Horsepower Requirement for a Big Circular Sawmill

Quick tips on the power needs of a large circle mill. August 30, 2007

Question
What size power unit (hp) is needed to run a circular sawmill with a 56" blade for cutting ties and lumber (hardwood)?

Forum Responses
(Sawing and Drying Forum)
From contributor G:
5 hp per inch depth of cut for slow feed, 10 hp for fast feed. You can saw slow with a 75 hp or fast with a 150 hp. Then you have to add if you are running the feed off the same motor.

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From Professor Gene Wengert, forum technical advisor:
Are you cutting oak or a lighter weight wood? What style tooth? Number of teeth? RPMs? Will you feed at 0.11: per tooth? Green logs? What is the larger size log diameter (not the largest)? Does the carriage have its own power?

The mandrel must be large enough to handle the torque. Unless you have really large logs, I suggest that you have the blade cut down to 52" or maybe 50". It will run with a lot more stability.

I think that 75 hp will be a bit scant in many cases and 100 hp is much better, but until I get your answers, I do not know for sure. (I managed a mill that had a 52", f-style, lots of 18" diameter logs, oak, and we had 75 hp and wished for just a bit more. We also ran the log turner off this motor, but since the turner is not used when sawing, this is okay.