Replies

1. 
   MBL | May 11, 2004 12:08am | #1

   Hi Matt,

   Would say that's normal.

   However, the play is only when changing direction from turning clockwise to counterclockwise, and viceversa.

   If the adjustment is in the same direction, there's zero backlash, and the depth of cut can be set quite minutely.

   So, after backoff, usually turn the knob back forward till it feels just tight.

   The Y lever can break if one tries to bend them or re-shape them. Seems like they are cast iron in the old ones.

   Backlash is almost impossible to eliminate in tools. The new Bosch routers are the same way. When one turns the screw the opposite way, the depth of cut does not really change right away. So all adjustments are to be done in one direction only to account for backlash, no matter what the tool.

   Machine shop precission mechanisms get to be more expenssive the less the tolerance, but they still get a minute amount.

   -mbl-

2. 
   hammer1 | May 12, 2004 05:10am | #2

   There are two places on the yoke that are sloppy, one at the Y where it contacts the adjuster knob and another where it is pinned to the body. The slot on the blade can also be loose. This is normal for almost anything that is screw adjusted, there has to be some free play between the threads. I set the blade a little strong and backoff until I get the cut I want that way the slop is taken up.

3. 
   Alan | May 13, 2004 02:15am | #3

   Matt,

   As the others said, backlash is unavoidable in mechanisms like a plane's adjustment.  But, as they both said, though you can't eliminate backlash, you can eliminate any and all problems that might arise because of it.

   It's very simple: sneak up on the depth setting from having the iron withdrawn so it doesn't cut at all, to where it is extended just right.

   Obviously you don't want the iron to move while you're using the tool.  Also obviously, the forces at work while you're planing are pushing on the iron, not pulling on it; the forces are pressing the iron back, trying to make the iron retract.

   The adjuster pushes the iron one direction or the other; it does not pull it.  When extending the iron, the adjustment knob pushes on the yoke, which pushes on the slot in the cap iron.  Once the mechanism is pushing the iron out--extending it--any backlash cannot push the iron back up; the pressure on the knob, yoke and the cap iron prevent this.  While the mechanism is extending the iron, any backlash can allow the iron to move forward only, not back.  Because of the forces at work when planing, there's no danger of the iron moving farther out.

   If you want to, try this out.  Set the lever cap loose enough that you can easily slide the iron back and forth.  Start with the iron withdrawn and then extend it some.  Without touching anything else, see which way you can move the iron.

   Alan--going on WAY too long--yet again

1. 
   Curtis | May 13, 2004 12:23pm | #4

   Hi

   I use to work in the machine shop.

   why not do as they do. you can not get rid of the back lash,so work with it!

   after your cut has finished, raise the cutter, and advance one (or more) turns of the screw. then ALWAYS  work the screw back to the setting. this will remove the backlash.

   it may be a pain. but soon it will become second nature.

   using this method machinist can use keep verry tight tolerances. Why not try.

   good luck.C.A.G.

4. 
   Alan | May 14, 2004 01:53am | #5

   Matt,

   I always hate to do this, but I'm afraid I have to directly contradict Curtis and Hammer:  they both have it backwards.

   You will have no problems from backlash if you move the iron from withdrawn too much, so it doesn't cut at all, to the proper setting.

   If you doubt this, do the little test I mentioned above.  To repeat myself:  After extending the iron, if you don't touch the adjustment, you cannot push the iron back towards where it will not cut; but you will be able to pull it farther out.  When you're planing all the forces at work try to push the iron back, not pull it forward.

   Remember though, in the test (as in use) you're looking for a very slight movement of the iron, almost so little you can't detect it--almost--but you can detect it.

   Alan

5. 
   haroldp | May 14, 2004 06:14am | #6

   Always make sure that your adjustment ends with you extending the blade. If you back the blade off without extending the blade again you will have some slack. hope this helps.

   Harold