Homelite410
Hack with a CNC Mill
- Joined
- Mar 9, 2010
- Messages
- 5,210
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Well put, yes I agree.But if like a lot of us that go to the woods with 45-50cc 16-20", .325 makes good sense.
Well put, yes I agree.But if like a lot of us that go to the woods with 45-50cc 16-20", .325 makes good sense.
I don't think that quite works though. In comparing a 0.325"x7 sprocket is smaller than a 3/8x7, the circumference will need to be 11% smaller. That equates to a diameter that is 3.5% smaller. So if the cutters were the same, the load with 0.325" would go up by 11%, but the diameter (gear ratio) would only go down by 3.5%. So 0.325" chain would present more load to the saw.
Diameter = Circumference/PI
I think it's all about cutter profile.
No, I was correcting what you wrote. There are 11% more cutters per inch of chain, so 11% more load. With the same number of teeth on the drive sprocket, the circumference must go down to match the reduced pitch, so the circumference must go down by 11%. That equals a reduction in gearing of only 3.5%.You got what I highlighted in the quote backwards - keep in mind in what direction the power/torque is transferred.
Of course. But more teeth per unit length will always always create more load, in direct proportion to the increase. 0.325" has 11% more cutters per inch than 3/8, and so from pitch alone creates 11% more load.Bottom line is that a smaller sprocket will allways make more effective torque availiable with a given powerhead, there are no way you can explain that away!
I have a Poulan that runs 0.325" chain, and it came with 33SL. It was so slow you would had time to see the grass grow while bucking a log - but the saw was not under much load, it was screaming away. the chain just doesn't cut fast. I removed all of the bumpers, tried everything I could to make that chain cut, and it is full chisel. It is much improved now - I have two loops and they are like razors, but it is still much slower than 20BPX semi chisel. The BPX has taller cutters.I don't have any idea on how the math works on comparing the .325 vs 3/8. I am not a professional nor do I cut cookies. I just cut a little firewood. Around 20 years ago my dad had a Wards (McCulloch 610) and he would out cut me at least 3 cuts to 2 maybe even 2 to 1 cuts. We sat down and looked at the two saws my Poulan Pro 365 it had the .325. At the time not knowing any better I thought it was the safety chain I had heard about. As a present my dad took my saw to a shop where they put on the 3/8 chain. It was a much better cutting saw with the new chain and I had no trouble with the saw being slow through the cut.
Oregon 20BPX is by far my favorite chain in .325. Very good chain!I have a Poulan that runs 0.325" chain, and it came with 33SL. It was so slow you would had time to see the grass grow while bucking a log - but the saw was not under much load, it was screaming away. the chain just doesn't cut fast. I removed all of the bumpers, tried everything I could to make that chain cut, and it is full chisel. It is much improved now - I have two loops and they are like razors, but it is still much slower than 20BPX semi chisel. The BPX has taller cutters.
Anyway, without changing to 3/8 I got a similar improvement.
Oregon 20BPX is by far my favorite chain in .325. Very good chain!
Well, the really small saws come with 3/8 - lo pro (and narrow kerf) 3/8.Okay, so if the "ease of pull" for lack of a better term is only marginally reduced by the smaller cutters then why do the small CC saws come with the small chain. There must be a reason besides thread fodder.
....
I still don't really understand how cutter height plays into it, as the depth gauges determine the cut depth. Unless it is just chip clearance.
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