Grade sawing - efficiently

[Redhorseshoe]

I'll get right to it, I'm working through a large order of pine 5x5 cants being sent to be turned into veneer.  The order is for clear wood but a knot or two every now and again is acceptable.  I'm working with logs ranging from about 20 - 30" diameter that are certainly producing the quality I need, I'm just not getting it done very fast.  This job is paying enough to deal with longer processing times but I'm hoping for some advice on how to make this a bit more efficient.  What's really slowing things down is all the inspecting, grading, resawing, etc.

How we've been doing it so far is forming the log into a cant, dropping down 5 inches, dropping another 5 inches, removing the two pieces just cut, then getting another one or two 5 inch thick pieces.  After that, turn them upright, cut them into 5x5's and pull them off the mill.  Once they're in 5x5's we sort out the clears from the ones with too many knots.  Some with knots we will trim into a 3x5 or similar as the veneer plant will take them as well so long as they have a 5" face.  After that, the ones that are too knotty or have pith will get resawn into either 1x or 2x then ran through the edger to a 4" width.

After typing it out, it sounds pretty straight forward but just feels like we're moving at a snail's pace through the day.  Any tips for improving effiency are greatly appreciated. 

I'm running an lt40 super wide with an edger behind it and have an employee helping me.

[moodnacreek]

That type of work is slow on a small sawmill. From time to time I saw multiple squares from big logs, sometimes locust. [4x4]   Also 5 1/2 x 5 1/2, 4 from 17" + logs. The buyer chops these 12" long so the bows don't matter. To do this I saw 5 1/2" 'planks [cants] and drop them back on the log deck after finishing the cut with a chain saw. The only way around this would be to have a resaw or even another, in your case, band mill and another sawyer and some kind of run around to get side material back to the edger. It always comes down to more machinery. If you borrow the money to buy it you loose the account and then there will be an auction. That is why there are sawmill auctions many times.

[scsmith42]

From a 20"+ diameter log, I think that I would square it into a 15" cant, and then make three passes down through the log every 5".  Then wrap a ratchet strap around the three-plank cant and rotate it 90 degrees, remove the strap and then make three more passes at 5", producing 9 5x5's.  Then offbear and grade / sort them.  The rejects can then be placed in a stack for resawing.

You'll lose the corner 5x5's due to wane, but should net 5 pieces w/o wane edge by using this method. 

Logs larger than 20" may net 9 good candidates instead of 5. 

[Ron Wenrich]

I had a job that needed quartersawn 4x4¼ clear white oak that proved to be a bit of a challenge.  The price was high enough that we could afford the time and waste involved.  Another job was to cut 6x8 and 4x6 no heart basswood carving stock.  Those were fun, too.

There are several ways to approach the sawing.  A lot depends your market.  You say they want a 5x5, but will take anything that has a 5" face.  Using multiples will give you a much better yield.  I would assume that you would have to separate the thicknesses.  It would make things a lot easier.  If you can cut a variety like 3x5, 5x5, 5x7, etc, then you have more options on how to saw the log.

I am also assuming that you can handle heavy slabs.  You're going to want to get to a target size.  If you want to keep it easy, your target size can be 5", 8.25" (cuts a 3 and 5), 10.25' (splits to 2 5s), etc.  This also assumes you can split your heart. 

My first cut would be to open to a 5" face.  You can drop down 3" or 5" and pull a slab.  A 5" slab would probably have something to recover in the slabs when you make a 5x5.  On big logs, you might want to pull another 5" slab, if you're going down to a 5" center.  Do the same on the opposite side.  Now you have a bunch of 5" material to pull your products.  When you hit too much defect, saw it into something else.  Using multiple thickness to the 5" gives you a lot of leeway in how you can saw a log.

I always found it helpful to sit down with a compass and paper and draw out a diagram of practical ways to cut lumber of different sized logs.  You know your operations and what you can handle.

[SawyerTed]

Are you sawing, edging, grading, sorting, resawing etc at the same time or as you are going?

If so, I would saw 5x5s and stack them.  When I had enough to grade and sort, I would do that.  Then send sorted stacks back to the sawmill or to complete the next order.  In effect working on one step at a time.  

Maybe cut 40 or so 5x5s, sort/grade them, then reprocess the ones that need it.  

[Redhorseshoe]

This is a good idea.  With the exception of edging, we've basically been doing one log start to finish then run the edger toward the end of the day.  Doing the grading/ resawing in batches would at least speed up break down of the logs.  Thank you! 

[GAB]

From a 20"+ diameter log, I think that I would square it into a 15" cant, and then make three passes down through the log every 5".  Then wrap a ratchet strap around the three-plank cant and rotate it 90 degrees, remove the strap and then make three more passes at 5", producing 9 5x5's.  Then offbear and grade / sort them.  The rejects can then be placed in a stack for resawing.

You'll lose the corner 5x5's due to wane, but should net 5 pieces w/o wane edge by using this method.

Logs larger than 20" may net 9 good candidates instead of 5.

Scott:
I need some help understanding your reasoning.
You wrote: "I would square it into a 15" cant, and then make three passes down through the log every 5".  
Why 3 passes?
If you take the two outer 5" pieces and put them aside and saw the center piece into three 5" pieces, then bring both outer pieces back and saw a 2" (or whatever is needed) piece off to get rid of the wane then take two 5" pieces you could get seven 5" pieces instead of five.
Is my thinking way off base?  Also not knowing the piece part value the extra time needed may not make it economically feasable.
GAB

[scsmith42]

From a 20"+ diameter log, I think that I would square it into a 15" cant, and then make three passes down through the log every 5".  Then wrap a ratchet strap around the three-plank cant and rotate it 90 degrees, remove the strap and then make three more passes at 5", producing 9 5x5's.  Then offbear and grade / sort them.  The rejects can then be placed in a stack for resawing.

You'll lose the corner 5x5's due to wane, but should net 5 pieces w/o wane edge by using this method.

Logs larger than 20" may net 9 good candidates instead of 5.

Scott:
I need some help understanding your reasoning.
You wrote: "I would square it into a 15" cant, and then make three passes down through the log every 5".  
Why 3 passes?
If you take the two outer 5" pieces and put them aside and saw the center piece into three 5" pieces, then bring both outer pieces back and saw a 2" (or whatever is needed) piece off to get rid of the wane then take two 5" pieces you could get seven 5" pieces instead of five.
Is my thinking way off base?  Also not knowing the piece part value the extra time needed may not make it economically feasable.
GAB

You make a good point about yield by netting two good pieces from the outer slabs with wane edges.
What my  method does is minimize handling.  None of the pieces have to be off-loaded and then reloaded.  Considering that they weigh around 100 lbs each that's a lot of handling.
Plus, when I'm grade milling I tend to located any defects at the 45 degree angles from the corners of the log, which means that the corner discards would be rejects anyway for his application.  So yield is reduced in the name of speed.
With a slightly larger log - such as a 24", then my method really shines since there should not be any wane edges and the material is never touched more than once (off-bearing it).  It only takes 30 seconds or so to throw a strap around the sectioned log before rotating it, but in my operation it takes a lot longer than that to offbear and then reload.
With a greater number of employees, then handling is not as much of a concern.

[customsawyer]

I'm similar to Scott but different. I would go for a 15 or 20 inch cant in one direction but not so much in the other since you are allowed multiples of 3 or 5 inches. What about 6,7,8 or any of the other numbers as long as it has 5" on one face. If you had a 15x15 cant but the corners had wane then I would cut the top 5 inch cant and flip it on to the loader arms. Flip the cant 10x15 remaining on the mill 180° and take another 5" cant. You can flip it to your loader, the two cants on loader should have at least a 10" face. Take the remaining cant on mill and get a good 5x5 off top and bottom with a remaining 5x5 with pith to be sawed while it is on the mill. Load the two cants off of the loader arms and remove wane leaving a 5x10 that will yield 4 good 5x5 or if you have to take them to 8x5 then you get two 3x5 and two 5x5. Now some of these will have knots that put them below grade but since you can inspect while it is on the mill just saw them while they are on the mill. This way  the sorting is done on the mill by the sawyer. All timbers coming off of the mill meet the grade and everything is only handled once as it comes off of the mill. No sorting and reloading. Timbers in a couple of different sorts based on size and all lumber staged for edger.

[scsmith42]

Good advice Jake.  I've done it that way too.  Anything to avoid humping those heavy pieces back and forth!