New Design?

JPG · Post by **JPG** » Fri Jun 04, 2010 1:30 pm

dusty wrote:I'd go for it in a big way but Shopsmith has not called for volunteers. I suspect they already have a crew of "Shopsmith Die Hards" to chose from.

Yes! One particular forum member does come to mind!:D

SDSSmith · Post by **SDSSmith** » Fri Jun 04, 2010 2:05 pm

JPG40504 wrote:I agree with the good indication re 'redesigning' parts for older machines.

I do however think the idler shaft WILL be part of the Power Pro. I think the Power Pro is likely the reason the shaft was redesigned.

The current design causes the idler shaft to run at 1.6x the main shaft speed. This allows the router(and sprayer) to be driven at a faster speed. The router... still needs the shaft AT ITS CURRENT 'LOCATION'.

It is my guess that an 'idler' shaft will still be present, but with a capability of tolerating the increased rpms possible with the Power Pro. For that reason, the bearings needed to be replaced with ones more tolerant of the higher speeds. IMHO the 'water pump bearing' in the original design is likely the reason the shaft gets so hot.

I also prognosticate the existing poly-v belt with that confounded eccentric tension adjustment will be retained so as to keep the parts differentiation minimal.

As I have posted b4, Power Pro motor replaces existing motor with a fixed pulley that connects(using the current motor belt) to an idler shaft with a fixed pulley also[the movable sheaves go bye bye-along with the need to lubricate them]. I do not have a guess re motor belt tensioning method. The current main shaft pulley is used with the current poly-v belt connecting it to the 'idler shaft'.

The idler shaft MAY be the same as the current(newly redesigned) idler shaft with a new poly-v pulley(maybe*) and a fixed pulley mounted instead of the idler/control sheave pulley.

*The differing idler shaft speed may be eliminated by making the idler shaft poly-v pulley the same size as the main shaft pulley(or changing both to the same size). This would make the speed selector/indication correct for both shafts.

Thats My 'Vision', and I am sticking to it (until further information causes me to alter it:D). That is a 'Management type' assertive statement!:rolleyes:

Typo corrected!

Router? I am guessing jointer.

JPG · Post by **JPG** » Fri Jun 04, 2010 4:31 pm

SDSSmith wrote:Router? I am guessing jointer.

Yep! I slipped up on that one! I have no idea where router came from! Correction about to be made!:o

JPG · Post by **JPG** » Fri Jun 04, 2010 4:36 pm

SDSSmith wrote:Router? I am guessing jointer.

Yep! I slipped up on that one! I have no idea where router came from! Correction about to be made!:o

8iowa · Post by **8iowa** » Fri Jun 04, 2010 6:02 pm

As has been disclosed, Dusty has the new idler shaft. Mine, along with the idler sheave, retaining ring, and sheave clip are being shipped today. (according to Dave in customer service)

My problem has been that the idler sheave was free to move back and forth about .025" between the retaining ring and sheave clip. This created a knocking/clicking noise. The grooves for the ring and clip can clearly be seen in Dusty's picture above. The idler sheave fits between these grooves and is held in place (hopefully very tightly) between the ring and clip.

dusty · Post by **dusty** » Fri Jun 04, 2010 6:21 pm

8iowa wrote:As has been disclosed, Dusty has the new idler shaft. Mine, along with the idler sheave, retaining ring, and sheave clip are being shipped today. (according to Dave in customer service)

My problem has been that the idler sheave was free to move back and forth about .025" between the retaining ring and sheave clip. This created a knocking/clicking noise. The grooves for the ring and clip can clearly be seen in Dusty's picture above. The idler sheave fits between these grooves and is held in place (hopefully very tightly) between the ring and clip.

I'm curious, 8iowa. Did you order an eccentric and if not why? Then on the other hand, you ordered an idler sheave. Why?

I ask because I did just the opposite and I wonder about my judgment.

Now that I have received the eccentric, I am as sure as sure can be that the old eccentric would have been fine. Was the clicking noise the reason for changing the idler sheave?

I need to research my recordings of comments from Bill Mayo but it seems to me that he has discussed that clicking but I don't recall his solutions to the problem.

8iowa · Post by **8iowa** » Fri Jun 04, 2010 7:55 pm

Dusty:

My headstock is '03 vintage and has the "stopscrew" on the excentric close to the screwdriver adjustment slot. There was nothing wrong with the excentric, so I'm not going to replace it.

I'm hoping that a new idler sheave will fit tightly between the retaing ring and sheave clip. My present sheave easily slides back and forth on the key about 25/1000" and is the source of my noise problem.

Hopefully the new parts will solve my problem. The alternative would be to use blue locktite to secure the idler sheave to the shaft once it is lined up properly with the poly V belt.

Bill Mayo is having a rough time recovering from surgery. He is in a lot of pain and cannot go out into his shop.

nuhobby · Post by **nuhobby** » Fri Jun 04, 2010 9:55 pm

JPG40504 wrote:I agree with the good indication re 'redesigning' parts for older machines.

I do however think the idler shaft WILL be part of the Power Pro. I think the Power Pro is likely the reason the shaft was redesigned.
......

It is my guess that an 'idler' shaft will still be present, but with a capability of tolerating the increased rpms possible with the Power Pro. For that reason, the bearings needed to be replaced with ones more tolerant of the higher speeds. IMHO the 'water pump bearing' in the original design is likely the reason the shaft gets so hot.
.....

Very interesting thoughts!

I'm wondering if you have some specifics to detail this theory.

E.g., I did some searching on water-pump bearings, which are usually double ball-bearings, and one cited a 9000rpm peak speed.

It looks like Dusty's new idler bearings are rubber-sealed, and that's not necessarily the lowest-temperature way to go; the rubber does make for some friction.

Some time back Bill Mayo mentioned that the latest Double-Bearing-Quill rear bearing has been redesigned for a relatively larger I.D. (> 5/8") compared to an earlier version, for greater reliability. Perhaps these new 6903 idler bearings @ 17mm I.D. are likewise made this way for greater reliability. Anybody know what the 2 Mark 7 idler ball-bearings were for I.D.?

JPG · Post by **JPG** » Sat Jun 05, 2010 12:55 am

[quote="nuhobby"]Very interesting thoughts!

I'm wondering if you have some specifics to detail this theory.Mostly speculation. Conclusions drawn from assuming the design goal and thinking of ways to achieve them.

E.g., I did some searching on water-pump bearings, which are usually double ball-bearings, and one cited a 9000rpm peak speed. I doubt the ss version can.

It looks like Dusty's new idler bearings are rubber-sealed, and that's not necessarily the lowest-temperature way to go]
Sorry I do not have something more 'enlightening'!

nuhobby · Post by **nuhobby** » Sat Jun 05, 2010 4:31 am

No problem!

I did find that Mark 7 idler bearing posting:
https://forum.shopsmith.com/viewtopic.php?t=5606
(which suggests 5/8" bearing I.D.)

So at least the New Design appears to have thickened the inner parts of the idler-shaft beyond 5/8" (0.625") -- to 17mm (0.669") at the bearings, and thicker yet between the bearings. This is probably deliberate, since Bill Mayo reported a similar progression on the 2nd Quill bearing design.