stephen thomas
Diamond
- Joined
- Jun 3, 2001
Might as well ask here, too.
Anyone conversant with harvester chain?
We lost some trees over the winter and it has become interesting to possibly rip them for walkboards in our near field (swamp).
For a gearhead, this provides a great excuse to revisit the idea of trying to put a modern (read "available & productive") saw chain on one of my Disston KB7-AY's.
Specific chain is Stihl .404H 80 ga.
.350" kerf appears it should work well with the .250" - .255" thick bar.
AFAIK, all actual harvesters run center drive/rim support sprockets.
Center drive sprocket would be easier to machine and probably more stable in heat treat.
In use, sprocket alignment is critical. (this is not a technical problem. Would it be a problem in use under dynamic conditions?)
Manual saws generally run spur sprockets.
Alignment is not much an issue with a spur sprocket, the chain finds its own axial position to align with the bar during break in period.
Spur drive is somewhat more involved to machine.
In order to build the new sprocket, final questions are:
Is there any reason that a spur drive should not be used for my app on a 2 man chainsaw outfitted with same originally (albeit 3/4" pitch original chain)?
If a center drive sprocket is used, how compliant is is under dynamic conditions? (is there increased risk) with using it on a manual saw with the bar flopped over sideways for ripping/sawmilling?
Here's a link with pictures & more involved discussion on the chainsaw forums. PM'rs often have a deep and diverse knowlege base. so asking here as well. Scroll back one page for full discussion.
https://www.arboristsite.com/community/ ... 557/page-2
smt
Anyone conversant with harvester chain?
We lost some trees over the winter and it has become interesting to possibly rip them for walkboards in our near field (swamp).
For a gearhead, this provides a great excuse to revisit the idea of trying to put a modern (read "available & productive") saw chain on one of my Disston KB7-AY's.
Specific chain is Stihl .404H 80 ga.
.350" kerf appears it should work well with the .250" - .255" thick bar.
AFAIK, all actual harvesters run center drive/rim support sprockets.
Center drive sprocket would be easier to machine and probably more stable in heat treat.
In use, sprocket alignment is critical. (this is not a technical problem. Would it be a problem in use under dynamic conditions?)
Manual saws generally run spur sprockets.
Alignment is not much an issue with a spur sprocket, the chain finds its own axial position to align with the bar during break in period.
Spur drive is somewhat more involved to machine.
In order to build the new sprocket, final questions are:
Is there any reason that a spur drive should not be used for my app on a 2 man chainsaw outfitted with same originally (albeit 3/4" pitch original chain)?
If a center drive sprocket is used, how compliant is is under dynamic conditions? (is there increased risk) with using it on a manual saw with the bar flopped over sideways for ripping/sawmilling?
Here's a link with pictures & more involved discussion on the chainsaw forums. PM'rs often have a deep and diverse knowlege base. so asking here as well. Scroll back one page for full discussion.
https://www.arboristsite.com/community/ ... 557/page-2
smt