I've viewed several bandsaw mill manufacturer's product videos and noticed that some remove the boards after each pass and others cut the whole log without removing any of the cut lumber. Does leaving the weight of the previously cut lumber enhance the straightness of the cut by keeping the tension of the wood from being released, or does this method put undue strain on the bandsaw? Are there advantages or disadvantages of sawing in this fashion?
(Sawing and Drying Forum)
In my experience, if a log is tensioned, it's going to move whether there is a pile of wood on top of it or not.
Leaving the boards on the log doesn't put any undue stress on the blade, as it is so narrow that the kerf doesn't close up until the back of the blade is well cleared.
If you are grade sawing, you need to see what the log face looks like and every board should be pulled after it is cut. If you're cutting dimension lumber or siding material, it's okay to let them build up.
The biggest disadvantage of leaving them on the saw, to me, is you have to raise the saw up ever higher over the stack to return it. The advantage is, if you are going to turn the stack to make more cuts, i.e. for stickers or dimensional lumber, there is less handling. I will also let two or three boards build if they are relatively light, and then remove them at the same time in order to save time and energy. And if I have a pokey tailer (usually the customer), I will have him wait till I'm done and while he is offloading, I get the next log on the lift.
Once I've got a cant, and I'm ready to turn it into boards, I leave 2 or 3 boards on the stack. When I offbear, I have a trailer or a loader with a pallet behind me, and I drag three boards back with the mill head, right onto a single board which has been sticked. I then flip the boards onto the sticks, and fill out my layer of boards. (The drawback is that this leaves some sawdust on the boards, which then makes it into the stack).
When I return to the saw, I flip the cant 180 and saw a board for the next row. (Flipping 180 relieves the stress in the log evenly, and helps the lumber come out straighter when it dries.) Then I take 2 or 3 more boards to fill out the layer on the board stack. Sometimes, I can only take 1 or 2 before I have to flip to relieve the stress, though.
When I flip, I take 1/8" "veneer" off the top to even out any waviness or bowing of the cant. This helps keep a consistent thickness in the pile, and makes the graders happy.