Mark V grinding noise by motor pulley.

Forum for Maintenance and Repair topics. Feel free to ask questions or contribute.

Moderators: HopefulSSer, admin

chabear
Bronze Member
Posts: 2
Joined: Fri Aug 10, 2018 10:34 am

Mark V grinding noise by motor pulley.

Post by chabear »

Just got my first Shopsmith from craigslist. It's a Mark V according to manual. I got a good price because the thing was making a grinding noise. I figured it worth it to try and fix. So here's what I did...
The lower pulley was making a metal on metal sort-of grinding, screeching noise. Not super loud but enough to notice something wrong with it. When hand turned (no power) same thing, like the pulley was hitting something?
So, I removed the drive belt (the lower v-belt, not the flat one higher up) and tested power to motor, and the motor sounded flawless. Smooth and no noise. Sounds very good surprisingly.
I inspected the belt and it is a little worn and roughed up.
So, the question is, I was gonna buy a new belt, assuming it needs one at this point in it's life. I just dont wanna install it and ruin it only to find it wasn't the belt.
Is there anything I should be checking as to why it was making that noise? The upper assembly seems to be working right...no noises, smooth turning. And motor when no belt is on sounds great. just when the belt was on...
Also, if you can, jut explain to me how the pulley system works? Im guessing the spring-loaded pulleys add tension to control speed or power to accessories?
I must sound like a newbie. lol. so looking forward to learning more about how these machines work. I'll be honest, I got it cause I "needed" (i.e wanted) a lathe, but half of me wanted it because its just so cool looking.
Ophbalance
Bronze Member
Posts: 6
Joined: Tue Aug 07, 2018 11:23 am

Re: Mark V grinding noise by motor pulley.

Post by Ophbalance »

First posting, and I plan to detail this later on boards, but I just restored my shopsmith last week and it had similar sounds from the same area. I had to pull the sheaves off the motor shaft as they were bound together due to sitting for so long. I also had to file the key that keeps them in place just a hair as that seemed to be what both were ultimately glued to. It wouldn't be a horrible idea to pull apart the head stock and clean all the parts and lube it all back up.
User avatar
beeg
Platinum Member
Posts: 4791
Joined: Sun Oct 14, 2007 2:33 pm
Location: St. Louis,Mo.

Re: Mark V grinding noise by motor pulley.

Post by beeg »

More that likely the fan sheave has moved and rubbing. There's a set screw that holds the fan sheave, you can access it from the bottom of the headstock. Move the sheave about 1/16th" away from the motor.
SS 500(09/1980), DC3300, jointer, bandsaw, belt sander, Strip Sander, drum sanders,molder, dado, biscuit joiner, universal lathe tool rest, Oneway talon chuck, router bits & chucks and a De Walt 735 planer,a #5,#6, block planes. ALL in a 100 square foot shop.
.
.

Bob
chabear
Bronze Member
Posts: 2
Joined: Fri Aug 10, 2018 10:34 am

Re: Mark V grinding noise by motor pulley.

Post by chabear »

Thanks I’ll try those ideas and let you know how I make out. Thanks for your time in replying. Appreciate all the advice.
User avatar
everettdavis
Platinum Member
Posts: 2162
Joined: Thu Jul 17, 2014 11:49 am
Location: Lubbock, TX

Re: Mark V grinding noise by motor pulley.

Post by everettdavis »

Take the fan pulley completely off while you are in there. Behind it there is (or likely should be) a slip on spacer between it and the motor. It can wear and reduce the space to keep the back from scraping.

Take a look at the setscrew indentation where it locks down and clean it up to smooth it out. That will help you put it back and get it secured in the right place.

Look at some of the exploded parts listings for more info.

Everett
Ophbalance
Bronze Member
Posts: 6
Joined: Tue Aug 07, 2018 11:23 am

Re: Mark V grinding noise by motor pulley.

Post by Ophbalance »

So something I missed entirely first go round, the access to the set for the motor sheave is found at the very bottom of the motor tray. And I cannot recall the size on it but it wasn't the same as the ones to disconnect all the tools for the SS. You'll need to either remove the motor from the tray OR find a very long allen wrench that matches.
User avatar
everettdavis
Platinum Member
Posts: 2162
Joined: Thu Jul 17, 2014 11:49 am
Location: Lubbock, TX

Re: Mark V grinding noise by motor pulley.

Post by everettdavis »

everettdavis wrote:Take the fan pulley completely off while you are in there. Behind it there is (or likely should be) a slip on spacer between it and the motor. It can wear and reduce the space to keep the back from scraping.

Take a look at the setscrew indentation where it locks down and clean it up to smooth it out. That will help you put it back and get it secured in the right place.

Look at some of the exploded parts listings for more info.

Everett
This might help
Spacer Motor to Fan Sheave.png
Spacer Motor to Fan Sheave.png (649.29 KiB) Viewed 16981 times
Everett
User avatar
JPG
Platinum Member
Posts: 34608
Joined: Wed Dec 10, 2008 7:42 pm
Location: Lexington, Ky (TAMECAT territory)

Re: Mark V grinding noise by motor pulley.

Post by JPG »

Assuming it is the fan sheave rubbing, the spacer has a habit of embedding itself into the softer sheave. My suggestion(cheaper than a new fan sheave) is to slip a retaining ring between the spacer and the sheave.

As for how it works, the control process begins with the speed control knob. Rotating the knob causes the quadrant gear(porkchop) to move the control sheave towards/away from the idler sheave. Those two sheaves are the halves of the idler pulley. By moving the control sheave, the effective working diameter of the idler puller is changed. When that occurs, the motor belt tension is changed. The pulley on the motor shaft consists of the fan sheave(fixed) and the floating sheave(moves). When the belt tension changes due to the control sheave moving, the spring loaded floating sheave moves to compensate and maintain belt tension(both to increase tension when the control sheave opens the idler pulley AND to decrease it when the control sheave closes the idler pulley). The movable sheaves(control/floating) move in opposite direction(one opens as the other closes and vice versa).

The movement of the control knob towards slow causes the control sheave to squeeze the belt. The floating sheave must move to open the motor pulley in response. If the floating sheave is slow to respond(gunked up) or the control knob is adjusted too rapidly, the quadrant gear can become damaged. That is the reason for the "DO NOT ADJUST SPEED UNLESS MOTOR IS RUNNING" warning. Also IF the floating sheave is slow to respond when adjusting the control knob towards fast, the anti-rotation clip attached to the bearing in the end of the control sheave may get pulled apart.

Moral: keep both movable sheaves well lubricated!!!
╔═══╗
╟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
User avatar
everettdavis
Platinum Member
Posts: 2162
Joined: Thu Jul 17, 2014 11:49 am
Location: Lubbock, TX

Re: Mark V grinding noise by motor pulley.

Post by everettdavis »

In addition to JPG's explanation above this may help

Everett
How The Speed Control Dial Manipulates The Control Sheave.png
How The Speed Control Dial Manipulates The Control Sheave.png (192.62 KiB) Viewed 16863 times
the fan sheave rubbing motor plate repair.pdf
(118.2 KiB) Downloaded 1937 times
User avatar
davepk13
Gold Member
Posts: 23
Joined: Thu Jul 24, 2008 12:06 am
Location: Elk River, Minnesota

Re: Mark V grinding noise by motor pulley.

Post by davepk13 »

Wow! That is very helpful Everett. Thank you.
Post Reply