JJP-12 Combo...Mystery Part

[Larry Anderson]

This was in the box with the tools and guard. It's about 5x2x1 inch. Anyone know what it is?

[Matthew Bradburn]

I got one of those with my jjp-12hh! Hope it wasn't important...

[Van Huskey]

For use setting the blades. The real mystery is what the cutout is for.

[Trent Shirley]

Mine came with one of those as well but no cutout. May be they had a piece of stock with a cut in it and you happened to get that one.
I had the 10" rather than 12 though, perhaps it has a secondary purpose.

I did not use it, I put a straight edge on the table when setting up the blades.

Hope the 12" is more robust than the 10" was.

[Chris Nolin]

I remember this same conversation here on SMC about this weird part back about 5 months ago. I got the same piece, with the cutout, also. Yes, setting the blades. My theory is that the notch is there to indicate the distance that this "tool" should be dragged along the table by the knives when the knives are at the right height. Any more or less than the thickness of that kerf cutout means the knives are too high or low. But I admit, I've been using my JJP-12 for the last 4 months without ever having used it.

[Bas Pluim]

I think it's a safety device. Should you cut yourself on the knives/ carbide inserts, hold your finger next to the tool. If the cut is deeper than the kerf in the aluminum body, go to the ER. Otherwise, apply superglue and continue.

Yes, it's for setting the blades, but it is especially pointless if you have the helical head with carbide inserts.

[Van Huskey]

Mine came with one of those as well but no cutout. May be they had a piece of stock with a cut in it and you happened to get that one.
I had the 10" rather than 12 though, perhaps it has a secondary purpose.

I did not use it, I put a straight edge on the table when setting up the blades.

Hope the 12" is more robust than the 10" was.

The JJP-12 is a whole different world compared to the JJP-10BTOS, it probably weighs about 10 times what the 10" version does.

[Curt Harms]

I remember this same conversation here on SMC about this weird part back about 5 months ago. I got the same piece, with the cutout, also. Yes, setting the blades. My theory is that the notch is there to indicate the distance that this "tool" should be dragged along the table by the knives when the knives are at the right height. Any more or less than the thickness of that kerf cutout means the knives are too high or low. But I admit, I've been using my JJP-12 for the last 4 months without ever having used it.

Your theory is correct. Using a stick with 2 tick marks 1/8" apart to set planer knives has been around for a while. Both sides of the knife should drag the stick the same distance and each knife should move the stick the same distance. It seems quite accurate and doesn't require having the each knife at top dead center like using a dial indicator. Why would they be included with helical head machines? A worker/workers in Taiwan were told that each machine should have one of those. They were never taught to differentiate between straight knife models and helical head models. That's my theory at least.

[Van Huskey]

A worker/workers in Taiwan were told that each machine should have one of those. They were never taught to differentiate between straight knife models and helical head models. That's my theory at least.


I have not seen the packaging but if the bar is packed in a bag with other parts/paperwork needed for both machines it may be cheaper to just add it to every machine instead of having two line items and the hassel of the few straight knife machines that would certainly ship with the incorrect package.

[Larry Anderson]

Would have been nice if it was mentioned in the manual...but then we wouldn't have had this pleasant discussion.

[Jeffrey Makiel]

I think it's a safety device. Should you cut yourself on the knives/ carbide inserts, hold your finger next to the tool. If the cut is deeper than the kerf in the aluminum body, go to the ER. Otherwise, apply superglue and continue.

Oh man...you got me started: It's from a disgruntled Taiwanese employee that is slowly dismantling the factory and sending the pieces around the world.

-Jeff :)

[John Coloccia]

We did have a discussion about the notch some time ago, and I can tell you that it is NOT an accident. I've had two of these machines (one was a replacement) and the notched part came with both of them. I called tech support, they asked around, and no one at all can figure out what the notch is for. The "it's supposed to move a certain amount" theory is pretty good, but my knives are set dead flush with the outfeed table, so mine doesn't move at all.

[Curt Harms]

We did have a discussion about the notch some time ago, and I can tell you that it is NOT an accident. I've had two of these machines (one was a replacement) and the notched part came with both of them. I called tech support, they asked around, and no one at all can figure out what the notch is for. The "it's supposed to move a certain amount" theory is pretty good, but my knives are set dead flush with the outfeed table, so mine doesn't move at all.

I think the objective is to have a low tech no-batteries-required means to get all 6 ends of the straight knives set the same height & parallel to the outfeed table, then adjust the table height as required. At least that's what I did.