Worm gear removeal

Not for the feint of heart... I used 1/8"  flat bar stock about 2 inches wide and 12 inches long.  I put about a 1 inch or so slit in the middle of the bar stock at one end with my grinder (very thin metal cutting disc).  Placed motor in a vice, heated the gear up... slid the bar stock slit over the shaft behind the gear and whacked the bar stock with a hammer... off she came.

This was a Timko conversion of an NW-J... it could not pull your hat off and got hot as Hades ...I converted it back to Pulmor.

Are you trying to save the old motor?

If you can say 'no', I'd cut the motor shaft between the motor and worm.  You'll have a lot more choices of tool/technique with just the worm gear and a piece of shaft at hand.

BTW, I'm assuming you've verified that there's no evidence of solder or CA twixt worm and shaft?  ...In which case you might check with the folks at Northwest ShortLine (NWSL) and see what they have for replacement possibilities.

Just a couple of thoughts...

Have a blessed Easter Day!

KD

First, it’d be nice to know what kind of motor you’re working on. Then we can give the correct method.....

Pat

You may want to try this contact. Click on the link.  It has been a long time, since I've used his services. Had a Weaver 0-8-0 that the motor quit.  I sent him the motor, with the worm, received the a new motor with the existing worm installed. 

Frank is alive and well Mike, and he's the guy to get the worm off.

I've had limited success with getting them off, but I killed the pin on my gear puller and I'm out of commission until I get a new one made.

They are tough to remove.  You will have a hard time even with a Timko puller.  As John said, the pin usually bends.  The press on the end closest to the motor is much tighter than at the end.

I have had success using rollers from an old roller bearing for the pin.   

I would be curious to see what other people are using.

I'm actually using a more robust gear puller than the Timko one, and I bent the pin on that one!

Wow, I wish I could say I'm surprised, I guess I was hoping someone had a secret for success  on these and like most of the other folks have said all the pieces bent while trying to us them, even tried using a shaft out of an old motor thinking it was just as strong as what I was trying to punch out but no dice it bent as well.

I do have a former employee who is seriously into RC 4x4 and dirt racing vehicles and after seeing how those things get abused and how these guys rebuild them by printing their own parts he is printing a few gears for me to see which one may work, so if that pans out I will definitely share with everyone, I will post weather it works or not.

Thank you all for your thoughts and inputs and Hope you all have a Great Easter

@David Minarik posted:

They are tough to remove.  You will have a hard time even with a Timko puller.  As John said, the pin usually bends.  The press on the end closest to the motor is much tighter than at the end.

I have had success using rollers from an old roller bearing for the pin.   

I would be curious to see what other people are using.

I use dowel pins. This is actually my flywheel puller. My gear puller has smaller jaws but uses the same set of bolts.

Pete

I use the Great Planes Gear Puller, it's pretty robust, but it didn't survive the cut, and I bent the pin.  Still trying to get a replacement pin, hopefully from stronger material.

GRJ...Do you still have your bent pin?  If there is a fairly straight portion for about 1/8-1/4" of the small diameter portion of the pin below the neck, you could cut off the rest of the bent length, grind the end square.  On a situation such as this worm gear pressed to the motor shaft, my guess is that if you can get the worm gear to just 'break free' of its press fit...move it about 1/8" or so...you'd be home free substituting some other drive pin tool, such as...

drive pin tool set

...to finish the job.  There are many options less expensive than Starrett, too (I've been successful using a finishing nail to finish driving a gear from a shaft once the gear has started to move). 

My own experience sez that getting a press fit to just break free of its current position is more than half the battle for removal.

Just a thought.   

KD

Well, the pin is stepped, and it's bent right at the step, so that might not work.  In any case, I'll eventually get a new pin, hopefully from tool steel that will resist the forces necessary to do this job.

Another option for pins is to sacrifice a drill bit using the shank. Unlikely to bend one of those.

Pete

@gunrunnerjohn posted:

Well, the pin is stepped, and it's bent right at the step, so that might not work.  In any case, I'll eventually get a new pin, hopefully from tool steel that will resist the forces necessary to do this job.

I haven’t forgotten about making pins for y’all, ....I’ll get it done,....I just get distracted easily,..........oooh look!..a locomotive!...gotta run!!...😁

Pat

@Norton posted:

Another option for pins is to sacrifice a drill bit using the shank. Unlikely to bend one of those.

Pete

That only works if your pin doesn't look like this.  I don't have any drill bits that are shaped like this.

No problem John. You just need a lathe. A carbide cutter will cut high speed steel.

Pete

Pete, I need the skill to use a lathe as well.

The worm gears on most motors is stepped, so the pin that fits in the opening of the end of the worm may be bigger than the shaft.

I'm not following.  I have removed worm gears from Lionel and MTH motors.  Although I suspect there might be a slight taper to the shaft, I have never seen a step.  The worm gets pressed on, so I have to believe they can be pressed off.  Of course, if the worm is put on from the other end before they assemble the motor, that's another story.