Eccentric Bushings and Bearings

[Tylerh]

Im still in the process of restoring my old greenie, 54' A headstock. When I started the dissemble the Gilmer belt had snapped with the PO so some stuff was already loose. i didn't know anything about the machine when I started, but now that I've spent hours and hours on this forum and learned every part on the exploded view, I noticed that when I took the idler shaft and eccentric bushing out there was nothing "holding" it in. Well besides the bolt and square nut that pinch the wings. Now is it possible it didn't come with the "keepers"? I've heard that they're don't really work to well and most people get rid of them. Also there's no set screw in the eccentric that rides in the idler shaft. What modifications should I do to keep that all in place? Also some questions about bearings. When I hold onto the button on the control sheave and spin the sheave it spins very freely and fast. However the idler shaft, when I spin the bearing it doesn't keep spinning. How do I tell if the bearings are bad? Also any bearings for that matter.

[JPG]

Assuming the bearing is the converted water pump bearing, the eccentric is of unknown( it looks different from current design) origin and appears to have had the slot added. The set screw should have been in the thicker portion of the eccentric.

If it works, it should be ok to use(the newer design is very similar re the slotted eccentric).

[Tylerh]

The only thing is I've never seen it run so I can't say whether it works or not. I haven't even turned the motor on due to very brittle wiring. Would adding Bill Mayo's "fix" as in tapping the casting for screw and washer be helpful? I don't see anything to keep the idler shaft and bushing in place except for the bolt through the wings.

[JPG]

I neglected to address your bearing question. Bearings that have sufficient grease do not 'coast freely'. The control sheave bearing most likely has been 'oil fed' so continuing to do so is reasonable. If they are not rough, they should be ok.

Does the eccentric bearing have a groove in the center? If so, IIWM, I would get a different eccentric(old style with the set screw). The one in your pix looks strange. Or drill and tap the one you have.

Without the clips, I would CAREFULLY add the tapped hole and fender washer al a Bill Mayo. Personally I think the clips are satisfactory. Realize the clips also prevented the eccentric from moving inward also.

[Tylerh]

If you're referring to the idler shaft bearing when you said eccentric bearing then yes. It is the original water pump type shaft with the groove in the middle of the bearing. One problem I noticed while dissembling was that the control sheave had a little rotation play when on the shaft. The shaft does not have the key that "locks in place". It is just a straight flat slot with a straight key. It seems as though the key slot might be the culprit that is allowing the key to wiggle therefore the sheave moving. I had original plans of just replacing the idler shaft with a new one but still the water pump type. Would I be better off just getting the shaft from the MS since it seems I should get a new eccentric? I've heard that the new 2 bearing design isn't all that great that's why I was leaning toward the original design. I also plan on getting a 2 bearing quill for it from Skip since I plan on using it primarily as a lathe and drill press.

[JPG]

If you're referring to the idler shaft bearing when you said eccentric bearing then yes. It is the original water pump type shaft with the groove in the middle of the bearing. One problem I noticed while dissembling was that the control sheave had a little rotation play when on the shaft. The shaft does not have the key that "locks in place". It is just a straight flat slot with a straight key. It seems as though the key slot might be the culprit that is allowing the key to wiggle therefore the sheave moving. I had original plans of just replacing the idler shaft with a new one but still the water pump type. Would I be better off just getting the shaft from the MS since it seems I should get a new eccentric? I've heard that the new 2 bearing design isn't all that great that's why I was leaning toward the original design. I also plan on getting a 2 bearing quill for it from Skip since I plan on using it primarily as a lathe and drill press.

The 'original' water pump bearing/shaft is no longer available.

I like the newer two bearing idler shaft bearing mainly because the bearings are more easily obtained and replaced. I do not understand why the negative comments(I do not have one operating, but the design is the same as the Mark VII I am rebuilding).

I do not think the older eccentric is available from SS now either. However I believe the newer eccentric will work with he water pump bearing and has the added tapped hole for a retaining washer that retains the outer bearing. The headstock holds the eccentric of either new or old design.

So IIWM, I would get a new eccentric and move on! I am suspicious of your eccentric's 'origin'.

The control sheave rotary slop is common and not a problem(other than being noisy) until it gets excessive. Then a new key and control sheave fixes that. The slot in the sheave is what is worn(the aluminum is softer than the key). The key is softer than the shaft and wears also.

Why Skip as a 2 bearing quill source???


BTW the 'straight' key has a kink in the end that retains it in a dimple in the shaft.


P.S. Do not over tighten the bolt that pulls the ears. Compress the split lock washer fully, then stop.

[Tylerh]

Since its the last thing I read in your reply JPG, I've read that the first machines did not have the kink in the key, and mine does not. I will take pictures and post sometime. There's no circle at the end of the key slot that has the dimple. Just flat the whole way. From what I've read and seen online the only person offering the machining to add a second bearing to the quill is Skip. I would rather do that then upgrade to the poly-v to keep costs down some. Aren't there a few people still offering the original design idler shaft? I've seen it on that one auction site, as well as a gentlemen that rebuilds headstock's and sells parts from his website. Regarding the eccentric, when I get to the buying of all the parts in one shot I'll be more than happy to send it your way to try and discover it's origin. I will say that I thought it was the normal eccentric that came with the early greenie's (no tapped holes or any of that). It fits very snug, almost like a suction feeling when it's put into the headstock, as well as fitting good to the shaft.

I forgot to add that when I originally tore the machine down, the "adjusting" slot used to tension the belt on the eccentric was at 12 o'clock or right around there. From watching Sawdust Sessions I saw that it should start at 6 o'clock and be moved clockwise but doesn't need much movement.

[JPG]

Ok I fergit we were dealing with a Gilmer machine(DUH!).

Skip makes sense then.

I am curious where you discovered in writing about the non-kinked key(early greenie). That is 'news' to me. Did your fixed idler pulley sheave have the small clip that prevents movement towards the internal end of the idler shaft?

No kink/no depression would mean the key was free to slide along the shaft.

Thick(slot) part of the eccentric at 12 indicates a badly stretched belt or one too long(wrong size).

Since you apparently have not yet used it, I think replacing the control sheave and key(stock 1/8" will do since no kink...) would be sufficient until you determine more extensive replacements are needed.

The missing clips might be a problem, but the squeezable eccentric may overcome the need for them since the fit is tight.

Yes some third party stuff is out there.

Have you replaced the drive sleeve bearings?

[Tylerh]

Now im quite sure that I read somewhere about the key, but I do not remember where.. big help right? I want to say it was in MickyD's rebuild thread but could be wrong. I could also just be making stuff up. Wouldn't be the first time! Regarding the fixed pulley, yes it does have the clip that keeps it in place, as well as the ring that fits in a groove that I think is a spacer to keep the fixed sheave from hitting the bearing? The key does slide in the groove as well. Oil and sawdust and all that good stuff had it frozen in place but once removed it just slides. The drive belt is old and looks stretched compared to the new one I have. I have an Applied Industrial Technologies about 10 minutes from my house so I've already spoken to them and I going to change the drive sleeve bearings as well as the motor bearings. I have the bearing page on here bookmarked and the sizes I need written down so I know what I need when I go there. Finances are in the hole so it might be some time before it happens.

[JPG]

Did you remove the fixed(idler) sheave from the shaft? The 'dimple' in the shaft is inside the sheave bore(the sheave retains the key) .

Did you also read re replacing those bearings in MickyD's thread?