Speed changer handle came off...now what?

[jalex7672]

Did what JPG suggested, to the letter. The belt is riding high(about 1/32", maybe a tad more) above the rim of the drive pulley. The belt was hard to measure, as the edge closest to the motor is slightly "fuzzed", but it looks to measure 15/32". Does the belt riding so high on the pulley after making that adjustment mean the belt is getting near replacement?
Also, when adjusted as JPG suggested, the RPM's seem a little too high on the Fast setting, but maybe its just me.

Let me know guys, I sure appreciate the help!

[JPG]

Did what JPG suggested, to the letter. The belt is riding high(about 1/32", maybe a tad more) above the rim of the drive pulley. The belt was hard to measure, as the edge closest to the motor is slightly "fuzzed", but it looks to measure 15/32". Does the belt riding so high on the pulley after making that adjustment mean the belt is getting near replacement?
Also, when adjusted as JPG suggested, the RPM's seem a little too high on the Fast setting, but maybe its just me.

Let me know guys, I sure appreciate the help!

Something is not understood here!

Lets settle the jam nut questions first: The nut is about 3/16" thick. It tightens down on a spacer that is slightly thicker that the gear that revolves on it. It is not a nylon 'lock nut'.

The screw is 1 1/8" long. when adjusted even with the top on the nut, it extends almost 5/8" out the back.

If the belt is riding 1/32" ABOVE the outer rim of the motor pulley, it WILL run fast!!!

If the belt is riding 1/32" above the outer rim of the motor pulley, it must be riding low in the control/idler pulley.

This would mean the control sheave is further out towards the end of the idler shaft. Yet it is not hitting the porkchop??? This may mean the porkchop is too far away from it???

We are assuming the correct belt is installed. A too long belt could cause this. A missing button on the end of the control sheave might cause this.

Howsomever, this scene started with the crank dial 'falling' off. We have to assume this was caused by a loose setscrew.



In any event, it needs to not be run with the belt running above the outside rim of the motor pulley.

We need to check what is going on with the control sheave and porkchop when approaching high speed.

Looking in from the medallion access hole, verify the presence of the button and clip on the end of the control sheave, and if it aligns correctly to the porkchop.

At this point a picture would help ascertain just what is going on.


I have covered a lot of ground here, but it was necessary to help get everyone on the same page.

The bottom line is, something is amiss, We need to identify what!

[dusty]

Something is not understood here!

Lets settle the jam nut questions first: The nut is about 3/16" thick. It tightens down on a spacer that is slightly thicker that the gear that revolves on it. It is not a nylon 'lock nut'.
...........................

The question (restated) was what makes a nut a jam nut. If it is thinner than a typical nut (3/16"), is it then a "jam nut"?

If it is nylon, is it therefore not a "jam nut"?:)

[dusty]

Did what JPG suggested, to the letter. The belt is riding high(about 1/32", maybe a tad more) above the rim of the drive pulley. The belt was hard to measure, as the edge closest to the motor is slightly "fuzzed", but it looks to measure 15/32". Does the belt riding so high on the pulley after making that adjustment mean the belt is getting near replacement?
Also, when adjusted as JPG suggested, the RPM's seem a little too high on the Fast setting, but maybe its just me.

Let me know guys, I sure appreciate the help!

I fuzzy belt that does not seem to ride properly in the sheaves, on a machine with a speed dial setting problem, sounds a lot like "time for a new belt" to me.

[Ron309753]

A jam nut is a low profile type of nut, typically about half as thick as a standard nut. It is commonly used as a type of "locknut", where it is "jammed" up against a standard nut to lock the two in place. It does not lock by itself like a nylon lock nut.
It is also used in situations where a standard nut would not fit.

Sincerely,

Ron

Jalex,

I live about 30 miles north of Columbus. If you can't get this fixed, I am willing to make a trip to see if I can help.

[JPG]

A jam nut is a low profile type of nut, typically about half as thick as a standard nut. It is commonly used as a type of "locknut", where it is "jammed" up against a standard nut to lock the two in place. It does not lock by itself like a nylon lock nut.
It is also used in situations where a standard nut would not fit.

Sincerely,

Ron

Jalex,

I live about 30 miles north of Columbus. If you can't get this fixed, I am willing to make a trip to see if I can help.

OR, As I believe is correct for this scenario, What makes it a 'jam' nut is how it is used, not due to any of its physical properties. In this case, the nut is tightened against an opposing set of threads(the casting) so as to lock the screw in position.

[jalex7672]

Hey guys! I got the problem fixed!
Several things helped out, the help from all of you first and foremost!
Remembered that where I work, we had recently purchased a laser optical tachometer. Brought it home this evening, set it up, and was reading 6500 RPM's!!! Like I said, it was screaming. Dialed it down, removed the set screw stop for the Fast speed adjustment. Something JPG said made my mental gears start turning... the length of the set screw being 1 1/8". Mine measured 1". Went to local Ace Hardware, knowing I wouldnt find a set screw that long, but came up with something just as good. Found a button-head screw that is 1/4-20 thread same as the set screw, 1" long. It also takes a 5/32" allen wrench. Brought it home, screwed it in and was reading about 1450 RPM's, so carefully ground down the tip of the screw and re-installed, ran up to Fast, and re-tached the arbor. Re-ground length as needed until I got down to 5205 RPM's with it screwed all the way in and torqued. This fix eliminated the set screw as well as the jam nut, as the button head seats on the bushing under the gear, and also prevents the gear from coming off. And you can use the standard 5/32" allen wrench to install and remove it. My belt is riding 3/32 below the rim of the drive variator pulley.
I will take some pics and try to post on here.
The belt "fuzzing" on the motor side still has me concerned a bit, and I do feel I should order a new belt. The fuzzing isnt terribly bad, but I do feel I need to get one coming.
I hear the belts from Shopsmith are taking forever to ship. Does anyone know a source? I see ads on Ebay for Shopsmith belts... can they be trusted?
By the way, Thank for the offer of driving down here from Columbus, Ron! Its sure nice to know there are such good people on here who are so willing to help!
Oh, and to answer a previous question, I had thoroughly cleaned and lubed the entire machine approximately 1 hour running time prior to all this.
Thanks again for all your help guys!:)

[Ron309753]

Jalex,

See Bill Mayo's post in this thread:
http://www.shopsmith.net/forums/showthr ... Powertwist

I think you can get Powertwist belt sections at the WoodCraft store in Columbus. You can also order them online from numerous sources.

Sincerely,

Ron309753

[JPG]

Hey guys! I got the problem fixed!
Several things helped out, the help from all of you first and foremost!
Remembered that where I work, we had recently purchased a laser optical tachometer. Brought it home this evening, set it up, and was reading 6500 RPM's!!! Like I said, it was screaming. Dialed it down, removed the set screw stop for the Fast speed adjustment. Something JPG said made my mental gears start turning... the length of the set screw being 1 1/8". Mine measured 1". Went to local Ace Hardware, knowing I wouldnt find a set screw that long, but came up with something just as good. Found a button-head screw that is 1/4-20 thread same as the set screw, 1" long. It also takes a 5/32" allen wrench. Brought it home, screwed it in and was reading about 1450 RPM's, so carefully ground down the tip of the screw and re-installed, ran up to Fast, and re-tached the arbor. Re-ground length as needed until I got down to 5205 RPM's with it screwed all the way in and torqued. This fix eliminated the set screw as well as the jam nut, as the button head seats on the bushing under the gear, and also prevents the gear from coming off. And you can use the standard 5/32" allen wrench to install and remove it. My belt is riding 3/32 below the rim of the drive variator pulley.
I will take some pics and try to post on here.
The belt "fuzzing" on the motor side still has me concerned a bit, and I do feel I should order a new belt. The fuzzing isnt terribly bad, but I do feel I need to get one coming.
I hear the belts from Shopsmith are taking forever to ship. Does anyone know a source? I see ads on Ebay for Shopsmith belts... can they be trusted?
By the way, Thank for the offer of driving down here from Columbus, Ron! Its sure nice to know there are such good people on here who are so willing to help!
Oh, and to answer a previous question, I had thoroughly cleaned and lubed the entire machine approximately 1 hour running time prior to all this.
Thanks again for all your help guys!:)

Wonder who installed a 'shorter screw'?

Glad the 'mystery' is solved!!!!! It had me scratching my head!!

BTW the part number is 51398905. You oughta get one the next time you order from ss. ($0.80)

[dusty]

OR, As I believe is correct for this scenario, What makes it a 'jam' nut is how it is used, not due to any of its physical properties. In this case, the nut is tightened against an opposing set of threads(the casting) so as to lock the screw in position.

??An opposing set of threads?? Are the threads in the casting different than the threads in the nut?

Does "opposing" mean left hand versus right hand threads?