JPG40504 wrote:Thank You for these excellent pix. I did not realize the spacing was controlled by the shaft itself(one bearing inserted on shaft from EACH end of the shaft(that eliminates the need to secure a 'spacer').
The 'older' models used a modified water pump bearing as does the lower band saw shaft. I am guessing the water pump bearing is no longer available(radiator fans are no longer mounted to water pump shafts as in the past).
Your pix reveal some important differences between 'old' and 'new'.
1) The bearing is no longer secured in the eccentric bore by that set screw in the side of the eccentric(the one we should not tighten too tightly).
2) The eccentric is 'split' at the narrow portion of the wall. I assume this is to allow a slight squeezing action when the headstock ears are snugged up.
3) Any movement of the bearing towards the exterior end of the eccentric is limited by that NEW screw in the end of the eccentric.
4) Any movement of the eccentric(and bearing) towards the exterior end of the headstock bore is limited by the OLD screw and washer.See #5 for much older models.
5) The original greenie 'retaining clips' should be used if the old screw and washer were never used(originally they were one or the other).See comment below
6) With the new set of parts, I see no limit to inward movement of the eccentric other than the squeeze of the headstock ears, and the force of the belt in the pulley. The control sheave is 'stopped' by the pork chop, and the belt in the v shaped pulley would thus push against the idler sheave which does not move along the shaft. This is the same as with the 'older' set of parts.
The squeeze put on the eccentric by the headstock 'ears' is the same. The screw should be just snugged. Bill Mayo's recommended use of a split lock washer and tightening the screw/nut to just fully compress the lock washer is excellent advice.
Comment: Bill Mayo also recommends drilling and tapping the headstock on earlier models which did not originally have the screw and washer. As has been pointed out elsewhere, the older castings did not have as thick a boss as the more recent models having the screw and washer. I would agree with Bill IF the drilling and tapping can be accomplished accurately so as to not create a weakness in the casting. Otherwise, the original clips DO work when installed correctly. The end with the smaller 'hook' needs to go over the inner end of the eccentric(tis way too easy to get it slipped off inadvertently[check after tightening bolt]) . The clips are loose when installed correctly.
Dusty: I believe the models with the clips did indeed have two clips. I have observed them elsewhere(quite small sample however).
In my third post, referring to the screws and washers, does the one at 7 o'clock not prevent inward movement of both the eccentric and the bearing (idle shaft assembly) while the one at high noon prevents the outward movement.
Also, it seems to me that the eccentric captures both bearings on the idler shaft when the hex bolt (ears) is tightened.
The idler shaft assembly (on my twenty year old machine pictured here) cannot move in or out of the eccentric (which also is split) and is captured when the bolt is tightened.
