Wednesday, October 17, 2012

It's Forest Products Week!

Let's compare some old and modern technology and see how things have changed in lumber
production.  The sawyer has to be able to pass the log through the saw, and a belt drive, friction transmission is how it used to be done.  It still works well, and the sawyer had only a link to the steam engine governor and his lever to control the power.  Now, the drive is handled by hydraulic motors.


The old cable and drum system for pulling the carriage is still in use in many modern sawmills.  This is a timeless and simple system.


Dogs for holding the logs still work the same, but are now controlled electrically, and are linked to limit switches so the sawyer doesn't accidentally saw them off.


The old setworks, if maintained right, will saw lumber just as good as a modern sawmill.  It is human-powered on these old mills, but it moves the knees out just fine.



Adjustments to thickness of the cut is definitely analog.  Reach over and move a peg to set it.

 
Carriages still run on tracks, just like in the old days.
 

 
 
Watching the old mill run at Boonville is painful at times.  The Huber doesn't have enough power to keep the RPM up on the headsaw, and they chew through the logs at a slow pace.  They do have good inserts in the blade, so the blade doesn't heat, and it runs true.  It should zip through logs a bit faster, though.  Note that the sawyer has to roll the log up to keep it on the carriage.  That has changed on some of the new mills.  Watch the video below to see what a difference it makes.  
 


This mill video is courtesy of mcdonoughsawmills, and it shows a modern band saw headrig. The big advance that I see over older designs is the layout of the carriage. The bed is slanted downward, and turning equipment is on both the carriage and in front of it. For over a century, logs had to be turned up, so a 270 degree turn was needed to turn a log down 90 degrees. With the angled bed and dual log turner, half or more of the time turning the log is eliminated.

1 comment:

Anonymous said...

Great post!