Wobble on headstock with scroll chuck

[chief489]

Hi all. New Shopsmith user here - I was given it by my Dad, who in turn was given it by someone clearing out their place after their husband passed away.
I've got a Mk5 and have used it a couple of times to practice spindle turning with no problems. I bought a Nova G3 chuck and have had a go at turning a bowl. All fine.
I went to do some more practice today and there seems to be excessive wobble in the chuck when spinning. I have checked the chuck is properly seated and can't seem to see any reason for the wobble.
Any assistance with trouble shooting hugely appreciated!

[chapmanruss]

chief489,

Welcome to the Shopsmith Forum.

The first thing will be to locate the "wobble" source. It could be a bearing problem, a spindle problem or even a problem with the attachment, in this case the Nove Chuck. Try attaching the Drill Chuck with a Drill Bit in it and check for the wobble running on slow speed. If there isn't a wobble, then the Nova Chuck or it being mounted incorrectly is the problem. Anything mounted on the Quill's Spindle needs to be properly seated. If the wobble is still there, I would suspect excessive runout possibly due to a worn bearing. Older Mark 5/V units prior to 1984 have a single bearing Quill and tend to have more runout or wobble. Excessive wear between the Quill and Drive Sleeve Assembly can cause some wobbling. Another less common cause can be a bent Spindle end.

[JoeSark]

Turning a bowl, is the blank irregulaely shaped? The shopsmith is light enough that a slight imbalance will shake the machine. If that's the problem, just keep the speed slow until the blank is round.

[chapmanruss]

JoeSark suggested the first thing to check. I neglected to consider the most obvious thing to start with. I think my brain is still on vacation.

[chief489]

Turning a spindle with a drive centre is working ok. I've checked the mounting of the chuck and that seems to be ok too.
I've put a video up here to show the issue: https://youtube.com/shorts/xaPwKE_Ubbw?feature=share

[DLB]

That looks like excessive runout, as Russ mentioned above. Two things that you can try for isolating the source of excessive runout:
1) Try the G3, with the same adapter or insert, on the upper accessory drive instead of the main spindle. (Only try this with attachments that are reversible. My G3 is reversible but it is the insert type and I don't know if all G3s are reversible.)
2) Test something else of at least equal diameter on the main spindle and at the same speed. A 3-3/4" faceplate or 6" faceplate normally have low runout.

Results should give you a pretty good idea where the problem is. A Dial Indicator, or similar, is useful for quantifying runout but not usually necessary.

- David

[chief489]

I've tried with the drill chuck and a long drill bit and that seems to have excessive runout too. Guess it may be the bearing. :-(
Have found this useful video but does anyone have suggestions for replacing the bearings without a shop press?
https://www.youtube.com/watch?v=9CJDsykCzoE

[Username]

If you have runout it could still be a couple of things. It could be the bearing like you say. It could be the shaft itself has a bend. And it could also be a worn out plastic drive coupler at the back.

Here are some more videos you might like. One mentions the plastic drive coupler at the back. They both discuss some different types of quills and why there might be a wobble.

https://www.youtube.com/watch?v=QU4GE7e96Io
https://www.youtube.com/watch?v=Z4-ucD6_efI

In the video you linked, Jacob showed how fast he could remove and replace the bearings using his shop press where he had developed all the tooling specifically for that job. You can get the bearings off yourself without a shop press. I used a bearing puller/separator tool. It just takes longer but it's not hard to do.

[chapmanruss]

chief489,

The two videos from James Hopp show the differences between the Quill versions. We could debate single vs. double bearing Quill all day but when all is said and done worn bearings, a worn Ring and Drive on the Drive Sleeve Assembly or even a bent Spindle is a problem and causes runout or wobble. When I watched your video showing the wobble the other thing I noticed was the noise with your Mark running. It may have worn bearings somewhere in the drive system. These could be in the Quill Assembly, Drive Sleeve Assembly, Idler Assembly and/or the Motor.

In Jacob's video he shows replacing bearings, but it can be done without a Press. Prior to getting a Press myself I replaced Bearings with other tools. Somewhere there was a video showing how to do that without a press. Hopefully someone remembers it and can post a link for that. Care must be taken when replacing bearings on a shaft or in this case the Spindle. Only "press" on the inner ring of the Bearing when installing them. A piece of iron pipe with an inside diameter barely larger than the OD of the Spindle works for putting new bearings on. Use gentle taps of a hammer, not hard blows. Use a something to protect the ends of the Spindle if striking it directly during bearing replacement. Hitting metal against metal can deform the ends of the Spindle.

[chief489]

chief489,

The two videos from James Hopp show the differences between the Quill versions. We could debate single vs. double bearing Quill all day but when all is said and done worn bearings, a worn Ring and Drive on the Drive Sleeve Assembly or even a bent Spindle is a problem and causes runout or wobble. When I watched your video showing the wobble the other thing I noticed was the noise with your Mark running. It may have worn bearings somewhere in the drive system. These could be in the Quill Assembly, Drive Sleeve Assembly, Idler Assembly and/or the Motor.

In Jacob's video he shows replacing bearings, but it can be done without a Press. Prior to getting a Press myself I replaced Bearings with other tools. Somewhere there was a video showing how to do that without a press. Hopefully someone remembers it and can post a link for that. Care must be taken when replacing bearings on a shaft or in this case the Spindle. Only "press" on the inner ring of the Bearing when installing them. A piece of iron pipe with an inside diameter barely larger than the OD of the Spindle works for putting new bearings on. Use gentle taps of a hammer, not hard blows. Use a something to protect the ends of the Spindle if striking it directly during bearing replacement. Hitting metal against metal can deform the ends of the Spindle.

Thanks. It's been sitting in my Dad's workshop unused for years after he was given it, so could probably do with a good overhaul!