new belts, but head stock will not rotate, Now what?

[dknowswd]

I replaced the belts, cleaned everything. The motor runs when no tension on the belts. With belts installed the motor "bogs" and will not turn the belts or the head stock.
I can't adjust the speed by rotating the Sanding Disc. since the Gilmer belt slips on the pully. I checked the tension and it seams right (1/8" movement with finger pressure).
The lower belt seams to hang up in the fan of the adjustable pully.
What should I adjust?

Dean
PS
sorry if this is the second thread, I could'nt find the first one in the forum.

[BigSky]

I do not know how to tell you to go about this. I am not knowledgeable enough to give others instructions. I have seen this problem discussed on this forum recently. I'll look for the answer and post it if I find it but if I reember correctly Bill Mayo addressed this. One of the sheaves was stuck. After lubricating and moving the sheave by finger force the problem was resolved. Search Bill Mayo recent posts.

[JPG]

I replaced the belts, cleaned everything. The motor runs when no tension on the belts. With belts installed the motor "bogs" and will not turn the belts or the head stock.
I can't adjust the speed by rotating the Sanding Disc. since the Gilmer belt slips on the pully. I checked the tension and it seams right (1/8" movement with finger pressure).
The lower belt seams to hang up in the fan of the adjustable pully.
What should I adjust?

Dean
PS
sorry if this is the second thread, I could'nt find the first one in the forum.

You named this thread the same as the first. You posted this one b4 responses that are on the other. Check responses.the original.

The new information here (gilmer jumps while turning with sanding disc) indicates a control shaft/belt jam. Look at comment about control sheave rotating on shaft(it should not) which would indicate improper assembly!

[RobertTaylor]

can the shafts be rotated freely by hand when the motor is unhooked? are the moveable sheaves lubricated and move by hand? the 1/8" deflection is the test for the poly v belt not the gilmer. the gilmer should be snug then adjusted while running. turn the idler shaft eccentric tighter until the belt screams, then back off just until it stops. then snug the clamp/bolt. don't muscle it and break the ear.

[dknowswd]

the shafts can be rotated easily by hand with the belt removed and the motor runs fine this way also.
once everything is connected the motor just hums and statrs to heat up.
Both sheaves move easily also.
How do I tell whether I have gilmer or a v belt? Mine hase about 10 small grooves that match the pully. Would that mean that it is a V belt?
The tension on that could be the problem,
Thanks for the responce,
Dean

[BigSky]

With everything fully assembled, the power cord unplugged and the sanding disk mounted on the spindle - can you easily rotate the sanding disk? If yes, when you do this do all of the shafts turn?
What model Mark V are we working on? What is the serial number? It sounds as though you have a poly-v belt from your description.

[wa2crk]

DK
There are two shafts on the left side of the headstock. When the machine bogs down does just one of the shafts slow down or both of them?
If only the top one slows down then you may have a poly V belt problem.
In actuality there two moveable sheaves one on the motor shaft and one on the eccentric shaft that is controlled by the speed adjustment. If as you say the spindles do turn with very little resistance with the sanding disc attached the motor should not bog down
If the shafts and the belts have been properly installed and as you said that the motor runs normally with the belts removed I am beginning to suspect a motor with a lack of torque.
This can be caused by a bad start capacitor in the motor. When a motor runs on the start windings only they can sometimes appear to be running at full speed but they are actually running slower that normal. When a load is applied the motor will slow down.
If the belt has ten small grooves then it is a poly V belt
You did give me a hint in one of your later posts that the motor hums when the belts are in place and this really sounds like a motor problem (capacitor).
By the way all SS motors in the headstocks run at 3450 RPM and most all of electric motor problems are repairable by a good motor repair shop.

Bill V

[dknowswd]

With everything fully assembled, the power cord unplugged and the sanding disk mounted on the spindle - can you easily rotate the sanding disk? If yes, when you do this do all of the shafts turn?
What model Mark V are we working on? What is the serial number? It sounds as though you have a poly-v belt from your description.

It is a poly V belt after all. When I turn the sanding disc, only the quil shaft turns, not the drive belt or the v belt. When I turn drive pully by hand everything moves until the drive belt snags in the pully vents.

I finally got the motor to turn the quil by loosening the Poly V belt. Then I re-tightened the belt and everything seems to be working, although I can smell burning rubber when I change speed, which I hope is from new belts.
Thanks, Dean

[JPG]

the shafts can be rotated easily by hand with the belt removed and the motor runs fine this way also.
once everything is connected the motor just hums and statrs to heat up.
Both sheaves move easily also.
How do I tell whether I have gilmer or a v belt? Mine hase about 10 small grooves that match the pully. Would that mean that it is a V belt?
The tension on that could be the problem,
Thanks for the responce,
Dean

What do you mean by 'BOTH" sheaves move EASILY????? Do you mean both sheaves on the control shaft? Only the 'control' sheave should move back and forth on the shaft. The other sheave(idler) should be retained by a spring clip keeping it from sliding on the shaft. Neither should rotate around the shaft when assembled.

I assume the belt 'removed' allowing motor to run AND sanding disc to turn freely is the motor drive belt. When you say 'removed' do you mean into the next room? If not, can you pull on the belt and cause the shafts to turn(all of them)? Do the shafts turn free for SEVERAL revolutions???

The only other SHEAVE which slides on its shaft is the motor sheave and it should slide only with considerable force. It has a VERY STIFF spring forcing it towards the motor fan sheave .

If the 'grooves' go all the way AROUND the pulley concentrically? If so it IS a poly v belt.

Forget running the motor for a minute.

Take out the speed control mechanism.

Remove(completely) the drive belt.

Does the output shaft(disc sander) shaft rotate FREELY AND does the center shaft also rotate at a slightly higher rate??? About 1:1.6. Repeat for several revolutions.

Does ONLY the control sheave slide freely back and forth on the shaft?

Do neither of the sheaves on the control/intermediate shaft rotate WITHOUT the shaft rotating?

If any of these tests are NOT positive(as stated), determine why before going further.

If all 'tests' above ARE positive, then the belt needs to be installed correctly.

Slip the belt onto the control sheave while making sure the belt does NOT slip down in between the sheaves(tnx bm). Put it on the motor pulley.

Turn the motor pulley by hand. You may have to AGAIN make sure the belt is NOT slipped down in between the control sheaves(hold control sheave against belt). Every thing should rotate freely.

If it doesn't find out why and 'fix' it.

Take off drive belt and reinstall speed control(leave retaining loop OFF for the time being).

Reinstall drive belt.

Again rotate motor pulley. Again everything should rotate freely. If not find out why and fix it.

Reattach retaining loop.

Turn motor on. Every thing should rotate normally. If not check the motor.

There are a lot of must make it work properly before proceeding steps above.

DO NOT skip any.

I Know the "if not fix it" comments are not helpful by themselves, but they do point you to where to you need to proceed.

[JPG]

1) New belts do NOT burn!!!!!!!!!!!!!!
2) When describing symptoms, Be concise!!!
3) If you are burning rubber, your motor ain't weak!!!!!


DID you watch the sawdust session we referred you to before???????

Did you understand ANY of it??????


Have you paid detailed attention to ANY of the suggestions which SEVERAL people have given to you at considerable time and effort??????