DJ 20 table sag

[Frank Gilbert]

I have a DJ 20 in like new condition and getting taper cuts on edge and face. After searching the forum I dread the idea of aligning the tables so here is the question. I measured sag on the outfeed table of .20 at twenty four inches from the cutter head. The taper on an a cut is a 1/16 or more on a 24 inch board after two passes at about the 1/16th setting. Deal is maybe I need another day or so of experimenting with table heights in relation to the cutter head and personal technique, however, if the table sag is something I should deal with I will jump right in. I will jump right into alignment when I purchase a spanner wrench which is apparently with the former owner :)

[Chris True]

.2 is almost a 1/4", that is huge and needs to be addressed. So large it seems like something must be loose in the table attachment although I'm not famiiar with the DJ-20 myself.

[glenn bradley]

The DJ-20 is a paralleogram machine. Table adjustment should not be bad if the table is not bent. If your manual is missing or not clear, go to Grizzly's site and pull the manual for a G0490; very similar. Be sure you are not jumping in for nothing. A good quality 48" straight edge is your friend. I have a 36" steel Lee Valley and it did fine, longer would have been better but, I couldn't cough up the dough.

[Leo Graywacz]

I don't see how it could be sagging that much. If you meant .02, then very possible. You don't need a spanner wrench. There are 4 eccentric adjustments per table. To access these you need to look in the top of the eccentric ring and there will be a hole. In this hole there are 2 allen set screws. You need to remove the first one and loosen the second one so you can turn the eccentric ring. There is a little punch mark on the ring. Put a magic marker dot next to this so you can return it to that position and use it as a reference.

Here is a PDF guide (http://media.ptg-online.com/media/dm/Articles/FAQs/JointerTableAdjustmentProcedureforJointerswithParr allelogramTables/20040123145450_J05.pdf) to help you along

[Dan Friedrichs]

You don't necessarily need a spanner wrench (I've used a pair of needle nose pliers). It's really not a hard job, at all. Just read and understand the procedure, and it won't take you an hour to do. The tables really should be coplaner with each other and the cutterhead within thousands of an inch - if you really have nearly a quarter of an inch, that is really bad.

[Frank Gilbert]

.020. Sorry. So at twenty thousands is that something that I should tackle for sure? I rigged a six foot hardwood lumber into approximating a straight edge and now I am thinking maybe I need to borrow a 48' straight edge and start over. I also own a four inch Delta Homecraft Milwaukee from the 1940's which using a 24" straightedge sadly shows the same story. Ugh.

[Leo Graywacz]

.020 is still a bit of sag. You sure could make it better. Are you sure your front table isn't just a bit high or low to the cutterhead?

[Frank Gilbert]

Very grateful for the responses. And will hit this hard tomorrow. The front infeed is about correct as it takes off about a 1/16 on each cut when set at 1/16. I used the straightedge and a high quality rule to measure 1/16 from the top dead center of the cutter to the infeed front table. One thing I didn't do is check that on each of the three knives.

[Leo Graywacz]

When you do the adjusting don't do it to the knives but the apex of the cutterhead. Then after you fix the tables you can readjust your knives to the new table adjustment.

[Mike Barney Sr]

If I remember correctly, The infeed table is 42" and the outfeed table is 30", approximately. I cannot urge you enough to get at least a 48" machinist's straight edge like a Starrett or equivalent to gauge the tables' parallelism (is that a word?) regardless of the cutterhead. That is the first thing you need to address. I would even urge you to get a 60" straight edge for more reference. A straight edge from the local hardware or lumber store is not good enough. Once the tables are perfectly parallel, you can set the outfeed table's height, and then set the knives in the cutterhead.

I had one of the last 4" Delta jointers to roll off the American assembly line (post Rockwell) before it was discontinued and other models went overseas for production. It had dovetail ways on the tables. I forget how alignment was acheived on that. I never had any problem with it.

[mickey cassiba]

DJ 20s in all of their iterations from first to latest, are straightforward and while a little tedious to dial in, with the proper reference(+1 on the precision straightedge). Before you start, remove it from the base, flip it over, and carefully inspect the "innards", paying special attention to the adjuster mechanism. Everything is pretty beefy, but a bent or broken part will drive you buggy, if you're unaware of it. And things do break.
The actual adjustment has been pretty well laid out here, so I'll not add to the mash , except to add, take repeated measurements...and check them. The manual and parts list should still be available at Dewalt service net. If not PM me. I have the PL. Not sure about the user manual, but as I recall, it wasn't very forthcoming about adjustments.

[John Hollaway]

I too have a DJ-20 in need of some tweaking. Can anyone here identify any alternate sources of tune-up info that would apply to the DJ-20? Thanks.

[Ron Bontz]

My DJ20 adjusted very well just using the owners manual. I would only add if you are using a mobile base don't let it go thunk onto the floor. Heavy machinery can bend and break under it's own weight. Not to mention throwing things out of wack. A "person" did that to mine. He has never touched it since. Best of luck.

[Jeff Duncan]

.020. Sorry. So at twenty thousands is that something that I should tackle for sure? I rigged a six foot hardwood lumber into approximating a straight edge and now I am thinking maybe I need to borrow a 48' straight edge and start over. I also own a four inch Delta Homecraft Milwaukee from the 1940's which using a 24" straightedge sadly shows the same story. Ugh.

A couple things that will help you in the future....

.2 = 2 tenths of an inch = to roughly 13/64" strong
.02 = 2 hundredths of an inch = to roughly 1/64" strong
.002 = 2 thousandths of an inch = to less than half the thickness of a sheet of copy paper (roughly)

If your jointer is off by .002 I personally wouldn't recommend touching it. That's pretty darn close and your not likely to get it closer without a lot of anguish. Not to mention that much deflection over 4' will not cause your problems.

If your jointer is off by .02 I would re-check with a straight edge I was sure was accurate. If it still comes out off by that much then you will need to adjust. I would not trust a short (24" ) straight edge, nor one I don't know the accuracy of (piece of hardwood lumber).

I would first check to make sure your outfeed table is set correctly before messing with the tables. If the outfeed is off it can cause problems. As said the tables are not difficult to adjust, but it's not a picnic either. Then again my tables are 16" wide by about 8' long, so a little more effort was required!
good luck,
JeffD

[Chip Lindley]

Remember, a tapered cut on the jointer has as much to do with technique as it does alignment. If all pressure is maintained on the infeed and not shifted to the outfeed about midway, taper always results.

Alternate Source: If you do not like Delta's alignment method, get the manual for Grizzly's G0490. It's on the Griz site to download. I'm betting there's not a dime's-worth of difference between the two. Both jointers are pretty much identical, since Grizzly cloned the Delta/Invicta DJ-20. With either jointer, the table adjustments are turning a cam to raise or lower each side of the tables. Even an inferior straightedge should give results "in the ballpark" to joint a flat surface.