Four stroke chainsaw sawmill build has begun

[BobL]

Got me thinking, with your motor maxing out at 3700rpm and going to a 2.5" pulley, not even taking into rpm loss from the couplings (engine to jackshaft etc...) your chain would be at 9000rpm unloaded..........you might consider changing your ratios to be much higher unloaded and strive for the 9-10k loaded to achieve result similar to a two stroke, . . .

This is not necessary if you have enough torque which his 4 stroke obviously has. If he wants to cut faster he can just drop his rakers some more. The guys using lucas mills with the slabber attachments running at 3500 rpm use more than 0.05" (some use 0.06") rakers on new 404 chains. This just ploughs through aussie hardwood like a knife through hot butter.

 

[hamish]

Off to read about Lucas slabbers now!


Direct drive i can see the 4 stoke have the torque for the job, but friction loss in the drive to the actual chain..................no opion yet gotta go diggin!

 

[n8ghz]

The 4-cycle video was great. From what I think I read, it is now using 2 v-belts of some sort from the engine to the jackshaft? And on the jackshaft, some kind of chain sprocket off of a gas saw?
I assume that means no centrifical clutch? The OP mentions providing loading via an idler pulley.

Watching the video, makes me feel confident that my direct-drive hydraulic saw attempt will also work well in my homemade mill. I, also don't have the chain speed of a gas saw, but I do have the power/torque.

 

[cgarman]

I'd love to see closeup photos of the interface between the output shaft of the engine and the drive sprocket. Maybe you could just explain - did you have to make any parts? I have a friend with a go-cart engine he wants to get rid of. I'm trying to figure how to drive the sprocket without building some kind of jacked up adapter.

 

[jnl502]

This is not necessary if you have enough torque which his 4 stroke obviously has. If he wants to cut faster he can just drop his rakers some more. The guys using lucas mills with the slabber attachments running at 3500 rpm use more than 0.05" (some use 0.06") rakers on new 404 chains. This just ploughs through aussie hardwood like a knife through hot butter.

Hey BobL I always love your posts and try to catch them. You have seen and run these types of mills so when you speak on this subject it is LAW. Your post is true and alot of people do not know this. I have a Jred 930 on my alaskan 36" mill and I file the rakes on a new chain. The 930 don't turn quite the rpm's as Husky and Stihl of the same cc's. I think a slower chain speed and a bigger bite is easier on the bar and the bigger chips are not as dusty.