Out of round jointer cutterhead? Help

Same thing happened to me

Ellis Walentine

>Cutterheads aren't always perfectly aligned with the outfeed and infeed tables for one thing, so the fixed height magnets might not set the knives parallel to the table. If that is the case, you will have to revert to the original jack screws, which is not a sin or a crime. In fact, Dave will probably refund the cost of the magnets if you have to return them.

Your situation sounds a bit different, though, as you didn't mention an out-of-parallel condition but rather one of different heights from one blade to the next. I am fairly confident that Robland mills their knife slots accurately (within .001" of depth from one slot to the next), although an out-of-spec milling job can happen to anyone.

The first thing I would do is to be sure you have cleaned out and degreased the knife slots thoroughly so there can't be any dust or gunk preventing the magnets from setting properly. Also, check to be sure all the magnets are the same thickness. Try setting the knives again and if they are still out by that amount, odds are you will have to go back to the jackscrews. The nice thing is that the Esta system references off the bottom of the blade holder, so once your jackscrews are set perfectly, you shouldn't have to adjust them in the future.

See if this works for you.

Ellis Walentine, Host

I've used all the common knive alignment gadgets

Forrest Addy

>I've used all the common knive alignment gadgets at one time or another that referenced from the body of the head or used magnets and never ever got a good concentric installation where the knives were set within reasonable tolerance.

The only way of installing knives is one that (a) registers from the outfeed table and (b) gets the knives within 0.0005" TIR (total indicator reading) of each other at their zenith. You can run but you can't hide: the jointer knives (and the planer's too for that matter) have to be accuratly set if acceptable work results are to be obtained.

I use a Brown and Sharpe bench gage and a dial indicator with a mushroom button on the plunger. The "Roticator" gadget and others like it work well too.

If you want your knives to cut equally and in registration from the outfeed table you have to take steps necessary to ensure it does so. Shortcuts and magnets seem simple but they are plausible gimmicks sold by hucksters. You want good results; use proven methods.

Amen to everything in Forest's reply

bill tindal, E.TN

>I just set new knives in my cutter head and for the first time used essentially the arrangement Forest recommends- magnetic base, dial indicator, mushroom point. My cutter head doesn't have jack screws so things are more difficult. Never-the less this arrangement made for a quick stress-free installation, as opposed to all the other ways I have tried. I try to get them the same height to +/- .001 and without jack screws that is as good as I can do.

If the knives aren't all the same height you will joint a scallop,and the high one will get dull real quick.

PS Things will go better is the knives are ground perfectly straight. Some sharpening shops fail to get them straight.

slighty off the subject but...

Randy Johnson Connersville, IN

>although an out-of-spec milling job can happen to anyone.

A local gun dealer (50 + years in business, 92 years old, and still working) once had a revolver cylinder that was chambered in two different calibers, .22 LR and .22 mag. It was made by a quality maker. Roy said they told him over the phone that such a mistake was impossible. He told them it must have been possible because he had the evidence in his hand.

BTW, some of the boomers here that took machine shop in high school may very well have used a book he wrote.

Re: Same thing happened to me

Geoff in Madison

>the infeed and outfeed cutterheads seem parallel to the cutterhead.

I'll double check the height of the magnets, knives and knife holder.

Going back to jack screws isn't an option---the Robland doesn't have them. It uses springs which made it impossible to get the blades parallel which is a big reason I went to the ESTA system in the first place.

Take the head to a machine shop

Forrest Addy

>Take the head to a machine shop and have it drilled and tapped for UNF (fine standard thread) jack screws. Be sure they know what you're talking about and understand what you want them to do. Plain vanilla socket head sap screws should work fine so long as they are located soe the get good purchase under the knife and there is access for the allen wrench.