While trying to edge joint some 55″ and 65″ boards on my 6″ x 46″ jointer I am regularly ending up with some rocker on the jointed edge. The infeed/outfeed tables are parallel as near as I can measure, same for the knives being equal in height to the outfeed table. I think I am keeping the board registered on the outfeed table.
I am starting with the bow side down, take a few 1/64-1/32″ or so passes, the bow slowly goes away but by the time I get down to wood in the high zone, I seem to joint in some rocker – I’d rather have it be a spring joint. Once I have some rocker in the edge, I’d have to joint off a tremendous amount of wood to get back to flat.
I figure I am making a classic mistake of some sort or have something set up wrong that I am not thinking about. I’d sure appreciate some tips or help.
thanks,
Steve
Replies
I'd say the first problem is taking to thin a cut. Try going 1/16". When there is a hump, you almost need to hold the board right over it. Once the blades make contact and start cutting, you have to move your hands to the outfeed table only. You can flip the board and take a couple passes off each end rather than run the hump down. You can also make some extension tables for the jointer which will give much better bearing for longer stock.
Beat it to fit / Paint it to match
"I am starting with the bow side down" -- Hammer, he's jointing with the concave edge down. I wasn't sure at first but this was confirmed by "by the time I get down to wood in the high zone."
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
Edited 11/26/2005 12:50 pm by forestgirl
It doesn't matter if the poster is only skimming 1/64" off, FG. Up or down, he won't make much progress.Beat it to fit / Paint it to match
Hammer, I am with FG on this one. I would like to point out that if I chose to I could take a very large circle, and constantly feed it over the cutter of any jointer until there was nothing left of it. However, I am totally incapable of taking anything off of the underside of a bow if it is up, except for the ends where it rides over the table and can be reached by the knives, until I have a straight line.Now, What Sterve needs to know after telling us, is that if you are feeding with the crown down, you must feed in such a manner that allows no rocking, if the crown is down. Don't try to plane from end to end, but rather just the high. Inverted f course.If you are planing with the crown down, set the work onto the jointer with the high part against the table, and with even pressure on both sides feed it across the knives without changing the pressure from either hand while maintaining your effor down as constant as possible while crossing from in-feed to outfeed.
Thanks all - I guess "concave down" would have been clearer then "bow side down"; whoops. I'm working with vertical grain doug fir. It's brittle and pretty susceptible to chipping and tear out. The edges are face grain with the grain direction changing back and forth along the edge. That's why I've had to go to those thin passes to keep the tearouts down.
I'll experiment with flipping end for end on my edge jointing more regularly and see how that helps. I did a couple boards today by removing the bow in the edge by ripping a ~straight edge on the band saw and then a couple passes over the jointer. That was pretty fast and I've wasted more wood than a band saw kerf with the "rocker" problem I described.
Steve
Hey Keith, I thought you were lost! Haven't seen you post for a while. Glad you're OK.I guess my response wasn't that clear. You can join a crowned piece with either the crown up or down, as one chooses. If you go with the crown down, you have to sort of balance it on the hump, before and through the knives. This may require a longer infeed table depending on the length of the board and the position of the hump. In essence you may have the ends of the board off the tables for several passes, depending on the height of the crown.You can also join it with the crown up, but you don't make full through passes for the entire length of the board. You just take a few shots off just one end, turn the board end for end and take a couple shots off the other. This just wastes off the ends so they don't change the cut as they meet and ride up on the table, assuming the board is longer than the table. This is one place where the extension tables can help, not to mention the support they give to longer heavier pieces. It's not easy to run a 2"x12"x12' on a typical 6" jointer. If you ask me, with a board that has a fair amount of crown, you are better off to mark it with a straight edge or chalk line and cut it close before joining. Choose your weapon, circular saw, jig saw, band saw, hand saw, axe, draw knife, hand plane, etc. I also think that trying to straighten a rough board with the jointer set at 1/64" - 1/32" doesn't work that well. Making too many passes just beats up your knives for no good reason. If you want to take off a fine cut after things are straight that's a different story. All of this depends on the jointer set up and operator technique. Yes, you can join around a circle if you just keep your hands on the infeed table. Hopefully, the poster knows how to set the knives and use the jointer correctly. An important technique is to take a couple baby steps ahead with the board so that you aren't leaning out to reach the outfeed table, where you could slip. You also don't want the knives exactly even with the outfeed table, they should be just a hair higher or the work may ride up over the blades, especially on a skim cut. This could be another problem Steve is having. The jointer is fairly simple to operate unless you don't know how to register the progress of the cut to the outfeed table. You can't get a piece straight or flat if you don't.Beat it to fit / Paint it to match
HEY Hammer: those rubber mats on your shop floor. are they easy on the feet ? Tinkcount your fingers at end of day --have 10? --you've done good
Hi Tink, those mats are like walking on a cloud. Fine dust falls down in the holes so you don't track it all over or get slippery. The floor looks clean even when you haven't swept up for weeks. They are 3' x 3', pull up and lay down easily. I use a vacuum when it's time to clean. You don't have to worry if you drop that Preston shoulder plane and little nuts and washers don't roll off to neverland. Cats with small feet and ladies in high heels don't like them. The cats figure a way around them, you can just carry the ladies. $20 at HD.Beat it to fit / Paint it to match
Hammer thank you I'm headed that way this A.M. Tinkcount your fingers at end of day --have 10? --you've done good
Well, no one has mentioned this but have you checked the beds to see if they are co-planer?
One easy check is to take two large carpenter squares and set one on each table with the other side of the squares pointing upward. The two sides pointing upward should meet in the middle with no progressive gap from top to bottom. If that test is passed, then check the knives to see that the cutting edges are exactly in line with the surface of the outfeed table, or, no more than 1/1000" above.
If you have a 12" ruler that is straight, then the knives should not drag the ruler more than 1/8". Set the ruler on edge and hanging over the edge of the outfeed table enough to contact the knives at the high cut point. Gently rock the cutter head back and forth. If you feel the blade touching the ruler but not dragging the ruler, then you should be OK. A thin 12" stick with one straight edge can also be used.
PlaneWood by Mike_in_Katy (maker of fine sawdust!)
PlaneWood
what I do is just get one end straight. which means I usually joint with the crown up. then rip the other side on the ts to get a striaght edge then joint it the side i ripped..
I was wandering when somebody would come up with what Planeman has suggested. It certainly sounds to me as if the tables are not co- planar-I suspect they could have the opposite of the droops.
Or it is a question of technique.
If the knives are not level with the outfeed table at tdc they would have to be "wrong" by a fair amount-giving rise to a step at the trailing end of the board, so I wouldn't be suspecting that one.
Is this a machine with //gram beds or the dovetailed type?Philip Marcou
This summer I was faced with the EXACT same problem, except that I had 800 sq feet of lumber to mill up for a floor. The pieces were often wider than my jointer and too long to put through the jointer effectively (7ft long). To deal with the problem, I used two tips from Fine Woodworking. The first is the one that I recommend to solve your specific problem. A piece of 20 ft channel Iron clamped to your table saw as an auxilary fence. (actually I cut mine down to 16ft due to lack of space) Every piece of rough lumber has 2 high points. These will ride on the extended fence past the blade keeping everything straight. The second technique I used was the planer sled featured in a summer issue of FWW. Worked like a charm. (with 1 addition) With these two additions to my shop, my jointer has not been used in the past 6 months. I'm considering getting rid of it.
Cheers
M.Stehelin
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