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Speed changer handle came off...now what?

Posted: Sun Mar 21, 2010 4:19 pm
by jalex7672
Hey guys! I need some serious help here. The other night I was using my Mark 5, and when I went to turn down the speed to turn it off, the speed changer handle came off in my hand. I noticed that the set-screw had backed out. But when I reinstalled it, I'm noticing the speeds dont sound right. Thought I had it set to slow. Took handle back off, and was able to turn faceplate 360 degrees. Noticed how the spring on backside of changer seems to set at "stops" on back of faceplate. I dont know if these are the "slow" and "fast" speed stops, or what?
Re-attached handle temporarily, and turned speed down as far as I could while watching through the hole to see when I got to end of "porkchop" threads(at least as far as I could turn it without forcing it). I reset faceplate to the "slow" stop. But when I turn up the speed to "fast", it seems ok, but I am able to go beyond "fast". I didnt go much beyond "fast", but even going no farther than I did, it was screaming.

I'm on dial-up internet, so I cant watch any videos on how to correct this.

Could someone please tell me what I need to do to correct this problem and walk me through it, so to speak? I know the book says 700-5200 RPM, but how do you know where to reset the speed changer dial to ensure those RPM's?

Any help is greatly appreciated! And Thank You in advance!

Posted: Sun Mar 21, 2010 4:33 pm
by beeg

Thanks Beeg!

Posted: Sun Mar 21, 2010 7:45 pm
by jalex7672
Thanks Beeg! I'm printing these links out now and taking them to the shop. The one link from Nick Engler sounds like the one I might need. I'll let you know what happens.
Thanks again!

Posted: Sun Mar 21, 2010 7:51 pm
by JPG

THIS one is the one you need!!! The others are 'background' info. This one is specific to your described 'problem'.

Posted: Sun Mar 21, 2010 8:11 pm
by JPG
Here is another 'procedure'.

[ATTACH]8224[/ATTACH]

Not enough threads!

Posted: Sun Mar 21, 2010 9:16 pm
by jalex7672
I followed Nick's instructions in the link, as well as JPG's PDF link.
What I'm running into now is that the set screw is only held by about 1/4 thread of the nut and the nut cannot be tightened, when the belt is 1/8" from the rim of the drive pulley. If I set the belt 1/16" from rim of drive pulley I can tighten the nut, but I'm afraid it isnt being held by much thread. The set screw is 1" long, and its almost like it could stand to be 1/4" longer.
Any idea's as to what direction to take now?

Dont know how all this happened. Before the control handle came off, this thing was running great!

Posted: Mon Mar 22, 2010 1:33 am
by JPG
jalex7672 wrote:I followed Nick's instructions in the link, as well as JPG's PDF link.
What I'm running into now is that the set screw is only held by about 1/4 thread of the nut and the nut cannot be tightened, when the belt is 1/8" from the rim of the drive pulley. If I set the belt 1/16" from rim of drive pulley I can tighten the nut, but I'm afraid it isnt being held by much thread. The set screw is 1" long, and its almost like it could stand to be 1/4" longer.
Any idea's as to what direction to take now?

Dont know how all this happened. Before the control handle came off, this thing was running great!



Back the set screw out so that the end is flush with the top of the nut, and tighten. Rotate the output shaft by hand(sand disc helps) and adjust the speed up until the quadrant hits the set screw stop. Look from the 'medallion' hole and verify the control sheave is clearing the quadrant(if it isn't, it will let you know(clanging noise). Look at the position of the belt on the motor pulley. If it is reasonably near the outer rim of the pulley, button er up, set the dial to fast and get on with yer life.

All that assumes the sheaves(control(idler shaft) and floating(motor shaft)) are well lubricated and moving freely. If they BOTH have not been oiled lately, do so before doing the stuff above.

If the motor belt is worn, the situation you are describing can happen. The belt is slightly over 1/2" wide at the top when new. As Nick said, if it is worn too small, replace it. If you do not, the belt is susceptible to jamming in the bottom of the control sheave. That is a scene you do not be a player in.

Posted: Mon Mar 22, 2010 2:43 pm
by Ron309753
Jalex,

Make sure the nut on the setscrew is a jam nut and not a regular nut. On my greenie I discovered that someone had replaced the jam nut with a regular nut. I couldn't get the speed right until I replaced it.

Sincerely,

Ron309753

Posted: Mon Mar 22, 2010 7:40 pm
by dusty
Ron309753 wrote:Jalex,

Make sure the nut on the setscrew is a jam nut and not a regular nut. On my greenie I discovered that someone had replaced the jam nut with a regular nut. I couldn't get the speed right until I replaced it.

Sincerely,

Ron309753
A jam nut being "thinner" than a regular nut - or what?

Posted: Mon Mar 22, 2010 8:38 pm
by fjimp
dusty wrote:A jam nut being "thinner" than a regular nut - or what?
Am I correct that a jam nut has a liner that keeps it from coming loose or tightening itself?:confused: