Torture testing injecta-sharp lo-pro again

[mtngun]

Today's victim, a 16" doug blowdown.

The tree was bucked into three 12' logs, and the initial slabbing cut was done to each log, one after another. That way, I only had to adjust the Alaskan height for the slabbing cut one time.

This small tree would have been a good candidate for the mini-mill, but naturally, I forgot to bring the mini-mill.

The smallest log was made into an 8"x8" post, the other two logs slabbed into 2 by's. At the end of the day there were 10 boards, the one post, and some firewood.

No woodcutting report is complete without statistics.

-- 2 hours of run time on the CSM.

-- the injecta sharp lo-pro, which had been reground to 10 degrees and FOP'd, was used all day long without resharpening. It slowed noticeably toward the end, though, and probably should have been swapped out, but I kept running it just to see what would happen.

-- the nose sprocket is still giving me problems, as discussed on the lo-pro thread. It's basically functioning as a hard nose bar, and as with a hard nose bar, I had to run the chain tension looser than I like. Even with a very loose chain, significant power is being lost due to nose friction.

-- chain tension was adjusted around mid day.

-- the adhesive-backed UHMV is still sticking just fine. It looks like it's going to work out well.

-- mini speed test during pass #9, 14" wide including bark, 0.54" inch/sec.

-- speed test during pass #13, 14" wide, 0.36" inch/sec. Definitely sloooowing down.

-- speed test on the final pass #16, 10" wide, 0.55" inch/sec.

-- RPM's with sharp chain were typically 8000 - 9000, dropping to 7000 - 8000 toward the end of the day, as the chain dulled.

Injecta-sharp lo-pro seems to stay usefully sharp for 8 - 10 passes, or about half a day's milling, or about 1 hour CSM run time -- exactly the same as regular 3/8 ripping chain.

I don't have enough field experience with regular lo-pro ripping chain to say how long it holds an edge compared to injecta-sharp.

 

[BobL]

Great post with lots of useful info.

Can you notice any difference between running the bar on and off the mill?
I wonder if you have crushed the bar nose with your previous setuo and that is why it continues to bind?

 

[mtngun]

Can you notice any difference between running the bar on and off the mill?
I wonder if you have crushed the bar nose with your previous setuo and that is why it continues to bind?

I only ran the bar off the mill one time, for a few seconds, and it threw the chain. Haven't tried it since.

The pic explains why the sprocket is binding, though how it got that way is still up for debate.

I have a theory about the nose sprocket, and I ordered another 3/8 tip to test that theory. No guarantee that my experiment will work out -- sometimes they do, sometimes they don't. Such is the life of an experimenter.

 

[BobL]

I only ran the bar off the mill one time, for a few seconds, and it threw the chain. Haven't tried it since.

The pic explains why the sprocket is binding, though how it got that way is still up for debate.

My guess is that your original nose bolt arrangement made the nose sprocket get so hot that it expanded so the slot became wider than 050. When the nose had almost bound, one of the drivers actually pulled their way past its tooth trailing other drivers to do the same and forcing the teeth over to one side. I'd say that nose is toast.

 

[mtngun]

My guess is that your original nose bolt arrangement made the nose sprocket get so hot that it expanded so the slot became wider than 050. When the nose had almost bound, one of the drivers actually pulled their way past its tooth trailing other drivers to do the same and forcing the teeth over to one side. I'd say that nose is toast.

That's a plausible explanation. I can think of others.

Hard to tell in the pic, but the slot is about 0.100" wide. That's not helping.

That nose is now retired from service. An autopsy will be performed when I get around to it.

 

[BobL]

That's a plausible explanation. I can think of others.

Hard to tell in the pic, but the slot is about 0.100" wide. That's not helping.

That supports my theory (as well as some others, since a 0.100" gap will allow the driver to by pass the sprocket teeth.

That nose is now retired from service. An autopsy will be performed when I get around to it.

Can you post a picture of the nose gap covering the distance from the end of the nose to the point at which the nose joins the bar? is the gap uniform along this distance and the same on both side of the nose?