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7B Shaper Table Drive

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  • 7B Shaper Table Drive

    Hi

    I have a 7B shaper that had not run in over 10 years. I got it going but cannot get the table drive to work.

    Here is what happens:

    The lever moves from R to L and center just fine. In center I can crank table either direction with no interference from the ratchet drive.

    When I put it in R, with the drive rod on the R side of the slot, the drive sits there oscillating back and forth. The table drive rod that I used to crank in the center position just goes back and forth. It is as if the ratchet pawl will not release. If I grab a hold of the drive rod and give it some resistance, the pawl goes click-click and works. Otherwise as long as I put pressure on the rod it works.

    Is there an adjustment needed to get the proper "drag" or something?

    Thanks
    Bob

  • #2
    A couple things to check, how tight is the feed screw? Tried to add a ball thrust bearing to the feed screw, and had similar symptoms, there wasn't enough friction to allow the ratchet to reset. Remember, the friction of the table on the slide really isn't a factor here, because of the backlash in the nut. So, try a little more preload on the feed screw by tightening the end load adjusting nuts. Also you may need to adjust the stroke on the ratchet, it has enough travel for 1-3 clicks.
    I cut it off twice; it's still too short
    Oregon, USA

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    • #3
      Tim

      Thank You that worked. I saw that adjustment nut but read the part where you should not have the slide too tight. I get what you said about the table and rod being independent.

      Bob

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      • #4
        There was often a fibre washer under the end nuts to give a little friction here, just enough to stop the screw from rocking backwards when you don't want it to. I thought I'd be clever once and put ball thrust bearings in a shaper feedscrew. I had to take them out, because they reduced the friction to the point where the feed mechanism wouldn't work.
        Last edited by Richard P Wilson; 04-01-2018, 03:37 PM.
        'It may not always be the best policy to do what is best technically, but those responsible for policy can never form a right judgement without knowledge of what is right technically' - 'Dutch' Kindelberger

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        • #5
          Think of it like a ratchet wrench where it doesn't work if the bolt is too loose.

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          • #6
            Originally posted by Richard P Wilson View Post
            There was often a fibre washer under the end nuts to give a little friction here, just enough to stop the screw from rocking backwards when you don't want it to. I thought I'd be clever once and put ball thrust bearings in a shaper feedscrew. I had to take them out, because they reduced the friction to the point where the feed mechanism wouldn't work.
            Yep, same here. I did a big service on my 8" Boxford a few years ago, everything i thought was too tight. I loosened everything up, lubed it all up, so everything was a pleasure to use, and, - no auto feed. After days pulling everything apart again and again, i twigged shapers actually need to be "tight" and have that little bit of friction for the ratchet and auto feed to work....

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