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Post by Jugglerguy on Dec 7, 2013 22:44:36 GMT -5
The motor on my flat lap has been acting up for a while. I have to spin the lap by hand to get the motor going. I think I need to have it rebuilt or buy a new one. Today it seemed to be going slower than usual, so I disconnected the belt and ran it without. It started up fine the first time, but needed help getting going the next time. Do I need a new motor or is it better to have this one repaired?
I also noticed that the pulley seems to have slipped down the shaft because the belt is on an angle to the flat lap. Moving the pulley up the shaft would correct the problem, but I couldn't get it to move. I completely removed the set screw and noticed that the set screw was not on the same side of the shaft as the flat spot. I sprayed some WD40 on it to attempt to free it, but I don't think that's going to do it. Any ideas about how to move the pulley?
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agatemaggot
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Member since August 2006
Posts: 2,195
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Post by agatemaggot on Dec 7, 2013 23:20:56 GMT -5
It sounds like the pulley spun on the shaft. It may be galled inside pulley. You might have to rent or buy a bearing puller. Better yet , take the darn thing to the motor repair shop where they have equipment to do it right, tell them how it was behaving and get an estimate. Probably the cheapest route you could take !
Harley
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quartz
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breakin' rocks in the hot sun
Member since February 2010
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Post by quartz on Dec 7, 2013 23:54:08 GMT -5
Assuming you have some room behind the pulley, if you have the capability, make a simple puller. A piece of about 1/2" thick bar stock 2 or 3 times as wide as shaft diameter, length a couple inches longer than pulley diameter. For the inside of the puller, drill a shaft size hole through center of the bar stock about 1/3 of the width in, or to center. Cut one side of the hole to make it into a slot. At a point a little bigger than the pulley diameter, drill and tap for 3/8" threads, on the same horizontal centerline the center hole was drilled at. For the outside of the puller, drill a clearance hole for a bolt to fit the tapped holes in the inner part, on the same centers; or "match drill". On the same center line as the pair of holes, and in the center of the bar, drill and tap for a 3/8" or larger bolt. Join the inner and outer part of the puller with the slot over the shaft on the inside of the pulley, and use bolts to keep the puller parts close to the pulley on the back side and the end of the shaft on the outside. Use the center bolt to push on the shaft end, and pull on the pulley, best to pad it with a piece of metal or hard plastic so as to not chew up the shaft, or a center saver made for that purpose if you have one. Clean the shaft to remove any rust or crud, and oil it a little. Warm the pulley [propane torch works great], and turn the center bolt to pull on the pulley. Always want to pull against a pulley hub, rather than the flanges, to avoid bending the flanges.
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Post by Jugglerguy on Dec 8, 2013 12:32:36 GMT -5
Quartz, thanks for the instructions on how to make my own puller. Unfortunately, I don't have hardly any of the equipment to make one. I think I'll take Harley's advice and just take it in for repair.
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Post by catmandewe on Dec 8, 2013 13:04:59 GMT -5
Find someone with a hydraulic press, they can have it off in 2 minutes.
Tony
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Tom
fully equipped rock polisher
My dad Tom suddenly passed away yesterday, Just wanted his "rock" family to know.
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Post by Tom on Dec 8, 2013 17:37:39 GMT -5
Heat and a puller, my gut tells me the motor is no good. It sound like a slit phase motor with the start switch failed open, or a split phase cap start itHi a shorted cap. Tat would explain why it started once with no load on it.
I bet a motor shop would have a cheap used motor for you. Likely way less than fixing
Please let us know the outcome
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Post by Jugglerguy on Dec 8, 2013 21:15:44 GMT -5
Tom, I have no idea what you said, but it sounded intelligent. I'll see what they tell me at the repair shop.
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rykk
spending too much on rocks
Member since September 2011
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Post by rykk on Dec 9, 2013 4:51:40 GMT -5
Many times, the reason a pulley won't come off is because of the crater that the set screw makes in the softer steel of the shaft. When the set screw is tightened, steel pushes out and up around the set screw. If the pulley has been moved a lot, you'll have a heckuva time getting it off. Happens to me often - especially when trying to raise or lower the rpm of the driven shaft with different diameter pulleys. What I do is try to move the pulley down the shaft to expose the craters and file them down. Takes a while, but it works. C-ya, Rick
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Post by Jugglerguy on Dec 9, 2013 7:29:48 GMT -5
Thanks Rick, but it won't move at all. Since the set screw is no longer on the flat spot, I'm picturing it looking like a worm path behind the bark of a log.
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Tom
fully equipped rock polisher
My dad Tom suddenly passed away yesterday, Just wanted his "rock" family to know.
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Post by Tom on Dec 9, 2013 14:29:55 GMT -5
Well I can well imagine why you don't understand Rob, with the amount of typo's I have in that post I should be sent back to grade one. Serves me right to type a response while sick as a dog in bed with an iPad. I have a lot of years of electrical experience and now instruct electrical for the trades. Motors are one of my specialties. At any rate I think the motor is pooched and getting a new one will be the cheapest. But I am not there to test it, so I could very well be wrong, won't be the first or last time, that's for sure:)
Good luck with it!
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Post by Jugglerguy on Dec 9, 2013 16:58:42 GMT -5
Hi Tom,
I hope you feel better soon. I found a repair shop in town. Is there something I should ask or know before I end up spending too much money? I talked to someone ther on the phone and he told me he can give me an estimate.
Rob
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Post by phil on Dec 9, 2013 20:23:54 GMT -5
Hi Tom, I hope you feel better soon. I found a repair shop in town. Is there something I should ask or know before I end up spending too much money? I talked to someone ther on the phone and he told me he can give me an estimate. Rob One thing you should know is a set of bearing pullers only costs $20 at Harbor Freight, comes with 3 sizes, and will do the job you need. Just make sure to use a back plate, don't "pull" onthe flanges.
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Post by johnjsgems on Dec 9, 2013 20:38:17 GMT -5
Compared to the motor, pulleys are cheap. Back in the day motor shops cheaply repaired small PSC motors. Now labor costs make them pretty much a throw away. If the motor is shaft up (or down) see if it will run horizontal. I salvaged a lot of vertically mounted motors to use on lapidary equipment mounted horizontally. I've removed a lot of pulleys. A roll of sand cloth (like plumbers use) and WD40. Sand the exposed surface of the shaft. Squirt the WD40 on shaft surface and down the set screw hole. If there is room between the pulley and motor I usually use a 10" crescent wrench and lever them off. I've used the drive on farther and file the burs off the shaft method too but usually you don't have enough shaft length between the pulley and motor housing. The shaft is really soft so any issues are easily filed out if you can get to them. Never carry a motor by the shaft either. First time I carried a motor into a motor shop (1970's)by the shaft the guy tore into me for ruining the thrust washers in the motor andcausing more damage than I had to start with. Back then for a few dollars they could change a start switch or replace bearings and send you on your way.
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Post by DirtCleaner on Dec 9, 2013 21:27:48 GMT -5
Kinda going off topic on Jugglerguy's thread but could you (johnjsgems) give a brief descrip. about how to tell the difference between a horizontal vs vertical motor? And how critical is it to get the right type?
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Post by Jugglerguy on Dec 9, 2013 22:23:13 GMT -5
Hey John, I'm kind of wondering the same thing as David. My motor is vertical. The shaft comes out of the bottom. I need another motor for a saw and this one would work great if it actually ran properly. I can't understand why a motor would work horizontally if it won't work vertically. I always just thought it was the bracket on the motor that made it horizontal or vertical. Thanks for the additional info on getting the pulley off. I didn't know how much I could pound on the shaft without damaging the motor. If the shaft is that soft, maybe I can get it off.
Phil, thanks for the tip on Harbor Freight. I don't have one near me, but when I'm near one, I'll check it out if I haven't gotten results by any other method.
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rykk
spending too much on rocks
Member since September 2011
Posts: 428
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Post by rykk on Dec 10, 2013 0:06:55 GMT -5
Get some PB Blaster at an auto parts store or a department store. Set the motor up with the shaft vertical and spray the stuff all around the shaft where it meets the pulley. Wait a few days and try to move it then. What works better is a marine product called, Aerokroil, but it's hard to find unless at a marina or boating store. Rick
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Tom
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Post by Tom on Dec 11, 2013 21:12:32 GMT -5
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The Dad_Ohs
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Post by The Dad_Ohs on Dec 13, 2013 21:21:12 GMT -5
harbor freight website - www.harborfreight.com/store locator - www.harborfreight.com/storelocator/location/mapThe main difference between vertical & horizontal motors is the bearing orientation.... shaft up or down has bearings that don't support the weight of the armature/shaft where as a vertical, shaft out the side uses a stronger bearing because it has to support the weight of the armature/shaft on the 2 bearings. That's the most basic reason of it anyways. I learned that at a place back in CT that rebuilt electric motor. I would have the motor rebuilt and see about a 2nd motor, rebuilt if possible to keep you going until the rebuilt one is done and then keep it as a spare!! cheaper than new motors.
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Post by Jugglerguy on Dec 15, 2013 17:20:55 GMT -5
I took my motor to a repair shop and got it back today. The guy who owns the shop is mostly retired. He replaced some sort of internal switch and it's working again. I haven't reattached it to my flat lap, but it turns on and off nicely again.
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Tom
fully equipped rock polisher
My dad Tom suddenly passed away yesterday, Just wanted his "rock" family to know.
Member since January 2013
Posts: 1,557
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Post by Tom on Dec 15, 2013 22:19:32 GMT -5
Excellent
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