DustyDentist Posted June 27 Posted June 27 I got what i think was a great deal on it ($350)and I bought it knowing it has an alignment issue, but I am fighting a persistent left-to-right alignment issue that has me completely stuck. Right now, the blade tilts slightly to the upper left. I am trying to get the upper arm to come over to the right to square everything up, but I've hit a hard mechanical limit. Here is exactly what I have tried so far on the bench: Loosening the Base Screws (#28): I completely backed off the base screws to slide the C-frame over. If I slide it far enough right to try and align the upper arm, it forces the lower arm out of parallel with the motor. I've tried several permutations with this with the blade tensioned at 50% and 100%, with and without the motor mount screws loosened, etc to try to get the machine true, but every time, the lower and upper arm want to move together and stay out of parallel (the blade stays tilted) Loosening the Motor Housing: I completely loosened the motor housing on its base plate slots to give the lower assembly maximum play. The Deadlock: Even with the motor loose and the base screws backed off, shifting the C-frame just pulls the bottom arm right along with the top one. I cannot physically get the upper arm to shift further to the right. It seems to be mechanically bottomed out against the side face of that orange rear casting column. If I try to force the alignment, the motor linkage rod pulls out of parallel, creating massive high-speed vibration. My Theories/Questions for the Hegner Experts: Since the aluminum upper arm is physically blocked from traveling any further right against that orange mounting face, I'm wondering if anyone has run into this specific geometry issue before. Could it be a missing or misplaced shim? If a previous owner put an incorrect spacer washer between the blue upper arm and the orange casting face on that rear pivot axle, it would act like a permanent shim pushing the arm to the right. Are the ball bearings/needle rollers shot? If the internal bearings inside the upper blue arm pivot housing have collapsed or developed lateral slop, could the tension of the blade be causing the arm to "cock" and bind sideways against the mounting bolt? Is the arm actually twisted? The lower arm has its factory engineered sweeps and curves, but is it possible for these heavy cast aluminum arms to take a physical "set" or warp over 30 years of tension? I really want to restore this legendary machine to absolute "like-new" factory precision, but I've pushed past my confidence limit trying to guess the geometry on my own bench. Ill also say, the previous seller put some cheap aftermarket bellows on it, I assume that wouldn't be enough to prevent the realignment of this machine and make it true? I was planning on replacing it with a factory original at some point unless anyone thinks its critical to do so to true up the machine? I've attached a few photos of the upper arm line-of-sight and the rear pivot joint below. Any insights on what to look for before I start tearing down the upper axle assembly would be deeply appreciated! Also this sounds dumb, but i'm feeling discouraged like maybe I bought a lemon that can't be fixed, but I'm trying to believe in the superior german engineering of this machine and I am hoping that anything on this machine can be fixed. Any words of encouragement would be appreciated. Thanks in advance, Dustin OCtoolguy 1 Quote
rjweb Posted June 27 Posted June 27 I would call advancemachery on Monday they are very helpful, sorry I don’t know anything about hegner saws, RJ Old Joe, OCtoolguy and Wichman 3 Quote
Wichman Posted June 27 Posted June 27 I agree with rjweb, call advancedmachinery Monday ( 1-800-727-6553 [email protected] Mon-Fri 10AM-3PM EST website: https://www.advmachinery.com/collections/hegner-scroll-saws To me, sitting here away from the saw it looks like the table needs to be squared to the table ( the markings on the bevel adjustment are notoriously inaccurate ... on all saws) With the blade taken off the machine, can you move either of the bearings ( in the middle of the arms)? Is the movement of the blade consistent throughout the stroke? tomsteve and OCtoolguy 2 Quote
OCtoolguy Posted June 27 Posted June 27 (edited) I was told by a very knowledgeable person that the bolts holding the saw to the stand are to be left alone but if you do loosen them they should be tightened the correct order. The 2 front bolts first a bit at a time evenly. Then the one rear bolt. As for the frame, it should never be loosened but if you must, accurately mark everything so that it all goes back together in the same spot. The same goes for the motor. From what I can see from your pictures the table is not 90 degrees to the blade. That's an easy adjustment. Don't go by the angle gage. Use a machinists square. To Align the slot to the blade loosen the table mounting screws and align and retighten. I'm afraid you have gotten yourself into a mess by all the actions you've taken so far. As suggested, call Advanced Machinery for help. It used to be Wolfgang but not sure who it might be now. Let us all know what you find out. Edited June 27 by OCtoolguy Quote
treebone Posted June 28 Posted June 28 (edited) The lower arm definitely has some issues. I have no idea how that got buggered. Possibly someone tried to lift the entire saw by the upper arm. It seems like an obvious lift point, but a major mistake. The rubber bumper (part #54) is missing. As others mention, the table is not level, but easy enough to adjust once you have the arms corrected (most likely replaced) Chances are the drive connector will need replacement as well (connects motor to lower arm) Bellows are a not the issue, and are commonly replaced with inexpensive bellows from ebay. You will rarely find older machines for sale that have original bellows still intact. As others advised, Advanced Machinery is your best bet. If the arms need replacement, you can figure at least 500. bucks. Good used ones would be a rare find. There is a lot of good info on taking care of these fine machines. Skrimper's Fretwork site is a good start. Edited June 28 by treebone OCtoolguy 1 Quote
OCtoolguy Posted June 29 Posted June 29 (edited) I might also add that Hegner parts are quite expensive. Many folks have replaced the bellows with a CV joint boot from an automobile. They work fine. To answer your question regarding bearings, the arms are bushed, no bearings. There are 2 bearings in the connector between the motor and the lower arm. That connector is often cracked or broken because it is made of a bakelite type of material. I honestly believe that your saw may have had a couple of minor alignment issues that you have now compounded by what you have attempted. Sorry to say that but from my own experience that is what I surmise. Edited July 5 by OCtoolguy Quote
Old Joe Posted July 15 Posted July 15 My stars must’ve been aligned in the right order, as I bought a virtually unused Hegner and stand a couple of months ago and have had no issues. The seller had removed the saw from the stand. I got it home, plopped the saw to the stand and bolted it together in no particular order with the bolts. I didn’t know there was a secret handshake involved as to proper order of tightening the bolts. As to parts being expensive, I think that’s an understatement. I bought 2 bottom blade holders from Advanced Machinery for extra fine blades and was gobbling smacked by the price. Though I will say that Bonnie at Advanced was quite knowledgeable in answering a few questions I had regarding the saw. i wish you luck, Dusty. I’ll bet it’s something much simpler than is meeting the eye. Call Advanced! OCtoolguy 1 Quote
garryatpa Posted July 24 Posted July 24 Hegner saws are quite simple in that there is only one pivot point on the upper and lower arms which are bushings so no bearings there and on the lower arm is a short connecting link made of bakelite type plastic to connect to the motor. These bearings can wear and create a "knock" or the plastic can crack and cause the bearing to come out. The only maintenance really is to put a couple of drops of oil (3 in 1) on the bushings between the orange frame and the arm after each 10 hours of operation. I have done this on a regular basis and never had a problem with the bushings in over 30 years on my saw. When lifting the saw NEVER, NEVER lift by the blue arms. Use the table at the front and the orange frame at the back of the saw. In looking at your pictures I note that the upper arm looks to be okay as the space between the arm and frame is about the same along the arm. The lower arm on the other hand looks to be closer to the frame at the back. Not sure if this is caused by the angle that the photo is taken or not. Check to see if the arm may be bent and need replacement of arm and bushing and bolt. The arms should not be able to be moved side to side at the front of the arms. If there is excessive movement side to side the bushing and bolt securing it may be worn and need replacing. To check this install a blade and set tension. Run saw and when standing in front the blade should look like a solid black line.. If blurry and wide indicates the blade is moving side to side. Also another indication of bent arm or worn bushings. As has been noted by another contributor the table should be checked with a small machinist square, do not go by the degree markings on the adjustment. There is a circler rubber bumper that goes on the back of the frame under the upper arm that is missing and should be replaced. Most likely cause of your problem in my opinion is a bent lower arm if I am interpreting the photo correctly. Garry OCtoolguy 1 Quote
rash_powder Posted August 17 Posted August 17 Did you ever get this sorted out? Lower arm - Being it is twisted ast it is, when you tension it, physics is going to pull the rear toward the frame and the front out. Why it is twisted and bent I cannot say. Some definite trauma in its past. It will need replaced. Upper arm - it appears your upper arm is not aligned, checking with a square is a fantastic idea. Be sure that your square is square though - adjust it all the way out, strike a line, flip the square left to right and it should match the first. If not, there are tiny pads inside the 'handle' you can file to adjust. The table will have to be dead parrallel to the base of the saw for that to work also, otherwise your square will point off somewhere else. Outside all that, there may be tiny grub screws on the bottom of your arms that impact the bushings. They are used to take up any minor slop that may be in the bushings. If your arms are excessively loose, try adjusting those screws or replace the bushings. It is possible that the 'C' casting is bent. That will be a bear to straighten and $$$ to replace. Ebay and time will be your friend in this. Or deep wallets. OCtoolguy 1 Quote
kmmcrafts Posted August 17 Posted August 17 2 hours ago, rash_powder said: Did you ever get this sorted out? Lower arm - Being it is twisted ast it is, when you tension it, physics is going to pull the rear toward the frame and the front out. Why it is twisted and bent I cannot say. Some definite trauma in its past. It will need replaced. Upper arm - it appears your upper arm is not aligned, checking with a square is a fantastic idea. Be sure that your square is square though - adjust it all the way out, strike a line, flip the square left to right and it should match the first. If not, there are tiny pads inside the 'handle' you can file to adjust. The table will have to be dead parrallel to the base of the saw for that to work also, otherwise your square will point off somewhere else. Outside all that, there may be tiny grub screws on the bottom of your arms that impact the bushings. They are used to take up any minor slop that may be in the bushings. If your arms are excessively loose, try adjusting those screws or replace the bushings. It is possible that the 'C' casting is bent. That will be a bear to straighten and $$$ to replace. Ebay and time will be your friend in this. Or deep wallets. They asked this question on June 27th and haven't visited since June 29th.. Likely found their answer somewhere and never come back.. could be a lurker in the background without logging in but my guess is they they aren't going to see this.. Lots of new people come and ask questions and then never come back to follow up or anything.. and that's okay too but, it always does make some wonder what the outcome was and somewhere down the line their answer could help someone else but we'll probably never know. OCtoolguy 1 Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.