Motor question

redrock · Post by **redrock** » Thu Dec 23, 2010 6:41 pm

I just changed belts on a used Mark V every thing related to that seems OK. I just bought the machine used and it was noisy and with the age I figuared it couldn't hurt to take it apart clean it and change the belts. Easy enough. Here is the problem the fan sheave is rubbing on the sheet metal fan cover behind the fan sheave. It is very loud and I am sure it isn't susposed to do that. Is there a way to get to the cup set screw is my question. Is it user serviceable? The sheet metal fan cover appears to be riveted to motor front. From the blown up parts picture it appears that the cup set screw is behind the fan cover or shroud. Any help would be appreciated. TY.

JPG · Post by **JPG** » Thu Dec 23, 2010 7:05 pm

redrock wrote:I just changed belts on a used Mark V every thing related to that seems OK. I just bought the machine used and it was noisy and with the age I figuared it couldn't hurt to take it apart clean it and change the belts. Easy enough. Here is the problem the fan sheave is rubbing on the sheet metal fan cover behind the fan sheave. It is very loud and I am sure it isn't susposed to do that. Is there a way to get to the cup set screw is my question. Is it user serviceable? The sheet metal fan cover appears to be riveted to motor front. From the blown up parts picture it appears that the cup set screw is behind the fan cover or shroud. Any help would be appreciated. TY.

1) There is a spacer on the shaft that spaces the fan sheave away from the motor. It can get damaged if the floating sheave is allowed to bang against the fan sheave(like pulling it out and it slips and the spring slams it into the fan sheave).

2) The set screw is accessible through a hole in the bottom of the motor pan.

This may require replacement of the spacer!:( That would require removal of the floating sheave spring!:(:(

redrock · Post by **redrock** » Thu Dec 23, 2010 7:09 pm

Thank you for the reply. I was going to take the motor off tomorrow and see what there is to see I was worried when I saw the rivets. I will see what can be done then. Thanks again.

beeg · Post by **beeg** » Thu Dec 23, 2010 7:47 pm

See if this PDF helps ya.

[ATTACH]11247[/ATTACH]

JPG · Post by **JPG** » Thu Dec 23, 2010 7:54 pm

beeg wrote:See if this PDF helps ya.

[ATTACH]11247[/ATTACH]

Gotta think a washer would rube goldberg fix this!(between the spacer and fan sheave)

redrock · Post by **redrock** » Thu Dec 23, 2010 11:47 pm

The Rube Goldberg idea sounds like a plan to me. I will post a msg. once I see what I can do tomorrow. That temp fix sounds like it would work.

stew · Post by **stew** » Fri Dec 24, 2010 2:26 pm

This exact same thing was happening to me. After taking it apart and back together several times and still the rubbing sound. I then looked very close at the fan sheeve and saw that it had split and that my key was really bent. I replaced the fan sheeve and key and everything is running great now. See pictures of crack/split right where the key goes.

redrock · Post by **redrock** » Fri Dec 24, 2010 8:08 pm

I took the fan sheave off today. The cup set screw was loose but to be sure I used the Rube Goldberg approach installed a washer put some thread tightener on the set screw and the Mark V is running great. I am doing the alignment now then setting up to do some lathe work. Thanks for all the help. This forum is great very helpful group. Merry Christmas and Happy New Year to all.

JPG · Post by **JPG** » Fri Dec 24, 2010 8:12 pm

redrock wrote:I took the fan sheave off today. The cup set screw was loose but to be sure I used the Rube Goldberg approach installed a washer put some thread tightener on the set screw and the Mark V is running great. I am doing the alignment now then setting up to do some lathe work. Thanks for all the help. This forum is great very helpful group. Merry Christmas and Happy New Year to all.

With it up and running(quietly) I am sure yours will be!

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