JET - JJP-12HH Planer/Jointer Combo with Helical Cutterhead (Rating: 4)

After two months with the JJP-12HH, I'm ready to share what I've learned. The bottom line: this is a great tool and I'd recommend it for the serious amateur. I wanted a lot of capability in my small (12×15) shop and am very happy.

Shipping & Unpacking

This is a large and heavy tool (my wife says I'm no longer the "biggest tool in the shop"), and it comes almost fully assembled. You will need to get the crate where it's going intact. Do not expect to bring in pieces. Also, I highly recommend asking the shipping company exactly what service they are providing and what that means. I got "threshold service" which meant they bring it past the threshold of your house. What I didn't understand is that I don't get to choose the threshold. Lesson learned with no real harm done.

Once the crate was in the shop, getting it unpacked and onto the rolling base (the recommended JET-brand base) can be done by one person with some patience and leverage. Others have complained about the thick "goop" protecting the beds, and I understand why. It is indeed a real pain to remove with kerosene (the manual-recommended solvent). The machine comes with a cord (3 wires) but no plug, so you'll need to supply your own.

Setup and Tuning

I didn't need to adjust anything for planer-mode, and honestly don't know how I would, although I gather it is possible. Tuning the jointer was a bit of a pain. I know, it's always a pain, but I'll say this. Although I haven't set up any other jointers, I have (in my profession capacity) tuned laser cavities and other complex fussy devices with lots of knobs and tight tolerances. This thing could have been engineered better to make the process easier. For each table, you have two screws at the front with locking nuts. At the back you have a plate with three bolts holding it down, and four allen set-screws to adjust its position. For clean adjustment, that's too many degrees of freedom. Also, they're all very close together, which makes the table angle pretty sensitive to that adjustment. Don't get me wrong. You can do it systematically and get the thing dialed in to perfect. I got mine to within 0.001" everywhere in about an hour. I gather that the HH (helical head) model is actually a bit easier as there's no tuning of individual knives and the cutterhead itself is fixed.

Switching between modes is very easy and the jointer seems to be very repeatable. That is, the act of switching doesn't screw up your jointer tuning. The only downside is that you lose your planer height setting when you switch to jointer mode. I will probably get a digital height gauge to help, but the scale and knob are really very good, so you could certainly get away without them.

Planer Use

The thing is fantastic. The longish bed along with the VERY firm and widely set rollers mean that there's really no snipe. I've planed 8/4 maple 8" wide and 6' long, and from the moment it grabs the wood, there's really nothing for you to do but walk around to the other end and grab it when it lets go. The capacity is 12", which is slightly smaller than a lot of lunchbox planers, and I've run into that, but it hasn't been problematic. By the way, it's VERY close to 12", no more, no less. There are little guard rails on the sides of the planer bed to help track and align the wood if you put it in at too much of an angle (which works great) but they do set a hard limit on what will fit.

Height adjustment is very smooth, very easy, and very precise. It's easy to take some calipers to a just-planed board, decide you need to take off 0.037, and then (using the scale on the handle) raise the bed by exactly that much.

Jointer Use

I'm similarly pleased with the jointer mode. Sure, the bed is not super long. You'll want some rollers if you're doing long and heavy boards. After quite a lot of both face-jointing and edge-jointing, though, I"ve got no complaints. Some have complained about the fence. It is indeed flimsy-seeming compared to the rest of the device, but it has stayed solid and square for me.

Helical Cutterheads

These things are magic. I have basically stopped paying any attention to which direction I feed in. I see no tearout whatsoever. Also, within the first week I dinged a couple blades (a knot came loose while planing some aromatic cedar) but a couple minutes with the included torx driver and I'm up and running with perfect results. Magic. Worth the extra $1000? Your call, but I'm happy with my choice.

Dust Collection

I think the thing claims to need 400 CFM or something like that. I plan on a better DC system some day, but figured I'd plug my tiny shop vac (with 5-gallon dust deputy) in and see what happened. It works great. although getting the hoses all set up was a bit of a pain. I see the occasional chip left on the bed, but it works really well. I'm sure with a real DC system the thing would be perfect. As others have noted, the host points in different directions in the two modes so you'll have to plan for that. Also, you need to come up with a solution to keep the hose out of the path of the planer outfeed. This is not a big deal, though.

Mobile Base

The thing works well on a mobile base. I'm very happy I did that. I need to move it a bit to plane more than 5 feet or joint more than 6, and the base makes it easy. When it's locked however, the thing is rock solid, even when dragging a 10-inch wide piece of maple over the jointer, which takes a surprising amount of force.


OK, here's my only other "problem". You cannot run this thing continuously, as the motor will overheat. To JET's credit, it's designed to cut out gracefully. It just shuts off and won't turn on until it cools. After a break, though, just push the button and you're back in action. From a cold start, you might get about 45 minutes in one go. It's hard to say for sure though, because who works that way? I called JET to make sure a) I wasn't doing anything stupid and b) there wasn't a problem with the machine. After careful debugging of my electrical system, they basically said "this is for a serious hobbyist and not a professional shop, and is not intended to be run all day". That seems reasonable to me. The guy even offered to duplicate my circumstances in their shop if I decided to push it. That is, he was willing to run the same wood (type, width, length, cut depth) for the same amount of time as me just to see how well their machine took it. That impressed me. Since then, I've just tried to mix up my routine a bit more. There's always other stuff to do.


Overall, I'm very happy with this thing. My two annoyances (jointer tuning and heat) are easily surmountable, and the performance and capabilities of this thing are fantastic. I stressed about the purchase for a while, but ultimately I'm thrilled and would do exactly the same thing all over again.

If you find this helpful or have any questions, please don't hesitate to post.