Removing pulley from a motor spindle

[Jonburt83]

Hi, I would like to remove a pulley from an old motor but am not sure how to go about this. There is no taper lock; I've attached some photos which show the pulley. There seems to be a rectangular 'lump' on the face of the pulley partially covering that end of the spindle, I'm not sure if this has any bearing on removal.

If anyone could point me in the right direction, I'd be very grateful!

 

[ShopShoe]

It looks to me like there is a key to keep the pulley from spining on the shaft. Is there also a setscrew (grub screw) bearing against the key to keep it from slipping out? There may may be a setscrew elsewhere on the pulley to retain it, or two setscrews 90 degrees apart. If you can find setscrews and remove them you will have started toward disassembly.

It is also possible that the key is tapered and someone hammered it in from the front. This may be why it is not flush with the shaft. If it is rusted in it may be very hard to remove.

How much do you think the motor is worth to you? You might want to consider that if you decide to follow what I am about to say as you could cause more damage if you are not careful.

Your best bet is to use a gear puller to try to get the pulley off. I put in two links to show what I am talking about. I know you are in the UK and what you can get is most likely different. I just wanted to get pictures for you and I do not suggest you get the exact items I show. Here some auto-parts stores will rent tools, so check into that.

https://www.eastwood.com/powerbuilt-4-inch-gear-puller-648907.html
https://www.eastwood.com/5-ton-bar-type-puller-bearing-set-atd-tools.html
DO NOT apply the puller without first checking for setscrews and getting them out. I also suggest you soak the shaft end and pulley with penetrating oil ("releasing fluid") for several hours before trying the puller.

Careful application of heat to the pulley could also help break the bond between pulley and shaft and cycling heat, then cool, then heat several times could help as well. Heat/Cool/Oil cycles can also help do this. BE CAREFUL as some penetrating oils are flammable and you don't want a fire.

Some people would also suggest doing the heat/cool with putting the part in a freezer or using dry ice. I have never done that.

Another thing that could help is heating, then lightly tapping the pulley hub with a hammer to help break things loose for pulling or to make it easier for the penetrating oil to get to the stuck area.

All I said is AT YOUR OWN RISK. Please be careful as you are upping the forces involved and possibly using dangerous methods to get heat. I have never been hurt with pullers and presses, but the "bang" that happens when something breaks loose is always scary.

And now encouragement: I was restoring a car and had a brake backing plate with a stuck adjuster that took several days to get unstuck. Soaking in oil for overnight, then applying force, then heat, then force, then soak overnight and etc. Eventually I got it apart with no damage to the screw, no damage to the backing plate, no damage to the shop, and no damage to me.

Good luck,

--ShopShoe

 

[aka9950202]

The rectangular lump is a key which may be tapered. Look up shopdogsam on youtube.com. he has several videos on how to remove such a key.

Cheers,

Andrew in Melbourne

 

[Jonburt83]

Many thanks for the replies, I've gone back and had another look and seen that it's a key which looks like it's tapered and is held in place by a 1/8" hex setscrew at the bottom of one of the pulley grooves. Put some penetrating oil in and tried heating the pulley, but the screw seems stuck pretty fast and it's not budging. I plan to keep topping it up with penetrating oil and will have another go at heating it later.

 

[WisJim]

I'm assuming that when you say "1/8" hex set screw" you mean an internal hex or Allen screw. If so, be sure you are using the exact correct size wrench in good condition, and carefully clean out the hex in the screw head to minimize the chance of stripping or damaging that internal hex. You don't want to make it harder to remove by damaging or rounding off that internal hex.

 

[SmithDoor]

Hi, I would like to remove a pulley from an old motor but am not sure how to go about this. There is no taper lock; I've attached some photos which show the pulley. There seems to be a rectangular 'lump' on the face of the pulley partially covering that end of the spindle, I'm not sure if this has any bearing on removal.

If anyone could point me in the right direction, I'd be very grateful!

There are special puller for that. A regular puller will break the flange.

Dave

 

[Charles Lamont]

As well as judicious use of heat and a puller, lots of not too heavy impacts may help. Eg. put tension on with the puller, then keep giving the head end of the puller screw many sharp taps with a hammer - just not quite hard enough to damage it.

 

[Mike Ginn]

Tricky problem. The advice above is sound - check very carefully for set screws and be very very careful to use the correct size hex wrench. You are in the UK so the age of the motor could indicate imperial size - again be careful with the size. I usually drill and tap 2 holes either side of the shaft and use a substantial bar with a centre tapped hole to use as the puller bolt. Ideally M8 size. I would torque up the central bolt, apply some heat and tap the pulley with a copper mallet.
Best of luck
Mike

 

[Badhippie]

If after removing the set screws that hold the key. You can drill and tap the end of the key and use a slide hammer to remove the tapered key. Or sometimes you can drill two holes into the sheave straight across from each other and use H-bar puller to remove the sheave with the key. The problem with that is if the key is stuck good in the shaft keyway sometimes the sheave will climb higher on the tapered key causing it to get tighter. Good use of heat will help with this.
But your best bet is to remove the key first

 

[Steamchick]

Must remove the key first.... Lots of excellent advice above so I shall say no more, except PENETRATING OIL = loads, + Time = loads, +patience, Bucket loads! and tapping the end of the puller when there is some load applied "shocks" the job apart (breaks the friction) - WHEN all the rust (bonding) is destroyed by the penetrating oil.
Just please remember, that all the hammering, heat and brute force needed to disassemble this job is NOT what the bearings and windings were meant to resist, so check for damage before running the motor afterwards. "Gently, gently catchee monkey".
K2

 

[Jonburt83]

The set screw holding the key is proving difficult to budge; I've ordered a new 1/8" hex key with a T type handle to perhaps enable me to apply more torque - until that arrives I'll just be intermittently applying more penetrating oil.

IF the set screw doesn't budge, would it make sense for me to try and drill it out? (I don't have a drill press that would accommodate the bulk of this motor so it would have to be a hand drill)

 

[Mike Ginn]

I think you are onto a looser! I doubt that you will shift the set screw and drilling could work. I think I would drill several holes in line and tap with a tapered tap to about half way then force bolts into the casting (I am assuming cast iron) to split the pulley. Could use an angle grinder to create a slot and use a wedge but any hammering must not be against the bearings - only across the pulley and against a solid surface.
Mike

 

[Ken I]

I'm with Steamhippie & K2 - drill and tap and use a sliding hammer to remove the taper gib key. Time, penetrating oil, thermal cycles and patience.

That looks like a tapered Gib-Head key - can be very hard to remove,

Drilling all the way through (at tap size for thread / sliding hammer) will help relieves stress and aid extraction - trying to simply pull the pulley off almost certainly won't work. - drill largest hole you can.

I know you don't have the headroom but accurate drilling to split the key in two is often the only way to get these things out especially if it was bludgeoned into place by a gorilla with a large hammer which might well be the case here.

You normally use a wedge to extract these - but that's not possible because it's not flush - you might be able to force in a small custom wedge to prevent the key wedging in further if you want to try brute force extraction against the pully as suggested by Steamhippy.

Regards, Ken I

 

[Steamchick]

Really, the pulley to shaft joint splitting forces should ONLY be contained within the shaft and pulley. Which is how pullers work by putting tension onto the pulley rim, while pressing (reacting the forces) against the end of the shaft. Once the puller is wound to a respectable load, - without distorting everything! - a shock load from a moderate strike with a mallet on the puller centre bolt will send a shock wave through the joint to (hopefully) break the static friction. If the rust has "welded" the shaft to the pulley, it MUST be chemically reduced by the release oil first. Which is why it can take days or weeks of soaking....
Then all the puller is doing is shearing the rust in the joint, Which often destroys pullers, pulleys or shaft ends! Once distorted, the shaft end will retain the pulley forever.... So it is good to put a hard steel bush on the end of the shaft (Often a socket from a socket wrench set is good enough - flat surface to shaft) for the puller centre bolt to impinge upon. Or a piece of round steel - like a disc - so the pulley can pass over it.
Enjoy, - tell us the result after a week or so. A big "hoorah" is always welcome on this site.
K2

 

[ajoeiam]

Hi, I would like to remove a pulley from an old motor but am not sure how to go about this. There is no taper lock; I've attached some photos which show the pulley. There seems to be a rectangular 'lump' on the face of the pulley partially covering that end of the spindle, I'm not sure if this has any bearing on removal.

If anyone could point me in the right direction, I'd be very grateful!

A tapered gib key is a great holding tool - - its also a tough thing to remove.

You have a bit of room as I can see (photo isn't quite sharp when magnified) between the pulley and the body of the motor.
What I'm going to suggest is counter intuitive but I've had it work a few times (but no guarantees!!).

If you try to pull the pulley off the shaft you will be tightening the assembly (you're drawing over the increasing part of the key - - remember).

1. carefully clean up the shaft between the pulley and the motor body (need to be very clean - - - not just sorta!!!)
2. support the off end of the shaft (important or you have a decent likelihood of damaging the interior of the motor)
3. motor needs to be supported so that you can use two hands on other bits (a second pair of hands is one possibility)
4. place some kind of heavy cup like bit that goes over the gib key and around the shaft on the pulley
5. strike the cup on the pulley firmly with a solid beating stick (a 3# blacksmith's hammer should work)
6. a few shots may be necessary, it may also help to use a bigger hammer (I'm not proud - - I'll use an 8#er if necessary)
7. using something to try to break the rust bond before the bull work will make your life much easier.

There are some decent forces that can happen with this kind of thing so care is warranted.

Another option is to mill off the end of the gib key.
Then carefully drill down into the gib key.
I would tend to drill right through the bleeping thing.
Then collapse the key and it should be reasonably easy to extract at this point.

Easier to buy another key than to try and extract it in one piece.

 

[metalmangler]

The set screw holding the key is proving difficult to budge; I've ordered a new 1/8" hex key with a T type handle to perhaps enable me to apply more torque - until that arrives I'll just be intermittently applying more penetrating oil.

My father-in-law had this problem with the grub-screw on a Fobco Star motor pulley. He chopped-off the bent end of a new allen key, and silver-soldered the straight key into a hole drilled into the end of a bit of 3/4" round MS. He then cross-drilled a 1/2" hole in the other end of the MS for a tommy-bar. He tried various sizes of tommy-bar without success until he got up to 15" when, with both of us heaving at it, the grub-screw suddenly released - after which it unscrewed perfectly easily with an ordinary allen key.

 

[Rdean33422]

Many of the old machines we had on the farm had these keys and they were mostly removed by welding a length of threaded rod to the key head. Then put a piece of bar stock with a hole for the threaded rod and use this like you would use a puller to remove the key. The heat generated from the welding helped loosen the key. I would try to get the key out first even if you have to drill it.
Ray

 

[57mm_M18]

Lots if good advise here. I decided to add my experiences to the list.

First, I would do a good cleaning up of the shaft and pulley where they meet each other.
Second, like everyone has said I would check and remove all grub screws. Pay attention to the fact that sometimes a set screw is place on top of another to
to lock the first one in place.
Third, I would use a quality penetrating oil and let it do its thing. I usually apply heat to the pulley to assist in the penetrating process. Only warm it to the where it is uncomfortable to touch.
Forth, the previous suggestions of using a H style puller and tapping the end of the key to pull it is a good idea if there is enough meat to do so.
Fifth, even though this is a 4 groove pulley & has some value, if you are after saving the motor then carefully cut the pulley off either in a lather or mill.

 

[HMEL]

Hi, I would like to remove a pulley from an old motor but am not sure how to go about this. There is no taper lock; I've attached some photos which show the pulley. There seems to be a rectangular 'lump' on the face of the pulley partially covering that end of the spindle, I'm not sure if this has any bearing on removal.

If anyone could point me in the right direction, I'd be very grateful!

If you wish to retain the motor and the shaft and IF you can get another pulley it is possible to cut the pulley off. This might sound a bit brutal but with care it can be done. A cut is mad on the outer rim of the pulley towards the shaft. Its done with care and eventually the stress will be relieved and the pulley will come off. Other wise take your time as the other recommendations suggest. It might take two cuts. But if you have the time use penetrating oil and slowly work it off. Corrosion and time and some times galling can make things very difficult. I learned this from a man who used to salvage parts for a living.

 

[Steamchick]

I agree that "the final" option is cutting off the pulley. Carefully drilling the hub next to the keyway - radially out from the keyway ( maybe only 1 or 2 x 1/8" holes?) - after drilling the key with as large a hole as to think safe before risking damage to the shaft - should release stress in the hub when the hub cracks open. Thus enabling it to be pulled-off the undamaged shaft. If cast, the pulley will be scrap. It otherwise you may be able to recover it by welding (depends on your skill) with some finish machining. But I understand you want to fit a different pulley?

K2