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motor slow down
Posted: Thu Apr 05, 2018 7:09 pm
by wayy999
Hi I have a mark 5 1 1/8 amp model and when I go above "r-s" on the speed adjustment it starts slowing down and stops at "z " , belt looking ok and did oil where the manual said to. any ideas? thanks
Re: motor slow down
Posted: Thu Apr 05, 2018 9:01 pm
by JPG
Did you oil the floating sheave on the motor shaft?
Take the belt cover off. Observe the motor pulley/floating sheave.
I am guessing it stops moving above "R" and the belt slips.
Oil it* with 'vigor'. Make sure it will slide all the way.
*Shaft as well as the dinky hole.
Re: motor slow down
Posted: Fri Apr 06, 2018 5:43 am
by dusty
JPG wrote:Did you oil the floating sheave on the motor shaft?
Take the belt cover off. Observe the motor pulley/floating sheave.
I am guessing it stops moving above "R" and the belt slips.
Oil it* with 'vigor'. Make sure it will slide all the way.
*Shaft as well as the dinky hole.
Don't oil "it". Oil the sheave.
Re: motor slow down
Posted: Fri Apr 06, 2018 1:30 pm
by JPG
dusty wrote:JPG wrote:Did you oil the floating sheave on the motor shaft?
Take the belt cover off. Observe the motor pulley/floating sheave.
I am guessing it stops moving above "R" and the belt slips.
Oil it* with 'vigor'. Make sure it will slide all the way.
*Shaft as well as the dinky hole.
Don't oil "it". Oil the sheave.
"IT" is the space between the shaft and the sheave that the sheave slides on.
I did not state that clearly above.
Re: motor slow down
Posted: Sat Apr 07, 2018 6:52 pm
by wayy999
Hi Rusty
I looked at the motor with the cover off and see that the upper (control sheave) opens up way wide to the point the belt is loose. so it is no longer turning the lower one. so ideas on how to fix? thanks Wayne
Re: motor slow down
Posted: Sat Apr 07, 2018 8:32 pm
by JPG
wayy999 wrote:Hi Rusty
I looked at the motor with the cover off and see that the upper (control sheave) opens up way wide to the point the belt is loose. so it is no longer turning the lower one. so ideas on how to fix? thanks Wayne
For starters, the lower pulley(motor shaft) drives the belt.
The upper control sheave alters the effective diameter(opens/closes) of the idler pulley.
The lower floating sheave adjusts the effective belt tension.
Thus at high speed, the upper control sheave opens and the lower floating sheave must close(belt moves to the outer circumference)to maintain tension. Since your belt is slipping at high speed, I suspect from your description that the floating sheave is NOT closing sufficiently to maintain tension.
Re: motor slow down
Posted: Sat Apr 07, 2018 10:19 pm
by wayy999
yes so what can I do to close the upper sheave? or stop or adjust so it does not open so much at the higher speeds?
Re: motor slow down
Posted: Sat Apr 07, 2018 10:52 pm
by JPG
wayy999 wrote:yes so what can I do to close the upper sheave? or stop or adjust so it does not open so much at the higher speeds?
Your problem is not the upper sheave opening too much.
It is the lower sheave not closing enough.
It is called the control sheave because it is what is adjusted to control speed. The floating sheave responds to that so as to maintain belt tension.
Take a look at the lower pulley. At 'fast' the belt should ride near the outer rim.
If this is not making sense, perhaps some pix of what is occurring would help.
Re: motor slow down
Posted: Sun Apr 08, 2018 6:54 pm
by wayy999
Here are pics
Re: motor slow down
Posted: Sun Apr 08, 2018 6:56 pm
by wayy999
JPG wrote:wayy999 wrote:yes so what can I do to close the upper sheave? or stop or adjust so it does not open so much at the higher speeds?
Your problem is not the upper sheave opening too much.
It is the lower sheave not closing enough.
It is called the control sheave because it is what is adjusted to control speed. The floating sheave responds to that so as to maintain belt tension.
Take a look at the lower pulley. At 'fast' the belt should ride near the outer rim.
If this is not making sense, perhaps some pix of what is occurring would help.