Need help building up shaft

[John TenEyck]

The main 1" shaft on my Delta drum sander has a groove worn in it where the bearing set screws slipped. Worse, the shaft is slightly worn, not much at all at one end of the bearing but maybe as much as 0.005 - 0.008" at the other. It still sands well but has a lot of vibration when I first shut it off. Of course I could take it to a machine shop to be repaired but I'm interested if anyone else has had a similar situation and found a good DIY solution. Thanks.

John

[CPeter James]

That shaft has a metric outside bearing measurement and an inch inside. You can get a metric/metric bearing that is slightly smaller than 1" on the inside bore and then have the shaft turned to match the new bearing. The shaft is aluminum so this seems to be a common problem. I have fixed one of these before for someone else. I don't remember the bearing number off the top of my head, but if you give me your old one, I can get it for you. I may have the old one in my shop and I will check it later.

CPeter

[CPeter James]

Update!

The bearing is a UC205-16 in Inch size. If you get a UC205-25 you will get a bearing with a 25mm bore. that is .984" or .016" less that the 1.000" shaft. If it is the driven end, you will find that the pulley mounting area is smaller than the 25mm. I don't remember how much, but it is enough to allow you to turn down the bearing mounting area to the 25mm. On the far side, it is not an issue, just turn the bearing mounting area down to 25mm and mount the bearing.

Now that you have had this problem, make sure the set screws are tight and you may want to use some blue Loctite on the set screws.

A new shaft is almost $300 so this is a cheap fix!!

The bearings can be had on EBAY. Replace both of them.
http://www.ebay.com/itm/New-UC205-25-25mm-High-Quality-Insert-Bearing-/300612903834?pt=BI_Heavy_Equipment_Parts&hash=item45fdece39a

If you have any questions, contact me.

CPeter

[John TenEyck]

Thank you very much CPeter. What an elegant solution. Wish I had thought of that before I ordered two new 1" ID bearings. Guess I'll have to buy one more at 25 mm. FYI, the shaft is steel; only the drum is aluminum. Thanks again.

John

[Bruce Wrenn]

the shaft is steel; only the drum is aluminum. Thanks again.

JohnHow is the drum attached to the shaft? (set screws, pressed on, etc.) 1" shaft stock is a common item, available from ENCO, MSC and others.

[Charlie Velasquez]

Another something to consider. A brass insert will apply all the stress to the brass. If the situation arises again, the wear will all be to the insert and not the shaft. If you do go this route, chuck the insert and file off a couple thousandths off the diameter of the end of the insert. If it deforms at all, it will still be easily removed.

[Ronald Blue]

If the shaft can't easily be removed as Bruce suggested you can also knurl the shaft to increase the diameter. This can get generally good results but the drawback is the more you have to knurl the smaller the contact area you end up with and it may loosen again. .005-.008 is not much so I think it would work well. Unless you have a metal working lathe you would need to have it done. Good luck.

[CPeter James]

It was some time ago that I fixed that one I did. Maybe the shaft was steel. Either way, it worked out great. You need someone who can handle about 28 inches in their lathe to turn down the shaft. I have worked on several of these drum sanders of different makes and one of them had aluminum drum/shaft in one piece. It might have been a Performax I did about 10 years ago.

Peter

[John TenEyck]

The shaft is steel and looks to be swaged against the aluminum drum at both ends; no way it is coming out easily. I took the whole thing to a local machine shop I used to have do work for me back in my corporate days and the guy who looked at it said the easiest fix was to build up the area worn by the loose bearing with weld and then re-turn it to fit the stock bearing. He liked the idea of the smaller ID bearing, too, but correctly pointed out that that would not take off enough to eliminate the groove worn into the shaft by the set screws. So I left it with him and we'll see how much the damages are when he calls me. Thanks all.

John

[CPeter James]

Welding and turning the shaft may result in the drum not being round. I had one once that the drum was out of round and it would not run smooth. If you take any amount off the drum diameter, it may affe4ct how the paper wraps onto the drum. If the machinist turns down the shaft to the 25mm size will that eliminte most of the damaged area and leave some the is perfectly round and a groove? If you can get most of the bearing bore onto good material, that should be enough.

Welding with that aluminum drum on there would concern me. Also, before you spend too much on that fix, you can get a new shaft for just under $300.

Peter

[John TenEyck]

The shaft has centers in both ends, so adding weld and re-turning should not change the C/L. In the end, I trust these guys to know their business; I've known them for 15 or 20 years and they have topnotch equipment and do some marvelous work. If they think building up the shaft and re-turning it will work, without damaging the aluminum drum, I'm willing to take a chance. Worst case, they ruin it, I don't pay them, and I get to buy a new, really big drum sander !

Thanks.

John