Jointer knife adjustment...

Re: Jointer knife adjustment...

Jake

>I don't have an answer for you but I am curious as to where you got your knives. I too have a 6" PM jointer which needs the knives replaced. It will be the first new set of knives since I bought the jointer.Thanks,Paul

I agree 1 inch is too much

Chad Pearson

>My jointer manual says 3 mm. It's a different brand but the physics should be the same.

Re: Jointer knife adjustment...

Jerry Nicholson

>I go for about .25 inch on my 6 inch Delta. One inch might be right if you had a really big cutter diameter but I think on a small jointer you would get grossly convex results.

Jerry

Re: Jointer knife adjustment...

Barry Irby

>I set mine by ear. I set them to be level with each other and then adjust the outfeed table so that they "snick" the knife. I can barely feel it and actually listen for it. In the end, my test is that I take a piece of hardwood that is already straight and joint it. I look for two things. As the knives start to cut, the piece slides onto the outfeed table without hitting the leading edge and being stopped. And, that there is no snipe on the trailing end.

I have tried the method of letting the knife lift and move the ruler, but it did not prove reliable for me.

Disclaimer. I am not a jointer technician and I fumbled through the process and found that the above works for me. YMMV

Thanks Jerry,. Makes sense, Harvey Smith's

vlparisian - Houston

>article was for a 30 + year old Rockwell Delta Jointer. I suspect his cutter head must have been significantly larger than on the PM.

I went ahead and used approx 3/8 inch movement of my steel rule. This produced a good sized snipe at the end of the jointed edge.

In the mean time found the owner's manual for my PM. (In a notebook on the shelf where I keep these things duh.) The owners manual specifies -0- height for the knives, but that setting is just wrong, and I have some convex jointed edges to prove that.

I'm going back to it now with the approx 1/8 inch movement that I measured on the damaged knives.

Victor, wasting time with this.

Re: Jointer knife adjustment...

vlparisian - Houston

>Paul, Call the Cutting Edge in Houston 713-981-9228 or on line www.cuttingedgetools.com. Steve has them in stock I believe Amana brand and be able to help.

I Think Size Does Count...

Jim Rahbe, Bedford, TX

>Victor,

I use this basic idea to set my jointer knives and I believe that a one-inch movement is about right. I think the goal is that no matter which knife, or where on the knife you set the ruler, that the movement is the same amount, not that it move a specific one-inch. I would think that the smaller the movement, the less you could tell the difference between one test position and another.

That said, I�ve only had experience with my little 6� Jet Jointer, but it works for me.

Jim R.

Re: Jointer knife adjustment...

Bob Lemon

>Victor, The distance that you move the rule means very little, but somehow you have to get back to your original starting point with the out feed table and have the knives the proper height above the cutter head. I've always used the 1/8" travel when using the straight edge method. I do set the out feed table, so that when sliding a trued board across the cutter head FROM the out feed table, I get a slight noise but no detectable cut.

One little hint that never seems to mentioned, after putting a little clamping pressure on your blade, they can be tapped up or down with a small brass or aluminum rod. This allows very precise setting.

Bob

Re: I Think Size Does Count...

Mark Nowicki

>Jim:

I follow the same method. I marked two vertical lines on my fence to make it easier to observe the distance, (about 3/4" on my 6" General)

Mark

Re: Jointer knife adjustment...

vlparisian - Houston

>Brass or aluminum Hmmm.

I was using a scrap piece of oak to tap the blade home against the jack screws, and at one point the knife caught the end grain and the knife came up about an eigth of and inch. oops.

I believe the theory of the straight edge or steel rule method helps to by getting the knife height even front to back and uniform for each position on the head.

Seems that the Badger Pond article could be updated a bit to reflect some new information. For instance, I know I will go through this again in a few months, so instead of marking my lines with a pencil, I used a scratch all. two results, #1 a finer line and #2 that's a step that won't need to be repeated next time. Another thing, if you use the markings on the rule to measure exactly how far the rule is moving, you will only need one line. Just drop the ruler down so the end of the rule touches the line and read the distance off of the ruler each time.

Victor

Re: Jointer knife adjustment...

James Dillon in MD

>I have had good luck using the 1/8 inch forward movement on my 8 inch General. Like Barry, I have it nice and quiet in the shop and aim for the jointer blade just grazing the edge of a steel combination square that is sitting edgewise on the outfeed side. I end up doing it more by sound than anything else. I may have to do it several times to get it consistant on both ends of the blade. Works for me 8-). One inch seems like way too much IMHO.

Jim

Humm, The length of travel would ~

Keith Newton

>More or less be equal to a chord, which would mean greater height for a smaller diameter cutter head.

For something with a 2" diameter head, one inch of travel might be more than 1/8" deep snipe.

Even for my 5" diameter head on a 12" I usually shoot for ~1/4".

Something to remember about snipe on the trailing end of the board. For each consecutive pass, it will be lengthened or added to the last one. That is to say, that if you had a 1/16" snipe 2" long on the first pass. On the second pass, when the first snipe dropped off of the infeed bed, it would induce a 4" long snipe, and 6" on the next pass. Not to mention the other ills associated with knives set too high.

Question for Victor...

Jim Rahbe, Bedford, TX

>Victor,

I re-read your question and have a question for you�

Are you using Harvey�s method to set the knives all to the same height, or to set the out-feed table height in relation to the knives?

Step 7 of his instructions says �All that remains is to set the out-feed table level with the knives�. This is done after all the knives are set to the same height with the ruler method..

There is not doubt if you used one-inch movement and just left the out-feed table at that position, the knives would be too high.

Once I set the knives to the same height, I adjust the out-feed table so I get a little snipe at the trailing end of the board and then very very slowly adjust the table up until the snipe just goes away..

Jim R.

Re: Humm, The length of travel would ~

Jerry Nicholson

>I just went through that exact same problem with the snipe at the trailing end. My knives were a tiny bit high and not completely consistent. I had to readjust the knives and move the outfeed table a tiny bit.

Jerry

Re: Question for Victor...

vlparisian in cold and wet Houston

>Yep, I'm a bit of a slow head. Never actually read that part.

Let's think abut this for a second. Why go through the trouble of getting the 1" travel and not maybe 1/8 inch or so that I just went through. Is the 1" mark easier to achieve than 1/8"? theory?

victor in cold and drizzly houston

PS. This was all on Sunday, and I got everything fairly close but something must have slipped in my final tightening of one of the knives because when I ran a test piece over the stationary knife i was getting very slight drag on the inside edge (which I was shooting for)and none at all on the outside edge. Very weird. I'm totally disgusted with the ordeal (mostly the manufacturer) and figure I have to walk away and cool off before I hurt something.

Re: Question for Victor...

Jim Rahbe

>Victor,

It appears to me that the specific distance the ruler is moved is not important, just the fact that the movement is identical for any point on all the blades.

Being a wise $#%# my question to you is why use 1/8th inch? Why not a movement of 1/32nd of an inch? My guess would be you�d say that it would be pretty hard to tell if the ruler moved a little more or a little less than 1/32nd of an inch.

I�m not sure it is scientifically true, but it seems that the larger the movement, the larger the resulting error between knives would be..

If these are used knives, you might want to make sure there is no dip (wear) at the back edge where a lot of edge jointing takes place�

Jim R.

I'm having trouble vizualizing that since it seems

Don Henthorn

>to me that unless you moved the out feed table, the distances between the out feed table and the top of the blades would remain constant.

Sorry, this should have followed Keith's post.

Don Henthorn

>