Reverse snipe?

[Cliff Polubinsky]

This started a little while ago, but I thought I was imagining things. But tonight I measured 4 different boards and they are all coming out the same.

I'm getting what I'd call reverse snipe on my Dewalt 734 planer. The ends of the boards are 1/32 to 2/32 thicker than the middle of the board. I can run the wood through the jointer, turn and run it immediately through the planer and it's not coming out parallel. Anyone have a guess what I'm doing wrong?

Cliff

[Rick Christopherson]

In the past, many people have incorrectly attributed snipe as being caused by the bed rollers being too high (and chastized me for suggesting otherwise). Their incorrect analysis didn't realize that if the bed rollers were too high that it would actually cause an inverse snipe, which is just the situation you describe.

I do not know the DeWalt planer well enough to know if it even has bed rollers or not, but it is a feature in the lower line of the workpiece nevertheless. That is to say, that the workpiece is being driven upward into the head, whereas most normal snipe is caused by the cutter head being driven upward away from the wood. If the planer has bed rollers, then lower them. Some of the planers I have seen have folding infeed/outfeed trays. If the pivot point of these trays is high, it will be the same result.

The best way to identify the source is to measure the distance between the end of the board and the transition of the snipe. This will be the same distance between the centerline of the cutter to the offending piece of the planer.

[Richard Keller]

Are you living in a parallel dimension?

Seriously though... With the planner un-plugged take a block of wood, say two or three inches, (Doesn't matter exactly) and crank the planner cutterhead down so it just touches it on one side. Then slide the block over to the other side and see it it's the same, or tighter/looser. Possibly the cutterhead is not parallel to the table. Also, take a straight edge and lay it across the table and extensions and see if they are flat.

Richard.

[Cliff Polubinsky]

Rick,

You're a genius. I kind of wondered if it might be a infeed/outfeed table thing, but I hadn't adjusted either for a long time. Evidently the vibration of the machine had caused the adjustment screws for the tables to unscrew, raising the table levels. I lowered them both and the problem went away. I'll have to make sure the lock nuts are tightened down so it doesn't happen again.

Thanks very much.

Cliff

[glenn bradley]

I've got a 734. Rick's got it!