Author Topic: Difficulties in removing ER-chuck from BLDC spindle motor  (Read 430 times)

Offline PekkaNF

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Difficulties in removing ER-chuck from BLDC spindle motor
« on: August 15, 2019, 11:15:00 AM »
Bought this sort of pagage years ago, but really haven't put it to any good use yet.


I would like to remove the ER-chuck from the motor shaft and replace it with a poly vee belt pulley.

The chuck has two oposing set screws - they are easily removed. I noticed that they bear on plain shaft - there are no flats.

I supported the chuck and pressed the shaft with an proper drift punch and shop press with moderate force. It did not move. motor shaft is 8 mm and drift was slightly less. I did expect it to pop out with a very little force. No sign of glue, but there could be some.

Plan "B" is to make the poly vee pulley mount over the ER11-chuck. Possible, but not ideal.

Wondering how tight it should be?

Offline djc

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Re: Difficulties in removing ER-chuck from BLDC spindle motor
« Reply #1 on: August 15, 2019, 12:49:17 PM »
I would like to remove the ER-chuck from the motor shaft and replace it with a poly vee belt pulley.

Remove in one piece for possible re-use or just remove?

If you do not want the chuck, use the motor as its own lathe and turn down the chuck until it is thin enough to peel off. If you can shield it a bit, the redneck version of this procedure uses an angle grinder.

You might be able to dismantle the motor sufficiently to keep the important bits cool and heat the chuck to denature any thread locker.

Offline awemawson

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Re: Difficulties in removing ER-chuck from BLDC spindle motor
« Reply #2 on: August 15, 2019, 12:49:24 PM »
Could it have had Loctite or similar put on it when assembled?

If so moderate heat should break the bond
Andrew Mawson
East Sussex

Offline Joules

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Re: Difficulties in removing ER-chuck from BLDC spindle motor
« Reply #3 on: August 15, 2019, 01:21:54 PM »
The screws will have scored the shaft and pretty much locked it in place.  You could try bagging the motor and put it in the freezer overnight.  Then hit the chuck with some heat and see if it will budge.  That would also sort out any Loctite if present.
Just get doing and make swarf, you can decide what its going to be later.   :thumbup:

Offline PekkaNF

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Re: Difficulties in removing ER-chuck from BLDC spindle motor
« Reply #4 on: August 15, 2019, 03:28:47 PM »
Fine if it comes out voluntarily, but I don't need to save the chuck. It would be really slow going if turned from 16mm OD near down to 8 mm of steel chunk. The motor is sort of 12000 rpm 400W model, pretty low torque for turning.  Might work out by mounting it onto grinder table and wearing it down with grinder.

Maybe I wrap it into cling film and chuck into freezer overnight and hit it with a hot air gun when it is in shop pres and give it one more try before resorting into anything more destructive.

This model has HAL-bits and I would hate to wreck the motor sensors or bearings. These are not as robust as typical AC-motors.


Offline philf

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Re: Difficulties in removing ER-chuck from BLDC spindle motor
« Reply #5 on: August 15, 2019, 04:00:45 PM »
Pekka,

If you're not bothered about saving the chuck grip the chuck and mill it down to shaft diameter (or slightly above the shaft). If this doesn't release it turn it over and do the same to the other side.

Phil
Phil Fern
Location: Marple, Cheshire

Offline PekkaNF

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Re: Difficulties in removing ER-chuck from BLDC spindle motor
« Reply #6 on: August 15, 2019, 04:40:51 PM »
Pekka,

If you're not bothered about saving the chuck grip the chuck and mill it down to shaft diameter (or slightly above the shaft). If this doesn't release it turn it over and do the same to the other side.

Phil

That is a great idea. Thank you. It is cylindrical outside (minus key flats). Small v-block sorts it well between milling vice jaws and then that should not present any problems.

I have it allready in the freezer, I might try as well hot air gun and shop pres Tommorrow. It's wraped into clingafilm that should keep the swarf away if I need to mill it.

Pekka

Offline PekkaNF

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Re: Difficulties in removing ER-chuck from BLDC spindle motor
« Reply #7 on: August 16, 2019, 12:41:15 PM »
Thank you for good alternative methods.

Love to have Plan "B", sometimes "C" etc. I would hate to paint myself into corner.

Overnight in the freezer, little heating with hot air gun, moderate power with press and it come out.

Pekka

*interesting thing is that the shaft and chuck hole are bit more under 8,00 than I expected. Luckilly I had a hunch and turned the drift diameter to 7,95 mm. Drift got stuc to chuck while pressed out the chuck from the shaft. I though there were debris, but looks like the chck ID is prety coles to that.

Now I have to remember that when I turn the pulley for this motor. Can't use reamer, it would make oversized hole for this motor shaft.
« Last Edit: August 16, 2019, 01:52:36 PM by PekkaNF »

Offline Joules

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Re: Difficulties in removing ER-chuck from BLDC spindle motor
« Reply #8 on: August 16, 2019, 01:03:39 PM »
 :D

Glad it worked, the plastic bag is more to keep moisture out of the motor once removed from the freezer.
Just get doing and make swarf, you can decide what its going to be later.   :thumbup:

Offline PekkaNF

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Re: Difficulties in removing ER-chuck from BLDC spindle motor
« Reply #9 on: August 16, 2019, 01:56:38 PM »
Exactly, kept the wrap on until the temperature was equalized. Still the front flange sweated.