Calibrating Jointer Bed Parallelism

[Patrick Kane]

Had a few minutes to look over my used machine last night, and the beds are definitely not coplanar. My 36" straight edge is showing 1/32" gap with the beds set level to one another. In other words, the infeed table slopes down as you move away from the cutterhead. Ive never actually adjusted a parallelogram bed jointer before, and i dont have a manufacturer's instructions to go off of on this one. My DJ20 was ok and not worth messing around with for the 8 months i had it. After that, the 12" grizzly was surprisingly dead on the whole time i had it. Truth be told, the only time ive adjusted a jointer's beds were for a friend with his 8" dovetail ways.

Unfortunately, youtube only has grizzly and the woodwhisperer to go off of, so hopefully someone here can give me some real insight on how to do this task. Looking at the machine, there are 8 holes in the beds that correspond with the nuts that adjust the cams. I assume these holes hold set screws or bolts that keep the cams in place after adjustment. They are filled with years of crud right now, so i cant confirm whats in there. Next, ive seen two ways of doing this. Setting the outfeed table parallel to the cutterhead body, then adjusting the infeed table to be parallel to the outfeed table. OR, ive seen people suggest to raise both beds to their max height and then set them parallel to one another that way. I imagine all roads lead to rome in this instance, but which is the preferred/easiest method? The cam adjustment nuts dont line up too well with the chassis cutout on the infeed table, which leads me to wonder if the makers didnt intend for the beds to be raised to max extent when making adjustments. Finally, what am i supposed to do with these cam stops on the side of the beds? I dont think ive ever seen anything like that on a jointer, and im not sure what purpose they serve. I kind of get it on the outfeed table to always brin it back to exact height with the tersa knives, but i might be missing the point.

Thanks, apologize for my noobness on this one. I know its been covered before, but a few of my challenges are specific to this machine.

[Ken Fitzgerald]

I'd set the outfeed table parallel to the cutter head. Then I'd set the infeed table parallel to the outfeed table.

[Warren Lake]

I just have the regular old style head. On jointers I set outfeed parallel to the head, then knives .050 above the head to within .0005 at least on the 14" jointer, havent put new knives in the Griggio yet but they are waiting. Wider might be harder to get that accuracy though found with knives you can tap them up and down a bit. Then make the infeed parrallel to the outfeed.

IF the knives are worn it will change your measures, no idea how far those type of knives extend above the head but curious to know. Is that the type where you tap them and they come out. Then they just set exactly the same each time new ones go in so then I wonder what tolerances they have.

[Brian Holcombe]

Warren, Tersa’s are pretty consistent in my experience. I have mine set above the outfeed enough to barely lift the material when I rotate the head. If I change knives and check again it will be exactly the same. However they make those knives they’re extremely consistent.

[Warren Lake]

thanks Brian, there should be a difference for wear id think as there is with regular steel, you likely adjust your outfeed for it at times. Be nice to know from a dial what they are above the head. I tested to get my number and its worked well on my machines.

[Mike Kees]

Patrick that jointer is freaking identical to the Paoloni that I just bought. I set the outfeed table parallel to the cutterhead and then the infeed to the outfeed. The holes in the top of the tables are indeed adjustment screws. First you loosen off the nuts behind the rubber covers on the side and then adjust the set screws from the top. When all is good re-tighten the nuts on the side and install the rubber covers.This system is far easier to adjust than the DJ-20 that I have. Do you have a cutterhead guard with this machine ? I had a post on that topic and there were some great ideas shared .In the end I designed and built my own bridge guard. Mike.

[Andrew Hughes]

I think your going to need a longer straight edge. The 36 inch is good for checking tables for dips or humps
I would recommend a 72inch ideal. The best prices I’ve found are at suburban tools.
Some get the job done with less, I admire their perseverance

[Bill Dufour]

You might get better answers if you tell us the make. If the makers name is missing can you at least determine the country where it was made?
Bill

[Patrick Kane]

Mike, I appreciate the info. That’s actually the complete opposite of what I was going to do. Plan on tackling this tomorrow if I can.

Yeah, I assumed 38” would be short, but man a 5-6’ straight edge is $500-1000. My Craigslist has a long aluminum or cast iron straight edge for sale. Guy is claiming it was $2000, so I’m sure he doesn’t want to sell for $200. There are a couple 4’ starretts I might get. In the meantime I’ll see what results I get with the 38”Er.

[Darcy Warner]

You can make a pretty true straight edge with three play tips and 4 screws in each. Directions on line some place.

[Kevin Jenness]

One suggestion for an inexpensive long straightedge; if there is a shop nearby with a good panel saw, have them straightline a pair of 6" ply rips. If they mate well with no gaps, use one to set up your jointer and keep the other as a control. If they get out of whack over time repeat the process.

The Laguna Tersa head jointer I worked was quite consistent for knife height after changes, but sometimes needed a slight nudge of .001" or less on the outfeed table to get edge joints right on. The M42 knives we used seemed to require more frequent changes than the conventional HSS in the other jointers in the shop, but the ease of doing so made up for it.

[Patrick Kane]

I didn’t even think of that, I have a slider in my shop. I also thought about using the back side of a festool rail, but then I wasn’t sure how flat/straight those actually are. I might try a few plywood rips off the slider wagon to see how straight they are.

Ok, need a bit of advice on this snag I ran into. One, I just spent 3 hours on this damn thing. Started out with both beds sloping down and away from the cutterhead by about 1/8” over my 38” straight edge. Started on the outfeed table and got it level and parallel to the cutterhead. Went several rounds of slowly fighting the cam bolts before I had the whole thing +\-.001” over the 500mm. When you snug down the locking nuts, everything moves slightly. Moving on, set the outfeed table so the top arc of the knives hit .002”. The infeed table is really what tested my patience. Like I said, I had 1/8” to make up, and apparently that is just out of the extent of the cam adjustment. I needed like one extra quarter or half turn on the Allen wrench to lift the table up to be parallel to the outfeed. However, if I cranked that extra bit, the cam would begin to reset and the table would drop down doing the exact opposite of what I needed. Ended up lowering the front cams a bit to make up for the angled difference. Got everything to where my .001” feeler gauge was just biting into the straight edge and not sliding under. That’s within my tolerances, so I called it a night. Tightened the nuts up and then set the table st about 1/16” and started to spin the cutterhead. It went a quarter turn before a knife caught the lip of the infeed table. It’s just nicking it a bit, but enough to halt the rotation of the head. I need to lower the table to take 1/8” cut before the cutterhead is free to rotate without contact. A bit stumped on how to correct this. Not sure how to lower the whole cutterhead a smidge or raise the infeed table a bit without knocking it out of parallel with the outfeed. Kinda sucks, because I have the whole thing just about dead nuts on. 1/8” is a bit more wood that I normally need to take to clean up edges off the table saw, or even facing rough stock. On most shorter work pieces, 1/16” will just about get me flat on one face. Not to mention cleaning up tapers or any other finesse work I do at the jointer. Kinda need the full range depth of cut on this machine.

[Warren Lake]

something up there you should be able to take off what you want as little or as much. Never talked much about that with the old guy but talking once it was clear he took bigger amounts than I do or most of us. Patrick did you check how much the knives stick out to the top of the arc above the head with a dial im curious on that number.

[Matt Mattingley]

The first thing you should do is inspect how flat is the outfeed table. A dial indicator and a good flat straight edge Will be helpful here... as well feeler gauges.

Depending on what your machining… A good average should be the cutter-head knife edge should be 0.001 to 0.0015 above the outfeed table and parallel to a good knife circle. If you have adjustable knives cutter, the cutter block it should be at least within 0.005 parallel to the outfeed table. The infeed table should always be (within 0.001) parallel but with an offset to the outfeed table.

I have a segmented inserted head that usually takes a little longer to dial-in than conventional knives. But… once dialled in, usually there is no more fiddling. The inserts just fine their place.

I only have short (30”)in feed and outfeed table and I usually maintain less than less than a 0.010” ark on 8’ boards (maxing 0.025 arc). Clamps usually pull this together. But I like to orientate the arc if any and depending on grain. I usually like to flip-flop or (Bookmatch) the grain for table tops.

[Kevin Jenness]

It's hard to believe the machine was designed and set up that way originally but it is what it is. The fact that you raised the far end of the infeed table so much that you ran out of adjustment suggests that you might be able to correct the problem by changing the pitch of of the outfeed table so that its far end is relatively higher than at present and readjusting the infeed to parallel with it, but obviously that will require more hours of fiddling (now I think I know the origin of "fettling" a hand plane").

It appears from your previous thread that the tables have sacrificial aluminum lips. It may be that the infeed lip can be filed or otherwise modified to allow the cutterhead to clear it at a minimal cut depth.

Does the outfeed table lip show a large gap to the cutterhead at this point? If so, that would argue for readjusting the tables' pitch despite the time involved.

Does the outfeed table have a height adjustment mechanism separate from the four bolts that you are dealing with now? If so, that will make fine-tuning the machine much easier once you are satisfied with the relative planes of the tables.