how do I move on....

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Albert Beerstein

stihl learning
Joined
Dec 28, 2014
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Location
Australia
Timed cuts in 500 mm wide pine log with squared sides, 1000mm long.

660, 7 tooth, 3/8 LP full comp, TPFA 10°, DG 8.5°, smooth finish, 114 sec/mtr

660, 7 tooth, 3/8 LP 2 skip, TPFA 10°, DG 8.5°, smooth finish, 129 sec/mtr

660, 7 tooth, 3/8 regular, 2 skip, TPFA 10°, DG 7°, smooth finish, 106 sec/mtr ??!?

090, 7 tooth, 3/8 regular, 2 skip, same chain as above, 74 sec/mtr…

retest 660 again with same chain – 109 sec/mtr

the 090 revs slower, the 660 only bogs slightly, why is the old bastard so fast?? I wanted the 660 with 3/8 LP to be as fast as my old setup (3/8 regular 2 skip, 090) as I’m getting a sore back lifting that bulldozer motor up and the 660 is light… what am I going to try next??
 
Timed cuts in 500 mm wide pine log with squared sides, 1000mm long.

660, 7 tooth, 3/8 LP full comp, TPFA 10°, DG 8.5°, smooth finish, 114 sec/mtr

660, 7 tooth, 3/8 LP 2 skip, TPFA 10°, DG 8.5°, smooth finish, 129 sec/mtr

660, 7 tooth, 3/8 regular, 2 skip, TPFA 10°, DG 7°, smooth finish, 106 sec/mtr ??!?

090, 7 tooth, 3/8 regular, 2 skip, same chain as above, 74 sec/mtr…

retest 660 again with same chain – 109 sec/mtr

the 090 revs slower, the 660 only bogs slightly, why is the old bastard so fast?? I wanted the 660 with 3/8 LP to be as fast as my old setup (3/8 regular 2 skip, 090) as I’m getting a sore back lifting that bulldozer motor up and the 660 is light… what am I going to try next??

Listen... you hear that sound?
It's the sound of dozens of forum members running to the classified for an old 088 or 090 :D

Impressive time difference. Maybe the 660 is getting slowed down more than it seems?

Since I'm going to start using a winch with a 661, I just ordered a $25 Tachometer/Hour meter to keep an eye on such things.
When pushing you have a better sense of resistance and speed loss.
The winch gives some feedback but much less although, the ears can still tell (just not how much rpm is lost).
 
"Impressive time difference. Maybe the 660 is getting slowed down more than it seems?

Since I'm going to start using a winch with a 661, I just ordered a $25 Tachometer/Hour meter to keep an eye on such things."

I think you're right, a tachometer might be the next step, I've found no matter how much I think something may give a certain result, empirical testing shows the real situation. And "feel" can be unreliable for deciding whats best!
I have also been concerned that whilst the 660 cuts its fastest with enough pressure to load the motor down a bit, maybe it's asking too much of it continually?
 
"Impressive time difference. Maybe the 660 is getting slowed down more than it seems?

Since I'm going to start using a winch with a 661, I just ordered a $25 Tachometer/Hour meter to keep an eye on such things."

I think you're right, a tachometer might be the next step, I've found no matter how much I think something may give a certain result, empirical testing shows the real situation. And "feel" can be unreliable for deciding whats best!
I have also been concerned that whilst the 660 cuts its fastest with enough pressure to load the motor down a bit, maybe it's asking too much of it continually?
If you want a very good tach, I've got a few new Opamma PET-1100R tachs on a shelf somewhere...
 
Had bit more of a think about your results.

All chains have same tpca, 55° on grinder ,or a 13/64 file in a 3/16 holder in the field.
I'm not sure the 3/16 holder with a 13/64 file produces 55º - it would be good to see some close up pics of each cutter
Also grinder cut teeth are slightly different to file cut as they clear sawdust differently.
Can you also indicate which of the chains has what TPCA.?
Is the LP self feeding or close to self feeding

One test missing is for full comp regular 3/8 chain.
If the full comp LP is faster than the 2 Skip LP , then the full comp regular should be faster than 2 Skip regular.
Mntgun found LP, full comp, was significantly faster than regular, full comp and he tested lots of cuts.

All that aside the 090 seems to continue to work its charm as I would have expected the times to be a bit closer than that.
I'd like to see what time the 090 could pull cutting with an 8.5º DG!
 
Had bit more of a think about your results.


I'm not sure the 3/16 holder with a 13/64 file produces 55º - it would be good to see some close up pics of each cutter
Also grinder cut teeth are slightly different to file cut as they clear sawdust differently.
Can you also indicate which of the chains has what TPCA.?
Is the LP self feeding or close to self feeding

One test missing is for full comp regular 3/8 chain.
If the full comp LP is faster than the 2 Skip LP , then the full comp regular should be faster than 2 Skip regular.
Mntgun found LP, full comp, was significantly faster than regular, full comp and he tested lots of cuts.

All that aside the 090 seems to continue to work its charm as I would have expected the times to be a bit closer than that.
I'd like to see what time the 090 could pull cutting with an 8.5º DG!

no worries Bob, I'll get onto those trials and get some photo's this week, I like a bit of experimenting!
 
US$80 delivered.
This tach model is the real deal, not some cheap tacky ( :) ) toy.
 
090 on mill with 3/8 reg 2 skip, 8.5° DG
090 38 reg 2skip 8.5 deg.JPG

The chain R&D department
IMG_2707.JPG

finish on cut with 8.5° DG, time 70 seconds per metre, but I could improve that with practice as it self fed so well it was more a matter of being smooth and careful not to allow it to stall the saw down, rather than push it into the cut.
My other chains self feed well but still need a bit of pressure, the 8.5° DG chain fed so easily that I had to guide the mill very smoothly or it started to pull into the wood very hard, and would start to stall down the motor. Will try full comp. chain on the 090 with 8.5° DG this arvo.....Had another try with 8.5° 2 skip, thought i did a really smooth pass through the cut, but still 71 seconds per metre?


finish 38 2skip 8.5 deg 090.JPG
 

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