jointer setup

[Eric John]

evening all,

So okay , been playin a bit with the jointer i brought home (dj20), I do need to change knives.
I have been cautious to not get overzealous, I dont want to overadjust my self into a useless machine.
However, I notice the cutterhead is .003 out of alignment. That is to say, when the outfeed table is .015 above the cutterhead at TDC at the fence side, the cutterhead is only .012 at the operator side. Shouldnt that be dead-on? or d o most guys try to make up the difference setting the knives to the table.
I guess the question is how close is close enough? I dont mind spending the time to adjust it. I'd just like to know what is a reasonable tolerance in the real world.

Thanx in advance for any advice guys

Eric

[John TenEyck]

Yeah, they should be the same on both sides, and everywhere in between as well. First, I'd check to see what they are in the middle. If it's half the difference then the knives are most likely straight and were just set lower on one side than the other. If it's not half the difference in the center then the knives probably weren't sharpened straight, and might not have been set the same side to side, also. I don't know how wide your jointer is, but I try to get mine within 0.002" over their 10" length, and I try to get them no more than 0.002" above the outfeed table. Sharp is good, so if yours aren't it's worth the effort to sharpen them or buy new ones and get them mounted correctly. Then wax up the tables and fence and you'll be good to go. Hope this helps.

[Andrew Hughes]

How about the infeed side?If it measures the same can you shim the cutter head?

[glenn bradley]

You are wise to be careful not to put the machine out of alignmet if it is actually the knives that need adjustment. Position the cutterhead so that the knives are out of the way and confirm that your tables are coplaner with your straight edge. If they are not, go ahead and take care of that first but, I'm betting on the knives. From your desctiption, I would say that initially the knives were just not set well and I would adjust those first and see how the machine performs.

As Andrew mentions, the cutterheads are positioned at the factory with shims but, I assume this is a used machine and someone probably would have noticed before now. Adjusting to worn knives may not be the best use of your time either depending on how bad they are. JMHO.

[David Kumm]

The cutterhead is likely that far off and there is no easy way to fix it. Check that the bolt on lips are actually at the same level as the table. On my DJ20 they droop .003 from the edge of the cast iron table to the cutterhead-three inches away. Make sure you set the knives from the cast iron as well. .003 isn't that bad and the knives can make that up as you want to set them relative to the outfeed table. If you carefully look at your tables with a good straightedge you may find they are not straight by that amount. The dj20 is a great jointer but jointers today are not made to very tight specs. The only jointer I know of that has a cutterhead adjustment is the old Porter 300. The tables can be adjusted on the DJ by loosening the set screws and turning the eccentric discs so you can get the tables dead on to the cutterhead if you desire. The most important thing is that they are coplaner. Dave

[zayd alle]

Eric -- I just sold a DJ20 I had for a few years. Glenn is right to first check coplanarity of the tables -- the probability is that the alignment issue is in the knives. But keep in mind that the DJ20 has more adjustment flexibility than a jointer with tables that ride on sloped dovetailed ways. There are four eccentric bushings under each table (one at each corner) that can be adjusted separately. So if you discover that your tables are coplanar and still sloped relative to your cutterhead (which you can measure against the body of the cutterhead rather than the knives), I'd adjust your tables to the cutterhead using those adjustment bushings rather than try to shim your cutterhead. A spanner wrench is all you need for the adjustment. There is a recommended order/procedure for the table adjustment. I found it online. Good luck!

[Frank Drew]

I think you could live with the slight cutterhead/outfeed table misalignment if the infeed and outfeed tables are coplanar and if you accurately set the knives at tdc to the outfeed table.

[Eric John]

Thank you everyone for your help,

spent today on and off, tweaking it a little bit. I believe the tables are co-planer to about .001 to .0015. And set the new knives to the out feed table, (actually the knives are a little high, about .001) still have to play with that a little I think. So far i tried using a little and the results are pretty good, not great, but I think thats the operator inexperience. (a little convexity on some of the boards.
I guess there is to be a learning curve.
Thanx again to all

Eric

[Andrew Hughes]

I had to shim the cutter head on my oliver.It was really easy.Loosen one nut slide two sheets of paper in and tighten.Keeping the tables inline with the cutter is important for squaring your stock with the fence.Just make sure the fence is square after the cutter head.Thats how i roll.Hope this helps.I was looking at the dJ20.Before i got my oliver.It seems like a good machine. Andrew

[Paul McGaha]

I use a jointer pal to set my jointer knives. Really easy. Sets the knives even with the outfeed table.

If my knives are out a couple of 1/1000's I dont think I would notice?

PHM

[Russell Sansom]

It's not practical or necessary to shim anything on a DJ-20. The 4 eccentric bushings allow you to tilt each table to you can make it level with the cutter head then coplanar between the tables. Unless there's something terribly wrong, you have complete freedom to adjust the two tables. The system is a bit fiddly to adjust, and the several I've worked with all have personalities of their own.
I hope you realize that you need to map the surface of the two tables before you proceed. This is mentioned in Delta's set-up instructions. If you try to measure co-planarity and one of the planes has a .007" dip right where you're measuring...you will inadvertently be .007" off. This is completely avoided by mapping first.

BTW, there are several other modifications and adjustments that a DJ-20 might need. See my recent post. If you don't fix the sawdust chute, a dust collector will be moderately worthless ( the chute is open on the top! believe it or not ). And the factory installed many motor mounts backwards, so the pulley is backwards and can harm the motor. And several others.

[glenn bradley]

Shop made Jointer Pal - - I used a piece of scrap 1/4" glass left over from an old glass shelf. A drop of super glue to apply 3 rare earth magnets in a precise row (watch your polarity) on top of the glass near the leading edge. Hold the glass to the outfeed table with the knife to be set loose. The knife is pulled up to the glass by the magnets and you tighten it. Rinse and repeat.