Thread: Chainsawmill running really hot :-(

Calm came over today and had a look at my setup. I'm off to Melbourne tonight so I don't have time to post pics of the latest results but I'll get on to it tomorrow afternoon.

Quick summary though, had a good day, chains doesn't appear to be too tight (according to Calm), oil good, need a much better winch and two things broke but no biggy.

Thanks for your help today Calm I really appreciated it. Good to have someone to work along side with again.

There are issues with running motor oil as opposed to good bar oil or way oils for that matter. Bar oil as well as having tackifiers added also has a more cushioning effect which motor oil just does NOT have. As BobL has said previously chains don't just slide along the bar they porpoise their way through the cut so they need an oil that cushions their impact on the bar when they are pulled back to it. Motor oil does NOT do this. I deal with different types of oils in my work and in my younger years worked for shell and studied the effects that different oils have and how they work. Oils don't just work by making a slippery coating on metals, Certain oils resist being flung and others resist extreme heat while others work to absorb shock. This can be demonstrated by mixing corn flour and water, pour it into your hand and it is a liquid, punch it or squeeze it and it is a semi solid. Certain oils work in a similar way providing a cushion when under impact but being liquid when being moved along the groove of a bar or pumped through gears etc. I will use the gearbox of my lathe as an example. the oil needs to be thin enough to be pumped easily and rapidly but also needs to have enough cushioning ability that the messhing gears do not squeeze it out from between the teeth so easily that it does not provide sufficient "cushioning" and lubrication. Motor oil does NOT have the properties to do this. Motor oil works on the principle that it is forced under continuous pressure into the galleries which supply the bearings with lubrication continuously at a much greater rate than that which your oil pump on your chainsaw can maintain. It is the high continuous supply pressure that provides the continuous protection in a motor, In a gear box the oil is not pumped but carried on the gears and thus must work differently and supply cushioning of the impact of the meshing teeth as well as lubricating. A chainsaw is similar the oil needs to be carried by the teeth of the chain as well as lubricate between the individual components of the chain and provide cushioning when the tooth pulls back into contact with the bar. Thus if you are not using BAR oil you should use GEAR or WAY oil over MOTOR oil. Personally the best oil I have seen was rockdrill oil I believe that shell used to call it torcula 100 Or something similar. mega tacky really cheap exceptional lubricating and cushioning abilities.

I disagree with the statement made of it cutting in a curve until it jams. 5 thou is 1/8th of 1 mm or 0.125mm approximately. I have run bars where you could move the drive tang of a chain more than 0.5 mm left and right in the groove without any fear of them cutting a curve or for that matter jamming. one thing that you do get from it is increased wear similar to what weaver is experiencing on his bar. I believe that this is because the force of the right hand cutter being pulled through the timber forces it hard to the right which is then equalled by the force of the left hand cutter doing the same but opposite. This forces the strap harder than it should be into the rails of the bar causing the excessive wear similar to what is shown on weavers bar. And any ony who does not agree with this is welcome to come and visit me and I will show you a bar that does this and will show how it wears. I have one that is in this state which still works fine as a crosscutting bar but I do not expect to work much longer, I use it when I am cutting burnt or crappy, dirty timber for fire wood..

Originally Posted by Travis Edwards

I disagree with the statement made of it cutting in a curve until it jams. 5 thou is 1/8th of 1 mm or 0.125mm approximately. I have run bars where you could move the drive tang of a chain more than 0.5 mm left and right in the groove without any fear of them cutting a curve or for that matter jamming. one thing that you do get from it is increased wear similar to what weaver is experiencing on his bar. I believe that this is because the force of the right hand cutter being pulled through the timber forces it hard to the right which is then equalled by the force of the left hand cutter doing the same but opposite. This forces the strap harder than it should be into the rails of the bar causing the excessive wear similar to what is shown on weavers bar. And any ony who does not agree with this is welcome to come and visit me and I will show you a bar that does this and will show how it wears. I have one that is in this state which still works fine as a crosscutting bar but I do not expect to work much longer, I use it when I am cutting burnt or crappy, dirty timber for fire wood..

I also have had the same experience with 063 chain on sloppy 063 bars and 050 chains on worn 050 bars but the problem seems to show itself when a used smaller chain is used on a sloppy bigger bar.

I have an old Homelite given to be because the owner said it wouldn't cut straight. It was pretty obvious that the bar needed serious dressing so I did that and it cut straight for 5-6 tanks but then then it started to cut curves again even though the bar was OK. Only then did I look at the B&C and saw it was an old 058 chain on a very sloppy 063 bar - so I put a used 063 chain on and it worked fine. Another saw I looked at for a mate because it was not cutting straight had a newish 050 chain on a well worn 0.058 bar. This thing wouldn't even cut more than two barwidths before jamming, same fix worked.

Originally Posted by Travis Edwards

Personally the best oil I have seen was rockdrill oil I believe that shell used to call it torcula 100 Or something similar. mega tacky really cheap exceptional lubricating and cushioning abilities.

Not being a chemist or engineer or the like I can only go off what I read. This topic comes up regularly and the forum has several threads that have discussed oils used on bars at length. If what you say is true shouldn't it be clear. Shouldn't people with lots of experience sooner or later notice that they get better results from bar oils than other oils?

Having said that where can I get rockdrill oil from? If it is not much more expensive than the motor oil I'm using then I'd probably get it just for piece of mind.

The main reason the bar oil needs to be reasonably tacky for regular chainsaw use is so that too much does not get flung off at the nose. This becomes more important for higher chain speed saws of today than the slower revving engines used in the past when a basic oil could be used.

However, if the oil is too tacky it will retain too much grit, gum up the chain and smother the bar in a greasy rope which is why grease is not used on saw chains. A chain saw is designed so that as much of dirty sawdusty oil comes off at the drive sprocket and fresh oil is added immediately thereafter.

If an auxiliary oiler is used to deliver oil after the bar nose the oil does not need to be very tacky at all, which is why stuff like canola can be used in an Aux but does not work as well in the saw itself.

Originally Posted by Travis Edwards

. . . chains don't just slide along the bar they porpoise their way through the cut so they need an oil that cushions their impact on the bar when they are pulled back to it. Motor oil does NOT do this. I deal with different types of oils in my work and in my younger years worked for shell and studied the effects that different oils have and how they work. Oils don't just work by making a slippery coating on metals, Certain oils resist being flung and others resist extreme heat while others work to absorb shock.

The need to cushion impact is important but the temperatures and pressures/shock experienced in an internal combustion engine are far greater than what any CS chain does on a bar. Regular motor oil still works fine in some bar and chain situations. For example Lucas slabber operators (as recommended by Lucas) have successfully used regular engine oil for many years. The bar shock experienced by lucas slabbers, with their heavily cut down 404 rakers tearing big chips from a kerf, will be far greater than that experienced by a regular chainsaw B&C.

The main reason that CS bar oil needs to be reasonably tacky for regular chainsaw use is so that too much does not get flung off at the nose. This becomes more important for higher chain speed saws of today than the slower revving engines used in the past when almost any basic oil could be used. The centrifugal force at the nose is proportional to the square of the speed. If everything else is the same a 12,000 rpm saw generates 4 times more centrifugal force at the nose than a 6000 rpm saw so it will fling off 4 times more oil.

In milling, if an auxiliary oiler is used to deliver oil after the bar nose, the oil does not need to be very tacky at all. This is why thin, not very tacky stuff, like canola can be used but it does not work that well in the saw itself because too much of it comes of at the nose.

Super tacky oil is also not the answer. A chain saw is designed so that as much of dirty gritty sawdusty oil comes off at the drive sprocket and fresh oil is added immediately thereafter. If the oil is too tacky it will stay on the chain and retain too much grit, gum up the chain and smother the bar in a greasy rope which is why grease is not used on saw chains.

Originally Posted by weaver

Not being a chemist or engineer or the like I can only go off what I read. This topic comes up regularly and the forum has several threads that have discussed oils used on bars at length. If what you say is true shouldn't it be clear. Shouldn't people with lots of experience sooner or later notice that they get better results from bar oils than other oils?

Having said that where can I get rockdrill oil from? If it is not much more expensive than the motor oil I'm using then I'd probably get it just for piece of mind.

If you have a good oil distributor I.E. a shell or caltex or mobil DISTRIBUTOR, not just a servo, nearby they would be the go. When I worked for shell about15 years ago we uses to sell it to all the guys falling pines. From memory we used to sell it for about 80 cents a litre, they supplied their own container, a 5 litre of shell helix (bottom of the line one) was about 12 bucks at the time I Think, may have been a bit more. don't know if your local distributor will sell it like we did though. we had it on tap like beer, 44 gal drum connected to a tap driven by air pressure.

Originally Posted by BobL

I also have had the same experience with 063 chain on sloppy 063 bars and 050 chains on worn 050 bars but the problem seems to show itself when a used smaller chain is used on a sloppy bigger bar.

This would probably be because cutters varied slightly in length or cutter angle (no one files exactly the same on the right as they do on the left.) or more remotely the raker heights were slightly differing from left to right. I had this with a customers saw several years ago had me baffled for a while, when his chain was new no probs, brought his chain in for sharpening and as it had been used to the point where the wear on the top plates was Excessive (had to sacrifice 4 or 5 mm of cutter) I decided to grind it on our oregon grinder. Sent the chain back out and all of a sudden it was cutting half moons in a 5 inch log, got the rep to bring both the saw and chain in as I had never had the problem before. started with the saw chain I found that due to a worn pushfinger on the grinder That there was approx 0.1 mm difference in length of the left and right cutters. I corrected this and checked the rakers all within a range of approx 0.1 mm, checked the bar it had wear similar to weavers dressed it thought all was good ran a cut found it was ok. sent it back to the customer heard nothing more for about a week then got the report it was cutting half moons again. once again the saw came in checked it out and noticed he had tried filing the teeth. got them all looking right again the saw would cut straight but it was cutting a wide kerf thought this is not right looked further into it and found he was running 50 thou chain on a 58 thou bar. sent it back to him sold him a 58 thou chain never had a prob again.

Calm had a suggestion that I cut back the block that I am using to hold the tip of the bar on to the carriage. He thought that it might be possible that the block was pinching the groove of the bar.

My current plan is to redo a bunch of things and then have another go at it. When I'm done I'll post pictures here.

PS I checked the width of the groove 1.5mm and the width of the drive links 1.5mm. My calipers are a bit old but they are not too bad. So I'd say that the question of whether the right chain is being used on the bar is settled?

I can tell from the photos that you are running 58 thou chain by what is stamped on it on your bar you should see some numbers stamped near the powerhead some of these numbers will designate bar groove size, i.e.063, 058, 050, these refer to the groove width. Just a bit of trivial info for future reference.

Originally Posted by Travis Edwards

I can tell from the photos that you are running 58 thou chain by what is stamped on it on your bar you should see some numbers stamped near the powerhead some of these numbers will designate bar groove size, i.e.063, 058, 050, these refer to the groove width. Just a bit of trivial info for future reference.

Yeah I forgot about that. As to the bar there is nothing stamped on it that I can see.

However I do have another bar that is a solid nose with "28052" and "798xc" stamped on it. I've been thinking of using this as my short milling bar. It is about 32" inches long (38" from nose to very back).

Mods to do today is to redo the carriage winch and add a jack to the mill bed.

Does anyone have an easier way of getting the pith of a log level than just running backwards and forwards from each end of the log and the jack with a measure?

Originally Posted by weaver

Does anyone have an easier way of getting the pith of a log level than just running backwards and forwards from each end of the log and the jack with a measure?

By pith, do you mean grain?
And what do you mean by "a measure"?

Originally Posted by BobL

By pith, do you mean grain?
And what do you mean by "a measure"?

Pith is the very center of the heart of a soft wood log. I'm not sure if hardwoods technically have a pith or not for practical purposes they don't. In many soft woods the pith is so soft that you can chisel it out with a tough finger nail.

By measure I meant ruler or tape measure. What I find is that I measure the distance from the mill bed to center of the heart/pith at the thick end of the log and then go up the other end of the log and measure the distance from the mill bed to the pith. I then raise the thick end of the log with a jack by a bit. Unless the thick end of the log is actually resting on a joist of the mill bed it pivots so that the distance from mill bed to the pith changes (decreases). I then repeat the process until the distance from the mill bed to the pith at both ends is the same. Depending on how fussy I am being and how well I'm concentrating this can mean going backwards and forwards several times until I've got it right. If I'm milling dimensional lumber then I have to do this twice per log (1st cut and 2nd cut at right angle to 1st.)