1st trip to woods/lo-pro/csm mods/injecta-sharp/066BB

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mtngun

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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.
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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.
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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. :clap:
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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. :angry: 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:
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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.
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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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A good post mtngun!

Stuff learned today:
-- drivers all measure 0.049" - 0.051" at the end of the day. The modded 404x7 rim looks like a winner.
Excellent! - did you see my post about my lopro experience?

-- 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.
I have a big black tool box for CS work I work out of in my shop and I just put that in the van when I go milling so I have just about everything with me, including a set of spare nuts and bolts.

-- new BB top end has more torque and a broader power band compared to old BB, at least with lo-pro.
Interesting!

-- typical operating speed with lo-pro and 7-pin is 8500 - 9200 rpm in 16" wood.
I'm surprised but it is possible I guess. If it were me once everything else is bedded down I'd be looking to mess with the cutter profile to see if that could be increased by 500 rpm or so. I'd start by decreasing the amount of hook and increasing the cutting angle very slightly.

-- 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.
My next mill will have 4" ID wheels

-- Need more and/or better attachment points for unistrut rail.

-- Need UHMW edge for Alaskan because it doesn't slide smoothly on unistrut.
Yep - it helps quite a bit

-- Need new set-up blocks because set-up height is different with unistrut (and will change again after I add the UHMW).
Yeah - this is a PITA and is why I went for an insert on the mill that holds a ruler and work to that.

-- no conclusions on injecta-sharp yet because endurance test was interrupted by loose nose bolt.
Please keep us posted.
 
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Excellent! - did you see my post about my lopro experience?
Haven't found it -- yet. :confused:

If it were me once everything else is bedded down I'd be looking to mess with the cutter profile to see if that could be increased by 500 rpm or so. I'd start by decreasing the amount of hook and increasing the cutting angle very slightly.
Not sure about the OEM angle specs on injecta-sharp -- looks to be 25 or 30 degree top plate angle, dunno about the rest -- but the plan is to gradually regrind it to standard ripping chain specs.

Eventually I'd like to experiment with a Granberg style chain, but I've got enough on my plate at the moment.
 
Haven't found it -- yet. :confused:

Its the last post in your "Getting serious about lo-pro" thread

Not sure about the OEM angle specs on injecta-sharp -- looks to be 25 or 30 degree top plate angle, dunno about the rest -- but the plan is to gradually regrind it to standard ripping chain specs.

Eventually I'd like to experiment with a Granberg style chain, but I've got enough on my plate at the moment.

I can see that :)
 
On your first few cuts, how did the chain handle the Doug Fir? I know it is one of the harder coniferous trees just curious how it did compared to say a standard full chisel chain, which is what I use. I know it is hard to say in that little amount of time, but some times you can tell how a chain will do on the first few cuts.

Thanks, Jim
 
Very informative post. Nice pics too!
I am dying to give my new mill a try, just have had too many irons in the fire as of late.
:cheers:
 
On your first few cuts, how did the chain handle the Doug Fir?
Hard to say. Too many variables today.

First cut is the slabbing cut, only 6" - 8" wide, so it goes very fast. But it's mostly bark, which dulls a normal chain quickly.

All day I was having to push harder than usual, because the Alaskan doesn't glide smoothly on unistrut.

The CSM wheels kept getting stuck in the bark and on knots. Sometimes it seemed like the wheels caused more problems than they solved.

The main difference today is that the saw never bogged down, even when pushed hard. That's partly due to the lo-pro and partly due to the new top end. Again, too many variables.

Eventually I'd like to do some timed tests in a good sized doug fir cant, but I'll have to find the right tree on the right day.

BobL, I had missed your post on the lo-pro, but went back and found it. Thanks for the excellent data.
 
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-- 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.

+1 to both. I'm currently in the process of finishing the conversion of all the 3/8" head, M6 bolts on a Briggs World Formula motor to 10mm. Why carry two sets of tools when one does fine? And, people are always bugging me to 'loan' them hardware since I keep/carry a pretty good selection of metric hardware.

Another useful item is safety wire. Whenever vibration is an issue, having something that prevents hardware from rotating can be quite helpful. :D I'll admit to being frustrated by drilling 1/16" holes in black oxide hardware, but it beats the alternative.

hth, la

EDIT: Just remembered - there's a lot of wheels out there for those razor scooters that are pretty cheap. Saw a pair at wallys for $5 with ~4" diameter.
 
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Eventually, I'll probably put a 6mm helicoil in those 1/4" threads and use the Stihl torx bolts. Gotta remember to pick up some Stihl bolts next time I visit the dealer.
 
Still digesting all the info... Good stuff so far though!

If you were using a regular bolt, I could offer you a makeshift solution that has helped me out of a bind once or twice. In your case, with a 1/4" bolt, you would need a 7/16" wrench for the head. If you have a 1/2" scrench and another flathead screwdriver handy, you're in business - just insert the tip of the flathead screwdriver in the excess space between the head of the bolt and the scrench, and it'll tighten up enough to turn it with a reasonable amount of torque. Not ideal, but it'll work in a pinch.
 
If you were using a regular bolt
It was a button head bolt requiring an allen wrench, just because I keep a bunch of those bolts on hand for another applicaton.

I had been using blue loctite to secure the bar bolts, but apparently, blue loctite is not good enough for this application.

There are no nuts on the modded bar bolts, just a drilled and tapped hole in the Alaskan frame, so locknuts are not an option.

When I got home, I reassembled the bolt with Hondabond, just because I had some Hondabond laying around. We'll see if the Hondabond holds.

The only other strategy I can think of is to put studs in the Alaskan frame, secured with red loctite or perhaps even tack welded, and then use locknuts to secure the bar to the studs. Studs would make it easier to install the bar, anyway.

In any event, my field kit now includes the allen wrench and spare hardware. :D
 

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