meta7
starting to spend too much on rocks
Member since June 2010
Posts: 164
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Post by meta7 on Aug 12, 2010 13:49:14 GMT -5
Hi everyone, I am in the process of expanding my 2 wheel arbor into a 6 wheel. I just finished setting up the 2 outside bearing blocks. I am using a 36" threaded shaft. My problem is the following: I am using Nova-type wheels with a washer and nut on each side of them. When I tighten the nuts, the Nova wheel tilts a little bit, making the wheel rotate unevenly, and thus feeling 'hard' and jaggedy when I sand a stone on it. What do I need to do or what can I buy to fix this? Also, if I use a non-threaded shaft, how to I make the wheels stay in their place? Thanks ahead of time.
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Post by jakesrocks on Aug 12, 2010 14:00:35 GMT -5
The shaft you are using should not be threaded all the way. Only the last inch or so of each end. The left end of the shaft should have a left hand thread, and the right end a right hand thread. When you put your wheels on the shaft, they should barely slide on. Use spacers between your wheels. These can be cut from heavy wall PVC pipe, but must be cut absolutely square. Don't use ordinary washers. They are mass produced and may not be flat and true. They make special washers for grinders that are ground flat and true on both sides. There was just a quite lengthy discussion on this very topic. Go to the following link for much more info about your project. forum.rocktumblinghobby.com/index.cgi?action=display&board=hmequip&thread=39379&page=1Don
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Post by jakesrocks on Aug 12, 2010 14:20:38 GMT -5
Oh, before I forget, Welcome aboard meta7. Don
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meta7
starting to spend too much on rocks
Member since June 2010
Posts: 164
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Post by meta7 on Aug 12, 2010 17:32:58 GMT -5
Thanks Don. I went to Home Depot, and they do not have 5/8" PVC pipe - my shaft is 5/8". Do you have something else you would recommend for spacers? Given the current situation of my arbor, it would require way too much work to change shaft diameter right now.
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meta7
starting to spend too much on rocks
Member since June 2010
Posts: 164
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Post by meta7 on Aug 12, 2010 17:51:40 GMT -5
Also, if the ends are not threaded, is there some kind of washer/spacer that can be tightened to the bar (maybe with an Allen wrench like the bearings are fastened) to hold everything in place?
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Post by jakesrocks on Aug 12, 2010 18:30:55 GMT -5
You could use Schedule 80 pipe, but it would have to be cut in a metal lathe to get true square ends. To prevent your wheels from slipping on the shaft, it will have to be threaded on both ends. Schedule 80 pipe is a heavy walled high pressure pipe. You may also be able to find heavy walled aluminum pipe to use for spacers. Don
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Post by johnjsgems on Aug 12, 2010 18:33:18 GMT -5
You could use a thrust collar on left side, slide all wheels on tighten with nut on right side. I don't know if threaded rod is round like shaft stock and how it will affect your bearings and wheels. Also tighten end nut only tight enough to keep wheels from slipping. As far as spacers you could use thrust collars or use wheel bushings in pvc pipe. You may be better off buying 3' of 5/8" shaft stock at a machine shop and having ends threaded.
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meta7
starting to spend too much on rocks
Member since June 2010
Posts: 164
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Post by meta7 on Aug 12, 2010 20:28:57 GMT -5
Cool, So what exactly is a machine shop? and What am I exactly asking for? I know it is a 36" shaft 5/8" diameter with 2" threading on each end. But what exactly is the name of the shaft? The reason I ask is because I have a 16", 5/8" shaft and when the nova wheel bushings are put on that, they are quite snug. With this threaded shaft, or a similar non-threaded shaft (5/8") from Home Depot, the wheel bushings have a little bit a looseness about them. I will just bring the bushings with me when I pick one out, but it would be great to know what I am exactly asking for. Thanks,
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Post by jakesrocks on Aug 12, 2010 20:48:17 GMT -5
Your best bet would be to go to a shop that deals in metal. Ask for either cold rolled steel or stainless steel shaft stock. The round stock you're getting from Home Depot is most likely imported junk material that is made in metric sizes, as close to American standards as they can get it. By all means, take a bushing with you, to ensure proper fit. You'll have to take your shaft to a machine shop, (a place that has metal lathes and milling machines), and have them lathe cut right hand threads on one end, and left hand threads on the other. Make sure that they can supply or make a nut for the left end of your shaft. You might also want to have the right end of your shaft center drilled and threaded for a 1/4" - 20 thread. This will allow you to use the spin on polishing and sanding disks on that end. Don
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Post by johnjsgems on Aug 12, 2010 22:33:24 GMT -5
Look for "machine shop" or "metal fabricators" in your area. Cold rolled steel is the standard shaft stock. If the wheels don't fit the threaded rod snug then the bearings probably don't either which will lead to early failure.
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