Anyone run across this problem before? Or have any ideas as to what the problem is.
The moveable sheave on the idle arm sticks when it is fully engaged with the fixed sheave. When it is pulled away, it moves very smoothly.
This allows you to go up in speed very smoothly and then come down smoothly, but then it sticks and won't come apart and you can't go back up again. This causes the retaining loop to come out of the roller pin and then you cannot change speed again.
I have taken the sheave off and cleaned and inspected both the fixed and moveable sheaves. I do not see any rough spots that might be catching, after cleaning, oiling and replacing, it continues to stick.
Any help would be appreciated.
Jeff
Sticky Sheave Question
Moderator: admin
-
dusty
- Platinum Member
- Posts: 21481
- Joined: Wed Nov 22, 2006 6:52 am
- Location: Tucson (Wildcat Country), Arizona
Sticky Sheave
When I first read your post my first reaction was "needs to lubricate the sheave" but your description may indicate something with which I have NO experience.
I will be following this thread very closely. Actually, these guys will have you out of trouble and me better educated in no time.
Again, I welcome you to the group.
I will be following this thread very closely. Actually, these guys will have you out of trouble and me better educated in no time.
Again, I welcome you to the group.
Jeff, it sounds like the assembly that's giving you fits is the Idler Shaft Assembly. Am I right? I reached into the innards of one of the Mark Vs sitting around here and yanked this free:
[ATTACH]153[/ATTACH]
The assembly consists of the idler shaft, idler sheave, control sheave, and some other little parts hardly worth a mention.
[ATTACH]154[/ATTACH]
Slide the control sheave to one side and you'll reveal a long 1/8" x 1/8" key. On the explode in the parts list, this is jokingly referred to as the "short" key just to confuse people who know how to read and write the English language. (If you're an engineer, you'll probably think this label is perfectly logical.) The short key keeps the idler sheave and the control sheave aligned, and it's most probable that here is where your problem lies.
Without actually having my hands on your machine, my guess is that over the years a good deal of ackempunky has accumulated on the idler shaft, especially around the short key. ("Ackempunky," by the way, is a technical term for the black, sticky stuff that appears spontaneously in woodworking machinery wherever craftsmen apply too much oil. The extra oil mixes with sawdust and dirt and instead of providing lubrication, it generates frustration.) Because of the way the control sheave "floats" on the shaft, it has probably plowed most of this ackempunky up against the idler sheave. In your case, the assembly has about all the ackempunky it can accomodate and now the control sheave becomes stuck in the goo whenever it gets too close to the idler sheave.
Another (but less likely) diagnosis is that your machine has been the victim of a "hard stop" sometime in the past -- someone jammed something into the blade while the shafts were all running hell-for-certain and everything came to a crashing halt. In that crash, the portion of the key under the idler sheave bent slightly and the two sheaves are now ever-so-slightly misaligned. If they come too close, the parts jam together instead of meshing smoothly.
[ATTACH]155[/ATTACH]
In either case, the fix is to take the assembly completely apart. Don't just remove the control sheave, but disassemble the idler shaft, idler sheave, control sheave, and short key. Inspect the key. It will have a little bend on the end where it engages a depression in the idler shaft; this is normal. But if it is bent sideways or "pinched," then it should be replaced. Otherwise, clean all the parts with mineral spirits or naptha until they are free of ackempunky. I suggest you also polish the surfaces with some black Scotchbrite or some 1200-grit wet/dry sandpaper. Apply a light film of oil and reassemble. My prediction is that all your worries will disappear -- your wife will smile, your children will listen, the dog will stop peeing on the carpet, and the control sheave will slide smoothly. Best of all, you'll be able to get back to work on those flutes.
With all good wishes,
[ATTACH]153[/ATTACH]
The assembly consists of the idler shaft, idler sheave, control sheave, and some other little parts hardly worth a mention.
[ATTACH]154[/ATTACH]
Slide the control sheave to one side and you'll reveal a long 1/8" x 1/8" key. On the explode in the parts list, this is jokingly referred to as the "short" key just to confuse people who know how to read and write the English language. (If you're an engineer, you'll probably think this label is perfectly logical.) The short key keeps the idler sheave and the control sheave aligned, and it's most probable that here is where your problem lies.
Without actually having my hands on your machine, my guess is that over the years a good deal of ackempunky has accumulated on the idler shaft, especially around the short key. ("Ackempunky," by the way, is a technical term for the black, sticky stuff that appears spontaneously in woodworking machinery wherever craftsmen apply too much oil. The extra oil mixes with sawdust and dirt and instead of providing lubrication, it generates frustration.) Because of the way the control sheave "floats" on the shaft, it has probably plowed most of this ackempunky up against the idler sheave. In your case, the assembly has about all the ackempunky it can accomodate and now the control sheave becomes stuck in the goo whenever it gets too close to the idler sheave.
Another (but less likely) diagnosis is that your machine has been the victim of a "hard stop" sometime in the past -- someone jammed something into the blade while the shafts were all running hell-for-certain and everything came to a crashing halt. In that crash, the portion of the key under the idler sheave bent slightly and the two sheaves are now ever-so-slightly misaligned. If they come too close, the parts jam together instead of meshing smoothly.
[ATTACH]155[/ATTACH]
In either case, the fix is to take the assembly completely apart. Don't just remove the control sheave, but disassemble the idler shaft, idler sheave, control sheave, and short key. Inspect the key. It will have a little bend on the end where it engages a depression in the idler shaft; this is normal. But if it is bent sideways or "pinched," then it should be replaced. Otherwise, clean all the parts with mineral spirits or naptha until they are free of ackempunky. I suggest you also polish the surfaces with some black Scotchbrite or some 1200-grit wet/dry sandpaper. Apply a light film of oil and reassemble. My prediction is that all your worries will disappear -- your wife will smile, your children will listen, the dog will stop peeing on the carpet, and the control sheave will slide smoothly. Best of all, you'll be able to get back to work on those flutes.
With all good wishes,
- Attachments
-
- Idler Shaft 1a.JPG (62.55 KiB) Viewed 36372 times
-
- Idler Shaft 2a.JPG (57.32 KiB) Viewed 36353 times
-
- Idler Shaft 3a.JPG (68.25 KiB) Viewed 36350 times
Nick Engler
http://www.workshopcompanion.com
http://www.workshopcompanion.com
Wow, Thanks Nick for that detailed description. I have pretty much cleaned all the gunk out (with it in place - this is very difficult) So I don't think it is debris causing the sticking. Everything feels smooth and I don't see anything binding. I can't see the short key as it is inside when the binding occurs. I need to take it apart and check the short key. I think that is probably the problem. I found the directions to replace the poly v belt so I will take it apart today and check it out. I went ahead and added the key to my current order so if I need a new one it will be here pronto.
Thanks.
JeffG
Thanks.
JeffG
Nick,
If you are still with me. I took the whole thing apart like your photo's above. The short key looks fine and the with only the shaft and the control sheave (no key) it still sticks shen it gets about 1 cm from the transverse milled line in the shaft. I can push it down all the way, but it is hard to get it back off. I tried using a fine wet and dry with oil on the inside surface of the control sheave and 600 wet and dry on the shaft. Nothing seems bent and the surfaces seem smooth. How strange.
JeffG
If you are still with me. I took the whole thing apart like your photo's above. The short key looks fine and the with only the shaft and the control sheave (no key) it still sticks shen it gets about 1 cm from the transverse milled line in the shaft. I can push it down all the way, but it is hard to get it back off. I tried using a fine wet and dry with oil on the inside surface of the control sheave and 600 wet and dry on the shaft. Nothing seems bent and the surfaces seem smooth. How strange.
JeffG
When a Shopsmith is run at high speeds continuously and over a long period of time, there is a great deal of torsion on the control sheaves, short key, and the keyway in the idler shaft that holds the short key. At high speeds, the control sheave is not fully supported by the idler shaft. It hangs off the end and the pressure of the V-belt puts sideways loads on the key, keyway, and the inside surfaces of the control sheave. As these surfaces wear, the control sheave will creep out of alignment with the idler sheave and eventually the two will jam together. I suppose it's also possible that the hub of the control sheave will wear and distort under unusually long and frequent high-speed sessions. If this happened, the hub might jam on the idler shaft no matter how the sheaves were aligned.
In either case, the worn parts are beyond repair. If the jamming is the result of a worn or pinched key, you could just replace the key. But it sounds like the keyway is damaged or the sheaves are worn, poosibly because the machine has been subjected to some serious abuse. For this reason, it would be a good idea to replace the whole assembly. I suggest you order a new idler shaft assembly with both sheaves installed from Customer Service.
Sorry about that, but if you have brought me this ailing idler shaft a few years sooner, I might have been able to do something. I don't often lose a patient. Since it's your Mark V, I think you should notify the next of kin.
With all good wishes,
In either case, the worn parts are beyond repair. If the jamming is the result of a worn or pinched key, you could just replace the key. But it sounds like the keyway is damaged or the sheaves are worn, poosibly because the machine has been subjected to some serious abuse. For this reason, it would be a good idea to replace the whole assembly. I suggest you order a new idler shaft assembly with both sheaves installed from Customer Service.
Sorry about that, but if you have brought me this ailing idler shaft a few years sooner, I might have been able to do something. I don't often lose a patient. Since it's your Mark V, I think you should notify the next of kin.
With all good wishes,
Nick Engler
http://www.workshopcompanion.com
http://www.workshopcompanion.com
To find out where it's sticking, you could put some kind of thin colored coating, like chalk or liquid paper inside the pulleys, then reassemble them and push it all the way onto the shaft and then back off. Look for where the coating is removed. That should show where it is sticking. In theory, that should work even though I've never tried it myself. 
If it shows a high spot on one of the sheaves, then it is bent or scored. Depending on the damage it could need replaced.
If it shows a high spot on one of the sheaves, then it is bent or scored. Depending on the damage it could need replaced.Thanks Nick,
I kind of came to that conclusion this afternoon. I wanted to hear the prognosis from a real professional.
Service parts are on sale through next week and the whole assembly is only $84 so I think I will replace it and not have to worry about it in the future.
I got such a good deal on the machine that even with the extra cost I still think it was a great buy and am very happy that I bought it.
Thanks again for your advice. This is an invaluable service to your flock.
JeffG
I kind of came to that conclusion this afternoon. I wanted to hear the prognosis from a real professional.
Service parts are on sale through next week and the whole assembly is only $84 so I think I will replace it and not have to worry about it in the future.
I got such a good deal on the machine that even with the extra cost I still think it was a great buy and am very happy that I bought it.
Thanks again for your advice. This is an invaluable service to your flock.
JeffG
-
bullfeathers
- Bronze Member
- Posts: 4
- Joined: Tue May 01, 2007 4:49 pm
Introduction
I should have introduced myself before printing my first message,well let's see, I'm retired military ( Disabled Vet of the Korean War ). I,m an old fashiond long bow maker, and wood carver so I purchased a new SS a floor model at Lowes through one of SS sales demonstration three years ago.I band saw my patterns.My lack of knowledge (or better sense) I have been plagued with problems regarding the speed control.
I have been reading the forums particularly from Nick Engler, regarding
similar problems with other SS owners. The blow ups in the Bandsaw Manual
don't help me very much, however the information and photographs, Mr. Nick
Engler displayed for a request for help for someone with a similar problem was great.
I was informored by an SS Customer Service person that my SS was a floor model and probably someone messed around with the speed control and
messed up the gears. Customer Service sent me a new set of gears free of charge , a friend of mine replaced the them. it's still not changing speeds.
I ordered an entire new quadarant and when it arrives I will need guidance in taking out the old and replace it with the new.
I really appreciate all of the articles I have on the forum. I have one more question since I band saw the patterns I have drawn on, can I bandsaw four or five inch thick of wood, I use a 1/4 6tps bandsaw blade.
Thank you very much for your help, Oscar Legaspi aka bullfeathers
I have been reading the forums particularly from Nick Engler, regarding
similar problems with other SS owners. The blow ups in the Bandsaw Manual
don't help me very much, however the information and photographs, Mr. Nick
Engler displayed for a request for help for someone with a similar problem was great.
I was informored by an SS Customer Service person that my SS was a floor model and probably someone messed around with the speed control and
messed up the gears. Customer Service sent me a new set of gears free of charge , a friend of mine replaced the them. it's still not changing speeds.
I ordered an entire new quadarant and when it arrives I will need guidance in taking out the old and replace it with the new.
I really appreciate all of the articles I have on the forum. I have one more question since I band saw the patterns I have drawn on, can I bandsaw four or five inch thick of wood, I use a 1/4 6tps bandsaw blade.
Thank you very much for your help, Oscar Legaspi aka bullfeathers