Grinder drive wheel question?

R

Ratking20

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May 2, 2017
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im building my 2x72 grinder. I bought a set of wheels from ebay. When putting on the drive wheel. Should i have to force/bang it on. The drive shaft is 5/8 and so is the wheel(at least its labeled 5/8). I bought from vwjackstraw which a lot of people on here said were good.any help would be great?
 
These are a tight fit. Take a strip of a 220 grit sanding belt. Turn the motor on. And sand away as evenly as possible a little metal off the arbor. Check to see if you can slide the drive wheel on? Remove a little more if needed. Go slow on this.
 
Agreed with Laurence. Even just polishing the shaft up a little more with some 400 grit would likely help. If it's still a little tight, you can try heating the drive wheel a little bit with a heat gun.
 
Just take your time and get a nice solid fit without any slop that can lead to vibration! Have fun & stay safe!
 
You don't want any slop. Slop will mean run out, run out means vibration. I like to put a little nickle or copper anti-seize on pully sheaves/shafts because with a tight fit, even a bit of corrosion makes them impossible to get off without a puller.

So, just be careful and polish the shaft slowly. It doesn't take long to take .0005" off of a .625 shaft at 1750 RPM with 220 grit paper. So try frequently. Taking a bit too much won't be the end of the world, but it's easier to take more off than put some back on.
 
First thing I would do is insure there isn't any burrs inside the wheel. Look in the bore with a light, and make sure the ends of the hole are properly chamfered. If the inside doesn't look perfect, take a piece of 1/4-5/16" round rod, and cut a slit in the end with a hacksaw. Slide a strip of 220 grit Emery cloth through it, and Chuck the other end in a cordless drill. This will make quick work of polishing the bore.
Check the motor shaft for burrs as well, and as was mentioned polish it with some sandpaper or clothback.
It should be a slip fit with no beating required, but shouldn't require excessive force. If the bore of the shaft is substantially undersized it may require reaming (or boring in a lathe) to dimension.

You'll want to give the shaft a coat of light oil before sliding the wheel on as well. Antisieze and insted-a-led (or white lead paste) will work great as well, but they are generally used for press fits (that should be removable, otherwise it's retaining compound) rather than slip fits. The extreme pressure properties aren't really needed unless you're overcoming an interference fit.
 
I have changed drive wheels several times with Jackstraw aftermarket wheels as well as stock Beaumont drive wheels and I have always had to tap them on with a rubber mallet and remove them with a three point puller. I think the anti seize grease might help you with this but you want a snug fit for a wheel with no runout or wobble. Wipe everything clean with brake cleaner before mating the shaft and bore. Larry
 
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Just to reiterate, it really shouldn't take very long with some 220 grit, to polish your shaft down. I normally use either a piece of used 220 grit, or some 400. You may want to put it on a flat block just to keep even pressure against the shaft, though not completely necessary. I really wouldn't recommend hitting the inner bore of a precision turned aluminum drive wheel with anything but a precision reamer, but that's just me.
 
knife to a gunfight said:
Just to reiterate, it really shouldn't take very long with some 220 grit, to polish your shaft down. I normally use either a piece of used 220 grit, or some 400. You may want to put it on a flat block just to keep even pressure against the shaft, though not completely necessary. I really wouldn't recommend hitting the inner bore of a precision turned aluminum drive wheel with anything but a precision reamer, but that's just me.
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It depends entirely on the surface finish on the bore of the wheel. In machining polishing bores like this is very common. Even removing a couple tenths takes a surprisingly long time.
Heck, it's common practice to use a belt sander on the outside of large shafts to bring it down that last half a thou and insure a nice finish.

Now I definitely wouldn't recommend trying to take a couple thou out with a piece of 60 grit sandpaper, but polishing a bore with 220 or 400 is damn near impossible to screw up. I've done it hundreds of times on far more critical applications.
But yes, if it's actually undersized a reamer (assuming a boring bar in the lathe isn't an option) is the proper way to do it.
 
Also, make sure there are no burrs or dings on either. A slight chamfer on the drive wheel bore also helps get the wheel started on the shaft.

I always caution people not to reduce the shaft by sanding it a tad. This may make the current wheel fit, but may make any other wheel or pulley fit loose on the motor in the future.
The motor shaft being oversize is unlikely, but the bore on the wheel being a little too tight is very likely.

I suggest taking a 6" piece of 1/2" dowel and splitting it down the center half the length. Slip the end of a 3" wide piece of 120 grit sandpaper in the slot and wrap it around the dowel. Chuck in a hand drill or drill press and lightly sand the wheel hole. It may not take more than a few seconds, so don't over-do it . Clean the bore and check the fit often. A drop of oil rubbed in the bore hole is also a good idea.
 
Polishing a Burr off the shaft is one thing, making it smaller is another.
As has been mentioned if there is truly an interference fit, the wheel should be bored out.
 
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