Problems with thicknes planer

[GuitarMaestro]

I have access to a professional and huge woodworkshop at the company of my father which is not used anymore because the company only does metal work at this time. There is a very high quality HUGE thickness planer in that workshop which I would like to use for my guitars.

The problem is that it does not work as I want it to work. The problem is that the wood always looks like the brown line in the picture if viewed from the side after going through the router. Surely this is greatly exaggerated in the drawing but in reallity the low spot is about 2 mm deep.

The router looks like in the picture. The blue and red rolls move the wood through the router and the green circle is the knife. After opening the machine and dissasembling a lot of parts, I found out that I can adjust the height of the red rolls.

I tried adjusting them in three different ways.

1. Setting them with a steel edge so that they are EXACTLY level with the desk.

2. Setting them to be slightly lower then the desk

3. Setting them so that they are slightly above the level of the desk

With all three settings I still have the problem. Another thing I tried is to put a thick and large piece of wood under the wood to be planed in order to make it more stable against bending while going through the router. This decreased the problem a little but not enough.

My question: Is this just usual with such a planer and you have to cut away the ends of the leveled blank where the "holes" are? Do I have to set the red rolls in a very special way i did not try yet? Or is there something else wrong with the planer? I cannot imagine what, because the two red rolls seem to be the only thing you can adjust. The planer has a cutting roll with 4 knifes which are in excellent condition so it is definately not that the knifes are worn. Even if they were the could not cause the problem I described. I hope someone here with real knowledge of routers can help me....

Thanks in advance,

Marcel Knapp!

[krazyderek]

are they actually grooves at either end, or is it more like shelves that are lower then the middle of the board?

[GuitarMaestro]

are they actually grooves at either end, or is it more like shelves that are lower then the middle of the board?

A mixture of both. They are grooves, but the board gets never as thick as it was before the groove on both ends. So it is thicker in the middle then at the ends.

[MJ Hofbauer]

Just joined to see if I can help with some of the tooling questions in here. Question, are you joining one face of the blank first? A thickness planer cuts a smooth and parallel surface to the obverse surface of the wood being passed thru. Passing a rough piece thru, even if levelled will turn out with bad results. Not sure about the proper configuration of that individual planer. I have a Grizzly 16" planer and a 24" at the shop. If you are worried about the wood 'giving' as you said with mounting a piece under, just make sure not to take off too much material in one pass. If you find you are getting tearout or the piece is being compressed, make the cut in two passes.

-MJ

[GuitarMaestro]

Thanks for the answer, but I found out tha the problem I have is called planer snipe and seems to happen with EVERY thickness planer constructed that way. There are many workarrounds and ways to reduce it's effect. If somebody has a similar problem just search through google or google groups for planer snipe.

CU,

MK!

[daveq]

I didn't think it was snipe from looking at the drawing. The snipe that I have seen starts at the edges. It looks like yours starts in from the edge. Oh well.

[MJ Hofbauer]

Yeah, I wouldn't have gone with snipe because of the cuts inboard on the blank. Typically snipe only occurs at the beginning and end of the cut. As the board enters the planer, the wood digs in and the back rises slightly and causes the end gouge. But glad you got it sorted out.

-MJ