buffing wheels - balancing and repair

[kens]

Two somewhat related questions.

1. I've purchased several buffing wheels for my buffer. It seems like all of them are pretty seriously out of round. Without any wheels on the buffer it runs smoothly. With them on it vibrates a lot. Shaking the motor a lot to where I would worry about prematurely wearing out motor bearings. When applying compound, it skips areas of the wheel only getting the high spots. The wheels are securely fastened.

Is this normal? How can I fix this or true the wheels? Do I just use a rake and grind down the wheels until it is running smoothly? Would that solve the problem?

The wheels are 10" sewn cotton wheels, 1" width with 3/4" arbor holes on a 3/4hp 3600 rpm Baldor buffer.

2. I was buffing the side of a knife and caught an edge with the wheel. I understand WHY it happened and it was simply a stupid rookie type mistake from somewhat less than paying full attention. No injuries, the knife was thrown to the floor and wasn't damaged either. But it deeply cut into the wheel - about an inch deep gash at an angle.

How does one go about repairing the wheel? Do I just grind the wheel down with the rake to the bottom of the gash? This is going to be blowing one hell of a lot of shredded wheel around until I get to the bottom of this, probably loosing about 1" of wheel diameter. Is there an easier way to do this short of just throwing the wheel away, which I don't want to do?

Thanks in advance.

---
Ken

[Rasper]

Re: buffing wheels - balancing and repair

I have never run across an out of round wheel. Did you buy good wheels, or Chinese stuff?

I don't think you can repair that wheel.

When I'm buffing flat things such as knives, I use a piece of plywood as a back up and make some bolt clamps to hold the piece to the plywood. Then there are no edges to catch on the wheel. If you keep trying to hold a knife blade to a 10 inch wheel you are going to seriously injure yourself.

Richard

[baz]

Re: buffing wheels - balancing and repair

once you are positive that your polisher is running straight with no play on the bearings ( minimal play on the shaft or bearings will cause tons of vibration when Under tension)
two things can cause that problem first is the hole has been drilled off center or drilled at an angle . i had that happened when i tried drilling the holes myself without the proper Tools .
next is a hole that is slightly larger than the polishing shaft.
raking the Wheel should fix the problem.
as for the damaged Wheel , not much to do other than rake or cut and remove rows of stitches and use as a loose cotton Wheel.

now the IMPORTANT stuff .
buffing speeds should be between 3500 and 7500 sfpm (surface feet per minute) , a 10 inch Wheel spinning at 3600 rpm is covering over 9000 sfpm or about 102 mph .
what you are doing is putting a knife against a Wheel spinning at 100 + mph
even if you are wearing a face shield , gloves and apron you are seriously playing with your life .
i have been in the polishing business for long time and i know and have seen how dangerous polishing can be even for an experienced polisher
extra care MUST be takin when working with sharp objects , in addition to regular safety clothes you should lower the buffing speed and/or reduce diameter of Wheel ,
work with tightly stiched Wheels (ones with rows os stiches every 1/2 inch make for a harder Wheel with less flex so less chance of grabbing the part
and also a guard on the polisher to keep the part away from your body if it gets caught by the polishing Wheel.
working with knives i am sure you know what damage a knife flying at 100 mph can do .

[powerdoc]

Re: buffing wheels - balancing and repair

I have the same problem as the original poster of the thread. My wheels are Caswells. The vibration is really marked I'd guess at about 3000 rpm +. One end is a pair of loose buffs with what appears to be a masonite center and the other end is a pair of sewn cotton wheels, all 8", 3/4" mandrel. On the loose wheels there really isn't much runout; on the sewn wheels there is some. I've tried to move the sewn wheels around each other to no avail. Is there any way to rig any type of balance device or do I just have to try new wheels until I find ones that are balanced?

[baz]

Re: buffing wheels - balancing and repair

i am assuming that the polisher is in good condition with no loose bearings or shafts and adapters
if the unbalance is from low to moderate you can try to rake the Wheel (wear out ) until it runs smooth.
if the unbalance is too extreme you should contact your Wheel supplier

[powerdoc]

Re: buffing wheels - balancing and repair

New machine, this will be the first project. No runout on bearings that I can discern. Wheels are Caswells.

[powerdoc]

Re: buffing wheels - balancing and repair

Well I got some new wheels from a different supplier and they are some better but the buffer still wants to dance with me. I had returned the old wheels to Caswell (did not get a response to that BTW). Is there such a thing as a balanced buffer or do all of them have to be bolted firmly to the floor and just accept the fact that it's not smooth?

[Rasper]

Re: buffing wheels - balancing and repair

Does the machine vibrate when you run it with no wheels?

Are the holes in your wheels the right size for the shaft?

What kind of machine is it? A large floor mounted buffer? If so you certainly want to fasten it to the floor, or at least to a heavy base.

Richard

[powerdoc]

Re: buffing wheels - balancing and repair

The machine is a new one from Harbor Freight, 3/4 hp 3/4" arbor. The buffs are also 3/4". It is smooth as silk without the wheels. There is no static runout on the shafts. It's on a trapezoilal base which really doesn't have provision to firmly fasten it to the floor.

[powerdoc]

Re: buffing wheels - balancing and repair

Well a partial cure: I went to HD and got and anti-fatigue mat which is pretty spongy and it doesn't completely eliminate the vibes but damps them enough to make the machine usable. Now: Where to find wheels that are true and don't vibrate

[Rasper]

Re: buffing wheels - balancing and repair

Maybe it's just a temporary run of bad luck. I have been polishing metal for over 15 years and have never had an out of balance wheel.

Richard

[baz]

Re: buffing wheels - balancing and repair

Well a partial cure: I went to HD and got and anti-fatigue mat which is pretty spongy and it doesn't completely eliminate the vibes but damps them enough to make the machine usable. Now: Where to find wheels that are true and don't vibrate

i would not want to work with a polishing motor that is not secured to the floor.
the day that you see what happens if the buffer realy bites good into something you will bolt it down to the floor !(that is if you still want to do polising after that)

have you tried to rake the wheel to make it round ? it has worked for me many times