Removing shaft key from servo motor shaft

[wilfor03]

Hey All.....
Just got a servo motor (nearly new?) and need to remove the shaft key so I can get to the brake inside to remove it. Its an Omron, 600w servo (5/8" shaft size) that came with a shaft key already installed. Dang thing won't budge a bit, so I don't know if they glued or pressed or whatever. Already tried to moderately heat the shaft, used paint thinner, good ole WD40, etc? Anyways, I figured some of you smart fellas might have run across this problem before, and I ask your opinions if I may?



 And, thank you all for any help you can throw my way......

Bill

[Bruce S]

Bill;
 I had to blow the pic up real big to see, but honestly it looks close to being an interference fit, key.
Good luck getting it out. The good thing is that they key material is usually a softer material than the shaft, to act as a sacrificial lamb if something goes haywire.
You could try a cold-rolled chisel and NOT a cheapo one either, you'll need to get in under the very front of it with a good 3lb sledge.
Otherwise you could merely use a good chisel to shear the top part to be level with the shaft and go from there.
NICE looking motor 
The chisel and sledge has worked for me in the past, getting the tip up is by far the hardest part a good center punch may help with getting at it.
Best of luck
Bruce S

[DenisGCroombs]

Hey All.....
Just got a servo motor (nearly new?) and need to remove the shaft key so I can get to the brake inside to remove it. Its an Omron, 600w servo (5/8" shaft size) that came with a shaft key already installed. Dang thing won't budge a bit, so I don't know if they glued or pressed or whatever. Already tried to moderately heat the shaft, used paint thinner, good ole WD40, etc? Anyways, I figured some of you smart fellas might have run across this problem before, and I ask your opinions if I may?

 And, thank you all for any help you can throw my way......

Bill

Ok, the best way I know of is to drill and tap a hole in the KEY and then use a bolt to push the key out against the bottom of the key slot in the shaft.
Because you cannot tap a thread down the full depth of the key, you need to reduce the size of the end of the bolt before you try end screw it into the tapped hole.

But this is not easy the first time, but it can work and has saved me many times.

Good luck
Denis

[wilfor03]

Appreciate the info, Bruce, I'll go give it a try now. Just wasn't sure how "physical" I should get with it.

[TomW]

Just be sure to support the shaft when beating on it so you dont bork the bearings. I have busted stuff trying to BFH my way thru a stuck part.

Metal work is not my thing but just saying ..

Tom

[wilfor03]

Okay, got it AND removed the brake while I had it apart. I just used my chisel across the length of the stuck key. The metal in that key was very soft so it sheared even with the shaft. Touched it up with the faithful Dremel wheel and the front plate slipped right off. Boy, its got one hell-of-a magnet in there! Don't worry, it never came out. Sure do appreciate all the feed back though........I'll start posting more pix of the build as I go........

Bill
 

[taylorp035]

You can give those shafts a pretty good beating before they bend.  A lot of times, the key will be made of aluminum.  Last week, I took the flywheel off my treadmill motor, but it didn't gave up without a good fight.  Two ~8" C-clamps configured in a jerry rigged flywheel puller didn't do the job.... ended up suspending the flywheel in the vice and hammering the shaft out with a sledge hammer.

[Bruce S]

Bill, Glad it worked out:-)
Those are the killer gotchas  on lawnmower engines, they're made so the shear key gets tore up instead of the shaft, when people run over rocks or concrete or stumps 
I fixed a great number to trash-day mowers by just replacing the shear key.
Once you have the shaft out and want to try further removal of the rest of the material, put the shaft part in the freezer for about an hour, the metals will compress at different rates and you should be able to knock the rest of it out with a center-punch, if it doesn't fall out before hand

Cheers;
Bruce S

[wilfor03]

Bruce......Cool (pun intended there) I'll do that pretty soon. Finishing up some other things at the moment, but I do appreciate the advice. This is the best place for advice from all your knowledge (collectively) and I look forward to being able to help others also. Thank you....

Bill

[Bruce S]

Bruce......Cool (pun intended there) I'll do that pretty soon. Finishing up some other things at the moment, but I do appreciate the advice. This is the best place for advice from all your knowledge (collectively) and I look forward to being able to help others also. Thank you....

Bill

Always glad to help.
I forgot to warn you, DO NOT put the magnets in there too, they won't be worth a darn if you do afterwards.