Friday, November 2, 2012

V3.43 - Our ‘snipe hunt’ continues.


Last week, I gave you the most basic description of what snipe is and how it happens. The “why” it happens and how to minimize it, is the subject of this week’s column.

Setting the stage, your lunchbox planer has a movable head for depth of cut. It has no bed rollers, and the distance between the infeed roller and the outfeed roller is 4 inches. With that foundation, our snipe would be 2” long at the front and 2” long at the rear of the board. “Why” do you ask? Good question.

Here’s why- as long as the board is underneath both rollers, the head will be shoved upward by the force of the rollers pushing down against the board.

The early lunchbox planer designs were notorious for the problem of snipe. Later designs, and the ones most often found now, had a head locking mechanism made into the planer that allowed the operator to actually lock the head in place, which has pretty much eliminated snipeing on this design.

One thing that will do much to decrease your snipeing is [on the movable head style] to ALWAYS make your final depth of cut setting by moving the head downward. If you will do this, it will remove the backlash out of the lead screws [the threaded rods that the planer head moves up and down on] and their nuts. In other words, if you need a ¾” thick piece, take your adjustment to 1” and bring it down to ¾. Do not start at ½” and go up to ¾ and then plane it. If you do that, you are leaving the backlash in the lead screws & nuts and that will be increasing your chance of snipe.

On the early design lunchboxes, there were many different methods attempted to eliminate snipe. Some were easy, some were weird and most did not work every time. Once the planer makers figured out that customers were not in the mood to accept snipe as a way of life, they went back to the drawing board and did something about it. Hence, the head lock I mentioned earlier.

So far, we’ve been talking only about the lunchbox planers. Let me tell you straight up, snipe on industrial planers is a real happening, too. The Industrial planers have an inherent advantage because most of them have a movable bed, not head. This design difference makes snipe a lot easier to control, but there are so many adjustments that other things can go wrong. We’ll ‘go there’ next time.

Oh, and watch out for the kids that might be out Wednesday night...and/or the punks that might be armed with eggs…

Send your questions or comments to:
Toolsmartz@bellsouth.net and we’ll see what we can do to help you.

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