Align Jointer Tables Parallel with a Dial Indicator 

What he said.👍

And he never said coplanar either!

Awesome! I hope this helps.

Nice!

Ha! I couldn't agree more! :) Thanks John

Zero a digital angle finder on the cutter-head and check that on the tables in the same orientation, adjust to zero :)

Actually it dosn't matter, they can be slanted left or right as long as they are slanted the same.

Thank you

+ponkkaa No sweat. Please let me know how you make out.

Great point! :)

Think about it logically though. All you need to be correct is point A (the base) and point B (the indicator). The bar in between can be any shape.

Any bow in the infeed would be indicated by a up and down dial indicator reading (non-linear) as you traverse the table. Using a straight edge and feeler guages to verify this method would be similar to using a tape measure to verify the accuracy of a digital caliper. You only need to confirm flat once - which can be done with this method. Periodically checking for parallel should be done with regular maintenance - a quick and painless process using this method.

Make a shorter setup and check the table against itself as you move across it. Or temporarily move the dial closer to the stand on the same rig if you can attach it half way.

First get the outfeed/infeed parallel with the long axis of the cutterhead. Then confirm that the infeed/outfeed tables are parallel to each other. Set the outfeed table to be flush with the cutterhead cutters at top-dead-center. Coplanar with regard to jointer tables is a misnomer. A jointer with coplanar tables will not function as a jointer - think parallel.

You could try. I’m not sure that it would support the weight.

Much easier to flatten and guarantee flatness for 4 small legs. Significantly less surface area.

thankyou

Keep in mind that the two tables are only coplanar when the depth of cut is zero. All other depths of cut other than zero are no longer coplanar - they are maintained parallel. It was an assumption that I made as well. I never explored changing the depth of cut and it’s impact on maintaining parallel.

Way easier adjusting parallelogram jointers. I have a hammer a3-31, and I’d much rather turn a few nuts that mess with shims. As far as keeping adjustment- I prefer not to mess with the jointer depth much, if at all. Keep it shallow and multiple passes. Moving things around always has the potential for shifting something.

The method described is very robust and very repeatable. I don’t understand the source of error that you are attempting to describe. Try it.

Thank you.

If you need to shim your jointer, only shim the outfeed table. After shimming the outfeed table you don't want to adjust it anymore. Only make adjustments to the infeed table.

I understand that. What I'm wondering is can the in feed table go out of plane by adjusting the depth of cut? If so I wold think that it would be wise to get the depth of cut you want and make sure the two tables are still totally parallel. Therefore I would want to leave the in feed side alone as well and what is the ideal depth of cut, 1/16th?

+sandmandave2008 The infeed table shouldn't go out when adjusting the depth of cut. I don't know if there is an ideal depth of cut. I increase my depth when boards are really out of flat and decrease when they're not. If it does go out of plane when adjusting then I'd do what you suggested by setting it at a non aggressive depth. A 1/16" should be good.

@@sandmandave2008 If your infeed table goes out of plane as you change cut height, you have a problem you cannot fix with adjustments. It is a flaw in the engineering of the machine. Should not be a problem if your system uses ways. I had a small, cheap jointer whose infeed pivoted on four parallel swing arms as you changed cut height. One or more pivot points was machined "off" so the arms were not really parallel. I set it to be on plane with my outfeed at 1/32" cut. If you moved it up or down it went off plane.

Pretty close? Ok.

Yeah. It's possible that my jointer was more closely aligned when I bought it, but over time it has sagged; I'll never know :)

Great! You can still use the DI. I think I've demonstrated close to a dozen alignment uses for a DI on my channel so far :)

I don’t see any problem with that. Would eliminate the need to flush four feet.

@@GarageWoodworks Just used this method to setup the new Grizzly Jointer Planer Combo I got last month....thanks for sharing

The only time the tables of a jointer are coplanar (in the same plane) is when the cutter depth of the infeed table is set to zero. If your infeed and outfeed tables are parallel with each other, and the infeed table is set to a greater than zero cutting depth, then they WILL be coplanar at a cutting depth of zero. If both tables are 4 degrees tilted but are parallel you will still have a perfectly functional jointer (as long as the tables were tilted about the axis of the cutterhead) that will also have coplanar tables at a cutting depth of zero; the only difference will be that the tables will be not parallel to the floor the jointer is resting on and will be tilted by 4 degrees. I think it's possible that part of your confusion is coming from the term "coplanar". Coplanar only means that two planes would occupy the same plane in space. Parallel jointer tables can cut wood whereas coplanar jointer tables will not. Please let me know if this is still not clear.

Agree.... I need to ponder more and perhaps have more coffee. :) It isn't setting well with me. :) It seems like the goal is to have them coplanar while flush with the cutters (0 cutting depth).

Again, if the tables are parallel with each other they will by default be coplanar at a cutting depth of zero; it's unavoidable.

Agree. All that is being aligned here are the ends of the tables. You did a great job and it is a novel idea for solving a vexing problem, and I agree that three points of reference make parallel surfaces, but that is by measuring from one stationary point. Your jig is moving as you measure. Also, that .003 difference early in the video should be made zero because that affects every measurement thereafter. I tried different methods to align my jointer tables also, but the best method seems to be a straight edge. You don't need to spend $100 to buy a straight edge. I use an extruded aluminum (window) mullion from Lowe's +-.0005 accuracy. If you could back up your method with a straight edge measurement after you were done, I would be impressed and concede that your method works. Dude! Take a breath before you pass out. lol

Robyn Secor How would I know if a mullion is within that kind of tolerance if I were to go to Lowe’s and buy one?

$100’s? Try $45. Why would I need to use a straight edge for this? This is a much better method.

@@GarageWoodworks I'm not saying I'd use the straight edge, but I would definitely own one. They really come in handy for other purposes. Ad $45 for a vood surface plate is SUPER cheap, where did you get it?

What makes you think I don’t own one? I own a long straight edge but I’d never use it for alignment. It’s not accurate enough and it’s a much slower process. See Woodcraft or Amazon for the plate.

@@GarageWoodworks the first of the video you said you did not have a precise straight edge...

Key word is “precise”. They need to be long enough to extend over a good portion of the in feed and out feed tables. And be precise.

It resulted from the act of pushing the jig. You want to take your start and stop readings at rest.

+Randy Allaway Chances are that if your jointer is performing ok, then it won't be that far off. Be brave :)

Funny, I actually took the knives out to sharpen them the other day, so I guess I might as well! Oh, and thanks for the video, Brian!

+Wave Trader Actually no. Once the shims are in you don't want to touch the outfeed adjuster again. I realigned the knives.

No. You are incorrect. This method would still detect non-flat tables as the indicator needle would rise then fall for non-flat. This method can also detect a twist: a twist could be confirmed by following the method in my video and use two paths down the length of the table - one away from the fence and one near the fence; both paths would not have the same readings on the dial indicator if the table is twisted. The straight edge method would also have to be done twice to detect twist. The ONLY way my method does not work is if both the infeed and outfeed tables have identical (and symetrical) twists/deformations which would be so statistically improbable that it could be stated as impossible.

Sorry... who says the infeed table isn’t rising as you slide the the base.

+Sigurd van de Wiel I squeezed this video in while filming a different project. I was running around.

What error? There is no flex. If there was flex I’d see it in the needle as noise. This method is repeatable. Double check with a straight edge? This method is accurate to the +|- 0.001”. That’s like confirming a caliper measurement with a tape measure.

@@GarageWoodworks Have you ever checked it with a straight edge or drafting triangles?

FAW3 It’s not rational to check an alignment performed with a high degree of accuracy with a less accurate method.

+attainableapex Incorreect. The tables are ONLY coplanar when they are in the same plane. Because a jointer does not function when the tables are in the same plane AND because the alignment occurs when out of the same plane, it is more correct to say "parallel". Think of bicycle tires when riding straight; the tires in this case are coplanar. Jointer tables, when cutting, are always non-coplanar; they are however parallel.

Parallelism is not limited to 2D in mathematics. Here's a 3-minute refresher on parallel objects (plane and line, two planes, two lines). Here we're concerned with two parallel planes, which when perfectly aligned end-to-end (zero cutter height) they become coplanar and thus useless as a jointer. www.brightstorm.com/math/geometry/geometry-building-blocks/parallel-planes-and-lines/