Need help on jointer operation

[Andy Pratt]

Apologies for the seemingly redundant post, but even after reading related posts I'm still not getting the hang of making perfectly (or even close) flat surfaces on my jointer. I'm really frustrated and would greatly appreciate some experienced advice.

I should preface this by saying that I have a 6" jet "deluxe" jointer which I've checked and double checked the settings on and I'm 99% sure the machine is working fine and I'm the source of error. I'm currently trying 1/32" cuts and have experimented with anywhere from 1/64th to 1/16th with similiar problems.

To keep this simple for me, lets limit the discussion for now to edge jointing 2" thick boards which is the project I'm currently having problems with.

The issue I can't get around, no matter how much I practice, is that I consistently get a board that is wider toward the middle and has somewhat drastic deviations toward the board ends. To make sure we're visualising the same thing, lets say the board comes out 2"thick by 3' long by 10" wide at the ends and 10.25" wide at the middle.

I've read various posts about where to apply pressure and have seen a lot of differing advice. I've tried very little pressure until I'm a few inches past the cutters, then only downward pressure on the outfeed table. I've tried just pressure on the infeed table (seems wrong but worth a shot) and I've tried somewhat balancing between the two. No matter what I do, I still end up with varying degrees of the same problem.

If I had the luxury of working with the concave side of the stock it would be a different problem I imagine, but I'm forced to use the convex side in this case, any recommendations on what I can do?

Thanks in advance for reading through all this and offering your advice, I'm pulling my hair out and I'm glad to have this awesome forum as a place to fall back on.

Andy

[Mike Heidrick]

Andy, do you have a woodcraft nearby. Call them and ask if they can demonstrate for you. I am sure it is siomething very simple. One of those times demonstartion is worth a thousand words.

[glenn bradley]

Not trying to make you repeat yourself now that you're at the point of frustration because I know how frustrating that can be. I just want to be sure I understand what I'm reading.

You are starting with a board that is convex on both edges. After jointing this condition worsens or at best is the same with the board just being a little narrower. I'd like to eliminate the machine as a problem although we are reasonably confident it is OK.

To test, take a piece of scrap, 1 x 4 pine, a 2 x 6, whatever. Rip it on your table saw so you know you have a good straight edge. Joint this board. I'll be redundant here as you've said you've read up on a few techniques. Start with the pressure on the infeed table and against the fence ( I always laugh when I read that step because there is no board on the outfeed side yet). Once there is about 6 inches or so of material past the cutter head shift the majority of your pressure to the outfeed side while maintaining your pressure against the fence. By the end of the cut all your pressure is on the outfeed of course because there's nothing left on the infeed table by now.

Check the board for the problem. If it appears on a board that started straight I am inclined to think your machine should be rechecked -or- you are putting a hella lotsa pressure on the board while feeding it. The board only needs to be firmly controlled, not crushed.

If there is no problem on the the test board, we can look at technique. A convex board if curved enough will either start or end with no material contacting the tables. In other words if you press the front of the board flat to the table (the rear comes up) and feed, you will cut to the point that the curve causes the board surface to leave the table before the pass is complete. This type of pass would need to continue until the removed material is sufficient to allow the rear of the board to contact the table throughout the pass.

Now at this point I'll stop because if I am misunderstanding, I am wasting your time and a lot of forum storage space. Please let me know if I'm getting what you're dealing with.

P.s. the videos in this article are quite good as well. One covers edge jointing. http://www.newwoodworker.com/basic/usejntr.html

[Randall Frey]

I am trying to visualize what your results are and it sounds like you are edge jointing a 2x10x3 and ending up with a big crown in edge of the board. If this sounds right , I would lay the board on a flat surface ie, table saw table. Place the edge you want joint down. See if it is high in the center (crown), if it is, 1st read the direction of the grain to establish the correct feed direction. Then you need to do a (take the crown out pass) which is setting the heel of the board down on the jointer and lowering the board onto the spinning knives about 8" from the leading edge, run it through and the lift it about 8" from the exit. This should remove material from the center removing the crown. Make as many passes as nec. checking it often until the crown is gone then you can run it through and it should be ok. This is however providing your jointer is set up correctly and knives are in good shape.

[John D. Thompson]

Hey Andy,

Sorry to hear of your frustration.

If, in fact, your tables are set up correctly, I would suggest that you try taking a bigger bite out of the edge. By setting up to take, say 3/16" or even a little more, you may find it easier to establish a "flat" in the center of the board. While you are establishing this "flat" you should hold the work in the center and push it forward until it begins to engage the cutterhead. With boards as curvy as these seem to be, you may well have 8 to 10 inches of lumber sticking over onto the outfeed side of things before you even begin to cut! After your workpiece has about an inch or so solidly on the outfeed, you can begin to apply light pressure onto the outfeed and bring it on through the cutter. With the second pass you will probably want to raise the infeed for a 1/16" depth of cut or so and, having established your flat spot on that convex curve, you'll be able to feel the work rest solidly on the infeed to guide your efforts.

A steady hand and a slower than normal feed rate are necessary here but, once you get the feel of it, I think you will be pleased with the results.


By the way, my favorite device for checking jointer tables for parallel is a pair of LARGE drafting squares. Hold them flat against the fence so they point straight up over the cutterhead with one resting on the infeed and the other on the outfeed table. Bring the two upright edges together and adjust the tables until they meet perfectly. You can check the gap between the squares with a feeler gauge and, when the upright edges are parallel, the tables are parallel.

Hope this helps!

JT

[Dewayne Reding]

Andy

I feel your pain :) . I'm the guy with the other jointer thread. How wacked are the boards you are attempting to joint? Among other errors, I found that I was complicating my learning process by trying to practice with wood that was tweaked in several planes. As suggested, I took a pencil and marked the edge of some practice boards. It was easier to critique each pass with a quick look and see what technique was inducing snipe before I proceded.

[Al Willits]

Not sure where the posters from, but if we knew maybe, someone in his area could stop by and try to help??
Al

[Steve Roxberg]

I know you said the machine was setup properly but is sounds to me like the ends of each table are too high.

Think about the edge you are getting.

As the board enters the knives it cuts because it's going slightly downhill.

The front edge of the board passes through the cutters and begins a slight uphill journey which after a few inches lifts the center of the board up away from the cutters. (giving us the start of the crown)

As the end of the board begins it's downward journey it eventually gets to the bottom of the infeed table (downhill side) and again begins to enter the cutters. Thus forming the end of the crown.

How do you know that the tables are co-planar?

Just my guess, but it seems logical.

[Wilbur Pan]

If I had the luxury of working with the concave side of the stock it would be a different problem I imagine, but I'm forced to use the convex side in this case, any recommendations on what I can do?
You've already gotten a lot of good advice and tips. I'd agree with Steve that you should check to see if your in and outfeed tables are coplanar. The fact that the problem gets better when you put all the pressure on the infeed table is a sign that your tables are out of plane.

But, you should also realize that edge jointing a convex side on a powered jointer is not the easiest of things to do. As Randall mentioned, because of the convex shape, if you want your finished edge to be square with the rest of the board, you'll need to knock down the high point in the middle first. To do this on a powered jointer means dropping the board down on the blades with the machine running and the guard out of the way. I'm sure that Randall gets excellent results with this method, but I'm too much of a klutz to think about doing this myself.

You might consider other options:

1. Hand planes. Edge jointing is really easy with hand planes. If you've never tried it, it's a lot easier than you think. Really. I have a jointer that's 10" wide, and I use it primarily for face jointing. For edge jointing, I'll use hand planes.

2. Draw a line and rip the convexity off using a bandsaw with a wide blade (my pick), tablesaw, or router/straight edge.

[Andy Pratt]

Thanks for all the advice guys, I'll start running through these options when I get home from work today and let you know how it comes out. I appreciate all of your thoughtful responses.

Andy

[Chuck Lenz]

Sorry, but I just gotta ask, did you read the manual ?

[Jeff Raymond]

Sorry, but I just gotta ask, did you read the manual ?


Geez, there's one in every crowd.

[Chuck Lenz]

What do you mean theres one in every crowd ? Do you know how many people don't read the manual ? I had a friend of mine call me one day, he was haveing a problem with a new Contractors style Powermatic tablesaw vibrateing, so I went over to his place and we looked things over and decided it must be the pulley on the arbor, so we attempted to get the pulley off and broke the pulley but still didn't get it off the arbor. Well after all that and feeling bad about breaking his saw I said to him, did you read the manual ? He said no. Well in the manual under trouble shooting it says to make sure that the hand crank for the blade tilt is tight before starting or it may lead to vibration in the saw. Because he didn't read the manual, I wasted a trip and my time, and he had to take the saw back to the local tool store where he had just bought it to get the arbor pulley off and have a new one installed. Alot of unessecary wasted time because he was too lazy to read the manual. So from now on when someone asks me about a tool they are haveing problems with the first thing I ask them is did you read the manual ? Sorry if you think thats out of line.

[Jeff Raymond]

What do you mean theres one in every crowd ? Do you know how many people don't read the manual ? I had a friend of mine call me one day, he was haveing a problem with a new Contractors style Powermatic tablesaw vibrateing, so I went over to his place and we looked things over and decided it must be the pulley on the arbor, so we attempted to get the pulley off and broke the pulley but still didn't get it off the arbor. Well after all that and feeling bad about breaking his saw I said to him, did you read the manual ? He said no. Well in the manual under trouble shooting it says to make sure that the hand crank for the blade tilt is tight before starting or it may lead to vibration in the saw. Because he didn't read the manual, I wasted a trip and my time, and he had to take the saw back to the local tool store where he had just bought it to get the arbor pulley off and have a new one installed. Alot of unessecary wasted time because he was too lazy to read the manual. So from now on when someone asks me about a tool they are haveing problems with the first thing I ask them is did you read the manual ? Sorry if you think thats out of line.

I was just joshin'

Y'know, Real Guys don't read instruction manuals. They'd rather break the machine and go get another one.

Call me a smart aleck.

[Al Killian]

Have you cleaned and waxed your tables and fence yet? This will help the boards slide easy and in turn make it easier to slide the boards with less pressure on the boards.