chassroc
Cave Dweller
Rocks are abundant when you have rocktumblinghobby pals
Member since January 2005
Posts: 3,586
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Post by chassroc on Mar 20, 2005 13:22:01 GMT -5
I purchased a used star diamond 6 inch combo grinder polishing unit and I'm wondering if there is any trick to changing the grinding wheels. Unfortunately no instructions were included and I just have a little nagging doubt about forcing things and breaking something. So I am wondering if there is some technique involved in removing a stuck grinding wheel and replacing it. The unit has a 5/8 inch arbor and I have no trouble removing the end nuts and the saw blade on one side and spin on polishing head on the other. The rest is quite snug on the arbor ( and yes I've removed any hex retaining nuts ). Probably just paranoia on my part but does anyone have any advice? tks csroc Some pictures of the unit:
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RedwoodRocks
freely admits to licking rocks
Member since March 2003
Posts: 762
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Post by RedwoodRocks on Mar 20, 2005 13:46:30 GMT -5
Sorry, I don't have any suggestions on taking that apart to get to the grinding wheels.
It looks like you have to take the arbor/drive shaft off completely to change the grinding wheels. A good reason to use long lasting diamond wheels rather than silicon carbide.
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Post by docone31 on Mar 20, 2005 19:25:42 GMT -5
There is a threaded bushing between the wheels. Most times it comes off easily, but sometimes you need penetrating oil to get it off. You will need to take the entire shaft out of the bearings to change wheels. It is worth it however, and it is a good time to give a general check.
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WarrenA
fully equipped rock polisher
Member since November 2003
Posts: 1,530
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Post by WarrenA on Mar 20, 2005 21:43:44 GMT -5
when you reassemble the unit coat the shaft with grease so you won't have to fight it to get it apart again
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Post by docone31 on Mar 20, 2005 22:49:38 GMT -5
No grease! Water displaces oil, with oil floating on top. With a fairly tight tolerance situation, you should use a wax. A dry spray wax is best, car wax is next best. No candle wax, it is petroleum based. With the spacers, they are really not that tight. it is more the nuts, or spacers that have rust rhime inside. When I take my Loretone cab station abart, I spray penetrating oil first, followed by WD-40. Things come apart fairly easily then. I have taken to disasembling the unit, just for hars and giggles every six months. So far, I have not used it in six months so I have skipped a cycle. I also use anti-seize compound on the threads.
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Post by stoner on Mar 20, 2005 23:18:09 GMT -5
Hey Chassroc. I've got a unit similar to yours. Mine has(left to right) a face plate, expanding drum, wheel, wheel, pulley, expanding drum, faceplate. You need to lift the entire shaft out of the machine. There are collars with set screws on the outside of each bearing. Remove the collars and the bearings. Actually you can access both wheels from one end. You'll probably need to shoot some WD40 on them to loosen them up. Use a large pair of channel locks to work the collars free. Those 2 collars are what hold the grinding wheels in place also. Between the bearing and the grinding wheel is a sleeve. If you notice, the thread at the end of the shaft is 5/8", but the shaft diameter next to the grinding wheel is 3/4". It's 3/4" because of the sleeve. So work the sleeve off and then the grinding wheel. Again, use WD40. I had to also use a 16oz pursuader and tap on the side of the grinding wheel. Once that's off, there will be another sleeve and then the other grinding wheel. Clean everything up, replace your wheels and sleeves and bearings and slide the collar up tightly against the bearing and tighten the set screw. Replace the faceplate, put the shaft back into position, and close the top. While you have it apart, you may want to make sure the water valves and lines are clean and working properly. Good luck, and if you need more info, send me a PM and and ask away. Here's a few pics of my setup. close up Ed
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WarrenA
fully equipped rock polisher
Member since November 2003
Posts: 1,530
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Post by WarrenA on Mar 20, 2005 23:47:21 GMT -5
You are correct Doc I should have said anti-seize compound.
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chassroc
Cave Dweller
Rocks are abundant when you have rocktumblinghobby pals
Member since January 2005
Posts: 3,586
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Post by chassroc on Mar 21, 2005 11:10:42 GMT -5
Hello to all and tks for your replies.
I did not try penetrating oil and did not think the spacers/bushings might be threaded. I feel more confident with this information.
tks csroc
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