Bit of a pickle

[Amiers]

So the motor that turns a stage prop went out so I got a replacement and put the sprocket on and everything worked fine yesterday after I finished it up. Today I went to test it and got nothing. So I opened the case and the sprocket had moved. I have wrenched on this thing for a while lubed it and everything and can't get the thing to do anything but spin on the shaft.

Any ideas on how to get this thing off so I can reset it to the desired location on the shaft.

 

[BillConnerFASTC]

 

[BillConnerFASTC]

Home Depot, Menards, Lowes, Northern Tools, Harbor Freight, Grainger, Fleet and Farm, and others - one must be near you.

 

[derekleffew]

@BillConnerASTC has pictured a "gear puller," which is different than the guy who fills your shop order at the rental place. Before looking at @Amiers' photo, I suspected the keyway had broken or a set screw wasn't gripping. But has nothing to do with a pickle, as far as I can tell.

 

[BillConnerFASTC]

 

[Amiers]

@BillConnerASTC has pictured a "gear puller," which is different than the guy who fills your shop order at the rental place. Before looking at @Amiers' photo, I suspected the keyway had broken or a set screw wasn't gripping. But has nothing to do with a pickle, as far as I can tell.

I was on the right track with the puller I just couldn't think of the name. I kept coming up with automotive tools in my searches.

Tbh I'm not sure how the sprocket moved as I had both set screws tightened.

Also no pickles were involved in the possible desruction of this motor.

 

[techieman33]

I was on the right track with the puller I just couldn't think of the name. I kept coming up with automotive tools in my searches.

Tbh I'm not sure how the sprocket moved as I had both set screws tightened.

Also no pickles were involved in the possible desruction of this motor.

What you'll find easily available will be an automotive tool. That's the route I would take, in fact most auto parts stores will let you "rent" stuff like that for free. You just leave a deposit to cover the cost of the tool and then get it back when you return the tool.

 

[JD]

I'm not sure how the sprocket moved as I had both set screws tightened.

Problems that defy all logic are often the most fun, at least after they're solved!
Do tell us what you finally find out is going on. In looking at the picture, it almost looks like there is a stationary sleeve that extends out of the front of the motor. Any chance the screws are tightened down on the sleeve as compared to the shaft?

 

[lwinters630]

So the motor that turns a stage prop went out so I got a replacement and put the sprocket on and everything worked fine yesterday after I finished it up. Today I went to test it and got nothing. So I opened the case and the sprocket had moved. I have wrenched on this thing for a while lubed it and everything and can't get the thing to do anything but spin on the shaft.

Any ideas on how to get this thing off so I can reset it to the desired location on the shaft.

I don't see a set screw in the gear in the picture, that missing would only let the gear spin free on the shaft.

 

[Kurt]

Well, here's an utterly silly question, but I see there's a flat spot on the shaft. Is it possible you've not been tightening the set screw onto that flat spot? Seems impossible to me that it could go anywhere if you did. You also mentioned two set screws; I'm not sure if it's better to tighten one before the other, but it might be worth testing if doing it one way might produce more torque

Anyway, it's entirely possible that your set screws are loosening over time, as silly as that may seem. I used to lifeguard, and we had these lane ropes that I used to have to constantly tighten because they came loose over time and they'd fall apart. Not exactly the same application but I feel like greasy set screws may act similarly to screws that get wet all day long.

Wasn't sure if the screws were getting grease as well, but if they are it may be worth getting any grease off of them as well as their threads and tightening them. If you were still getting problems you might try some loctite. Not the greatest solution in the world but your screws wouldn't come loose until you seriously wanted them out.

That's my two cents.

 

[bobgaggle]

I can guess one reason the sprocket won't come off, but it seems so highly unlikely.

It looks like the set screw has been removed, probably to eliminate that as a reason the gear won't come off. Maybe it was wrenched down so tight that when the load (whatever prop is rotating) bound up on the something the torque of the motor sheared off a piece of the screw and it wore a groove in the shaft as the motor forced it around the bore of the sprocket. It would result in a blind keyway and key, perpendicular to the shaft, keeping the sprocket from being removed, yet allowing it to spin on the shaft. Of course this theory is easily debunked...is the set screw intact?

 

[Amiers]

All good questions.

The set screws were intact just not in the picture as it was taken after I took out the set screws to try and moved the sprocket.

There is a sleeve at the front of the shaft, no I didn't screw it to the sleeve as it is to big to get the sprocket hole to go past it.

This is a new motor so nothing over long time happened It worked first installed turned it on the next day and the sprocket moved.

I did have one of the set screws tighten on the flat of the shaft.

I do believe that Bob does have it right though as everything was turning somehow something sheered above or below the set screw hole and will let me rotate but not remove.

Sadly it snowed today and crazy people are still getting used to the new weather so attempts to find a gear puller will have to wait til tomorrow.

 

[Amiers]

Bit of an update:

Found the puller today. Took two store to find it.

It literally took 30 secs to pull it off. Amazing what the right tool can do for a job.

I reset the sprocket and hopefully it doesn't move this time.

 

[derekleffew]

... Found the puller today. Took two store to find it.
It literally took 30 secs to pull it off. Amazing what the right tool can do for a job.

Okay, good. Now that you've purchased the difficult to find, single purpose, and expensive(?) tool, I purposely neglected to mention (I can be evil that way) a solution I found while googling images:

It might not have worked in your case, or you might not have had the correct c-clamps, but perhaps in the future someone might have a need and want to try this before hunting down the proper tool.

 

[techieman33]

Okay, good. Now that you've purchased the difficult to find, single purpose, and expensive(?) tool, I purposely neglected to mention (I can be evil that way) a solution I found while googling images:

It might not have worked in your case, or you might not have had the correct c-clamps, but perhaps in the future someone might have a need and want to try this before hunting down the proper tool.

Hopefully it just borrowed one from an auto parts store like I recommended.

 

[Amiers]

Nah I bought one as I can make a use for it in other places and not just this one application, golf carts, lawn mowers, other moving parts with gears. The one they tried to rent me was one without the claws.

@derekleffew unfortunately all I have on hand are cabinet pipe clamps which would of be a monster of a contraption to rig up for something as simple as a 35$ tool.

So I leave you guys with the final finished product that the motor runs.

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