Adventures in Lopro Milling

[Coralillo Lo Pro]

So I've been starting to mill with lopro chain for the past month or two, and thought I'd share some of my experiences. I started with adding an open ended small log mill to my arsenal for the purpose of resawing 2"+ hardwood slabs to single piece cutting/charcuterie board thicknesses. I got a 20" bar, lopro sprocket from Chainsawbars in England because lopro gear isn't sold in the US except for chain and got Stihl PMX from Baileys because they were out of Woodland Pro (just as well, I later bought some WP that I returned because the teeth were irregularly ground in the most haphazard fashion imaginable). I paired it with my 64cc Makita. I get about a 17" cut with the small log mill. Found you have to be careful not to put the inside post too close to the powerhead or it will butt up against it and force the bar out of level. Worked fantastic for resawing short pieces, super light rig I could work on a table top with. Ultra smooth finish, the best I've gotten out of milling yet. Even went through a lead slug from a bullet embedded in mesquite without any harm at all to the chain and minimal dulling.

I started on some mesquite logs I had but due to crooked lumpiness of mesquite had to go to a wider setup after a couple of cuts. I bought a 36" setup as well which I meant for a larger saw but ran it with the Makita on my regular Alaskan mill doing seven slabs out of a six foot long, 15-18" mesquite log (for the Aussies, the hardness of mesquite is roughly comparable to blue gum). Though I would have done better touching up the chain after three slabs or so, I did seven slabs without sharpening or retensioning the chain. Noticeable loss of speed in the latter slabs, but still acceptable. Now the common wisdom of why lopro is not good to mill with is chain stretch and breakage in larger saws. No evidence of that, and if anything the chain stretched less than some of my 3/8 and .404 chains do breaking them in. I think the lesser resistance from much smaller teeth combined with not pushing hard at all and letting it self feed means much less force applied to the chain when cutting, so stretch not an issue.

I finally got my 87cc 045 Super running okay after a long and problematic top to bottom rebuild, and tried it with the 36" setup on some short 25" ash slabs yesterday. I thought I broke the chain after a bit only to find one of my bar mount bolts had vibrated loose and the bar had popped off the tensioner and thrown the chain. Resharpened the chain and second cut started well but then thought it was a bit slower than hoped through the rest. Took that slab off the log to find I'd gone right through a nail. Now conventional wisdom again on lopro is nails will destroy it. It continued to cut amazingly well after going through that nail and no obvious chain damage. Sharpened again and did one more slab which went quite well though still maybe not as fast as hoped for, but might have been more to do with my sharpening. Have been using a Pferd 2 in 1 file with good results but doesn't take down the rakers as much as I'd like, particularly when the teeth get filed back a fair bit as they've been already (I think the one I'm using was a Stihl PMX used chain I got as a bonus in a demo package) and the rakers need to come down to .040-.060 how BobL likes them. I think the Pferd raker file in the 2 in 1 is non-adjustable and set for only .025.

My thoughts have been that lopro may have diminishing returns in cuts over 30" which is why I only got a 36" bar (plus greater chance of bar flex). It may be over 24" or so that its advantages become less noticeable. Someone on another forum doing a 30" spruce thought maybe it was a little slower than his old 3/8 setup but liked the finish a lot more. For dimensional lumbermaking with a CSM I think it's hands down the way to go, and for resawing to thinner stock, but will likely depend on the 880 for larger full sized logs. Mainly got it for mesquite which I mill a lot of and rarely gets over 24" and is the third hardest wood in North America. Smaller logs are usually milled for thinner boards which means you want the narrowest kerf you can outside of a bandsaw to get the least waste.

 

[BobL]

FWIW I use Lopro with a 441 with a 25" bar and find I can take the rakers down a long way.

In the hard woods I mill, the raker angle I use with Lopro is 7.5º which translates on a new chain to 0.033" raker depth. In softer woods you could go to at least 8.5º (0.037"), I At those angles you may run out of raker before the cutter wears out. At this angle the chain also makes a lot of sawdust which well used chains may have trouble clearing

There's no such thing as a free lunch and there will be more vibe and general wear and tear so mar maintenance is even more important.

 

[Coralillo Lo Pro]

FWIW I use Lopro with a 441 with a 25" bar and find I can take the rakers down a long way.

In the hard woods I mill, the raker angle I use with Lopro is 7.5º which translates on a new chain to 0.033" raker depth. In softer woods you could go to at least 8.5º (0.037"), I At those angles you may run out of raker before the cutter wears out. At this angle the chain also makes a lot of sawdust which well used chains may have trouble clearing

There's no such thing as a free lunch and there will be more vibe and general wear and tear so mar maintenance is even more important.

Yeah, the numbers I remembered you talking about weren't for lopro and of course were just measurements that corresponded to certain angles, the angles were the important part, not the actual depth numbers. So the depths would be different with lo pro as different angles. I was surprised how much I've taken down the rakers already filing at .025 depth. I can see that you could possibly run out of raker before the cutter wears out with your angles. Both the 20" Stihl PMX chain I have I've only hand filed once or twice, and the 36" demo/used PMX I bought and filed a few times have notably shorter teeth now than the new Panther lopro chain I have in reserve. I understand the 36" one from Chainsawbars was likely used, but not sure why I got shortened teeth in a new chain from Baileys, except that they sent me similarly ground back Woodland Pro chain new, so dunno if they're grinding back crosscut chains when they're out of ripping chain stock and sending them out or what.

 

[thenne1713]

FWIW I use Lopro with a 441 with a 25" bar and find I can take the rakers down a long way.

In the hard woods I mill, the raker angle I use with Lopro is 7.5º which translates on a new chain to 0.033" raker depth. In softer woods you could go to at least 8.5º (0.037"), I At those angles you may run out of raker before the cutter wears out. At this angle the chain also makes a lot of sawdust which well used chains may have trouble clearing

There's no such thing as a free lunch and there will be more vibe and general wear and tear so mar maintenance is even more important.

pico (LOPRO) recommended for short bars (16-20), for MILLING, and not for bars over 25-30(??) because of the risk of chain breaking/ injury, according to many websites/ MFR in my past research; there are groups that do use on longer bars, but hard to find any PICO/LP bars over 25, even custom made?

 

[Coralillo Lo Pro]

pico (LOPRO) recommended for short bars (16-20), for MILLING, and not for bars over 25-30(??) because of the risk of chain breaking/ injury, according to many websites/ MFR in my past research; there are groups that do use on longer bars, but hard to find any PICO/LP bars over 25, even custom made?

This is my new crusade, to educate on this in the US lol. There are in fact an entire range of lopro bars made by GB from 20" to 60". I assume you can buy them in Australia as GB is an Aussie company (though maybe not) and they're available in the UK and Europe through the British distributor chainsawbars.co.uk where I order from - convenient because they ship super fast by DHL (receive orders in 4-5 days) with free shipping over $120 orders from the US. Just can't buy them from anyone in the US. My understanding is that the availability of lopro in the UK and European market came about through Logosol wanting to use lopro setups on their chainsaw mills in Europe. That gave GB the incentive to produce a line of bars and lopro sprockets for saws bigger than 60cc - a sprocket that had never been made available before - for a guaranteed market so that Stihl 461's and 661's could run lopro in Logosol mills. As Logosols are primarily intended as a dimensional lumber making chainsaw mill, lopro made the most sense for ease of cut and less kerf waste.
Once lopro bars, sprockets, and chains were made available, with a ton of research and info about them provided by Rob at Chainsawbars on his website and their own line of Panther milling products, a lot of UK and European millers took up using it on their Alaskan mills. All the people across the pond I've been in contact with have had no issues with chain breakage and are as happy as can be with the speed and finish of their milling. They tend to be using 36-42" bars on Stihl 661's.
Now Logosol USA has chosen not to offer anything with lopro, so there's been no reason for anyone to carry GB lopro bars in the US. Unless an online milling company like Chainsawbars starts up in the US to sell lopro, I don't see anything becoming available. Baileys will make you lopro chains in any size, but don't sell anything you can use them with - no bars over 18", no sprockets.
The whole chain risk/injury thing is typical corporate ass covering that is way overblown. For fear of lawsuits from people using lopro who have no idea what they're doing, no manufacturer in the US will touch it beyond use in baby saws. The only person I know in the US who has been using it a long time and shared a lot of knowledge with me, ground down a .404 sprocket to work as a 3/8 lopro sprocket over a decade ago, and has used lopro sprocket noses on regular bars. He's been running 70-85cc saws with lopro and says nothing touches it milling cants. He does a Malloff grind on his chains.
There's a lot to be learned yet about its limitations, best uses, etc, as it's hard to find anyone with a lot of experience using lopro in a lot of hardnesses and sizes of wood. I'm so impressed with its bandsaw-or-better finish that I don't see using normal 3/8" again for milling though and will only step up to my 880 and .404 when I need chip clearance on larger logs.

 

[thenne1713]

Interesting, and I agree on your LOPRO USA assessment. I use the full comp WP30RP Woodlan Pro chain from Baileys, (many say Carlton rebrand?) w/ my Logosol, get 1/4" kerf and great surface, so I am happy.

 

[Coralillo Lo Pro]

Interesting, and I agree on your LOPRO USA assessment. I use the full comp WP30RP Woodlan Pro chain from Baileys, (many say Carlton rebrand?) w/ my Logosol, get 1/4" kerf and great surface, so I am happy.

No reason to change anything if you're happy with it. Seems to me there would be marginal gain in speed in using lopro for dimensional softwood lumber, mainly just a bit less waste. To me the great advantage of lopro is in milling serious hardwoods, the likes of which there are few of in the US - mesquite, osage orange, and live oak mainly, with hickory and pecan to a lesser extent. If you've ever tried to run a router bit or any planer blade through serious hardwoods, you know you have to take much thinner passes than softwoods, or have a way more powerful machine than normal. So running a chainsaw kerf as narrow as possible helps a tremendous amount in extremely dense hardwoods. For the most part, everything I mill and use in woodworking is the hardest of native US hardwoods - mesquite, pecan, white oak, red oak, rock elm - so that's what has led me down the lopro path.