# 108 Re: Planer Question

From: michael@uvphys.phys.uvic.ca (MRENSING)
Date: 7 Nov 90 16:16:03 GMT

In article <13300001@hpmwgde2.HP.COM>, budn@hpmwtd.HP.COM (Bud Noren) writes...
>My roommate just bought a 12" Makita planer. Seems like a pretty nice unit
>except for one thing - it leaves the last 2" or so of stock a bit thinner
>than the rest. I don't have the tools to measure the step height of the
>surface but I would guess it to be around 1/32" or so. In any case it's
>noticible and it happens consistently. It appears that the deeper the cut
>the more pronounced is the effect.
>
>The machine has two hold-down rollers, one on each side of the cutting
>blade. They hold down the work as well as feed it into the blade at a
>controlled rate. The lead roller will grab the piece first and feed the front
>end of the board into the blade and on under the second roller. For most
>of the cutting both rollers are holding down the work. For the last two inches
>or so of planing, the board is held down by only the second roller. I thought
>that maybe this last section is allowed to pop up slightly when the very
>end of the board leaves contact with the leading roller. Funny that we don't
>see the same effect on the leading two inches of stock.
>
>Not only is this just a theory, but I don't know how to fix it if the theory
>is right - short of trying to somehow reduce the hold-down pressure of the
>rollers which is a scarey proposition from the point of view of stock being
>jetted out of the thing and through the garage wall.
>
>Anybody have any experience with this kind of thing that they might care
>to relate?
>

This is something that I have observed also. Your guess is the correct answer,
in my experience. The answer is to get a roller, or just a sawhorse at the same
height as the planer bed, and let the outfeed go over that to prevent the plank
from sagging.

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