plastic sleeve was removed from grinding wheel

[andicugino]

The grinding wheel on my Tormek was rusted onto the shaft. Therefore I removed the shaft from the driving wheel side. Then I tried to remove the stone from the shaft by slightly hitting it with a mallet.

I was able to remove the wheel from the shaft without breaking it. But my joy was short-lived, unfortunately the plastic sleeve remained on the shaft. I don't think there is any chance of removing the sleeve from the shaft without breaking it.

I would like to use the stone again as it still has a diameter of about 235mm. My idea is now to drill a 12mm hole in a 22m POM rod and glue it into the stone. Could this work? What glue should I use?

Does anyone have a better idea?

Andi

[tgbto]

I would 3D-print a piece of PETG with cross-hatched outer surface, as I wouldn't know where to procure POM with the proper dimensions, and don't know if I'd drill it dead center.


I'd use PUR glue.

[andicugino]

Unfortunately, I don't have the option of 3D printing. I've often thought about getting a 3D printer. Then I'd have to deal with CAD, which has stopped me from doing so.

I could order a POM rod from eBay for a small amount of money. I could drill with sufficient precision on the wood lathe. After glueing I would dress the stone with the TT-50 in hope that the concentricity would then be restored. As for the adhesive, I'm not sure what to use best for POM and water stone.

Andi

[andicugino]

I decided not to glue in the new sleeve. I used POM and made the sleeve press-fit:

You cannot view this attachment.

[tgbto]

Nice work !

[RickKrung]

Good fix.  What is "POM", please?  It is an unfamiliar term for me.  I'm surprised you were able to find something that fit so nicely in the hole in the stone and that has a 12mm center hole.

Rick

[andicugino]

Hello Rick,

POM (Polyoxymethylene) is a plastic that, like PA6 (Perlon/Nylon), can easily be turned with hand tools on a wood lathe.

Both, POM and PA6, are available inexpensively as rods, for example, on eBay. I paid 1.70 Euro for a 200mm long POM rod (plus shipping, which was more expensive than the material itself).

I drilled a 12mm hole on the wood lathe and adjusted the thickness with a scraper until the sleeve fitted snugly. That only took a few minutes.

If you have the opportunity, you can of course print a sleeve as described above (cross-hatched). Then "UHU Quickset" would be a good adhesive to use, according to Bolton Adhesives customer service.

Andi

[RickKrung]

Hello Rick,

POM (Polyoxymethylene) is a plastic that, ...snip...
Andi

Ah... Good old Delrin... or known by some as acetal. 
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Love working with this stuff.  Have loads of it.  Turns and cuts really nice, holds its shape and slippery.  First learned of this stuff in the 1960s, working in my father's machine shop. Just never heard its chemical name.

Rick

[Herman Trivilino]

I decided not to glue in the new sleeve. I used POM and made the sleeve press-fit:

Have you trued the grindstone? Have you tried sharpening something to see if the sleeve doesn't slip?

If you do need to glue it you would of course need a water proof glue. And you would have to make sure the grindstone is good and dry. I'm thinking maybe gorilla glue?

[RickKrung]

I decided not to glue in the new sleeve. I used POM and made the sleeve press-fit:

Have you trued the grindstone? Have you tried sharpening something to see if the sleeve doesn't slip?

If you do need to glue it you would of course need a water proof glue. And you would have to make sure the grindstone is good and dry. I'm thinking maybe gorilla glue?

Hopefully, the sleeve is short enough (or can be shortened if not) so as to not interfere with the thick washers on both sides of the grindstone, which should grip the wheel and not the sleeve.  Not much sticks to delrin (Polyoxymethylene), so if one were to try to glue it in place, it would need to be deeply grooved in an angular or lengthwise a way such that the dried glue would act as keys, locking the sleeve in place.  The circular grooves in the photo the OP showed may not be adequate. 

Rick

[tgbto]

Not much sticks to delrin (Polyoxymethylene), so if one were to try to glue it in place, it would need to be deeply grooved in an angular or lengthwise a way such that the dried glue would act as keys, locking the sleeve in place.  The circular grooves in the photo the OP showed may not be adequate. 

Rick

This is why I recommended PUR glue : it expands when setting and is waterproof. So it should work on a crosshatched/crisscrossed/rough surface, even made of POM.

[andicugino]

Initially, I wanted to add grooves along the sleeve and around to allow space for the glue. But then I decided to try it without gluing. Therefore, I didn't file the grooves lengthwise. I could do that later if necessary. But I don't think this will be necessary, nor do I think the sleeve will slip. The rotation isn't transferred to the stone via the sleeve. The sleeve recoils 1 mm on each side so that the stone can be clamped between the washer and ezy-lock-nut.

However, I haven't been able to use and true the stone yet. The practical proof is missing. I'm still waiting for the MSK-250, which is delayed by a few days. I also removed the powder coating from the Tormek yesterday. Next, the rust needs to be removed and then new paint applied. So that will take some time until the Tormek can be put back into operation.

Andi