About to throw jointer in the river

[John Vollrath]

I appreciate everyone’s sympathy in these trying times. Fortunately, yesterday my new hobby (traditional archery) arrived in the mail, so I had a good reason to pause the jointer tinkering.


It sounds like my understanding of setting up this baby is pretty spot on. In order to avoid more confusion, I started from the beginning with measurements. The indeed table is pretty flat, with a .0015” dip in the middle (front to back), and the outfeed table is similar, perhaps .002” in the middle. Both seem pretty in spec to me.


I then took to double checking parallelism. One thing I’ve struggled with in measuring this is using the feeler gauges under the straightedge on the far end of the outfeed table. Since that end of the straight edge is far from the support, I found it difficult to discern whether the feeler gauge was fitting, or actually raising the straight edge. I decided to whip out my magnetic dial indicator to help me see if the feeler gauge was raising the straight edge.



Here's how it worked with the 11mil feeler gauge (you can see the feeler gauge raised it 1-2mil):

And here's it with the 10mil feeler gauge:


So after doing this in all four corners of the outfeed table, I found the edges closest to the cutterhead to have 13mil clearance, and the rear edges to have 10mil clearance.

Before continuing further (next I would measure the cutterhead being level with the infeed table), is this 3mil tolerance acceptable? Should I shim the outfeed table to raise the cutterhead end a tad?
Also, do you think it's accurate to use the straightedge like this? The veritas 50" straightedge is pretty heavy, and I've always wondered if having it extend so far from it's support point would have it sag?

[Kevin Jenness]

I am not understanding your use of the straightedge. Are you registering the short end of the bar on a short section of the infeed table? If both tables have a dip in the center, why don't you rest the ends of the straightedge on the ends of the outfeed table and measure the gap below the overhang to the infeed table?

This is where a straightedge that is as long as the jointer can be helpful, as you can assess overall parallellism without being thrown off by the table deviations. Also, I see that the spec for the Lee Valley straightedge is +/- .003" so you are doing some guesswork from the start as to the table flatness. I know that many people are able to adjust jointers adequately with extruded aluminum levels, but I have never regretted having a 6' steel bar qualified by a certified inspection shop to .001" for this kind of work. Maybe it's overkill, but if you could rent or borrow one you might get some different measurements.

I would be wary of using a dial indicator on the rounded top surface of that bar.

Let's say that your measurements are correct and that the far end of the outfeed droops .003" from the plane of the infeed. Looking at a picture of the 1018 it appears that the inclined ways are about 8" long while the tables are about 30". A .001" shim at the bottom of the ways would kick up the table end about .004" in theory, and that might do the trick. Or it might be too much, but experimentation will tell.

This demonstrates a weakness of this jointer design. If the (well seasoned cast) tables are accurately ground after assembly to the base they should come from the factory coplanar and stay that way. If not, the possible adjustments by shimming the inclined ways are gross at best.

Have you checked the tightness of the gib screws? if the upper ones are loose that could cause a table end droop.

If the jointer worked well prior to swapping out the cutterhead, it is hard to see why the tables need adjustment other than outfeed table height. If the cutters are not parallel to the tables then shimming the pillow blocks and adjusting the outfeed height should restore the situation. Use a straightedge and feeler gauges rather than a dial indicator for this assessment.

[Mikail Khan]

Does this jointed produce an edge that is not straight?

If it gives straight you a straight edge on the jointed side you are ok.

How much you take off the back half of a board could be as a result of the board or technique. Bowed boards should be jointed with the bow down (front and back touching).

MK

[Matt Day]

You might have a severe case of analysis by paralysis. A straight edge, feeler gauge, and dial indicator - new one to me.

They’re called feeler gauges right? So if you feel resistance when under the straight edge, that’s where to stop. You shouldn’t need to shove it under so hard you lift the straight edge up.

I suggest taking a break from it for a week or so, coming back and starting fresh. The woodwhisperer’s video I linked to is a great instruction, as is Bob Vaughn’s Classic one here:
https://youtu.be/VRnrWOwun68

Don’t over complicate it. But I know how crusting it can be sometimes.

[johnny means]

Any nicks in the cutter head will magnify the problem. Even dull cutters is a problem. But you did just install the head back in January and the inserts should be fine. I suspect your new cutterhead produces a scalloped surface finish similar to the Byrd head. The outfeed table should be set just below to the lowest cutting point of the head by a couple thousandth. This assuming the jointer is true (flat, tables parallel )

Will this idea ever go away? What is the lowest cutting point if a jointer's depth of cut can be adjusted?

[glenn bradley]

Assuming the tables are already coplaner the quick and easy way to set outfeed height that I have seen is:

Lower the outfeed table below the cut height and make a cut that extends over the outfeed table surface as shown in the top image of the diagram. Hold the material in place and shut off the machine.

outfeed height setup.JPG

Raise the outfeed table till it touches the cut surface as shown in the bottom image of the diagram. You're done.

It seems all too easy to get lost in the woods with these machines. If the difference between highest and lowest spots on the table is a few mil I'm sure you are within tolerances of the manufacturer. Out favorite measuring stick is the result and you are getting poor results.

I don't know that we have confirmed that you are using a board no longer than your infeed as a test board. This will assure your material is fully supported and that you and the machine are in control of the cut. Things to help you keep your sanity while making test cuts:
- nice slick, waxed tables and fence
- the board is not longer than the infeed
- the board is not convex (belly) side down
- pressure on the material at the infeed is only sufficient to control the material, not excessive
- pressure and feed effort is shifted to the outfeed as soon as there is sufficient material leaving only controlling pressure at the infeed
-- the freshly cut surface is your reference surface
-- pressure on the outfeed is hand over hand in the same basic area of the table

Consistency during each test cut will yield results that can be compared. A slightly different method for each pass can yield varied results, wastes your time and increases frustration. The good news is that once you've got it set, it should work consistently for a very long time.