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https://www.youtube.com/live/JFHqQg5wZEg?feature=share
Wolfgang makes a very important point in this online class starting at 13:45. (He mentions this in several other online classes.) He correctly states that it is better to start with the support bar a little too low and then adjust the support bar up. Unfortunately, he does not explain why this is important.
Gears and adjustment screws are designed to allow a little BACKLASH. This gives them a little breathing room in order to function. It is important to note that backlash is not limited to the KJ-45 jig; it effects all jigs requiring an adjustment of the jig and the support bar. It is also not limited to the Tormek; all machinery with screw adjustments (and gears) have some backlash. Nor is backlash limited to tools of lower quality. Both a bargain and a Lie-Nielsen plane have backlash in their blade depth screws, although the Lie-Nielsen will have less.
Following Wolfgang's recommendation of always raising the support bar for adjustment insures that the microadjust is under strain, (no backlash) and therefore more accurate. It should become a habit.
Ken
Quote from: Ken S on February 04, 2023, 09:44:07 PM... snip
Gears and adjustment screws are designed to allow a little BACKLASH This gives them a little breathing room in order to function.
... snip
I don't think the 'backlash' you indicate in the drawing is the problem. I think Wolfgang is referring to the fact that the USB doesn't just slide down smoothly. The USB must therefore be pressed down when adjusting downwards, otherwise the screw thread will prevent smooth lowering.
I know that when I'm using a metal or Rose Engine lathe, I must work similarly. I leave space so that, when I back out from the operation, I have room to absorb the backlash before moving back into it.
Déjà vu? (https://forum.tormek.com/?topic=5019.0) ???
I always try to maintain an open mind. I may be incorrect in my idea about backlash with adjusting the support bar height. However, I am not convinced that my backlash idea is not correct. Regardless of what causes lowering the support bar to be bumpy and raising to be smooth, raising is still smoother. I contend that smoother is the habit to cultivate.
Ken