed the belt, reassembled it, and realigned everything. Seams like I had a better angle of attack in the vertical position.
I believe my problem steamed from the fact the lathe was dropped on end during shipment enough to crack the bed. At that time I didn't feel any bind anywhere. Nova sent me a new bed the next day. Great service!
Art

 

[greenacres2]

Any chance the spindle bearing is no longer completely seated?
earl

 

[KMCloonan]

Any chance the spindle bearing is no longer completely seated?
earl

Yes, that is possible. There two bearings - one on the handwheel side, and one on the chuck side. When I removed the spindle by tapping it out, the chuck-side bearing also came out (it remained attached to the spindle). So when I reinserted the spindle, as I tapped it back into place, the bearing looked like it seated ok, but possibly not deep enough. Should I remove the spindle, remove the bearing from the spindle, and seat the bearing first, then tap in the spindle?

Thanks,
Kevin

 

[KMCloonan]

Hi,
I had the opposite problem getting mine apart to replace the belt and was ready to take it to Nova. I removed the headstock to make the trip easier. While I had it apart I decided to lay it on the bench with the shaft vertical and got a bit more aggressive, my problem was resolved, changed the belt, reassembled it, and realigned everything. Seams like I had a better angle of attack in the vertical position.
I believe my problem steamed from the fact the lathe was dropped on end during shipment enough to crack the bed. At that time I didn't feel any bind anywhere. Nova sent me a new bed the next day. Great service!
Art

Thanks Art - I definitely agree with you about Teknatool's Customer Service. I have always been very happy with them.

 

[randyrls]

Yes, that is possible. There two bearings - one on the handwheel side, and one on the chuck side. When I removed the spindle by tapping it out, the chuck-side bearing also came out (it remained attached to the spindle). So when I reinserted the spindle, as I tapped it back into place, the bearing looked like it seated ok, but possibly not deep enough. Should I remove the spindle, remove the bearing from the spindle, and seat the bearing first, then tap in the spindle?

Thanks,
Kevin

To join the thread; To make sure the bearings are seated, use a socket just slightly smaller than the OUTSIDE of the bearing. You want any force to go on the outside ring of the bearing, NEVER the inside hole. It is fairly common for the bearings to be force fit. Loose means an out-of-tollerance and rejected lathe, but a too tight bearing is OK. This is also true of the shaft "journal" (where the inside of the bearing meets the shaft). This should be handled by someone experienced or the manufacturer. I've done this on my metal lathe, but it was a real butt-tightener!

 

[KMCloonan]

To join the thread; To make sure the bearings are seated, use a socket just slightly smaller than the OUTSIDE of the bearing. You want any force to go on the outside ring of the bearing, NEVER the inside hole. It is fairly common for the bearings to be force fit. Loose means an out-of-tollerance and rejected lathe, but a too tight bearing is OK. This is also true of the shaft "journal" (where the inside of the bearing meets the shaft). This should be handled by someone experienced or the manufacturer. I've done this on my metal lathe, but it was a real butt-tightener!

Thanks Randy. I was on the phone with Nova Teknatool earlier today, and we confirmed that the left bearing crept out of its seat, thereby obscuring the snap-ring groove. Problem is, I can tap the bearing back into place when the spindle is out of the headstock, but when I reinstall the spindle, the bearing gets pushed out as the spindle advances. That's where your suggestion will come in handy. I need to get a deep 28mm socket that I can slip over the end of the spindle, and tap against the bearing to reseat it fully and replace the snap ring.

Thanks for the tip!

Kevin

 

[KMCloonan]

Just to close this thread, I ended up going MacGyver on my lathe. Nova Teknatool suggested I send my headstock to them and they would reseat the bearings, starting at $60, plus shipping. I decided to give it one more go.

I figured I needed to hold the left bearing in place while I tapped the spindle all the way home, so I used a hole saw to cut a hole in a board - I placed a rear-pinion seal installer (that was the same diameter as the bearing) up against the bearing, placed the board with the hole over the seal installer, and clamped the board in place. Then I was able to tap the spindle home, and the bearing stayed put. I snapped the snap-ring back on the left end of the spindle, and was back up and running. I may need to replace my bearings sometime in the not too distant future (they took a lot of "gentle" pounding with a deadblow), but now I have more confidence I can do this again. See attached photos.