Circ mill question on blade RPM

[yellowrosefarm]

Is there any standard RPM people run a circular mill at? I know the blade has to be hammered for the speed you run, but is there a general range? Could you run one straight from a 540 pto onto the mandrel shaft or do you need to use pulleys to speed it up? I've seen a bunch of mills at steam shows but they were all on flat belts with a small pulley on the tractor and a big one on the mill. I have an old 00 Frick that I would like to set up and run with the tractor someday if that would work.

[bandmiller2]

Theirs quite a range probibly between 400 and 700 RPM,alot depends on the diameter of your saw,you can spin a smaller one much faster than a large one.Tractor PTO speed is fine.My saws are hammered for 600 RPM mostly because it worked out well with the pulleys I had.Some of the modern production mills may go over  700. For older mills I'd aim for between 500 and 600 RPM. Frank C.

[steamsawyer]

I have mine hammered for 500 rpm. My arbor pulley is 20" and my engine flywheel is 42" that gives me a 1:2.1 ratio to get the engine rpm around 250.

If you have a left handed mill, or a Belsaw mill you can run directly from your tractor PTO and hammer your blade in the 500 to 540 range. A right handed mill would probably require belts and pulleys to get the right rotation.

[Ron Wenrich]

Here's a handbook that has been around for a good number of years and is probably the best one written.
Its by Lunstrum and gives tons of information:

http://www.fpl.fs.fed.us/documnts/misc/circsaw.pdf

Older mills run well at about 540 RPM.  I've run mills as low as 350, but wouldn't recommend it.  I've also run them as high as 710, but saw maintenance and performance is hard.  I wouldn't go direct from pto shaft.  The reason being that every once in awhile, you might hang a saw.  With a belt from your drive, the slippage would help save things. 

[loggah]

A lot of the belsaws were made to direct couple with a PTO shaft from a tractor. Their PTO shaft has 2 shear bolts in it just in case you did hang up a saw. Belsaw recommends in their catalog to have the saw hammered for 525-575 R.P.M. Don

[yellowrosefarm]

Thanks for all the information. Now I know it is at least possible. I hadn't thought about the rotation but I'm sure I can solve that. I'd like to run the carriage using a hydraulic motor to turn the cable drum and a pulley off the mandrel shaft to run the hyd pump. I have an old mobile home frame for a platform so it would be portable. Still obviously in the planning stages.

[bandmiller2]

YRF,hydraulic feed is fine but like your tractors you want live hydraulics.With a pump driven from the engine you can move the carriage and run all the functions without the saw spinning. Frank C.

[Ron Wenrich]

I had an old mill that we ran right off the arbor with hydraulics.  We used an old fuel tank for the reservoir.  It worked good.  But, we didn't run our hydraulic motor directly to the cable spool.  We put a sprocket on at the husk end of the shaft, if I recall.  Its been 30 years and several sawmills ago. 

We didn't have hydraulics for anything else.  We used the armstrong method of loading and turning logs.  Its also the method we use to push a carriage with the hydraulics turned off.  Even the heavy ones.