Replies

1. 
   forestgirl | May 26, 2004 07:22am | #1

   Here's the link to John White's book:
   http://www.taunton.com/store/pages/070551.asp

   IMO, you'll want to get that 3rd knife in the right position.  Otherwise your cut will not be as clean as it should be.

   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" .... :>) 

2. 
   forestgirl | May 26, 2004 07:30am | #2

   Here's another book I like, has technique stuff in it in addition to "care and feeding":

   http://www.amazon.com/exec/obidos/tg/detail/-/0806967552/qid=1085545776/sr=1-1/ref=sr_1_1/102-7791818-6281716?v=glance&s=books

   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" .... :>) 

1. 
   mudman | May 26, 2004 07:38am | #3

   THank you FG,

     I think that the most importaint tools I have are books. It took me 4 hours to set the damn 90 deg. fence stop, so I am afraid to spend that kind of time on this knife thing if it don't matter.

     What about the spring thing?

   Mike

1. 
   forestgirl | May 26, 2004 09:22am | #4

   'fraid I can't help with "the spring thing."  I'm sure you'll get some pro responses though.

   You can do the knife adjustment -- just be sure you're turning the screws in the right direction (seem to remember they're reverse-threaded) and don't loosen them too much.  I keep some rare-earth magnets around to help with handling jointer knives.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" .... :>) 

3. 
   AlanTurner | May 26, 2004 07:38pm | #5

   Mike,

   A "sprung" joint is an edge joint, where the ends of the boards meet, but the centers are off a bit.  Perhpas 1/16" or so in 8 feet.  There were developed when houses were not so climate controlled, on the theory that in the winter, the ends of the boards of a table, for example, would dry more than the centers, and then the ends would separate a bit.  Older jointers had a lever where, on the last pass, you could cock the outfeed table to achieve this slight curve.  It is antiquated, and noone that I know uses them anymore.  My old jointer has such a lever, but I have never even tried to use it.  Couldn't tell you if it works or not.

   Alan

   Alan

   http://www.alanturnerfurnituremaker.com

1. 
   RickL | May 26, 2004 09:05pm | #9

   Alan, those old jointers with the lever were a special type made for patternmakers. It tilted the outfeed table to allow for what they called "draft" in a jointed piece of wood.  This feature was only found on patternmakers jointers.  I've founf most folks who advocate a spring in the board couldn't set their jointer right.  Been setting jointers for over 25 years and allow no spring nor does anyone I know of with a shop want spring.

1. 
   TomMGTC | May 26, 2004 09:10pm | #10

   I don't want sprung joint from the jointer but I do use them often and use a handplane to acheive them quickly and easily.Tom

   Douglasville, GA

2. 
   AlanTurner | May 26, 2004 09:53pm | #11

   I know that you are far more knowledgable than I on tools, and on jointers.  But I bought this from a dealer in used machinery, whom I believe to be knwowledgable.  He expained to me that this was for sprung joints.  Thre was sometimes another lever, but only on a patternmakers jointer, used for the angle which released the mold from the pattern.  Maybe I misunderstood him, however.

   AlanAlan

   http://www.alanturnerfurnituremaker.com

2. 
   mudman | May 27, 2004 09:44am | #16

   Excellent,

     I love having yall as an asset!

     I suspected that springing a joint was some antiquated practice. It can't see how it could possibly help. I already adjusted the outfeed table to fix that.

   I love you hand tool purists. It takes all kinds. But Im all about wired woodworking, or battery power for that matter! I do use planes to flatten panels as planed surfaces finnish nicer than wide belt sanded surfaces.

   As for the third low blade I am inclined to agree that I couldnt make it better. I dont think I could turn the screws little enough to get it better. The sujestion of jointing from the center out makes sense too. The problem seems that when I start the cut even the lightest pressure flattens the board as it is 3/4" poplar.

    To check the knife height I was running the machine without a gaurd while drinking heavly and used my saw fence. Just kidding, actually I did the same thing that hammer described, and I rotated the head by turning the belt with my hand. I feel good that I came up with that on my own.

   Sawdustmaker, I fear that they have changed the manual and it no longer describes that. In fact there were several mis-spellings and misuses of words. Plus there was no mention of technique, like where to put the pressure.

   Thank yall very much for the feed back,

   Mike

1. 
   AlanTurner | May 27, 2004 03:15pm | #17

   As to technique, I will make a suggestion. Set the height of cut to very shallow, perhpas 1/64". Then put the board on the jointer in the middle, and with very light pressure (i.e., not cut at first) push the baord to the outfeed table to finish. FLip the board 180 deg., and do the same. May have to do this twice. The joint the who baod till flat again. Be very careful with this, and use a push block, of course. On a badly warped board, I do this regularly, without problem. There is less waste this way, I think. And, this goes for both face surfacing, and edge jointing.

   AlanAlan

   http://www.alanturnerfurnituremaker.com

2. 
   bobJackson | May 28, 2004 05:48am | #18

   Just a little additional info to add to the others post. In FWW a few years back  Robert Vaughn outlined a procedure for setting jointer knives with a dial indicator. I have used this method ever since I read the article and can tell you that it works very well. When my knives are fresh from being sharpened it is hard to tell if they are in contact with the wood as the cut and vibration is so smooth. I have a Jet 8" model 12 or so years old . After a few times I can change out knives (3) in about 40 min. I always have a spare set of jointer and planer knives at hand so that when I change out I never h ave more than one knife out of the head at one time. That way the tension forces dont get unequal. Try  Vaugns method, the indicator is relatively cheap (under 50 bucks) and accuracy is to three decimal points(.001)   Good luck  Bob

1. 
   KeithNewton | May 29, 2004 12:36am | #21

   MORE ABOUT SHARPENING

   I don't know if any of the earlier threads have covered this, but I often hone my knives right in the cutterhead. Mine is a 12" Brown and Hall with 4 knives, and this really saves a lot of time.

   First I loosen and slide the outfeed table back about 6" out of the way, then I use

   a little wedge that fits between the front of the knife, and the end of the infeed table to hold the blade at the top of its arc.

   Then I hone the top bevel with the 2"X6" diamond hones which I glued a handle onto the backs and off the ends. i can hone the 4 knives three or four times between taking them off and regrinding. Since this cutterhead doesn't have jack screws, it takes me a lot longer to replace them. And whenever I do that I use a dial-indicator head to set the knives.

   While I am on this subject, I would like to also add that my cutterhead holds the knives at about 30 degrees of hook angle. Since most of the work that I do is from hardwood, I grind and hone a 20 degree face bevel to reduce the hook down to 10. If you have never tried this, you probably think I'm crazy, and I can't deny that, but I never have to worry about tearout around knots, block mottle or fiddleback figure.

   If you work with a lot of softwood, you want that extra hook to be left in

3. 
   mlbfreestyle | May 28, 2004 07:26pm | #19

   A sprung joint may be an antique practice; but so is sex. I don't see any move to something better!

   I don't care what kind of machine or tool you use.  Wood is still wood and will behave the way it has for thousands of years.  IMO a sprung joint is most useful if you think the wood will dry further from current moisture content; such as when moving from a garge to a heated house.  You are much better off having a minor amount of glue-line tension near the center of the board rather than the ends.  A much sharper "stress riser" is created when the tension is at the ends of the board.  Furthermore, I think glue-up is easier when the joint is sprung (easier to clamp and control board alignment).

1. 
   tsproul | May 28, 2004 08:41pm | #20

   quoting:

   "IMO a sprung joint is most useful if you think the wood will dry further from current moisture content; such as when moving from a garge to a heated house.  "

   I'd agree that springing edge joints is a good thing but disagree on your reasoning...

   Here is my take on it. Forget about keeping the glue line together. Any wood glue you use will hold up fine, if not better than the wood itself. Think about it this way. The end grain loses and gains moisture about 10 time faster than the long grain surfaces. Often, you will see end checks in really old boards. Why? After 100 or so seaonal changes, the ends split. When you go from humid to dry, the ends dry out faster than the middle of the panel....they want to shrink but most of the panel wants to stay put...a bit wider than what the ends want. After many cycles of this, eventually you'll get splits. If you spring the joints, you are minimizing this effect of the ends wanting to pull apart along the grain line. When the seasons change to more dry air, the ends will shrink faster still, but since you've sprung the joint, the difference between the middle of the panel and the ends (in size, not moisture) is less so than a perfectly flat joint. Hence, the sprung joint is less prone to end checks over the years....

   This reasoning should then make you think....well, shouldn't springing a joint just lead to checking in the middle of the panel rather than the ends? Perhaps...but the middle of the panel has much more long grain strength to resist splitting as you've got much longer long grain as well as having support on both sides (end only has long grain on one side). The other thing too is that you shouldn't spring the joint too heavily....1/16 inch gap along 8 feet isn't much. That is a 1/32 dip in each board over an 8 foot length. If you spring the joint to heavily, I would imagine you'd get splitting in the middle of the field rather than the ends.

   ---edit---

   I forgot to add this note....properly springing a long edge joint is not for the faint of heart. At least if you're discerning about any gaps in the edge joint. You have to cut the crook just so in both boards so that when you clamp tight, they form a seamless joint.....seems easy, but it is difficult not to have some minor (a few mils or so) gaps when springing. This concern, of course, depends upon how demanding you are with that particular edge joint.

   Tim

   On the neverending quest for wood.

   Edited 5/28/2004 2:04 pm ET by tsproul

2. 
   mudman | May 29, 2004 01:51am | #22

   So how much spring is good for a 4 foot board? 1/32? I know my statement sounded flippant but it was not ment that way. I have thought a lot about the idea and it seems like for the pressure to make any difference there would need to be a 1/16" or more of a gap. If there is only 1/64 the weight of my hand will close the gap on a 5 " board. Also, do you glue up two sprung boards then rejoint them to get another sprung joint repeating untill the panel is done? Or do you spring both sides of every board then clamp the snot out of all of them to compress the ends untill the gap closes?

   Mike

4. 
   Clay | May 26, 2004 07:51pm | #6

   Mike;

   The low knife you describe is so VERY close to perfect set that I doubt you could improve on it by resetting ... there is a very good chance that you would absorb many hours to get it as good as it is now.  If you want, hone a very slight secondary bevel on the two high knives instead.  This is approach will give you a much finer adjustment.  I would probably not even do that though as long as my cut was acceptable.  When you need to hone the blades just hit the two high ones a few extra strokes.

5. 
   MarkRoderick | May 26, 2004 07:59pm | #7

   I just want to suggest that with a good handplane or two it is so easy to get a perfectly jointed edge and to give it just the amount of "spring" you want. By "so easy" I mean that even I can do it. And there's no danger of cutting off fingers and it's fast and quiet and dust-free and enjoyable. . . .jointing an edge on a board just seems to be one of those things where hand tools actually work better.

1. 
   mlbfreestyle | May 26, 2004 08:11pm | #8

   I like to put about 2 to 5 thousandths or so spring in a 4 foot board.  For non-critical things I don't worry too much about spring.  In a special piece of furniture I would also finish up with the hand jointer.  I agree that the hnad method has certain advantages such as the ability to finesse the fit.

6. 
   sawdustmaker | May 26, 2004 10:11pm | #12

   Mike

   I purchased the same jointer a couple of years ago. You may have to re-adjust things after a little use. The biggest thing I noticed is the infeed and outfeed table being level relative to one another. The manual does a pretty good job walking you through the procedure. As far as the "sprung joints", I don't know. Keep in mind that the length of the tables are not long enough to accurately measure a "true" straight edge over an 8 foot board, IMO.

7. 
   joinerswork | May 27, 2004 04:06am | #13

   Mike,

   I think a gnat's a**is a bit much for a sprung joint; I usually aim for 3-4 frog hairs;-)

   If you are getting a reasonably smooth cut with the knives as they are, leave them alone, see if you can do better when you have to swap them out.

   The way I get rid of a persistant bow in a longish board is to pull back the blade guard, (MACHINE IS OFF) and lower the board onto the outfeed bed  with the middle of the board (or the high point of the bow) over the cutterhead. Rest the far end of the board on the outfeed table, and, holding the near end of the board, lower it till you can let go of the guard cover. The rear end of the board is still elevated at this point.Now that the blades are covered again,turn the machine on, and  gently ease the board into contact with the outfeed table. Feed the remainder of the board past the cutter, with all pressure on the outfeed table. 

   If your board has internal tension (reaction wood, or drying stresses) sometimes it will continue to move, even as you continue to flatten it.  If this is the case, I'd discard it, or at least let it rest for a couple days (or more) at 1/8" over final thickness, then try finishing up.

   Regards,

   Ray

8. 
   ackkacilliac | May 27, 2004 05:47am | #14

   Hi,

     From what I have observed in learning to use a jointer over the last year or so, is that  given co-planar tables,   and  knives set properly, I was heavy handed. Using less pressure, the knives  pulled the board down to the table by themseves, resulting in satisfyingly flat  stock.

   Ken

9. 
   hammer1 | May 27, 2004 08:14am | #15

   I hope you are not checking the jointer with it running!!! Unplug the machine. Take a blade, 1/8"x1x12, from a combination square and stand it on edge on the outfeed table. Align the 8 inch mark with the table opening edge close to the blade, longest side away from knives. Rotate the cutter head by hand in the cutting direction. The blade will grab the metal ruler and move it. Raise or lower the outfeed table until the knife moves the ruler 1/8". Lock the outfeed table. Test both ends and the center of each knife. If any move the ruler more or less than 1/8" you have to adjust the knives. Do not change the outfeed table. The outfeed table cannot be absolutely even with the blades or they won't cut. If your stock is wide enough to resist hand pressure you should be able to get that 1/32" once your jointer is set correctly.