It cut OK but I noticed an upward bow of the blade between the guides. Timberwolf suggested a 1/8 inch downward deflection of the band....I think I was off a little on that measurement. Also, I think my tension is close but as of now I don't have a way to actually measure the amount of force on the blade. I was cutting pine as a test run, it was dead but useable. My question is the upward bow, does that indicate a certain condition or a range of conditions? Any help would be great. Thanks in advance!
duaneb
It sounds like you are saying the saw climbed in the cut?
If so check to make sure the saw is level.
Timberwolf has a flutter test to determine a working tension. Have you tried that?
Any pictures?
Yeah, the saw is level, I may have a slight out-of-level (back to front) condition on my blade though. I can adjust that out with my guides. I have not tried their flutter test yet but I will give that a try tomorrow.
duaneb
Read the troubleshooting guide on the Timberwolf website and also on the Cooks Saw website. They're both very informative on issues like this.
My gut tells me that I'm having a tension problem......my saw, blade and frame is very level so tension looks to be the culprit. Thanks for any and all advice!
duaneb
I should have described my problem with a little more detail, my blade cuts uphill for a couple of inches just after entry into the log then runs the length of the cut with a small crown of around 1/8 inch. Although I have a crown in the log, the blade does not try to ride higher and higher the farther down the log you go. So I'm thinking tension could be a place to start?!?! Also, I've noticed while removing each plank after the cut a great deal of fine sawdust between the lumber and the remaining log, could this be a kerf problem or is it normal? My saw is level, the band is level length wise and if you place a level across the blade, it's very close to level. Thanks for reading my posts and any suggestions are appreciated.
duaneb
I believe that is called push off . The band isn't penetrating the wood enough for the feed rate. Decrease the hook angle and increase the set.
Thanks for the info.....which of the symptoms are you refering to as "push off", the bow or left behind sawdust? Or both? I'm real close to having it dialed in but I still have some work to do!!
duaneb
Even with a bandmill just right you will get alot of sawdust on the board.What are you using to tension your band?? Frank C.
If your blade is climbing in the start of the cut I would say that your blade has upward tilt to it front to back. The mill doesn't have to be level but the blade has to be aligned to the bed rails. It does sound like your tension is low also.
The bow is caused by push off. Excess sawdust can be caused by a lot of things, but unless it's packed tight against the wood causing the blade to bind I don't worry about it. A dull blade can cause push off but it generally causes wavy cuts.
My cut is actually pretty smooth, it just has a slight crown. I tension with screw force and springs to compensate for thermal growth but I'm gonna change my tension device to hydraulic in a couple of days.
duaneb
If you can incorporate a high pressure gauge on the hydraulic tensioner it would give you an accurate reading. Just a thought. :)
Quote from: customsawyer on March 25, 2012, 07:34:05 AM
If your blade is climbing in the start of the cut I would say that your blade has upward tilt to it front to back. The mill doesn't have to be level but the blade has to be aligned to the bed rails. It does sound like your tension is low also.
Had the same issue with mine when I first got it. Blade guides were horribly off. When the blade exited the cut it would drop ¼". I too have screw-type tension, the flutter test gets mine close but added ½ - ¾ turn and the cut ("crown") leveled out. When I bought my mill 95% of my problems were the guides....soon to be remedied ;D
If I had known about the FF, I would have less grey hairs :D But I've learned alot of preventative measures for in the future!
Worked and adjusted more today, cut a 18 inch white oak log and still had the same problem with the upward bow in the board. I believe that my tension is good, alignment seems to be good but blade guides may be a contributor. In an earlier post "push off" was mentioned and caused by low set and to much hook angle. I called timberwolf to order a blade that may help to solve my problem, the technician didn't think changing blade specs would correct the problem so....maybe tomorrow will bring better results.
duaneb
I have seen pictures or video of a few home built mills that the drive wheel was pushing the saw blade instead of pulling it through the log and thought this would be the end result in the cut, probably not your problem but I thought I would mention it. If you get a chance I would like to hear or see more about your mill.
Quote from: Hilltop366 on March 26, 2012, 10:45:45 PM
I have seen pictures or video of a few home built mills that the drive wheel was pushing the saw blade instead of pulling it through the log and thought this would be the end result in the cut, probably not your problem but I thought I would mention it. If you get a chance I would like to hear or see more about your mill.
Yeah, my mill is pulling the band through, learned to make sure of that on this site, but it remains a perplexing mystery.
Although I don't have, at this time, a way to measure my tension, I don't think tension is the problem....I tightened the band much more today and still have the upward bow. The band drops near a 1/4 inch when it exits the log so the sequence of the events goes as follows: blade makes contact with the log, climbs up 1/8-3/16 inch then cuts a slight crown the rest of the way and then drops back down after exiting the log. I'm starting to think my guides are part of the problem....Uuuuuugh, but we'll get it figured out, with the help of my pals on the FF!
duaneb
duaneb, IMO I would say you need to adjust your guides. You can buy the tool or just make your own. I used the ruler from a tri-square, a wide rubber band, and peice of ¼" round stock. With the 16" straight edge exagerating the agle of the blade, was just a matter of adjusting the guides (with a torch) until both ends were equal to the bed. It was crude, but suprisingly accurate. I'd bet good money the crown will disappear when the guides are corrected.
Hope this helps, Good Luck!!
^^^I think you may be right.^^
duaneb
Have you tried a new blade? With it having crown in the cut I would think the blade might have something wrong with it. There have been a few times that I have gotten a bad blade even though it is brand new. I don't know if they are damaged in shipping or what.
I believe Kcwoodbutcher nailed this one. Check your set. Blades set to the heavy side can take care of small alignment problems , temporary of course.