Sawing the Biggest Logs Your Mill Can Handle
Will that bandsaw mill really cut a 36-inch diameter log? If only it were that simple. In this thread, owners of various mills discuss the tips and techniques you need to manage monster logs in the real world. July 12, 2005
I brought a LT70 saw, and was told it would saw a 36" log. Well, I have a 36" silver Maple on my saw right now, and I am having a lot of problems sawing it. If it was perfect it might saw, but it’s not and it has all of these ridges and bumps on it. I finally got it squared up by using my chainsaw about eight hours later. It is now 27 1/2" and my clamp is not wide enough. Has anyone had this problem?
(Sawing and Drying Forum)
From contributor T:
You can cut a log that maximizes your mill, but that doesn't mean that you can cut boards as wide as the log your mill will load. You can cut a 36" log because you can raise your blade to 30 inches and have a 6 inch or better slab. You have to take into consideration the width between your guides (the widest board you can cut) and the height of the throat of your mill. (That's what helps to measure the thickness of the slab you can remove.)
Keep in mind that a sawmill's primary purpose is to breakdown a log. Cut as deep of a slab as you can on a big log - it can be re-sawed and boards recovered. Turn the log 90 degrees and cut another healthy slab. Turn the cant another 90 degrees, and you might be approaching a size that your mill can produce boards. Take off another slab and be sure that the thickness of the cant that is left will be smaller than the distance between your guides.
Turn the cant 90 degrees once more and you should have a cant that your sawmill can handle.
Those big logs generally require a log of chainsaw work. Be happy that you have a cantelever sawmill. If you didn't, you would be trimming the log to get the head to pass as well as to get the guides to pass. This is one reason that most experienced sawyers shy away from those big logs. They are production busters. Lots of folks think that the bigger the tree, the better the wood and that’s not necessarily true.
From contributor C:
I regularly cut logs 33" and they sometimes need chainsaw work if they start to get bigger than 36". I split the log before loading onto my LT40.
From contributor S:
I've successfully and somewhat efficiently sawn 36" diameter logs on my LT30 by notching the log. On the face opposite your best (opening) face, notch out for each bed rail with a chainsaw - I make several kerf cuts side by side and knock out the waste with an adze. That way, the log sets down on the mill, effectively raising your top cutting height. You can also make notches where your uprights are to effectively increase the throat of your guides.
From contributor A:
I have shoved them as large as 42” through my LT40. The 36” is the widest spot on the log, and there lies the problem. I cut the bark out where it will lay on the bed rails and gain a few inches there. I also butt the large end to the front so I am not to far in if I hang up. A log that large does not really have to be clamped. The back stops and clamps should be to just keep it from rolling off the deck.
From contributor R:
Well I guess I have just been lucky cutting large logs. I haven't had any big problems cutting 36" to 42" logs (on the big end) on my LT40 Hyd, and I use the chain saw only rarely. I just roll it on and start sawing. 42" white oak is the largest I have run into to cut. What I do is start by removing a small amount off the big end making sure I don't cut to deep to get stuck. I then turn the log just a small amount, maybe 1/8th of a turn or even less, still cutting small amounts off the big end also cutting any knots off while I am doing this. By the time I get the log completely turned, I have the big end close to the size of the small end - then take it apart.
From contributor B:
I’ve used all of the above methods in sawing oversized logs on our Wood-Mizer – sometimes on the same log. One thing I would add is to be real careful when handling those big logs. There is a lot of weight and energy involved. It’s best to have the loading arms up when turning the log. The turner could tear out and the log could jump the clamp come rolling off the mill.
From contributor J:
Something else I have done is I have cut 27" wide cants by laying 3/4" stickers on the bed rails, and slid the cant over the stops just so the saw passes. The weight of the cant will keep it in place. On large logs, I have also lowered the stops with a 4x4 or 2x4 wedged between the log and the permanent stops, so the side of the log just clears the upright. This can give you a few more inches of clearance.
From contributor F:
I would suggest that if you want a saw to cut big logs, get a cutting edge with a 46 inch wide cut. It will be able to handle a 48 inch log and you don't need to spend all your time using a chain saw.
From contributor R:
Something else I would suggest is to lower your side supports down half way. Then you can move the log over and have more clearance.
From contributor P:
I have an LT70 and I cut the big logs regularly as well. As said earlier, log positioning is critical before you start your first cut. A trick I learned is to not put the blade on until I’ve got the log positioned. You can slowly move the head forward and find the whittling areas, or reposition the log some more. It’s time well spent.
From contributor L:
I agree with Contributor A and Contributor B. A large cant as the size mentioned has so much weight relative to the amount of sideways force of the band that it really doesn't need to be clamped on the WoodMizer, as Contributor A mentioned. If your guides won't let you past that 27" cant then that's a different matter. I thought the throat was 28" max though on my LT40HD when I had it.
Contributor B brings up another very good point and likely the best point. That is to be careful when trimming logs with the chainsaw. Never stand on top of the log while it's on the log deck. If things get hairy, you could seriously hurt yourself. If you need to trim a log, do it on the ground first. Pick your side (likely the worst side) where you don't mind having some waste from the chainsaw notch and cut it there. Load it with your arms and rotate the log until the notch in the log lines up with your blade guide roller bearing and then have at it.