Snipe with different materials?

[Lee roy]

Getting back into some woodworking after quite a few years of absence, expecting my first born in the next few months and have some toys/projects I'd like to accomplish.

Started by making myself a largish end grain cutting board from jarrah and american beech, I figured I've done one before and it turned out well so I'd boost my confidence and start here. (Its still in the clamps so wish me luck.....)

I splurged a little and bought a gmc thicknesser to go with some other tools I already have, I read pretty much every topic on this forum regarding the DIY/low-end type thicknesser and everyone mentioned snipe, so I was well informed on the unit can/can't do, but I figured for what I will be using it for it should do me.

Tested the unit out and as expected, the last 2" had some decent snipe, but only really on the beech. It was quite difficult to get the beech out of the machine without any snipe unless I used a sacrificial piece, but almost none with the jarrah. Infact I was just running the jarrah lengths through pretty much 1 at a time and so long as I grabbed it on the way out, no problem at all.

I am surprised that the beech would fair worse than the jarrah considering they are of similar density, although the beech was quite dry, cupped and splitting at the ends! :~

Is this a common thing to get mixed results like this with different species? I know why thicknessers snipe, but I figured it would have been at every board rather than species specific?

[Arron]

Ive never noticed any difference with timber species of roughly similar densities. I do a fair bit ofboth jarrah and beech and both snipe. Is it possible you were elevating the free end of the jarrah somewhat as it was coming out - thats what i do to prevent snipe.
arron

[silentC]

Likewise can't think of any reason why different timbers would be more susceptible to snipe. It's caused when the timber leaves the in-feed roller and drops slightly if the out-feed support is not set high enough. I also lift the out-feed end slightly as the wood gets near the end, which helps hold it down flat on the table as it leaves the in-feed roller.

If the beech was bowed though, and the ends of the board were sticking up, you might get a bit more snipe as it's like a spring which flicks up as it leaves the in-feed roller. Again you can counter that by lifting the out-feed end of the board up as it nears the end. Think of the out-feed roller as a pivot.

[Superbunny]

I set the out feed table with a straight edge and then as the timber comes out the other side I lift it a little with one finger ever so gently and this seems to work great to me. I'm of the opinion that as the timber leaves the cutters the weight of the wood forces the the last bit to be forced up so you get some snipe.:D:D

SB

[silentC]

That's pretty much what happens, although it's not as the timber leaves the cutters, because if it had left the cutters already, there would be no snipe.

Some people set their in-feed and out-feed supports a bit higher to make sure the wood is forced down on the table. There is a bit of give in the rollers though, so you don't want to lift it too high.

My thicknesser is one of those portable ones with the fold down tables and there is no setting for the in-feed/out-feed supports.

I once saw a story in one of the mags about a guy who made a curved table for his, which naturally forced the ends of the timber up as it fed through the machine - the longer the length the higher it was lifted to maintain an even pressure between the out-feed roller and the table. I don't know how he arrived at the radius of the curve. Trial and error probably.

Sounds like a lot of trouble to go to so I just lift the end if I'm concerned about it. 9 times out of 10 it's going to be cut off or machined into a tenon or something, so not an issue.