Go lo Pro?

[Alasdairs dog]

Ask me if their any good, I've used am and well, there we go. 

[Rough Hewn]

Some comment which might help broaden the experience.
 
The question was asked earlier in this thread about whether anyone had run lo-pro on a 660/661. I use it on my 066, both for milling and, because it saves carrying an extra bar and sprocket to remote locations, as a cross-cut felling chain. I have snapped one chain so far, when I found a series of hardened steel nails right in the heart of a log. It did make it through a couple before the chain went! I tend to be very careful around force, speed etc. I do not use a winch as I prefer the feedback and I often use it on the mini-mill for quartering so I am looking to keep 36" of vertical cut perfectly straight by eye alone.
 
For general milling I use an 090 with a 42" roller-nose bar. I like roller-noses as they are very simple and they are mounted largely clear of the bar so the sawdust falls away.
 
My general observation is that thinner kerf is not really about waste so much as reduced work by the saw which gives faster cutting and less stress on the engine. To get the best out of it, you want to run the chain faster as each tooth is taking out less, so you lose the advantage to an extent if you have a big, slow-revving saw. Faster chain/smaller bite is also less sensitive to how hard the wood is. With the 090 it really is worth filing down the rakers for softer wood as it will chew out big lumps and cut faster; for a faster revving, lower torque saw you don't get the same advantage as it is taking smaller bites more quickly. This has a bearing on the question of breaking chains as the torque is there to do it but to avoid it you need to use less force into the cut and not adjust the chain to cut too deep. You can gauge it to a point by engine note, but I find feel is easier. I also always sharpen with the Granberg precision grinder, using diamond bits, to keep everything absolutely even - I don't want that one long tooth to catch and put the extra force on the chain that it takes to break it.
 
Essentially, if you run standard .404" chain on a big saw or 3/8" on a mid-sized saw then you probably can't break it however much you bog it down, but if you run smaller, more delicate chain, the power-head is capable of breaking it so it is more down to user practice to avoid doing so.
 
Mind you, sticking an 88" bar on the 090 does reach its limits - that one needs skip-tooth chain to keep it going!
 
Alec
 
 

Check the compression on your 090.
I’ve just done a 50”+ ash with 84” bar and full comp .404 with the 881.
An 090 should walk that, (at 6krpm)
[emoji106][emoji106][emoji106]

[Rough Hewn]

Some comment which might help broaden the experience.
 
The question was asked earlier in this thread about whether anyone had run lo-pro on a 660/661. I use it on my 066, both for milling and, because it saves carrying an extra bar and sprocket to remote locations, as a cross-cut felling chain. I have snapped one chain so far, when I found a series of hardened steel nails right in the heart of a log. It did make it through a couple before the chain went! I tend to be very careful around force, speed etc. I do not use a winch as I prefer the feedback and I often use it on the mini-mill for quartering so I am looking to keep 36" of vertical cut perfectly straight by eye alone.
 
For general milling I use an 090 with a 42" roller-nose bar. I like roller-noses as they are very simple and they are mounted largely clear of the bar so the sawdust falls away.
 
My general observation is that thinner kerf is not really about waste so much as reduced work by the saw which gives faster cutting and less stress on the engine. To get the best out of it, you want to run the chain faster as each tooth is taking out less, so you lose the advantage to an extent if you have a big, slow-revving saw. Faster chain/smaller bite is also less sensitive to how hard the wood is. With the 090 it really is worth filing down the rakers for softer wood as it will chew out big lumps and cut faster; for a faster revving, lower torque saw you don't get the same advantage as it is taking smaller bites more quickly. This has a bearing on the question of breaking chains as the torque is there to do it but to avoid it you need to use less force into the cut and not adjust the chain to cut too deep. You can gauge it to a point by engine note, but I find feel is easier. I also always sharpen with the Granberg precision grinder, using diamond bits, to keep everything absolutely even - I don't want that one long tooth to catch and put the extra force on the chain that it takes to break it.
 
Essentially, if you run standard .404" chain on a big saw or 3/8" on a mid-sized saw then you probably can't break it however much you bog it down, but if you run smaller, more delicate chain, the power-head is capable of breaking it so it is more down to user practice to avoid doing so.
 
Mind you, sticking an 88" bar on the 090 does reach its limits - that one needs skip-tooth chain to keep it going!
 
Alec
 
 

Good post [emoji106][emoji106][emoji106]

[Rough Hewn]

If I was selling a product thats what Id say as well. [emoji3] 
 
I hear VW said there was no cheating with their diesel emissions. 
 
Till they where caught with their panties down. 
 
Id need thicker knee pads than you wear Saul if I was gonna get down on my knees and  swallow what that from the horses mouth. 

Had quite a long chat, guy knew his stuff.
Turns out, they make bars for other big companies.
I agreed not to name names.
There aren’t any manufacturing problems with the 3/8LP.
As has been said previously it’s a delicate bit of kit compared to many other mill set ups.
It comes down to personal preference.
I’m brutish with my kit, that’s why I use tank grade .404
[emoji106]

My knees don’t bend mate.
🤣🤣🤣🤣🤣[emoji106]

[agg221]

4 hours ago, Rough Hewn said:

Check the compression on your 090.
I’ve just done a 50”+ ash with 84” bar and full comp .404 with the 881.
An 090 should walk that, (at 6krpm)

As it happens, the compression had been checked (by Spud) just before I did that. It was a standing dead parkland oak, too wide for the mill so I had the top section stood back up on end and the full length of the bar was buried across the crotch as I slabbed it vertically by eye.

 

The saw was happily pulling away, spewing out muesli for over a tankful per cut. I think it's a combination of the extreme width and the wood being pretty hard - it suggests the limit lies somewhere between 50" and 86" (the useable length of my bar) for what the 090 is happy with on full comp. I suspect I could have got away with it with a part-worn chain and not filing down the rakers much to reduce chip size, but overall skip chain doesn't seem to slow the cutting down too much and is quicker to file. Not sure if it is now available in ripping - it wasn't when I bought mine and one of the most tedious jobs of all was re-grinding it!

 

Alec

[dumper]

Does anyone know how fast a chain contacts after being used and buy how much it obviously is dependant on chain temp and atmospheric temp differences ?

how long do you have between stopping cutting and saw bar damage?

[Rough Hewn]

As it happens, the compression had been checked (by Spud) just before I did that. It was a standing dead parkland oak, too wide for the mill so I had the top section stood back up on end and the full length of the bar was buried across the crotch as I slabbed it vertically by eye.
 
The saw was happily pulling away, spewing out muesli for over a tankful per cut. I think it's a combination of the extreme width and the wood being pretty hard - it suggests the limit lies somewhere between 50" and 86" (the useable length of my bar) for what the 090 is happy with on full comp. I suspect I could have got away with it with a part-worn chain and not filing down the rakers much to reduce chip size, but overall skip chain doesn't seem to slow the cutting down too much and is quicker to file. Not sure if it is now available in ripping - it wasn't when I bought mine and one of the most tedious jobs of all was re-grinding it!
 
Alec

You’ve got a spud ported 090????
Photos pleeeeeeease!
🤣[emoji106]

[Rough Hewn]

As it happens, the compression had been checked (by Spud) just before I did that. It was a standing dead parkland oak, too wide for the mill so I had the top section stood back up on end and the full length of the bar was buried across the crotch as I slabbed it vertically by eye.
 
The saw was happily pulling away, spewing out muesli for over a tankful per cut. I think it's a combination of the extreme width and the wood being pretty hard - it suggests the limit lies somewhere between 50" and 86" (the useable length of my bar) for what the 090 is happy with on full comp. I suspect I could have got away with it with a part-worn chain and not filing down the rakers much to reduce chip size, but overall skip chain doesn't seem to slow the cutting down too much and is quicker to file. Not sure if it is now available in ripping - it wasn't when I bought mine and one of the most tedious jobs of all was re-grinding it!
 
Alec

50”-86” max?
No way.
You can go much wider.
If your depth gauges are set around 0.7-0.8mm
You could pull 100” no problem.
The deep power stroke on the 090 is like nothing else.
On 50” wood an 880/881 will paste an 090.
But on huuuge wood the 090 is king.
With hyper skip chain you could do 120” easily.
[emoji106][emoji106][emoji106]

[Rough Hewn]

Does anyone know how fast a chain contacts after being used and buy how much it obviously is dependant on chain temp and atmospheric temp differences ?
how long do you have between stopping cutting and saw bar damage?

Don’t know the speed of contraction,
But chains cool quickly, minutes to seconds..
To test, take your chain off and feel for play in the rivets.
Worse possible scenario, it bends the crank shaft.

[peatff]

3 hours ago, Rough Hewn said:

Don’t know the speed of contraction,
But chains cool quickly, minutes to seconds..
To test, take your chain off and feel for play in the rivets.
Worse possible scenario, it bends the crank shaft.

They only contract to where they were before they got hot though so if they were not too tight before you started cutting they should not cause any damage.