Replies

1. 
   RickL | Dec 22, 2005 04:52pm | #1

   You said you lubed it and it worked well for a short time. If you use grease it can attract sawdust and cause binding. No lube is better or a dry type lube such as a mix of graphite and wax works fine. Had a saw in a shop that did the same thing with a sliding table and the guys were spraying WD-40 and who knows what else. Soon as I could clean it out and stop them from their good intentioned lubrication, the problem stopped. Give the saw a good cleaning and remove all lubrication and you should be fine. Apply a little paste wax or even candle wax. No sticky beeswax. The bearings are simple sleeve bearing and the binding is typically caused be sawdust on the gear rack not the pivot points. Can't tell you how many shops I've had to fix similar problems of good intentioned lubrication with the wrong product.

2. 
   highfigh | Dec 22, 2005 05:19pm | #2

   Is there a knob in the center of the wheel? That's for locking the mechanism in place and it could have grabbed while raising the blade. It can be progressive so you wouldn't notice it at first. Try loosening it and see if the problem goes away.

   "I cut this piece four times and it's still too short."
3. 
   PeteBradley | Dec 22, 2005 09:27pm | #3

   Time to figure this out before you break something. Is this one of the ones with the u-joint? I hear they're prone to problems of this sort.

   As others mentioned, if the lube catches a lot of dust, it will cause problems. I've been using "dry" wax bike lube on mechanisms like this lately, but not sure if it applies here. The dry lube doesn't catch much dust, but the tradeoff is that it isn't as slick as oil or grease.

   Pete

1. 
   WhatKnot | Dec 24, 2005 07:39am | #4

   Factory spec's call for nothing more than good old white grease and regular maintenance, (whatever that means). As mentioned before the dry lubes do attract far less sawdust and is what I prefer to use because regular maintenance is always something other than regular.

   I did have a case were the arbor yoke on a 66 was broken by a customer not long ago. We never did figure out  exactly what caused it but the stiffness that you speak of was the original complaint.

   As a side -- General claims that their saw has a better and stronger yoke than the other cabinet saws but they never mention the 66 specifically. I guess there might be some credibility to this being a problem but then again it may just be marketing hype.Steve

   "You can either be smart or pleasant, I was once smart but now I'm pleasant. I like being pleasant better." Jimmy Stewart - Harvey

1. 
   Yersmay | Dec 24, 2005 06:59pm | #5

   I had the same trouble with my Delta... it was very hard to diagnose and still kind of hard to explain but I'll try. Maybe something similar is happening with your saw. On my saw, there is a concentric bushing that is part of the mechanism... it covers the shaft that is driven by the turn handle. As I remember it is less than an inch long and it looks like a simple round bushing from the outside. But the inside bore is actually concentric (the reason for this is beyond me and my repair guy). At any rate, there is a specific sweet spot for the position of this bushing. My repair guy thinks that it was rotated from its best position because I didn't fully loosen the locking knob before raising or lowering the blade. Once this had been corrected, and now that I am more careful to fully unlock the mechanism before turning, there has been no problem. I know that this probably doesn't make a whole lot of sense, but simply cleaning and lubricating the mechanism had no effect until I brought the whole trunnion to my repair guy to ponder. Before re-assembling he scratched a mark on the outside of this bushing to help re-locate it perfectly when it is dissaembled again for maintenance. Who knows if your PM has this type of bushing but at least it's something to keep in mind. Best of luck!

1. 
   highfigh | Dec 25, 2005 08:13am | #6

   Actually, the bushing is eccentric, not concentric. Concentric means they share the same axis, or center. The reason it would be eccentric is so the correct alignment of the shaft and the adjuster doesn't require re-machining or disassembly. This way, it just needs to be rotated and locked down once it turns freely.
   "I cut this piece four times and it's still too short."

4. 
   philip | Dec 25, 2005 11:31am | #7

   As Rick says-the cause is gunge build-up on the worm and rack. I have an old Delta unisaw and that problem was a regular until I used a silicone spray which helped a lot. I now find that a regular blast with the airgun and the use of a graphite based lubricant powder like that used in locks is the best answer I have found-no longer becomes progressively stiff.

   Philip Marcou
5. 
   UnclePaul | Dec 25, 2005 06:23pm | #8

   Had a similar issue with a Jet saw. Not sure if the set-up is similar but..... On the Jet the knob that locks the blade height  is located at the center of the hand wheel. This knob has a pin connected to it which fits into the shaft. When it is tightened inward it pushes two little bullet shaped pieces outward through holes in the shaft, locking the handwheel in place. Can you say Rube-Goldberg? When this arrangement gets gummed up with whatever, the hand wheel gets stiff. Even if your saw doesn't have this exact set-up, I would start by looking at the mechanism that locks the blade height first. It may not be the worm gears or bushings that raise and lower the arm at all.

   -Paul

1. 
   Yersmay | Dec 25, 2005 08:06pm | #9

   Thanks for the correction, Highfigh. Maybe you could elaborate, since now I'm even more curious. Am I understanding this correctly in saying that either end of the bushing does not share the same center, which makes it eccentric? And this makes the piece more easily aligned since rotating it changes the axis of the internal bore and how it fits against the shaft running through it...? If I'm tracking this correctly, I guess my question now is -- what is this bushing really there for? Is it to keep the shaft from having lateral play? Why is it necessary to have such a close fit between the bushing and the shaft running through it? And I'm still not sure why this can't be accomplished with a simple well lubricated bushing that's a straight shot with identical centers on either end. Thanks for the education!

1. 
   highfigh | Dec 25, 2005 09:12pm | #10

   Look at the bushing as a rod with the hole drilled slightly offcenter. Now imagine trying to assemble as many units as you can, doing as little actual alignment as possible. The shaft has a slight chance of lining up with the hole so the easiest way to make it line up is with a bushing that can be rotated. The assembly will move in a way that the shaft will probably stay level and square to what's behind the adjusting wheel, but its range of misalignment would be within the eccentric bushing's tolerance. If you look at the hole and shaft as being on a graph, it will have coordinates somewhere in one quadrant or another. By rotating the bushing, you can effective match the coordinates of the shaft and the hole.Another good example of eccentric is the vibrator in a cell phone or a waterbed. This is just a small motor with a weight attached by way of a hole that was drilled slightly offcenter.
   "I cut this piece four times and it's still too short."

6. 
   seb | Dec 28, 2005 07:00am | #11

   Well I have a similar vintage saw and had the same problem...Fooled around trying to clean it to no avail...dumped some mineral spirits on the worm and rack...Sofened the crap and it was healed...smeared some white greas on it and its been going as new for three years....
   Bud

   
   

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   Edited 12/27/2005 11:00 pm ET by seb