Sawing logs longer than your mill?

[Deese]

I've got to saw 80 4x8's for a customer. Twenty of them have to be 24' long.
I've got 2 options. One is that I could take the long boys to the guy who bought my manual mill, which can saw up to...nevermind! Dang! While typing this, I was thinking my old mill could saw 24', but it only saws 22'.

So I'll be sawing them on my LT40. Now I've just got to decide on which sawing style I will use. The way Peter Drouin and Dave Shepard do it, or the method shown in the knowledge base link on the home page.

I'm thinking the way Drouin/Shepard does it will be a little faster. I could use one of my smaller chainsaws and just make sure not to scar the beam surface on the last cut...leaving just enough "meat" not to scar the beam and then just "tear" the board away.

OR I could use a circular saw to make clean, measured cuts. Both Dave and Peter's photos show that a circular saw would work as long as you make each cut a little shorter than the previous cut. That way, you've got a flat surface for the circular saw depth gauge to rest on.

To me, it makes better sense to put the BIGGER end of the log facing the front of the mill if using this method, right? This would reduce the number of cuts with the circular saw at the opposite end of the log, thus saving more time.

Step #1: Put the log on the mill with big end at the front.

Step #2: Use rear toeboards to level the pith.

Step #3: If there is a lot of taper, then your first few cuts may not make it all the way to the end of the frame. Keep dropping with
              each cut until you saw all the way to the end of the frame. Disingage blade, back out of the cut a few inches.

Step #4: With circular saw (I want to say "skill saw" so bad), adjust cutting depth to the same or slightly less than your board
              thickness and cut off first slab.

Step #5: Return saw head all the way to the front of the mill, rotate log 90°. Then repeat steps 2,3,and 4.

Step #6: Rotate log 90°. This is your 3rd face opening. Make sure the toeboards are all the way down. The bottom flat surface of
              the log should be in full contact with all of the sawmill bunks if your mill is sawing correctly and there isn't significant
              stress in the log. Repeat steps 3,4, and 5.

Step #7: Repeat step #6. This is your 4th face opening. Once this step is completed, you have a cant that may or may not have
              rounded edges at this point.

Step #8: Saw the cant to the dimensions you prefer by repeating steps 3-7 and keep toeboards down this entire time.  While doing
              so, make sure to follow the cathedral grain pattern and make adjustments to keep the pith as close to center of the beam
              as possible. 

Step #9: Once the beam is sawn to specifications, raise toeboards and push log toward front of the sawmill until the blade is able to
              exit the end of the log. Be sure that log is positioned where the uncut portion of the log does not contact the end bunks. 
              Lower toeboards and secure cant with clamp.

Step #10: Set blade to height of beam surface and finish cutting the beam by making cuts and rotating log.

I'm in a big hurry trying to finish this thing up, and I'm sure I've probably made some mistakes (maybe big ones)...I'll read it over when I get settled at home.  What do you guys think?  Basically, I'm trying to generate some conversation about doing this, what and what not to do, etc. Because I have no choice but to make this happen very soon.

[Ga Mtn Man]

First I would refer you to this thread as a warning:

https://forestryforum.com/board/index.php/topic,95523.0.html

That was my first foray into sawing over-length logs and I think I tried just about every log position possible.  I decided I preferred to have the butt end at the front of the mill, as you said.  This leaves less weight hanging off the rear of the mill making the log less likely to bend from its own weight and it won't tip as you move it back and forth on the toe rollers.  The downside to doing it this way is you have a smaller target to hit hanging off the end of the mill.  You will find out in a hurry that there are very few truly straight logs out there.

[Peter Drouin]

There's a bunch of ways of doing that.


  

 
Cut up out of the cut. Or cut with a chain saw. Mark how far the blade will go down the log. cut down with your chain saw, not too far and cut to the saw cut.




  

  

 


You can use a flat bar and lift the 1" board you just cut and slide a 1x4 down the cant as far as you can and cut on top of that with your chain saw.
The log in the pic has the big end to the front.
I did not plain that , I cut all my logs here the way they come, big end or small first I don't care. :D