I have an eight in jointer and old Rockwell-Delta. I have spent more time trying to figure out how to use it than using it. I have read and re-read on setting it up. We finally got the knives and out feed table even. Now as in the past when I run a board over it several times it forms a wedge. How do I check this? I am not too mechanically minded so go easy.
Thank you
Replies
The sole purpose of a jointer is to flatten one side of a board to prepare it for the planer, which will then give you two parallal surfaces. This is the normal wood workflow.
Run the board (one surface only) over the jointer to make it flat.
Then place the flat side down and run it thru a planer. Then you'll have a board with two parallal surfaces.
Next back to the jointer place one flat side up against the fence and run it thru to give you an edge 90 deg to the flat face.
Take it to the table saw place flat/90 edge against the fence and cut to (just shy) of final dimension. Then if you'd like run that sawn edge back thru the jointer to remove saw marks.
The wedge you see is due to the top surface not being parrallal to the bottom (jointed/flat) surface.
Edited 6/17/2006 12:25 pm by Scarecrow
Scarey old son, that is a scary answer you have dealt Bonkers!
From what he says it is clear that the jointer is taking a progressively deeper cut, or the opposite, a progressively lesser cut. Neither of these conditions are desirable .To put it another way: if one starts with a board that is a uniform 20mm thick and sets the jointer for a 1mm cut and surfaces one side then one should end up with a board 19mm thick-provided the machine is set up correctly.
Bad setting of the outfeed table is frequently the cause of bad planing:if the table is too high a tapered cut will result, which will be compounded when the cut is repeated.
If the tables are not parallel there will be grief as well.
The purposes of a jointer are to surface and straighten faces and edges.Philip Marcou
It sounds to me as if Scarecrow has given the proper answer to how to prepare a board to a 'true' state. Using these steps will ensure a sound and square board. The only way a jointer can achieve a wedge-shaped board is by not having the surfaces parallel to start. So using the steps Scarecrow outlined will make sure they are parallel. I'm not sure what 'Phillip' is referring to as "scary". To put it another way: the only way a parallel board could get jointed into a wedge shape would be if the blades magically rose up (or down) while doing the cutting. This isn't going to happen. the outfeed table doesn't move. the infeed table doesn't move. the blades don't change position. so, the board is not parallel to start. Use Scarecrow's steps.
I'll second (third?) Scarecrow's advice. This question comes up a lot on FWW. Fundamentally, there's nothing about a jointer that guarantees that the bottom side of a board will stay parallel to the top side when you face joint it. If your board isn't flat to start, it's very likely you'll get a flat side, but nonparallel surfaces. If you start with a perfectly flat and parallel board, it's theoretically possible to keep it that way, but even then it's really easy to make a wedge. Practice helps. Push pads help too.Pete
I stick to my guns.
Bonka says he is getting tapered boards, and Scarecrow tells him this is "normal" and that the sole purpose of a jointer is to flatten a board, then goes on to describe the procedure for preparing stock-I don't have too much difference over the latter part, but:-
1)If tapering results even when the machine is "right" then the technique of the operator is at fault.
Anyway, the board can be flipped end for end to cancel tapering.
2)The basic purposes of a jointer are to surface and straighten-not merely to clean one or more faces of a board. A long bed will facilitate straightening.My jointer bed is 96 inches long- I expect and must get straight edges from it, and no tapering or wedges.
The point I am making , which seems foreign to some, is that if one sets a cut of say 1mm, one can expect to uniformly maintain that cut from one end of a board to the other- provided set up is correct and technique is appropriate. I am stating that tapers or wedges are not inevitable or acceptable.
Philip Marcou
Are we guessing that "wedge shaped" means thicker at the leading edge than the trailing edge? If so, then all the prior responses may have some bearing on the problem. However, if "wedge shaped" means thicker at the front or back (as viewed from the user's perspective) in other words the width of the board, then the only answer can be the cutters are not parallel to the bed.
Thoughts???
He said he finally got the blades even with the table. I then assume his wedge is along the length of the board i.e a difference in thickness at one end compared to the opposite end. Iassume this especially as he has said that the situation arises when he has made several passes.
There are some other possible causes of the problem , but I am waiting to see what transpires....Philip Marcou
Edited 6/19/2006 1:38 am by philip
I guess well just have to wait on Bonka to tell us what the meaning of wedge is.Only two things money can't buy, True Love and Home Grown Tomatoes...Misty River Band
The board was wedged from front to back not side to side. I do not recall if it was less thick in front or back. I do know that the knives are getting toward the end of sharpening life. The man said that this was the last sharpening as he didn't have any material to hold onto.
Where does one find knives for an older Rockwell-Delta 8" jointer?
Thank you
Front to back vs side to side still is not clear to me. Sorry.... I'm an engineer by training and sometimes my desire for clarity is confused with stupidity!!!
So I am clear and can posibly help, is the board thickness different on the leading edge vs the trailing edge (lengthwise) or different side to side (narrow )..
I've run into both problems, know the fix(es) and they are completely different.
I'm not trying to be difficult but just trying to offer meaningfull assistance...
Dick
Providing your tables are level or coplanar the wedge issue would clearly be caused by your outfeed table being a few thousandths higher than you top dead center of your knives. Drop the table down until you get snipe then slowly raise it up until the snipe is gone. You will probably have to do this several times as it's easy to go a bit too high again. Typically you will take a seemingly full cut and it will trail off at the end of the board.
I've been repairing machines for 25 years and can sympathize with what seems like a simple machine is really complicated.I haven't seen one manual that dealt with these issues.
Knives can be gotten at many places such as Freud. Amana, etc. Try http://www.woodtechtooling.com They are professionals and not just sales folks taking an order. Also the steel will be better than the original knives.
Where does one find knives for an older Rockwell-Delta 8" jointer?http://www.cggschmidt.com/Pete
Bonka,Are you using a planer after you face joint once side? I hate to ask a stupid question, but when I first started woodworking, I read so much about how a good jointer was essential and shoudl be one of the first tools you buy, I assumed it could do everything. You know, get a face flat then flip and do the same so you get stock 3/4 thick. I have to agree that it is likely your problem is nothing more than incorrect prep technique if all of the above is true.Chris
This is my understanding of dimentioning lumber. First joint one face. Then use the jointed face to the fence and joint one edge. Then with the jointed face down run it through a thickness planer to desired thickness. Then witht the jointed edge to the table saw fence trim off the edge to desired width. One would then deal with the ends by squaring them to length as desired.
I think if I had not have felt I was the stupidest person around I should have know that I needed to proceed with the "wedged" stock as above and I would have come out allright. I am waiting for the right time to try again. You know how life gets in the way of tormenting ourselvse with woodworking. Thank you.
Bonka
"If tapering results even when the machine is "right" then the technique of the operator is at fault."
Hi Philip,
I agree completely. I can't tell you how many times a student has told me one of our jointers at school "is broken" when the fault was with his technique.
An understanding of the tool, and proper technique/muscle memory, are both required to produce consitently straight edges using either a hand plane or a powered jointer.
-Jazzdogg-
"Don't ask yourself what the world needs. Ask yourself what makes you come alive, and go do that, because what the world needs is people who have come alive." Gil Bailie
Thanks, Jazz. It amazes me that some folk , who one would assume would know better, seem to believe that a jointer is inherently not capable of accurate results.Philip Marcou
i know that to adjust a jointer that has a bed angling DOWN from center you can shim at the bottom, but do you know of any way to fix a bed that is angling UP from center after you have taken up all the available adjustment?
The adjustment of the dovetail gibs is only meant to get them snug but still free enough to slide. Making them loose to adjust the bed alignment was never their intended purpose and is a very bad practice, despite the fact that the technique is described in at least one book on maintaining power tools.
If you need to angle the table down, place shims at the top of the dovetails, the opposite of placing shims at the bottom to angle the table up.
John White, Shop Manager, Fine Woodworking Magazine
doesn't gravity kind of already have it forced as far in that direction as possible??? i guess i need to look at it closer but i thought it was already as tight as it could go in that direction, so i'm not sure shims could force it over any further...what am i missing???
Loosen the gibs so that a gap opens up between the table and the base at the end nearest the cutter head and then insert the shims at that end. When you readjust the gibs to tighten up the sliding action, the shims will be caught in the gap between the table and the base casting and will tip the outer end of the table down.
John White
C, it depends upon the type of machine you have . If it has doves , as an integral part of the body casting , you are limitedto what you can do with shims, and anyway they will only be effective if the manufacturer has made the ways with suitable space for shimming. If the dovetail ways are a separate casting that is bolted onto the body then one can either shim or have their faces machined-the latter ajob for engineer re equipment and measuring correctly.
If the machine is of the parallogram bar adjustable type it is then easy to level.
Another way is to have the beds machined insitu at an engineering shop- probably not viable economically unless you have contacts and the time.
So which type do you have?Philip Marcou
I've never seen a conventional dovetailed jointer that couldn't be shimmed quite simply.
John W.
Maybe you have only seen worn ones, or ones made by manufacturers with lots of tolerance issues(;).
Seriously, a well engineered dovetail sliding way is not meant to be shimmed for levelling purposes.The jib and screws are for eliminating play on the sliding movement-as you know.Philip Marcou
I'm not quite following you about only having seen worn or out of tolerance machines.
In any case, you are right that dovetail ways weren't made to be shimmed, but they can be shimmed relatively easily to bring the tables back into alignment. I covered the process in the book "Care and Repair of Shop Machines".
Being that the proper repair, remachining the tables while they are attached to the base, is very expensive, I covered the fix as an workable alternative to scrapping the machine. If only the outfeed table is shimmed, which is all that should be needed, the repair works well.
John White
In case anyone come accross this problem again here it what my wife and I did.
I got a new set of knives. The old ones were at the end of life. We installed them and using the owner's manual set them. The book said to set the outfeed table 1/2" above the cutter head. This we did. The knives all came out too high. Not much but too high. We used one of those magnetic devices and no matter what we did they all came out too high. We let this go over night and both came up with the probability that the table needed to be raised higher. This we did. We also quit using the magnetic jig. It is a worthless as tits on a tomcat. I used the flat heavy section of a machinist square. It still took a lot of repeat work but they all came out just right. We did have to raise the table a skoshe once again though.
We nest check the tables to be coplaner and they were. The fence was squared but it will not square the full length. We left the ever so slightly out of square end on the out feed.
I just ran a piece of 2X6 pine through it. The board is square from one edge accross the jointed face. I took about 1/32" at a time and had no tear out and it trued up in only a few passes. My wife and I are both pleased and moreover surprized. Thanks to all for you input.
You're going to have to watch out for that fence. You'll have a really hard time putting on a 90° edge.My goal is for my work to outlast me. Expect my joinery to get simpler as time goes by.
I've used it a few more times with excellent results. If I keep pressuer on the back part it works fine. How would one go about truing it up? Take it to a machinist?
That or replace the fence are the only two serious possibilities I can think of.My goal is for my work to outlast me. Expect my joinery to get simpler as time goes by.
I was wondering how much "ever so slightly" is. If it's really slight he might have other options.
Since the house is on fire let us warm ourselves. ~Italian Proverb
I haven't used a feeler guage to see how much it is out. As long as I keep it aligned with the fence on the back table things work fine. The board I used to test it was about 20" long and all came out square.
Gracie, I do not know why Scarecrow has told us how to prepare timber, but I am (still) grateful for any further snippets to add to my 35 years or so experience. Bonka wanted to know why he is getting tapered boards,especially when he makes repeated passes with the same board.
I have provided one or two of several potential causes for this problem- none of them involving magically undulating cutter heads or itinerant tables.However I must point out that, on my jointer at least, both the out and the infeed tables can be moved, but only when I require this and when the machine is being adjusted, by me: the board has nothing to do with it.
I repeat: tapered cuts can result from incorrect set up and or poor technique.Think about it.Philip Marcou
Philip,
Please correct me if I am wrong but if the outfeed table is too high, wouldn't the board butt against it ?
If the outfeed table is to low the result is a snipe. I don't really understand how he could end up with a wedge.C.
You are essentially correct about the board hitting the table it's too high but it only takes a few thousandths too high to create the wedge effect. With an adjustable outfeed table you should drop it down until it creates snipe then slowly raise it up until the snipe is gone. It 's easy to go a few thousandths to high and create the wedge again. Drop the table and start again. Takes but a few minutes to do. This is based on having your tables coplaner in the first place. If one of the tables is angled down slight the above procedure won't fix it.
For folks with a fixed outfeed table and wedged boards it means readjusting the knives.
"This is based on having your tables coplaner in the first place"
I agree with Rick. You should obtain a long & accurate straight edge (Lee Valley/Veritas is one source) to ensure the infeed and outfeed tables are in the same plane (are co-planar). If they are not, shims can be used to make the necessary adjustments - a job that's much easier with a helper.
What method did you use to ascertain that your blades are set to the height of your outfeed table? Dial indicator? Straight edge?
Lots of good books and magazine articles are available.
Good luck,
-Jazzdogg-
"Don't ask yourself what the world needs. Ask yourself what makes you come alive, and go do that, because what the world needs is people who have come alive." Gil Bailie
C , you are correct in theory. But in practice even if that edge is proud by as much as 1mm it is easy for the board to ride up. On much used planers the edge of the out table is rounded slightly anyway, and I actually like that condition. If one is applying down pressure at the back of the board rather than nearer the cutters it will ride up-remember the spinning cutter head is "hammering" away at the board trying to lift it off the table. Similarly if down pressure is more to the outfeed end rather middle-ish the condition will not result in a snipe.
I think that planing technique is as important as correct machine set up.Philip Marcou
I gave him the workflow for turning rough lumber into useable lumber. I do beleive that is what his question was.Only two things money can't buy, True Love and Home Grown Tomatoes...Misty River Band
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