LumberJocks

Aligning jointer knives, is there an easy way?

  • Advertise with us

« back to Power Tools, Hardware and Accessories forum

Forum topic by sreilly24590 posted 06-03-2017 09:14 PM 1164 views 0 times favorited 34 replies Add to Favorites Watch
View sreilly24590's profile

sreilly24590

87 posts in 271 days


06-03-2017 09:14 PM

I have finally gotten the 8” Powermatic 60, 1995 era, home and set up on a stable mobile base (HTC2000) and ran a poplar board trough it a number of times. I started with 4/4 and it did have some cupping. As I was working the board I felt that it was becoming wedged shaped. Looked closer and sure enough I was making a purity wedge and not the flat surface I wanted. Well it may be flat but that’s beside the point. When I looked at the jointer we ran a cedar board through a few passes and it seem to cut well. I did get a 50” straight edge to check the tables and that worked well.

Today’s first board tells me that something is amiss and I suspect it may be the knives are not adjusted properly. The truth is I’ve never checked or changed knives before so this is going to be new. There’s a ton of info out there but I’ve been steered in the wrong direction a few too may times to feel good about just trying something. So I figured the best place to check is where the guys that do this on a regular basis hang out. I did mange to salvage the board at 1/2” running it through my helix head planner but I haven’t checked to see how flat it actually is.

I have a new set of bearings and knives from Powermatic but wanted to avoid having to tear it down to the point of having to realign the tables which is what I am expecting would need to be done if I go that far. The bearing replacement requires the table to be removed from everything I’ve seen and then all I’ve heard is the nightmares about getting the table aligned again.

Which makes me wonder if I go that far maybe I should look closer at install a new Shelix head while it’s apart. Any words of wisdom or redirects to well respected sites on accomplishing this task? I should mention I did get a Woodstock Jointer Pal for 4-8” jointers.

Thanks a ton.

-- Steve, Virginia


34 replies so far

View MrUnix's profile

MrUnix

6010 posts in 2038 days


#1 posted 06-03-2017 09:26 PM

The jointer makes a flat edge, period. Even a perfectly setup jointer will produce a ‘wedge’ if you keep running the wood through it. If you want the opposite side to be parallel, then you need a planer.

Cheers,
Brad

-- Brad in FL - In Dog I trust... everything else is questionable

View jonah's profile

jonah

1471 posts in 3137 days


#2 posted 06-03-2017 09:26 PM

I use a magnetic base and dial indicator from harbor freight to align my jointer knives. Set up the dial indicator vertically, and get a flat tip for it. Using that you can align the knives a couple thousandths of an inch above the outfeed table. Marc Spaguolo has a good video about the procedure. It’s time consuming, but effective.

View jonah's profile

jonah

1471 posts in 3137 days


#3 posted 06-03-2017 09:27 PM

Sounds to me like you could also benefit from watching Marc’s video about milling wood. He explains the proper roles of the jointer, planer, and table saw in the video.

View Aj2's profile

Aj2

1178 posts in 1637 days


#4 posted 06-03-2017 10:14 PM

Isn’t the Pm 60 the jointer with Dovetail way.If so there’s nothing for you to adjust.Its the Dj one that has the cams in four corners that are adjustable.If your tables are droopy you could try shimming – I wouldnt be happy with a jointer that needed shims.
So it is what it is.If the tables are flat then proceed forward with new knives.It really isn’t that hard your just going to have to do it to get the feel.
I like the dial indicater method with a curved tip.My method is simalar to Bob Vaugans video.
I consider a Bryd head in a jointer a down grade.
So buy good knives and get on with it.
I wouldn’t mind stopping by and helping out because jointer are my favorite machine but I’m a thousand miles away.:(
Good luck

-- Aj

View William Shelley's profile

William Shelley

479 posts in 1308 days


#5 posted 06-03-2017 10:23 PM



Isn t the Pm 60 the jointer with Dovetail way.If so there s nothing for you to adjust.Its the Dj one that has the cams in four corners that are adjustable.If your tables are droopy you could try shimming – I wouldnt be happy with a jointer that needed shims.
So it is what it is.If the tables are flat then proceed forward with new knives.It really isn t that hard your just going to have to do it to get the feel.
I like the dial indicater method with a curved tip.My method is simalar to Bob Vaugans video.
I consider a Bryd head in a jointer a down grade.
So buy good knives and get on with it.
I wouldn t mind stopping by and helping out because jointer are my favorite machine but I m a thousand miles away.:(
Good luck

- Aj2

You’re the first person I’ve ever seen to say that a helical cutterhead is a “downgrade”. Hopefully not going offtopic here, but could you elaborate on your reasoning?

-- Woodworking from an engineer's perspective

View TungOil's profile

TungOil

747 posts in 334 days


#6 posted 06-03-2017 10:24 PM

the Powermatic manual has a decent set of instructions for setting the knives.

http://content.powermatic.com/assets/manuals/1610084_man_EN.pdf

-- The optimist says "the glass is half full". The pessimist says "the glass is half empty". The engineer says "the glass is twice as big as it needs to be"

View sreilly24590's profile

sreilly24590

87 posts in 271 days


#7 posted 06-03-2017 10:31 PM

Looks like I need a refresher in basics…again. Back in Jr High, more years than I care to do the math for, we used the equipment but did none of the maintenance and I see the mistake in that. I think between not picking the better rough cut lumber, was in a hurry, and not checking the knives I made too many mistakes. I had to run the boards maybe 5-6 times before I started to get overall full width cuts, easy to see on rough cut lumber. Marc’s video did address a few questions and seems to point me in the right direction. Need to get the rust out of the head.

Checking the knives seems important at this point as well as these machines in the video are known to be properly set up already. What I noticed on my jointer is a sticker saying to have the knives no more than .015 above the cutter head to prevent possible kick back. Wouldn’t the outfeed table need to be parallel to the cutterhead? As I said in my earlier posts when considering this jointer, I can’t swear it was ever properly set up but can only assume it was.

Any idea how to determine bad/worn bearings? Any obvious way to tell? I’m just trying to be prudent so I’m not chasing Red Herrings.

Typically, from memory, what I use to do is determine grain, warpage, cuping, and so on, determine the best approach to joint the board. Make several 1/16” passes until I got a good clean level board. That’s what I thought I was doing here.

-- Steve, Virginia

View sreilly24590's profile

sreilly24590

87 posts in 271 days


#8 posted 06-03-2017 10:36 PM

The boards in question are 7’ and 8’ so I looked at my longest needed pieces and cut the boards in two to make sure I could still get all I needed as well as shorten the boards for easier handling. But now I’m wondering if I should have maybe ripped the boards as well as I can get 3 rails and stiles width from each board with 3/4” left for edge jointing. Maybe this would result in better boards or is this not a good idea?

-- Steve, Virginia

View TungOil's profile

TungOil

747 posts in 334 days


#9 posted 06-03-2017 10:47 PM

The general idea when setting up a jointer is to get all of the knives set to exactly the same arc, on both ends of each knife. the knife setting jig in the PM manual is one way to do it, the dial indicator jigs mentioned above are another way. Personally, I used a large engineers square set on the outfield table and set each knife until it just barely lifted the square off the table. I set my knives that way for 30+ years without any issues. After you have the knives set equally, you then adjust the outfield table. Check out the section I linked to above in the PM manual, they do a pretty good job describing the process.

Bad bearings will be rough and/or noisy when turned slowly by hand. If the cutter head turns easily and is quiet when you rotate it by hand, the bearings are good. Don’t create unnecessary work for yourself- if the bearings are good move on.

-- The optimist says "the glass is half full". The pessimist says "the glass is half empty". The engineer says "the glass is twice as big as it needs to be"

View ArtMann's profile

ArtMann

688 posts in 655 days


#10 posted 06-03-2017 10:55 PM

I changed over from regular planer and jointer knives to a jointer/planer combo with a helical segmented cutter head and the improvement in performance on highly figured wood was remarkable. In every other way, the performance was at at least as good as knives. The machine is also quieter than my other machines, which I assume is partly due to the cutter head design. Finally, the carbide cutters are much more durable than HSS and eliminate the problem of knife alignment altogether.

From my experience, the change was a significant upgrade.

Isn t the Pm 60 the jointer with Dovetail way.If so there s nothing for you to adjust.Its the Dj one that has the cams in four corners that are adjustable.If your tables are droopy you could try shimming – I wouldnt be happy with a jointer that needed shims.
So it is what it is.If the tables are flat then proceed forward with new knives.It really isn t that hard your just going to have to do it to get the feel.
I like the dial indicater method with a curved tip.My method is simalar to Bob Vaugans video.
I consider a Bryd head in a jointer a down grade.
So buy good knives and get on with it.
I wouldn t mind stopping by and helping out because jointer are my favorite machine but I m a thousand miles away.:(
Good luck

- Aj2

You re the first person I ve ever seen to say that a helical cutterhead is a “downgrade”. Hopefully not going offtopic here, but could you elaborate on your reasoning?

- William Shelley


View sreilly24590's profile

sreilly24590

87 posts in 271 days


#11 posted 06-03-2017 11:08 PM

TungOil,

I like your thinking. The bearings are quiet and smooth as best I can tell. The reason I mentioned the outfeed table was I was using a digital gauge with rare earth magnets with the base (magnetics) on the outfeed table and went down the length of the cutterhead. It was off by tenths of an inch from one end to the other all the way around the cutterhead. I measured at each knife location so I was thinking the outfeed table may not be aligned to the cutterhead which should be the reference point I would think.

Art, I had heard good things about the helical heads with the biggest point being the cost. The benefits seemed worthy though.

-- Steve, Virginia

View MrUnix's profile

MrUnix

6010 posts in 2038 days


#12 posted 06-03-2017 11:55 PM

Bad bearings will be rough and/or noisy when turned slowly by hand. If the cutter head turns easily and is quiet when you rotate it by hand, the bearings are good.
- TungOil

Not really correct. You can have bearings that will not make any noise and turn freely that are completely toast. The only way to tell for sure is to pull the shields/seals and examine the grease, balls, cage and races. Or just replace them and be sure they are good.

Cheers,
Brad

-- Brad in FL - In Dog I trust... everything else is questionable

View Aj2's profile

Aj2

1178 posts in 1637 days


#13 posted 06-03-2017 11:58 PM

I think a Bryd head is best in a planer.I had a jointer with a Bryd head and never again.If your head doesn’t sit perfect alinement with the tables you will chase your tail trying to get square edges off the fence.
With straight knives you set the knives parallel with the outfeed table and if your infeed is in alinement with the out feed your good to go.
Some of the other things I didn’t like with carbide inserts is they don’t stay very sharp.And it takes more and more pressure to push wood thru.Its all fine and great if your boards are thick.
I remember pushing the crown out of a board just to hold it down.And it pops right back after the cut.Not good!
I also didn’t like the edges sometimes there was thick glue lines and it was hard to see square edges with the furrows from the inserts.
I have a powermatic planer with inserts and it’s good.

-- Aj

View Loren's profile (online now)

Loren

9633 posts in 3486 days


#14 posted 06-04-2017 12:25 AM

In terms of cutting a wedge on the jointer,
this can happen easily when jointing from
one end only.

In jointing the approach I use is to hold
a straight edge to the board and I usually
joint the concave face first. That often
means the concavity exceeds the depth
of cut on the jointer so what I do is joint
off a section on either end of the concave
board, perhaps 18” but varying depending
on the length of the board and length of
the jointer tables. On a really long board
I may joint in an additional pair of “steps”
in from the end of the board. Done with
care, the ends of the board are equally reduced
in thickness while the middle remains at
full or near-full thickness. More-or-less
the the straight edge (I use a 78” level) touches
the ends of all the steps, then the entire face
can be successfully jointed in one long pass.

View TheFridge's profile

TheFridge

8328 posts in 1325 days


#15 posted 06-04-2017 12:48 AM

I’ll have to disagree about the Byrd being a downgrade. After running 2 trailer loads of dirty barnwood through my setup I was impressed with longevity.

-- Shooting down the walls of heartache. Bang bang. I am. The warrior.

showing 1 through 15 of 34 replies

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com