Jointer Technique

[Alan Greene]

I have a Yorkcraft YC8J jointer. I am having an issue with getting my wood squared up. The wood is getting a taper in it:confused: . I have checked the beds and they are flat. The out feed table is even with the cutter head within .002. I am pretty sure that the problem is with my technique but I don't know what it is that I am doing wrong. I stand facing the out feed table and feed the wood through with two safety push blocks. I keep light downward pressure just past the cutter head with my left hand and feed the wood through with my right hand. I am taking a 1/16" cut. Anyone have any ideas? Thanks for your help.

I am cutting more wood from the front of the board.

[Richard Butler]

Are your knives sharp? Dull knives will cause all manner of issues. I was having issues with tapering until I put sharp knives in.

[Alan Greene]

Richard, Thanks for the quick reply, Yes the knives are sharp. The jointer is new and probably has less than 30 bd ft run through it.

[jonathan snyder]

Alan,

Check to see that you outfeed table is at the same height as top dead center of your knives. If your outfeed table is too low you will get snipe, if its too high, you will get a taper. I think thats right, maybe its the other way around, no I'm sure that right!!!

Hope this helps
Jonathan

[D. Hunt]

First, a couple of ?'s.

What kind of taper are you getting? Along the length of the board? Or, across the width of the board?

If it's across the width of the board, then it sounds like the blades are too high on one side of the cutterhead or your tables are not coplanar (on the same plane) with each other. The blades need to be set dead even with the outfeed table.

Are your knives in contact with the blades all the way through the cut?

If not, your outfeed table may be too high or your tables are not coplanar to each other. I had a problem on my 6" Grizzly where I lowered my infeed table and I locked it in, it was tilting the table. Solution was adjusting the allen screws that pressed against the plate in the dovetail ways. One was tighter than the other putting uneven pressure when locking it down. I just had to keep adjusting them until they had the same pressure on top and bottom.


As far as technique, it's all in practice. When you select a piece of stock, take a good look at it to find the cups, twists, bows etc... . I almost always put the cup or bow facing down. Pick a corner that is touching the table and move it to the front so it goes to the outfeed table first. I use my left hand to put firm pressure on the corner or part of the board that is making contact with the table and I use my right hand to put light pressure at the rear of the board as it's fed through. Try to find a spot on the back of the board that is also making contact with the table. By light pressure, I mean just enough to keep from vibrating up off of the table. Most of your pressure should be focused on the outfeed table and it shouldn't have to be all that much. Just enough to keep it seated firmly on the outfeed table. The one thing you don't want to do is alter the cut by applying too much pressure. One thing I don't like about running the board through with the cup or bow up is it has a big tendency to rock. If you have to put too much pressure on the board to pass it over the cutterhead, either your knives are dull or you're taking off too much stock at a time. I generally don't take off anymore than 1/32" at a time. Sometimes less. Well, I hope I didn't confuse you more. Good luck!!!

Darrell

[Paul Simmel]

Alan,

>>> I have a Yorkcraft YC8J jointer. I am having an issue with getting my wood squared up.

“Squared up”.

That’s what you said.

So based on that…

If your fence is perfectly square to the table (check it), you need to put pressure on the fence, just a bit past the cutters, more so as you push the piece through. The flat tables will make your piece flat… no problem. To square the piece, the piece also needs to be pushed against the squared fence more tightly. Forget about the downward pressure (the cutters will pull it down naturally). Focus on the fence as you push through. If you are not square then your fence is not square to the tables.

[Rick Christopherson]

The answer is fairly simple, but I will get flamed for suggesting it. Your outfeed bed is sagging (that's not a surprise), and by focusing your pressure on the outfeed like you were taught in high school (or wherever), your tail-end of the stock will lift off the infeed bed and you will cut more from the leading end of the board than you do from the trailing end. This results in a taper and/or convex cut.

People don't like it when I tell them that their former instructors were wrong, but then they wonder why they get poor results. However, that philosophy is based on having a perfect tool, which is not likely with a home shop.

[Alan Greene]

Thank you all for the replies.

D. Hunt: The taper is along the length of the board
Rick: Where do you put the pressure on your boards as they go through?

The out feed table is within .002 of Top Dead Center

I have checked the tables with a Lee Valley steel 24 inch straight edge and they are coplanar.

The fence is 90 degrees to the table. I have checked it with two different machinist squares.

I will check to see if the tables are moving.sagging with wood on them.

So far the wood I have been planing has not been to bad, I purposely started with "better" boards.

Thanks again

[Rick Christopherson]

Alan, I keep my left hand just inbound from the cutter head, and this hand applies the downward pressure. My right hand goes as far back as I can comfortably reach, and this propels the wood forward. Because you start out registering your surface from the infeed bed, you should keep it registered from the infeed bed for the duration of the cut. Switching pressure to the outfeed side changes your point of registration and introduces errors.

[Greg Funk]

Alan,

How long are the boards you are jointing and how much of a taper are you getting? You mention that you are taking off 1/16" at the start of the cut. If you stop cutting 3/4 of the way through a board and remove the board you should be able to see how much of a cut you are taking towards the end.

I don't know how long the beds are on the Yorkcraft jointer but you might want to get a longer straightedge for checking the tables. I used a 6' straightedge on my DJ-20.

Greg

[Alan Greene]

Greg the boards I have been jointing are between 30 and 48 ". The bed on the jointer is 72". About a third of the way through the board I stop cutting.

I checked the out feed table and have no sag. It was checked by using a level that I shimmed to get a good reference point with the bubble. I can get the whole jointer to move but not just the out feed table. I rechecked the set up and am square with the fence and the out feed table is still .002" across the blade, measured at 4 locations, in reference to the out feed table.

Rick I will try keeping the pressure of my left hand on the infeed side and see what I get. Thank You for all of your input.:)

[Tim Wagner]

If you wish to send it to my place I can put it through some serious testing. :)

Testing time may take anywhere from 1 week to 1 year.:D

[Alan Greene]

Tim, it would be cheaper to fly you out and you can test it here.:D I have some maple you can "test" that i need to get done for a project.

I just jointed a cherry board that measured 47 1/2" long. The board was very flat when I started (1.51", 1.513", 1.548", 1.517", 1.52" with no bow or twist). There was 1/16" differance when I got through the first pass using Rick's advice. When I did what I had been doing on the next pass it was 1/8".

I will change my technique to putting pressure before the cutter instead of after and see how that goes. Thanks for the advice, I will let you know how it goes. I was positive that the issue was what I was doing not the machine.

[D. Hunt]

Alan,

Try different techniques and pick one that you are most comfortable with. If you continue to have the same problem, I will reiterate what Greg said "you may want to get a longer straight edge".

Here's a good one.
http://www.leevalley.com/wood/page.aspx?c=2&p=50074&cat=1,240,45313

I also picked up the feeler gauges in the link as well. I have used these over and over again to setup and confirm setup on all of my tools. The feeler gauges start out at .001", .0015, .002, .003 etcl... For some reason, I just couldn't locally find a set of feeler gauges like this. I think most of them started out at .005". Before I bought these, I was using an aluminum straight edge that at the time I thought was good enough but found out it had too many dips in it to get a correct reading. I was also using a jig I made that held a dial indicator that proved to be very frustrating.

Here's a good article on Jointer tune up with illustrations:

http://www.woodworking.homeip.net/wood/

This is my preferred method for setting knives (using a piece of wood). It's unbelievably accurate and does an excellent job. All I can tell you is to keep trying and eventually you'll get it. One thing you can try, adjust your outfeed table up and down to see if it makes a difference.

Darrell

[Rick Christopherson]

Alan, you can't check for sag using a level, it's not accurate enough. You can almost guarantee that you have some sag. For that reason, it is best to assume that you do.

1/16-inch over 4-ft is a pretty significant error for a single pass. If you reduce your cutting depth, you might actually hear when the knives stop cutting and this will give you an idea of where the error lies.

Remember that you need to increase your downward force as you approach the last portion of the board to counteract the cantelevered effect from the outfeed side floating above the bed.

When you are trying to correct your feed methods, it is best to first focus on edge jointing instead of face jointing. Start by jointing two boards and examine the gap(s) between them when butted against each other.

[Jake Helmboldt]

Personally I wouldn't waste my money on an expensive, long straightedge unless you feel it is something you want/need. I use a 4' piece of 1/8"x1" aluminum bar stock. Pick up a couple pieces in the store, hold them edge-to-edge and with a light in the background you can see if they are straight. For basic machine setup you can have a 4' straightedge that is <0.001, maybe less than .0001 for $5-10. With that you can tell if there is any significant sag and whether the tables are truly coplanar.

As for technique I have to disagree w/ continuing to feed w/ pressure on the infeed side. I'm not saying it won't work, but after experimenting with technique and relying on feedback from others I find that by applying pressure on the infeed only long enough to get enough of the stock firmly registered on the outfeed table and then transferring the pressure to the outfeed gets the best result.

Here is the rationale: Once it passes the cutterhead the stock should be flat and in firm contact with the outfeed table. One there, you can apply pressure on the outfeed side and effectively drag the stock across the cutterhead, using the outfeed to register the cut. This of course requires the cutterhead to be set at the right level relative to the outfeed. You mentioned that your table is w/in .002 of the cutterhead, but you don't mention if it is above or below the cutterhead.

Also, which end is narrower, the front or back of the stock?

[Alan Greene]

Jake, I will look into the aluminum stock, thanks for the tip. The board is thinner at the front. The outfeed is .002 below the outfeed.

Rick: When you originally said "sag" I assumed (I know) that you meant a movement of the bed with weight on the table. I am going to assume again that I was wrong and that you are refering to the outfeed not beiing colaner over its length, which I can't properly measure with my 24" steel staight edge.

Darrel: I have the same set of feeler gauges and am very happy with them. I also use them a lot. I have read several articles and threads trying to figure this out. I will print out and follow the advice in your link

To All: I will try out your advice later today. I wil let you know how it comes out

[Rick Christopherson]

Here is the rationale: Once it passes the cutterhead the stock should be flat and in firm contact with the outfeed table. One there, you can apply pressure on the outfeed side and effectively drag the stock across the cutterhead, using the outfeed to register the cut. This of course requires the cutterhead to be set at the right level relative to the outfeed. The problem with this is that it assumes that the two beds are parallel, which is rarely the case for most non-comercial jointers. The result is either the tapered cut such as described here, or a concave cut when edge jointing.

I know that my philosophy goes against what most woodworkers were taught, but that's because the method that has been taught for ages makes an assumption that is not always applicable or true. I too was taught this same method years ago, including the rationale behind using it. It wasn't until I began doing woodworking professionally that I stopped to examine the why's and how's a little more closely, but with an engineer's perspective.

Don't get me wrong, I am not trying to suggest that everyone changes their methods. It's just that in an imperfect world, sometimes you have to take a different tack to get the desired results.
================
Oh Alan, yes, I was referring to the beds not being coplaner/parallel (like a "^"). Because the outfeed bed is generally not moved, it is the one that is considered to be out of plane with the infeed bed, because adjusting the moving infeed bed is more problematic.

[Tim Wagner]

Tim, it would be cheaper to fly you out and you can test it here.:D I have some maple you can "test" that i need to get done for a project.



Ahh the warm weather and sunshine would make it all worth it.:cool::cool::cool:

[Greg Funk]

The outfeed is .002 below the outfeed.

Alan,

Normally, I believe you want the outfeed table slightly below the blade (approx .002").

Greg