Motor humming but going nowhere.

brin · Post by **brin** » Tue Apr 09, 2013 5:26 pm

I just bought a shopsmith 3 weeks ago - 1957 model - and have used it sparingly while I studied up and got myself familiarized with it. Last night I turned it on and just as it finished revving up there was a lound screech and everything came to a halt. I turned it off and when I flipped the switch again the motor tried to turn the headstalk and could not - only a hum. The two belts that I know how to get a look at look relatively new. I don't think it is the motor and I am a bit baffled as I look and try to figure out how to dig deeper into the machine to look at other stuff. Suggestions/advice would be most appreciated. Bart

JPG · Post by **JPG** » Tue Apr 09, 2013 5:39 pm

brin wrote:I just bought a shopsmith 3 weeks ago - 1957 model - and have used it sparingly while I studied up and got myself familiarized with it. Last night I turned it on and just as it finished revving up there was a lound screech and everything came to a halt. I turned it off and when I flipped the switch again the motor tried to turn the headstalk and could not - only a hum. The two belts that I know how to get a look at look relatively new. I don't think it is the motor and I am a bit baffled as I look and try to figure out how to dig deeper into the machine to look at other stuff. Suggestions/advice would be most appreciated. Bart

Try turning the quill shaft by hand. I predict it will not turn very far.

I also assume it is set to a high speed setting.

Remove the belt cover, then remove the belt from the motor.

Try to start the motor. If it runs, the problem is in the sheaves.

The belt is likely jammed in the idler pulley.

If the motor does not start up immediately, quickly kill the power.

OVER;)

brin · Post by **brin** » Tue Apr 09, 2013 6:12 pm

Thanks JPG

I'm learning as I go on this one. I dropped the bottom cover by removing the four sheet metal screws and got the drive belt off that way - don't know if that is the approved way or not. Reattached and the motor hummed perfectly without the drive belt attached and so that is not the problem. I know you are not supposed to turn the speed settings without the machine running, I believe mine was set at about "O" when it quit. What to do next and how to do it? - thanks in advance. Bart

brin · Post by **brin** » Tue Apr 09, 2013 7:42 pm

A ps to my last post:

I finally got a look at the idler pulley and the belt was indeed caught under several of the flanges on the logo side of the pulley. With a considerable amount of finangling I got it loose twice and everything seemed to turn over smoothly until I attempted to re-attach the belt to the motor pulley at which point it promptly jammed again. I was starting to mutter words under my breath which would not be fit for mixed company and so I have knocked off for the day and will try again tommorrow. Is there an easier way to gain access to that verdampt pulley for a re-attach? And how can you tell if there is a problem with the pulley itself? The belt looks almost new.

joshh · Post by **joshh** » Tue Apr 09, 2013 7:48 pm

Mount your sanding disc (if you have one) on the left side (tailstock) and turn that by hand towards you while you slowly dial the speed control back down to slow. Then I would strongly recommended lubing the hell out of the motor and control sheaves (and every 10 hours of use) There should be a small hole that allows oil in. I read before that older models are without the oil holes?

Then do a high speed adjustment:
http://www.shopsmith.net/forums/showthr ... adjustment

joshh · Post by **joshh** » Tue Apr 09, 2013 8:01 pm

Ah, posted while I was typing. Don't get discouraged, these machines are very simple once you know all the ins and outs. The front motor sheave should slide forward (it takes a bit of force to compress the spring, don't remove the snap ring...just pull on the sheave) but don't pinch your fingers

The sheave should slide smoothly in and out. The oil hole for the motor sheave is on the shaft hiding under the spring. While you are at it, check the back of the speed control dial. Make sure the worm gear and threads look ok and that the gear sits in the center of the porkchop (that's slang for quadrant). The porkchop is a high fail item from lack of maintenance.

Edit: This picture may help also, it helped me "see" how everything fits together

[ATTACH]20914[/ATTACH]

JPG · Post by **JPG** » Tue Apr 09, 2013 9:16 pm

There are three major pieces to the headstock.

The steel belt cover on the left end of the headstock. It is merely that, a cover.

The motor pan is attached below the headstock casting and contains the motor and power cord strain relief.

The third and major part is the casting which contains all the drive and speed control stuff and unfortunately also the power switch.

'Normal' disassembly starts with the belt cover. It is secured with two(8 on older models) screws. If the two shafts have hubs attached, they must also be removed to get the belt cover off.

The motor pan(and motor) is removed by first setting the speed control to fast(manually rotating the quill shaft if necessary). This allows easier removal of the belt from the motor pulley. Last, the wires must be removed from the power switch.

FWIW, removal of the speed control also requires setting the speed control to 'fast'.

If you have not already done so, do remove the belt cover. It will make many things more accessible.

When the belt is NOT on the motor pulley, the speed control may be adjusted with no concern if the shafts are turning. Just make sure the belt does not get caught between the idler shaft sheaves.

I would oil the control sheave with it set to fast. Oiling the floating sheave on the motor shaft is easier with the belt off.

If you do pull the floating sheave out manually, do make sure you release it slowly so it does not slam it into the fan sheave.

A lot to absorb at one sitting, but it should prevent making things worse.

If your belt cover only has two screws, the sheaves should have oil holes. Do not be stingy with the oil. It probably has not seen much in the past. SS says a few drops, Our resident guru Bill Mayo says at least 10 drops. Lack of oiling is the single most detrimental thing you can do, and unfortunately most do not get that oil every 10 running hours. Those that do, seem to run forever(half a century at least). Any excess oil will be thrown out into the interior of the casting. A good step is to raise it to vertical after oiling so that the bearing in the end of the idler sheave hub will get oiled. It is a high failure rate item due to lack of lubrication.

As for the high speed adjustment, that can be done 'last' after it is reassembled.

And last, do check the belt width. A 'new' one will be wider than 1/2" across the outer surface. One less that 7/16" should be replaced(narrow belts have a propensity for getting stuck between the sheaves!!!!!;)).

Last + 1, With the smaller 3/4 hp motor, it is recommended that the speed be returned to slow before powering down. This greatly reduces the time the motor takes getting up to operating speed. Experience will indicate the relative importance of that to your situation(power source etc.). It is a good policy to return the speed control to slow when either shutting it down at the end of a 'session', or prior to moving it.

Whew!!

brin · Post by **brin** » Tue Apr 09, 2013 11:15 pm

Thanks a lot guys, out here in the middle of Wyoming where I am probably the only one for miles around with one of these machines help can be hard to come by! I did find a video that said the drive belt should mike out at least .50 wide and mine is a .511 so that is not the issue. You guys gave me a lot of information and tomorrow will see me back out in the shop with hope in my heart. Thanks again and I will post the results. Bart

dusty · Post by **dusty** » Wed Apr 10, 2013 7:37 am

If, for any reason, the belt gets too far down into the groove between the sheaves it can get stuck there and the motor will not be able to turn it. This can be a persistent problem when the belt gets worn to the point where it is too narrow. Yours is not too narrow so the problem is caused by something else.

I would guess "lack of lubrication". You cannot over oil so lubricate those shafts and then go for it again.

When I have this sort of issue, I install the sanding disk on the main shaft and use it to turn the shaft after reinstalling the belt. Once you get the shafts turning, the belt will normally walk itself into position between the sheaves.

You should be set at the high speed setting when installing (or removing) the belt. At the high speed setting, the shafts should not be difficult to turn. It gets noticeably harder to turn the shafts by hand at low speed.

Good luck with this.

sawmill · Post by **sawmill** » Wed Apr 10, 2013 8:17 am

If you still have the belt off lay it on a flat surface and see if one side is stretched. When I got my ShopSmith the belt was stuck in the sheaves and after I fixed it, it would run for a while and then get stuck again. When I layed it on a flat surface one side of the belt was streached and causing the problem. A new belt fixed it