any fix for loose fitting arbor on bearings?

[mickthetree]

Hi all

I'm pretty sure I have located the cause of my very slight blade wobble on my startrite table saw. The rear arbor bearing was worn.

I have stripped it all out and bought replacement bearings, however in putting it back together I see that, where there has been some wear with the old bearing, the arbour has been reduced in diameter. To the point where it is a sloppy fit on the new bearing. I don't have a micrometer, but my digital calipers measure it at 3 thou. The inside ring of the bearing does not rotate when the arbor is spun and if I give the whole thing a tug I'm sure I can feel some very minute slop in it.

Is there anything I can do / try before buying a new £120 arbor?

Would some sort of bearing lock fluid take up that much slack? Anything I do must keep the shaft central in the bearing or I will end up with a blade out of true again.

Many thanks

 

[deema]

Nope, there are solutions but most will cost more that the £120. I.e turn down the shaft and braze a sleeve on then re-skim to size, turn down the shaft to another bearing diameter, buy new bearing.

I had the same issue and bought a new shaft. Make sure it comes with the arbour nut, the older ,a hinds gad a different thread to the newer machines, and it's the latest thread they provide.

 

[mickthetree]

Grrrrrrrrrrrrrrr I was really hoping that wouldn't be the case.

 

[n0legs]

You could try a wrap or two of .001 engineering shim.
To be honest I've not bought or used any in years, but it quite often get you out of a spot of trouble.

 

[CHJ]

Alternate to turning down and re-sleeving is to build the shaft back up with something like nickel plating and re-skimming or grinding between centres.

Not a major job but as already said if you don't have the facility or a member close to you who can do it for the odd pint of beer it will be costly.

If cost of replacement is a serious issue then you might get away with someone just Knurling the worn end of the shaft for you.

 

[wallace]

I had the same issue on an old wadkin planer, the bearing had spun on the shaft and still been used for a while. I took mine to engineering company who built the area up with weld I think and then turned it back to original size. I think it was £100

 

[Hemsby]

I used Loctite products for many years in the engineering for securing gears bearings etc on large & small machinery components. In fact recently used it on a bearing on my bandsaw where the bearing had seized and rotated on the shaft.

Loctite 638 is a high strength quick setting compound for bonding cylindrical parts particularly with gaps up to .25mm (.009”)

Your 003” should pose no problems for their products. You could always give them a call to confirm best product to use. Technical 01442 278100

As mentioned there are a number of other options including machining but Loctite is by far the simplest effective and less involved.


Good luck

 

[xy mosian]

I can see the advantages of a liquid, Locktite, packing.
Just how are you going to centre the shaft in the bearing before adding the packing?
xy

PS. Sorry that sounds brusk.
The question remains however how will you centre the arbor in the bearing?

xy

 

[parvum]

Another for Loctite. Surface tension, at the clearances appropriate for this method, and three thou is as said, well within tolerance,will centre the shaft within the bearing bore, especially if you can arrange for the shaft to be vertical.Should you need to replace the bearing, heat will break the bond.

regards Paul

 

[Hemsby]

Loctite like other similar products are designed to expand equally around the gap that exists between the 2 items, maintaining concentricity.

These type of products were & probably still are used in aircraft and other industry applications removing expensive machining tolerance costs.

Application in the vertical or horizontal position should be fine.

I believe the Loctite 638 will accept a degree of surface contamination but a final clean before application with an alcohol wipe or similar will help.

Regards

Keith

 

[xy mosian]

Thanks for that guys. I did not know that about Locktite. I could imagine a tight fitting off-centre shaft.

I do remember using one of the first super glues, but not the Locktite number. I guess it would be mid-seventies?
xy

 

[mickthetree]

Thanks very much for the ideas guys.

I always intended this to be my final table saw and as such have decided I don't mind paying for a new arbor. Having said that I dont have the money right now to buy the new arbor so if I can delay this until I can save my pennies that would be much more useful. I will order some of the loctitee 638 and give that a go.

I certainly have learnt a lot about the saws construction and machining tolerances in this process and I'm even more confident that this saw will serve me well.

Deema, do you have a source for the replacement arbor?

Kind regards