Hello,
I’ve got a Delta DJ-20, 8-inch jointer that has started leaving my edges with a very slight bow. I’ve looked at all the books I have and found nothing even remotely suggesting a cause. I went to the Delta site and that was a waste of time.
The 3-1/2″ x 1″ hickory I just edge-jointed was about 36-inches in length and the center gap I got was about 1/32-inch. This is not acceptable. One article I looked at mentioned that if the out-feed table was lower that the cutters the result would be snipe at the trailing edge. This is not my problem.
I just checked the tables against each other with a feeler gauge and (as currently adjusted) I was consistently 0.015 across the full 8-inch width of the table. With my 24-inch machined straight edge on the out-feed table, I preiously set up my blades to just scrape the bottom of the straight edge when they were rotated. That is how they presently all are save for the centers which showed some wear from usage since I normally favor the center. I do use the edges when I think to do so to even out the wear. Regardless of this slight wear, I cannot understand why this is happening.
When jointing a piece, I always try my best to apply moderate and even pressure as I pass the stock over the blades. As a simple test, I re-jointed the same piece applying very light pressure and got the same exact results. In addition, I have a habit of always running my carpenter’s pencil over the edge to be jointed so I can gauge the results as I proceed. And, I always make several light cuts rather than hog off the stock in on pass.
This has me baffled and hope someone can shed some light on this.
Thanks,
Phillip
Replies
I just did a search here and found a post by John White of FWW. His suggestion about this same problem is that my out-feed table may not be set correctly. I will do as he instructed in his post and see if that helps.
Thanks.
PhillipB ,
Maybe the knives need to be honed or actually sharpened .
My jointers have always started cutting poorly when dull .
The cut you are getting does sound familiar from dull knives .
Sounds like you know to set the knives flush to the top of the outfeed table , but too high can snipe the ends .
dusty
I just finished re-checking all of my table vs. cutter head measurements with my feeler gauges and I think I'm a little off everywhere. I thought all of my measurements were spot-on but I guess not.Thanks for stopping in with your comments.
Can anyone tell me what the wrench that fits these eccentric bushings is called? I've seen these wrenches before but do not know what they're called. Hopefuly, they will be adjustable.Thanks.
Edited 11/17/2007 6:20 pm by PhillipB
It's called a spanner wrench (or driver). Go to http://www.mcmaster.com/ and type "spanner" in the search box to see a variety.
-Steve
Thank you very much,I was thinking that was the proper name but then I thought that a spanner wrench was more of a curved affair used for grabbing cylindrical objects. Guess not.I appreciate your help. I thought I had this bloody jointer set but I was wrong. I had to completely disassemble it to get it into our basement, then put it all back together a few years back. This is really making my day. Life.Thanks again.
"...I thought that a spanner wrench was more of a curved affair used for grabbing cylindrical objects."
Yeah, those are also called spanner wrenches. ;-)
-Steve
After looking at the spanner wrenches in the on-line catalog, I saw that my memory was correct save for the fact that the one I now need also goes by the same name.The slots in my bushings are retangular. The ones that McMaster has are all pin shaped. Guess if they don't fit I can file them down a bit and hope they don't snap off.I appreciate the help.
"The slots in my bushings are retangular. The ones that McMaster has are all pin shaped."
If you look under "spanner screwdrivers" or something like that, there are some that have rectangular pins.
-Steve
Steve,Thanks. I'll check that out.This is such a pain, but in a week or so, I'll look back and think it was a good learning experience. At least that's my plan. This was true when I put it back together after moving it down into the basement.I appreciate the help.Phillip
I may be wrong but it seems to me that there could be two reasons for the concave jointing. One would be a low outfeed table and the other would be either an infeed or an outfeed table that is sagging at the ends. Does that make sense?
Unfortunately, what you suggested makes perfect sense.As I mentioned earlier, on a 36-inch board, the concavity is about 1/32-inch, which is not much, but regardless, there should be no cavity at all. Else, why have a jointer to begin with.I really think I'm going to have to re-spec the whole machine from A-to-Z. No problem. I have to get my hands on the correct spanner wrench, and then get to it. Won't have time to even start this project for another week due to a planned Thanksgiving trip.Rather than look at this as an obstacle, I'll look at it as a challenge. Makes it all a bit easier, IMHO.Thanks for the great observation. I'll let you know if you were correct.Take care.
Phillip, I usually find that bolds/screws with odd heads are not meant to be adjusted. If you noticed wear in the middle of the blades and your work comes out bowed, why did you not try putting new blades in it first? Try measuring the height along the blade relative to the table. I got a 10 year old used jointer from someone and had lots of trouble adjusting it until I put a new set of blades in it. The $30 (6") would have saved me lots of valuable time if I had done that first. Andy
Cayra,Thanks for your comments.A few years back I had to disassemble this entire jointer to get it into my basement shop. Obviously, I had to put Humpty-Dumpty back together again. Because of this, I had no choice but to make adjustments to those eccentric bushings. However, now it appears that I didn't do such a great job. But, your idea may be the solution because I really believed that this machine could joint a perfect edge when I was done. Now, I will say that I did not perform the 'John White test', which is, jointing two edges and mating them together until the concave gap between them was gone. This is done (according to him) by slowly raising the out-feed table until a good fit is made between the two pieces. This is, of course, assuming that this was the problem and not some other misalignment in the machine. So, having said that, after I finished putting it back together and performing all of the alignment steps outlined by Delta, it may not have been up to spec, as I thought it was.I will remove the blades and run them through my TORMEK and re-install them. If I still have the same concave issue, then at least I know I didn't overlook the obvious solution (thanks to you) and now I have some sharp jointer blades, which are always welcome in any shop.We're going to be gone for a week beginning Monday, so I hope I can get to the blades before we leave. Might make the Thanksgiving Holiday a bit more restful.Thanks again.
Hold on......
See the set screw above the bushings?? THERE IS ANOTHER set screw below it!!!!
DON'T try to rotate the bushing until you loosen the second set screw or you'll burr the bushing!
After you remove the first set screw and then loosen the inner one, the bushing will rotate easilly without a special spanner wrench.... I used 2 small allens stuck in the bushing holes to rotate...
Dick J
Yep! You're absolutely correct about the double set screws. The Delta instructions I have show an image of the left out-feed table bushing and from their desciription, it sounds as though that is the only bushing with double set-screws. Wrong! Each bushing has two set screws. The set screws on the outermost in-feed table bushings were very tight, but I now have 'em loose.BTW, I'm using a small pair of channel-locks to rotate the bushings. They rotate quite easily. Now.Thanks for taking your time to point this out. Ok, Ok! What kind of pizza would you like to have?I appreciate the help.
Dick you are correct in there are two set screws at each of the bushings one on top of the other. The Delta parts sheet dosen't show this verywell. I just for the heck of it today had some time to check my jointer out and found it out of adjustment again. I then pulled out the two set screws from two of the bushings and both were flat on the bushing side. So if anyone was to move the bushing with out backing off the set screws, you would not do major harm to the bushings, but Yes, since the set screws are there, I would also recommend to back them both off. The set screws in my DJ-20 are metric by the way.
Sunday time to re-a- just.
Tony
Phillip, I have the same Jointer and had the same problem with the jointer not giving me a true jointed edges. I would try different things to no aval.
I finally pulled out my 6 foot level and placed the level on both of the tops, to see if both tops were in the same plane. Too my surprize, I found that the out bound ends on the in and out feed side the tops were dropping away. To fix the problem I was looking for the spanner wrench in the sq. tip format to do the job, but only came up with the round pin type from McMaster carr which I did buy. Leveling the tops take time don't rush the project.
What I did was drill round holes the size of the pins in the face of the brass CAM shaped bushings on both sides, 8 in all, four in the front and four in the back. I used my 6 foot level again as a straight edge to make both tops level with each other. Then once the tops are level, adjust the out feed to fit the TDC of the jointer knife and then the infeed as needed.
Important! use a sharpie and make a mark across the bushings where the two surfaces meet, before you make any adjustments. Because you will need this as a referance point, so you know where you started from in the first place. Make small adjustments at a time 1/16 of a turn or lesson each side then move on to the next set working front to back meaning, out feed bushings line #1 next set closer to the knife #2 then the infeed close to the knife # 3 and the in feed #4
Good luck
Tony Czuleger
Buy the way don't let anyone use the jointer top as a park bench to sit on? The jointer I have was abused by the original owner and has been brought back to life as a very nice tool.
Edited 11/18/2007 1:34 am ET by TonyCz
Edited 11/18/2007 1:44 am ET by TonyCz
I'M SHOCKED! I centered my trusty 48-inch STABILA level over the cutter head (between blades), held it firm against the out-feed table and saw an 1/8-inch gap at the in-feed end of the level. 1/8-INCH!!!! YIKES!! I should have been getting at least a full 2-inches of concavity in my edges. Musta been my excellent jointer feed technique that eliminated the other 1-31/32 inch. Yeah, right!Hey, Tony! What kinda pizza you like? Pepperoni? Double Cheese? Thick or thin crust? You name it, go got it 'cause you da, man!Seriously, I cannot thank you enough for taking to time to help me out with this. Your comments are invaluable because (1), you experienced the same exact problem with the identical jointer, (2) you solved the problem, and (3) you were kind enough to share your knowledge with me (us). It doesn't get any better than this.Looking back on how I re-assembled my jointer after I moved it into my basement, I may have made one major error with my set-up tools/technique to catch these significant misalignment errors: I used too short of a machined straight edge! The one I used was only 24-inches long and I now believe that I should have been using a much longer one. I just ordered a 50-inch machined straightedge from Lee Valley. However, in the meantime, I will give it a go with the STABILA just to get the tables back into the ballpark.I cannot thank you enough for your help.Phillip
Right now I've got two DJ-20s - one that works and one that doesn't! The one that doesn't has tables that are high at the ends and low at the bottom, like a shallow "V". I've spent a number of hours playing with the eccentric bushings, but I can't adjust the tables enough to get them parallel. If anyone knows another technique to further level the tables...
As a sidenote, when I picked up my second jointer (the working one), I planned to take the tables off so that I could move it myself. However, the Delta guy warned me not to, at all costs because I would never get it set up correctly.Chris @ flairwoodworks
Phillip:
I always adjust my jointer to produce a slight hollow edge when making flat glueups.
The edges will clamp up tight with slightly more pressure on the ends of the glueup.Thus,with the changes in moisture content,the glue joints are less likely to open up.Pressure is more or less equalized.I have never had a table top to open up because of this. If this presents a slight dimensional problem,you can always trin the outside edges for parallism and squareness.
Work Safely ¬¬¬¬¬¬¬¬¬¬PAT¬¬¬¬¬¬¬¬¬
Pat,Thanks for that bit of info. I understand the point you are making and it does make sense. In my case, I'm was laying the edge jointed stock on its side against a very true 2-1/2 x 2-1/2 x 36-inch laminated stock which, when completed, will form one of the legs for my new workbench. In so doing, I noticed the slight concavity as I was prepping the piece for glue up. Curiosity about this is what led me to my jointer concavity problem.BTW, your last comment about "Work Safely" has new meaning to me as I just 'activated' my old Sears 12-inch radial arm saw. It's been over 20 years since this baby has hummed. As to safety, this puppy gives me the willies because, as we all know, these machines take no prisoners. I just posted a sign over the arm which says: THINK!I appreciate your comments.
AS a patternmaker one of the main requirements is accuracy.You can`t afford to send work to the foundry and find an error after hundreds of castings have been made. If you visited my shop,you might think that you were in ####machinists place to see all the precise straight edges and precision measuring tools atop the 6"X48"x72" BLACK GRANITE SURFACE PLATE.
wORK SAFELY ¬¬¬¬¬¬¬¬¬¬PAT¬¬¬¬¬¬¬¬¬¬
Pattern,
"If you visited my shop,you might think that you were in ####machinists place to see all the precise straight edges and precision measuring tools atop the 6"X48"x72" BLACK GRANITE SURFACE PLATE".
Come now, let us see some pictures of your shop. Sounds like you will have some interesting old good stuff....
Philip Marcou
Phil:
I do have an assortment of old woodworking tools. Aquired by purchase from time to time of other shops closed mainly because of retirement.
In some respects of modern techology,I am behind the times.I do not have a computer.My internet access is thru a webtv service. I am not equipped to send pictures.However I seem to get all the spam.
Work Safely ¬¬¬¬¬¬¬¬¬¬¬¬PAT¬¬¬¬¬¬¬¬¬¬¬
Phillip-I've got a DJ-20 and was going to try the same table parallelism adjustment you describe. The concavity in mine is about half of yours. I've not seen any detailed instructions, would you take some photos as you adjust yours and post the process? I suspect there are number of DJ-20 and clones with the same issue. I understand it in concept, but am reluctant to try it without a bit more guidance.
Thanks.
Fred
Hello Fred,I'll be happy to accommodate that request for you and anyone else interested. The process is not that complicated and goes rather quickly once the bushings are freed up with lubricant and the fence and belt shield are removed. This is necessary in order to be able to rotate the bushings. And as one astute poster noted, don't forget that there are TWO SET SCREWS in this scenario: one below the other, save for the bushing on the inner right corner (as you face the jointer). This is the one with the cut indicator over it. This bushing has its set screws to the side as opposed to above the bushing like all the others.Unfortunately, I will be leaving for about a week and this will have to wait until then. I have been mulling over my adjustments, but my weak point is that I have been using my STABILA level and it is not a real substitute for a machined straightedge which I have on order. This should be here when I we get back. If you've read through this thread you will know that I previously used a 24-inch machined straight edge and I really believe that was a big mistake. A longer one I believe will be much better.One other thing that has bothered me is the length of the feeler gauges. Mine are only 3-inches in length and I believe that longer ones would be much easier to test with. All that is required for the DJ-20 are a 0.015 inch feeler gauge. I also use a 0.016-incher to make sure the lesser one was really a good fit and not too loose. Others may not be this meticulous. Briefly, I have gone so far as to remove one of the eccentric bushings for measurement with my digital caliper. I found it absurd that these bushings were not marked with their respective high and low points which would naturally, be opposed to one another. I was correct in that, in my case anyway, the spanner wrench notches did in fact represent these points, but you will have to guess which is which as that is all they represent. This is not too big of an issue because if you place a light source behind your straightedge, it will be very obvious which is which as you rotate the bushing.My final thought here is that a person will have to make a call as to how much time they are willing to spend on this complete procedure. To be clear, you may have to complete the entire process more than once. And, if you decide to re-check a third time, and find that things are still off, then I would draw the line after three attempts to get it all trued out. I am, of course, making the assumption that you are following the procedure religiously each time around. As for me, I really have no idea just how flat my tables really are to begin with and I have no way to find out either. Nor do I really want to spend the time and money to do so. I have to remember that all this effort is being expended to get an edge flat that will not lose form or function if its edge has a resultant concavity/convexity of 1/64-inch or less. As one other poster noted, he prefers slightly bowed joints for glue up.Thanks.
when gluing up boards for example table top a small gap is actually better as it puts more pressure on the ends and lessens the chances of them opening up later on in life. hasn't solved the jointer problem but.
Ok I had a chance to really get my hands dirty on the DJ-20 this past week and spent 45 plus minutes on the tables. Getting them so the cut would give me an acceptable joint for glue ups.
Remember unplug the power!
The important thing I found was you really need to take off the fence and the support base, so you can get the spanner wrench in to the tight space. Even so, it is still a bit tight for the spanner wrench to get into the square notches from the factory. So I drilled two additional holes to insert the spanner wrench round pins into the bushing. The two additional hole were drilled at 90 degrees to the sq. notches, + yes kinda like the plus. By doing this, the adjustment with the bearings was much easyer.
When I made my adjustments, I started with the infeed table first adjusting the two bushings closest to the cutter head. Then reset the set screws and moved on to the the two bushings farthest away from the cutter head. Once I was convinced I was close with my adjustments, I moved on to the out feed table and started with the farthest bushings from the cutter head, then reset the set screws then moved on to the bushings closest to the cutter head on the out feed table. All the while making test cuts to acheive the best jointed edge as possible.
Remember to make small adjustments on the bushings, being no more than 1/8 of a turn at a time and making the same adjustments on both the front and the back side is very important. Also make sure before you make any adjustments, use a black sharpie to mark the bushing for a referance point to find where you started from. You may have to reverse your moves the other way or back to the original starting point. Also look for the dimple on the side casting next to each bushing to place your mark on the brass.
When done remember to check the height of the knifes with the out feed table, because if the out feed table was adjusted the knifes may very well need to be adjusted as well to the new setting to prevent a snip. I also did my test cuts with out the fence installed being very carfull of the exposed rotating knifes while performing the test cuts, unpluging the power each time afterwards.
Once you have made the final adjustments re-set the last pair of set screws and then re-install the second set screws on all the others just snug, so you don't damage the head of the one below.
Reinstall the fence mounting base and the fence and check that the fence is square to your table. Plug back in the DJ-20 to the power and happy jointing.
Tony Czuleger
This thread has been really relevant to me. My ancient 4" delta has started doing the same thing. Now I know what to look for to fix it.
I've got to replace this old turkey - an 8" machine would be sooo much better, but I'll probably get a 6" since I can get that down into my basement workshop - the weight jump from 6" to 8" is substantial.
Mike D
Mike D
I had a similar problem with my Delta 6" jointer, and used a piece of aluminum angle, a strong flashlight and a piece of paper to find the problem.
I ran the infeed table fully up and laid the angle along the length of the tables (the angle was longer than the length of the tables).
Using the flashlight as a backlight, and sliding the paper along the tables under the edges of the angle, I found that the ends of my tables were slightly below the cutter head (i.e the tables were slightly humped).
A couple of hours of messing around with home made shims, finally got it dialed in just right.
Bump/
What's with the bump? It only disappears after you post and it only disappears on you. Anyone new can see your post. Just means no one had anything new to add.
http://home.usmo.com/~rfwoodworking/jointer.html
There was a person looking for information on a DJ-20 tune up and this is a easy way for that person to read an old post when they can't fine what they are looking for.
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