I think I know why the JJP12 is so incredibly hard to adjust

[John Coloccia]

I think I've finally identified the fatal flaw in the Jet design that's driven me to drink many nights. The two tables are joined by a piece of sheet metal. When you're trying to adjust the tables, you're always fighting the sheet metal that's trying to drive the tables back to wherever IT wants them to be. It's a very frustrating experience.

Well, it looks like the only reason to have the tables joined like that is so they both go up and down at the same time. My idea is to separate the tables (just cut the piece of sheet metal in half), and then rejoin them with something significantly more compliant. A metal rod, for example, that will have a good deal of flexibility but will still hold the tables more or less together when lifting or lowering.

Wondering if anyone's done this or considered this? I think it will make this a much more user friendly machine. Any thoughts?

[Mark Bolton]

Doesnt sound like a re-work would be that over the top but hard to say without seeing it. It sounds like you pretty much know the machine inside and out at this point so improving on it would seem probable. Perhaps hacking away at it with an angle grinder or whatever you choose will feel rewarding..

[John Coloccia]

I think my first try will be to simply remove the piece of sheet metal and see how it does. It can't permanently stay like that, but I can do the adjustment at least and see if it's significantly easier. If it is, it gets chopped up.

[Jamie Buxton]

Do you really need to tie the two tables together? For instance, my first-generation Hammer A3-31 wants me to lift each table separately. It isn't a problem.

[John Coloccia]

Do you really need to tie the two tables together? For instance, my first-generation Hammer A3-31 wants me to lift each table separately. It isn't a problem.

The lock is only on the infeed side, so there's nothing to keep the outfeed from slamming down unless they're attached somehow. Also, the fence attaches to both tables, so I'd constantly be putting a lot of torque on that flimsy sheet metal bracket also. If I had to guess, I'd guess that on the new Hammers, the fence only attaches to either the infeed side or outfeed side, probably for the same reason as I'm complaining about here. I don't think the fence attachment is much trouble, though, because it's pretty flimsy.

[Janis Stipins]

Holy cow, I just posted for the first time in many months to vent about this exact machine. I'm glad I'm not the only one.

I'll say that from my (hours of) experience aligning this machine, I don't think that the linkage between the two tables is the biggest problem. I have been able to adjust them more or less independently. The bigger problem, I've found, is that if you loosen the three lock bolts on the back of one of the tables (in preparation for messing with one or more of the cap screws), the ENTIRE TABLE can move, at which point you can cancel your plans for the next few hours.

-JS3

[John Coloccia]

Holy cow, I just posted for the first time in many months to vent about this exact machine. I'm glad I'm not the only one.

I'll say that from my (hours of) experience aligning this machine, I don't think that the linkage between the two tables is the biggest problem. I have been able to adjust them more or less independently. The bigger problem, I've found, is that if you loosen the three lock bolts on the back of one of the tables (in preparation for messing with one or more of the cap screws), the ENTIRE TABLE can move, at which point you can cancel your plans for the next few hours.

-JS3

Yes, you need to be very careful adjusting this beast. For this one reason alone, I just can't recommend the machine. The performance is fine, but the adjustments are amateurish. I wish wish wish I had just bought a Hammer.

But once the tables are separated, the whole irritation with the locking SHOULD go away, and that's a huge source of irritation, let me tell you. The way it SHOULD work is you bring the tables down and they come to rest on the front mounts. Then you lock it and nothing should move. The way it actually works is you bring it down and never really make solid contact with the bolts until you lock it, and that stupid sheet metal fights you the whole way.

I'm really pretty tired of adjusting this thing. The performance is really great, and someone's going to be very happy when they buy it from me used, but I'll be really happy when I have something like a Hammer or Minimax in my shop.

[Mark Bolton]

John, is there no way to somehow isolate the sheet metal piece from the tables either with some studs/jam nuts maybe some rubber grommets to keep the two tables connected yet put a little bit of more fudge factor in there. Just a thought?

[John Coloccia]

That bit of metal acts as the lock for the parallelogram mechanism, so it needs to be firmly attached to something. An interesting thought, though, is to do the adjustment with the cover removed, and then bolt the cover in place afterwards. At least you're not fighting it the entire time during the adjustment. After the fact, if it's warranted, I could even shim it with some washers so it's not contorted when I snug it down.

This time around, if I have a chance, I may actually video tape my procedure. I know a lot of people have trouble with this, and I do somewhat have it under control, sort of, so it might help someone else. We'll see how much ambition and time I have in the next couple of days.

[Steve Rozmiarek]

Just curious if one of you guys could post a picture of the offending piece of sheet metal, I've never even seen one of those machines in person, so a pic for reference would be great.

[Peter Aeschliman]

John, I've noticed a few posts from you on this topic over the years, so I know it has been bothering you for a long time.

Going up the causal chain one step, what do you think is causing the machine to lose its alignment so often?

With the machines I've owned, if they're out of whack, it's a pain to get them aligned. But once I get them aligned, they stay there.

Could your efforts be better invested in finding and fixing the cause of the misalignment? Or do you expect to have to keep realigning the thing going forward?

[John Coloccia]

John, I've noticed a few posts from you on this topic over the years, so I know it has been bothering you for a long time.

Going up the causal chain one step, what do you think is causing the machine to lose its alignment so often?

With the machines I've owned, if they're out of whack, it's a pain to get them aligned. But once I get them aligned, they stay there.

Could your efforts be better invested in finding and fixing the cause of the misalignment? Or do you expect to have to keep realigning the thing going forward?

It holds it's alignment pretty well, actually, but when I have to move the machine to reorganize, I usually have to realign it. I probably reorganize things every year or two, so I end up having to fiddle with it every year or two. Functionally, the machine is fine. It's just the setup that's really not easy. Every time I do it, I learn a little trick or two that makes it easier the next time. I think removing that stupid front cover is going to make things a LOT easier. I may not even need to split it. Just remove is for the alignment and then reinstall when I'm done.

[ian maybury]

Not a recommendation since I'm not familiar with your situation John, but might you be able to install some sort of flexible deal in the mountings. e.g. http://www.vibrationmounts.com/Store...=Products1.htm Lots of varieties if you Google 'anti vibration mount' and look in the image view.

[Janis Stipins]

Just chiming in here with my experience, which is more limited than John's...

I've had this machine for just over a year, and have had to align it twice: once when I first got it, and once just this week. It seemed to stay very well-aligned until all of a sudden last week I noticed I was getting pretty significant snipe while jointing. The outfeed table had lowered a bit relative to the cutters, and I ended up having to realign the whole thing.

I don't actually know what caused the alignment to change. It's possible it happened slowly and I just noticed it recently, or perhaps something slipped recently. I do keep it on a Vega machine mover, and (gently) roll it out about two feet before using it, and then back again when I'm done. But I've been doing that all year, and haven't had any alignment problems until just recently.

In general I agree with John that the machine works really well when it's working well, and somebody is going to be happy to buy it from me used. I'm not sure if I'll get another combo machine; I'm suspicious that the basic design of a combination jointer/planer is going to cause even the good ones to go out of alignment more often than a standalone jointer. Maybe I'll get the Grizzly Ultimate that weighs 1200 lbs. Its manual says it should only have to be aligned once in its lifetime. :-)

-JS3

[John Coloccia]

I've often thought of getting separates. The deal breaker is the pork chop blade guard. The European style guard is so much better and more useful that it's become an absolute deal breaker for me. IMHO, the pork chop guard is completely unacceptable in 2014 and it should be killed off. If not for that, I would consider separates.

But the combo machines are perfectly fine. It's just this particular one is a pain in the butt.