mtngun
Addicted to ArboristSite
I finally snuck away from work responsibilities and headed to the woods, for the first time this year.
This is the same blowdown jungle I was working last year. I'd already cherry-picked the bigger trees, so only the smaller, knottier blowdowns remain. At least I can drive right up to them. Today's victim is a 17" doug fir.
The first time to use my unistrut guide rail. It is more difficult to set up than the old plank, because there aren't as many places to attach drywall screws.
I'm running virgin lo-pro inject-a-sharp, the modded 404x7 rim, and the new BB top end on the 066. Lots of new stuff to test today.
The virgin chain had to be re tightened after the first pass. No surprise there -- it's standard procedure for any new chain (other than Stihl chain, anyway).
By the time I'd finished the first log -- 5 slabs -- the chain needed to be snugged up again. Again, about what you would expect for any new chain.
On the 4th pass, I did a little speed test. Rather than time the entire pass, which would have been interrupted by stops to wedge the kerf, etc., I used a pencil to mark out a stretch 30" long, about as long as I could go without stopping to move the wedges. The timed stretch was 16" - 17" wide. Speed was 0.33" inch/second (note: in another thread, we were discussing appropriate cutting speed in a 16" long, and whether an 880 should be faster than a 660. I would hope that an 880 would cut faster than 0.33" in/sec.)
Yes, that's quite a bit slower than the timed cuts I did in a dry pine cant, but this was wider, it was not-so dry fir, it had bark, the saw had to be wrestled around knots and bumps in the bark, and the chain had already made several passes so it was not razor sharp. In other words, it was intended to be a real-life test, with real-life conditions.
The new BB ran a lot better than the old BB. The old BB was bog city below 8400 rpm. The new BB could, if I pushed it hard enough, lug along as low as 7500 before it threatened to bog.
The top practical RPM with this particular chain was about 9500 rpm. You couldn't take a bite and keep the revs higher than 9500 for any length of time.
The happy zone was 8500 - 9200, about the same as the old BB. Nonetheless, I didn't have to baby the feed like I used to. The cut speed seemed to be about the same whether the engine was running 8000 or 9500 or anything in between.
While cutting the 6th slab, the bolt that clamps the bar nose to the mill rattle loose. This caused the bar to cut crooked and bind. Naturally, I had forgot to bring spare hardware or even a wrench for the allen head bolt.
I tightened it as best I could, which wasn't very tight, and finished the slab, with the chain cutting crooked and binding the bar, and stopping to retighten the bolt about every 6". :censored:
I reluctantly called it quits due to the loose nose bolt. Despite the problems, not a bad load of wood for only half a day.
Stuff learned today:
-- drivers all measure 0.049" - 0.051" at the end of the day. The modded 404x7 rim looks like a winner.
-- need to put spare bolts and allen wrench in my field kit, LOL.
-- if I had been smart enough to tap the Alaskan for 6mm bolts, rather than 1/4" bolts, then I could have used Stihl torx head bolts to attach the bar to the mill, so special spares and wrenches would not be required.
-- new BB top end has more torque and a broader power band compared to old BB, at least with lo-pro.
-- typical operating speed with lo-pro and 7-pin is 8500 - 9200 rpm in 16" wood.
-- CSM wheels helped a little, but they are too small (1.92" OD) to roll smoothly over typical doug fir bark and knots. Will try to scrounge up some 2.5" - 3.0" OD wheels.
-- Need more and/or better attachment points for unistrut rail.
-- Need UHMW edge for Alaskan because it doesn't slide smoothly on unistrut.
-- Need new set-up blocks because set-up height is different with unistrut (and will change again after I add the UHMW).
-- no conclusions on injecta-sharp yet because endurance test was interrupted by loose nose bolt.
This is the same blowdown jungle I was working last year. I'd already cherry-picked the bigger trees, so only the smaller, knottier blowdowns remain. At least I can drive right up to them. Today's victim is a 17" doug fir.
The first time to use my unistrut guide rail. It is more difficult to set up than the old plank, because there aren't as many places to attach drywall screws.
I'm running virgin lo-pro inject-a-sharp, the modded 404x7 rim, and the new BB top end on the 066. Lots of new stuff to test today.
The virgin chain had to be re tightened after the first pass. No surprise there -- it's standard procedure for any new chain (other than Stihl chain, anyway).
By the time I'd finished the first log -- 5 slabs -- the chain needed to be snugged up again. Again, about what you would expect for any new chain.
On the 4th pass, I did a little speed test. Rather than time the entire pass, which would have been interrupted by stops to wedge the kerf, etc., I used a pencil to mark out a stretch 30" long, about as long as I could go without stopping to move the wedges. The timed stretch was 16" - 17" wide. Speed was 0.33" inch/second (note: in another thread, we were discussing appropriate cutting speed in a 16" long, and whether an 880 should be faster than a 660. I would hope that an 880 would cut faster than 0.33" in/sec.)
Yes, that's quite a bit slower than the timed cuts I did in a dry pine cant, but this was wider, it was not-so dry fir, it had bark, the saw had to be wrestled around knots and bumps in the bark, and the chain had already made several passes so it was not razor sharp. In other words, it was intended to be a real-life test, with real-life conditions.
The new BB ran a lot better than the old BB. The old BB was bog city below 8400 rpm. The new BB could, if I pushed it hard enough, lug along as low as 7500 before it threatened to bog.
The top practical RPM with this particular chain was about 9500 rpm. You couldn't take a bite and keep the revs higher than 9500 for any length of time.
The happy zone was 8500 - 9200, about the same as the old BB. Nonetheless, I didn't have to baby the feed like I used to. The cut speed seemed to be about the same whether the engine was running 8000 or 9500 or anything in between.
While cutting the 6th slab, the bolt that clamps the bar nose to the mill rattle loose. This caused the bar to cut crooked and bind. Naturally, I had forgot to bring spare hardware or even a wrench for the allen head bolt.
I tightened it as best I could, which wasn't very tight, and finished the slab, with the chain cutting crooked and binding the bar, and stopping to retighten the bolt about every 6". :censored:I reluctantly called it quits due to the loose nose bolt. Despite the problems, not a bad load of wood for only half a day.
Stuff learned today:
-- drivers all measure 0.049" - 0.051" at the end of the day. The modded 404x7 rim looks like a winner.
-- need to put spare bolts and allen wrench in my field kit, LOL.
-- if I had been smart enough to tap the Alaskan for 6mm bolts, rather than 1/4" bolts, then I could have used Stihl torx head bolts to attach the bar to the mill, so special spares and wrenches would not be required.
-- new BB top end has more torque and a broader power band compared to old BB, at least with lo-pro.
-- typical operating speed with lo-pro and 7-pin is 8500 - 9200 rpm in 16" wood.
-- CSM wheels helped a little, but they are too small (1.92" OD) to roll smoothly over typical doug fir bark and knots. Will try to scrounge up some 2.5" - 3.0" OD wheels.
-- Need more and/or better attachment points for unistrut rail.
-- Need UHMW edge for Alaskan because it doesn't slide smoothly on unistrut.
-- Need new set-up blocks because set-up height is different with unistrut (and will change again after I add the UHMW).
-- no conclusions on injecta-sharp yet because endurance test was interrupted by loose nose bolt.
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