Motor clicks under load

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Mrehder
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Motor clicks under load

Post by Mrehder »

Installed a used 240v motor on my markv.
Model CA48L2A15 Smithcorp.
As I up the speed to about L, the motor starts clicking and slows down.
I checked the centrifugal starter cutout and saw no corrosion etc.
On a bench test, motor runs fine.
Any suggestions as to a possible cause?
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chapmanruss
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Re: Motor clicks under load

Post by chapmanruss »

First welcome to the Forum.

Was this a Mark V you already owned and changed to the 240 Volt motor on? Was it running okay before? It is interesting that the motor "clicking" starts as the spindle speed is increased. Is this happening under a load and not just running? If it is simply running and you are changing speeds, it may indicate that it is not the motor since it runs at a constant speed and the pulley system changes the speed of the output shafts. You also said the motor runs fine on a bench test. Does the Speed Dial turn smoothly and without difficulty? Has the pulley sheaves and speed control assembly been lubricated recently? Another thought would be to check the pulley sheave closest to the motor also known as the fan sheave to see if it is moving slightly toward the motor and making some contact. It is locked in place and shouldn't move on the shaft. Is there any "play" of the shaft going in and out of the motor that could draw the fan sheave into the motor? How fast is the "clicking" sound? If it is coming from the motor there would be almost 60 clicks a second at 1 per revolution provided I am doing my math correctly today. Sorry about going back and forth between the motor and other things to check. My best advice would be to try to locate the source of the click by checking all the moving parts in the headstock.
Russ

Mark V completely upgraded to Mark 7
Mark V 520
All SPT's & 2 Power Stations
Model 10ER S/N R64000 first one I restored on bench w/ metal ends & retractable casters.
Has Speed Changer, 4E Jointer, Jig Saw with lamp, a complete set of original accessories & much more.
Model 10E's S/N's 1076 & 1077 oldest ones I have restored. Mark 2 S/N 85959 restored. Others to be restored.
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JPG
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Re: Motor clicks under load

Post by JPG »

Is the motor slowing down, or is the quill shaft?
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Goldie(Bought New SN 377425)/4" jointer/6" beltsander/12" planer/stripsander/bandsaw/powerstation /Scroll saw/Jig saw /Craftsman 10" ras/Craftsman 6" thicknessplaner/ Dayton10"tablesaw(restoredfromneighborstrashpile)/ Mark VII restoration in 'progress'/ 10
E[/size](SN E3779) restoration in progress, a 510 on the back burner and a growing pile of items to be eventually returned to useful life. - aka Red Grange
Mrehder
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Re: Motor clicks under load

Post by Mrehder »

Thanks for the advice.
It is all oiled. No visible issues in the sheaves.
However the inner sheave pulley was loose. I tightened the set screw.
It now works better but I can only get to V before it starts to misbehave.
Past V it suddenly slows, back to about O speed. It clicks but I think that is due to the drop in power. I have to crank it back to slow speed before it revives and runs back at normal speed without clicks. I think it may be generating heat in the slow mode.
Is there a flaw in the motor windings?
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JPG
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Re: Motor clicks under load

Post by JPG »

I gonna speculate the floating sheave is sticking.

As you increase the speed setting, the control sheaves is opening the idler pulley.

Up until "V" the floating sheave on the motor shaft closes to maintain motor belt tension.

At that point the belt tension is decreased and rpm fallsoff.

Click 'may' be due to fan sheave moving as the belt load is diminished. (you said you tightened it?)

Off hand I can only explain the resumption of 'speed' after reducing the speed control to slow as a delayed release of the 'sticky'.

I do not see this as a load cause as only the drive mechanism is presenting any load variation.

I would take the motor belt off and concentrate on the floating sheave range of free motion(manually overcoming the spring tension to check).
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╟JPG ╢
╚═══╝

Goldie(Bought New SN 377425)/4" jointer/6" beltsander/12" planer/stripsander/bandsaw/powerstation /Scroll saw/Jig saw /Craftsman 10" ras/Craftsman 6" thicknessplaner/ Dayton10"tablesaw(restoredfromneighborstrashpile)/ Mark VII restoration in 'progress'/ 10
E[/size](SN E3779) restoration in progress, a 510 on the back burner and a growing pile of items to be eventually returned to useful life. - aka Red Grange
Mrehder
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Posts: 8
Joined: Sun Sep 13, 2020 8:17 am

Re: Motor clicks under load

Post by Mrehder »

Everything is well oiled and travels. Belt is new.
It still won’t start properly past G and when hooked up to the bandsaw, won’t start up properly at the lowest speed.
The remedy each time is to lower and adjust speed and it then recovers.
The inner sheeve on the motor has a slight dent in it so it is a bit off-round.
I don’t know what else to do.
In the end it’s not worth having to crank the speed to start it just for 220v.
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JPG
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Re: Motor clicks under load

Post by JPG »

Since this is a non-SS motor which you obtained used and it is being used at 240v, I have to ask "Is the start circuit properly connected across ONE of the run windings thus operating on only 120v as designed to do? Is it possible that the start circuit is incorrectly connected to 240v? If the motor is reversible by moving leads of the start circuit between terminals it is possible to misconnect them.
╔═══╗
╟JPG ╢
╚═══╝

Goldie(Bought New SN 377425)/4" jointer/6" beltsander/12" planer/stripsander/bandsaw/powerstation /Scroll saw/Jig saw /Craftsman 10" ras/Craftsman 6" thicknessplaner/ Dayton10"tablesaw(restoredfromneighborstrashpile)/ Mark VII restoration in 'progress'/ 10
E[/size](SN E3779) restoration in progress, a 510 on the back burner and a growing pile of items to be eventually returned to useful life. - aka Red Grange
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everettdavis
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Re: Motor clicks under load

Post by everettdavis »

Is there a possibility the drive belt is worn? It should be at least 1/2” measured across its face. Worn it can bind in between sheave spacing

The speed control mechanism adjust should position the edge of the drive belt about 1/8” or so from the outer edge of the control sheave in low speed setting.

I had one very distorted spring on the motor idler sheave make noises once. I didn’t notice it until I took it apart and it was trying to bend about 60 degrees from linear in the middle.

Is the drive sleeve assembly secure in the mount? The eccentric should not be able to move axially with the bearing.

If it’s a Poly-V is the belt off by one groove?

If it’s a Gilmer Drive, designed to slip when a blade seize occurs but drive solidly, the clutch may make noises that will be elusive.

There’s always the possibility that you have two separate issues you’re observing, not from one cause.

A Gilmer Belt with belt set can
make some cyclical noises.

Is there any way you could post a short video with sound?

Everett
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chapmanruss
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Re: Motor clicks under load

Post by chapmanruss »

Besides what JPG and Everett have talked about above I wonder about this item you mentioned.
The inner sheeve on the motor has a slight dent in it so it is a bit off-round.
A picture of the dent in the inner motor sheave would be helpful to determine if it is a problem. It may or may not be related to your current issues but could cause a problem of its own. If the dent is inward it would cause a narrowing between the sheaves forming the pulley and push the belt out of the pulley. If it is outward it would cause a widening between the sheaves causing the belt to drop in the pulley. It is likely that sheave should be replaced. Was this the original sheave from the previous motor?
Russ

Mark V completely upgraded to Mark 7
Mark V 520
All SPT's & 2 Power Stations
Model 10ER S/N R64000 first one I restored on bench w/ metal ends & retractable casters.
Has Speed Changer, 4E Jointer, Jig Saw with lamp, a complete set of original accessories & much more.
Model 10E's S/N's 1076 & 1077 oldest ones I have restored. Mark 2 S/N 85959 restored. Others to be restored.
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everettdavis
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Joined: Thu Jul 17, 2014 11:49 am
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Re: Motor clicks under load

Post by everettdavis »

JPG wrote:Since this is a non-SS motor which you obtained used and it is being used at 240v, I have to ask "Is the start circuit properly connected across ONE of the run windings thus operating on only 120v as designed to do? Is it possible that the start circuit is incorrectly connected to 240v? If the motor is reversible by moving leads of the start circuit between terminals it is possible to misconnect them.
I want to see this non-Shopsmith motor. They require a special armature length to function. Is this a hybrid motor with a Shopsmith armature?

How did they doi this? The end bells and thrust in and out could be an issue, as field strength of the motor/ armature combo. Could it be a European 50hz motor?

There is a spacer on the shaft for clearance for fan sheave. Is there a possibility the spacer is missing or worn?

The dented sheave is a concern as Russ states.

Lots more questions than answers I’m afraid.
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