Splitting Large Cants
Sawmill operators discuss ways to cut a 12x12 cant down into 4x6 cants using different types of mill. July 28, 2006
Question
On my band mill, I cut a 12''x12'' cant by first cutting down 4'' and then 8'', then flipping the 3 cant up and then splitting the 3 4''x12'' cants in half, and I end up with 6-4''x6'' cants.
I was wondering how a circle mill would go about doing what I can do with my band mill. These are pallet cants, by the way. And by circle mill, I mean one of those bell saws that are for farm use, with maybe a 48'' blade.
Forum Responses
(Sawing and Drying Forum)
From contributor J:
The same way you described would be done on a band mill. The only difference is the cutting plane and kerf. If the cant were a true 12 inches x 12 inches, then on my mill, it would be 5-27/32 X 3-27/32 since my blade takes a full 9/32 kerf. It would actually be slightly more, since the kerf is always a shade wider than the bit size. Of course, the circle mill would be lots quicker.
From the original questioner:
Don't the 4''x12''s fall off the mill when you cut them? The only time I clamp the cants is when I stand up the 4''x12''. I can't picture how a circle mill can keep the 3 cants on the bed.
From Professor Gene Wengert, forum technical advisor:
I managed a circle mill for a while. The saw was stationary and the log was on a carriage. To saw a 12x12, it would be easier handling to saw it in half (6") and then saw the three smaller cants from each half. This would mean less handling... We have only one half that has to be reloaded, rather than 2 third pieces.
From contributor J:
Once the cant is squared, the first 4 inch board is cut, then the second. The final board is then laid flat and the previous 2 boards placed on top and re-dogged. The pass is made and you would have 3 boards drop on the outfeed side, since boards are fed off the mill, rather than sitting on the fog as a bandmill works.
From the original questioner:
Okay, I get the picture now. You have to pick the cant back up and set them on the carriage to resaw them, which to me would seem like a lot of work.
From contributor J:
Since you would have to carry or return to the carriage the 2 off boards, and then reset them, I see no difference, unless you leave the 4 inch board on top as you saw the 8 inch line, then you still have to turn them. Only advantage you would see is the circle mill would fly down those cuts, but the tradeoff is obviously more fuel required, since unlike your Turner bandmill, you must have some real power to turn a head saw. My mill runs a 125hp Hercules, and gas is not cheap.
From the original questioner:
I leave the 2 boards on top of each other and then I turn all 3 up, then cut them in half.
From Professor Gene Wengert, forum technical advisor:
Sawing with a carriage, circle or band: Indeed, you have to drop one cant (6x12) on one side of the saw and then work on the other one (three cuts) and then pick up the first cant and return it and saw it. Lots of work indeed. In fact, the best idea is to have whomever is making the 12"x12" split it while it is being made. Note that things are different if the circle or band saw moves and the cant is fixed in position.
From contributor R:
I'm a part time portable band sawyer, and a full time plant manager at a large mid-Atlantic pallet plant. My suppliers of cants will bust larger cants on their circle mills using an old trick that is generally acceptable to pallet cant consumers. They will actually leave a small amount of wood when making the initial cut... That is, take a 12x12 and make 2 6x12's that are not completely separated. Just enough wood left to allow the piece to stay on the carriage long enough to be turned over and dogged (2-3 inches on the end of the piece). Then, you would make cut the 6x12's into 4x6's... and they break apart when they fall from the carriage. I've seen it done, and once the sawyer gets a feel for how to gently handle the cant to flip it and then sling it off to make it break apart, it's a pretty cool trick. It may not be the perfect way to saw, or completely safe, for that matter, but it's a process used over and over every day at small circle mills around Virginia.
From contributor S:
I used to saw almost all the way through something like this until it just about falls apart and bring the carriage back. Then I would have everything back at the log turner to roll over at one time... no reloading :) Large logs were the same way (all on a circle saw, producing about 25 to 33,000 BF in 7 1/2 hours).
