Thread: Chainsawmill running really hot :-(

Originally Posted by Travis Edwards

First of all are you cutting with the top of the bar or the bottom? If you are cutting with the top edge of the bar I would say that the tension problems are coming form the fact that when you hold the bar tip "upwards" during tensioning, (towards the top of the power head) then cut with the top of the bar, the bar is actually moving toward the bottom of the saw when cutting, thus increasing the tension on the chain. Or if cutting on the bottom maybe you didn't hold the tip up when tightening.

I am cutting with the bottom of the bar. I tried using both sides for a bit but it just didn't feel right.

Originally Posted by Travis Edwards

I do not like the idea of the washers as this would increase the chance of run out in the cut.

What do you mean by run out?

Originally Posted by Travis Edwards

Some of these things could be diagnosed by BobL and myself with a few good photos of things like the mill, close ups of the drivetangs and straps of your chain and your Bar.

I'll post pics of the chain and bar shortly.

Originally Posted by Travis Edwards

I rediscovered recently the difference between right and wrong can be less than 1/16th of a turn of the tension screw.

1/16th crap I would have thought that longer the chain the less sensitive. I'm glad I was being careful 1/8th turns at a time but maybe I wasn't being careful enough.

Take Photos of the drive tangs of your chain and the straps, do not worry too much about the actual cutters as even a blunt chain will cut crapiata. When taking photos of your bar take photos of the first 4 inches where the chain leads into the bar and also about the same at the tip end on both top and bottom edges. When taking pics of your mill show an overall mounted view and close ups of how the mill attaches to the bar.

Originally Posted by Travis Edwards

the chain should just suck up into the groove to the point where it just meets the bar all the way along the bottom edge.

This is basically what I do with all my saws. With the mill I tightened it up a little more because very shortly after starting to cut I could see the drive links clearing the bar groove. Are you and Bobl saying to have chain a little looser and not worry about it once the bar is completely in the log?

I will go and get the camera battery out of the charger and get some pics now.

Originally Posted by Travis Edwards

I am not going to go into the finer details of tensioning here but you should have the chain tight enough to sit in the groove of the bar without sagging down but still be able to freely turn the chain on the saw by hand. If this is correct then you should be able to lightly grasp the chain and with virtually no grip you should be able to lift one drive tang clear of the bar and one either side of it should come to the edge of the bar. However this is a guide and doesn't mean that you grasp the chain and yank with all your might to see this happen, or on the other hand be too nancy about it either.

We need a more quantitative definition of a "light tug", "yank", "pull, or lift" I think we need a standard weight we can hang off our chains to see this effect - I will try it with a spring balance and see how much weight it is.

another way of doing it is by holding the tip of the bar UP while winding the tensioner the chain should just suck up into the groove to the point where it just meets the bar all the way along the bottom edge.

Yep - that is a good way of putting it.

I have only got a pic of the bar tang and the drive links, I hope these are good enough.

I can get pics of the mill tomorrow.

Attachment 123345

As you can see the bar is grooved. Not good considering I have only run about 6 tanks of fuel with it. Nose is similar but I didn't get a photo because I have already started to dress it.

Attachment 123346

If this picture of the chain is not good enough then I can have another go at it.

Originally Posted by BobL

We need a more quantitative definition of a "light tug", "yank", "pull, or lift" I think we need a standard weight we can hang off our chains to see this effect - I will try it with a spring balance and see how much weight it is.

another way of doing it is by holding the tip of the bar UP while winding the tensioner the chain should just suck up into the groove to the point where it just meets the bar all the way along the bottom edge.[/QUOTE]
Yep - that is a good way of putting it.[/QUOTE]

With the lifting/pulling of the chain, I use about enough pressure between my thumb and pointer finger that if you were to hold a sheet of paper with just enough pressure that if you wave it vigorously it will not come out of your fingers, but any less it would, I find that at this point the chain will slide out of your fingers when you lift up and get to the point of 1 tang clear and 2 near the edge of the bar groove (within 0.5 mm of in or out of the groove.) unless if you have more tension It will not lift that far and if you have less tension then you will get the tang either side of the one you are lifting well clear. If that makes any sense.

Originally Posted by weaver

I have only got a pic of the bar tang and the drive links, I hope these are good enough.

I can get pics of the mill tomorrow.

Attachment 123345

As you can see the bar is grooved. Not good considering I have only run about 6 tanks of fuel with it. Nose is similar but I didn't get a photo because I have already started to dress it.

Attachment 123346

If this picture of the chain is not good enough then I can have another go at it.

The pic of your chain is fine. I would like to see both sides but that is fine. your rakers are very low and you should round the leading edge of them but there is no real peening on the drive straps that I can see, which is a good sign and there does not appear to be any peening on the tips of the drive tangs also good. The bottoms of the straps look very flat however

As for the pic of the bar I would like to see more of where the Chain actually starts to ride on the bar after leaving the sprocket. I.E. it should meet the bar about 1/2" or more from the rear end of the bar or approx 3 or 4 mm after where the groove flare finishes. The bottom of the straps on the chain and the lips on the bar are telling me that you have been running either too much tension, insufficient lube or incorrect lube, or a combination of 2 or all of the above, And the burnt dry looking sawdust on the chain would attest to this.

Post some more pics of the bar and when you get a chance the mill.

What I mean by run out in your mill is that the bar is not dead parallel in the cut. this will cause the opposite side of the bar to cut i.e. if you are cutting with the bottom of the bar the top will be cutting on one side also. This can also show up as the saw wanting to ride out of the cut or try to pull down against the mill. If you were crosscutting it would be like the saw would pull left or right in the cut.

Been away for a bit but I got back to the mill today. With the Camera.

First of all I've realised that I need to use a lot more oil out of the aux oiler. When I was checking if the drive links were lubed they did have a film of oil but not nearly enough. A comment of Bobls about the mess his aux oiler makes prompted me to run one of my cross cut saws through some wood and after doing so I checked the amount of oil on the drive links. There was a lot more.

So my current plan is to dress the bar and clean up the damage that I have done and then get new picks which will show the new wear.

Tomorrow I'm going to give the mill carrige an over haul and fix up a bunch of things I'm not happy with. To that end I'm posting a bunch of pics of the carriage so that I can get suggestions. In particular about better ways to mount the tip of the bar to the carriage.

First of all an over view of the mill carriage and mill bed.\
Attachment 123713

Next is the mount onto which the saw attaches.
Attachment 123714

Two 40mm coupling nuts go onto the studs to secure the bar and cover....Attachment 123715

Then 25mm bolts screw through the sawmount into the other end of each 40mm coupling nut.
Attachment 123716

The tip is currently attachec via a bolt through the bar.
Attachment 123718

The oil is supplied via a 13mm poly hose but is delivered onto the chain by a 4mm hose.

Attachment 123719

The height of the saw is adjusted by two threaded rods linked by roller chain.

Attachment 123720

The list of mods that I have in mind so far are:

Center oil tank so that I can turn it on and off more easily
Add rods supports as the 20mm thread rods flex too much when the saw is cutting.*
Modify tip mounting arrangement*
Modify saw mount so that it is easyier to get the saw on and off
Add lateral support to the saw mount*
Aux Fuel tank (since the fuel cap is on top of the saw and hence on its side when mounted in the mill)
In built measure
Replace winch
Remote throttle


Mods marked * are of particular import because I think that one of the problems is that there is too much movement of the bar. I believe this is what is causing the Kerf to be 9-10mm instead of 7.5-8mm. When the saw is off the bar is dead level but I suspect it is moving when the saw is under power.

If you want the power head to move as little as possible you are probably asking a bit much to do this using just one vertical connection to the carriage at each end of the bar. The inboard side would benefit considerably from having two uprights. Then I would remove the clutch cover and chain brake completely (it's already caused you enough grief). Then make up a flat plate that attaches between the two vertical on the inboard side of the carriage. The plate should have two bar bolt holes that allows you to bolt the saw head direct onto that flat plate. Now also connect that flat plate to the hole in the crankcase left behind from the chain brake. This creates a 3 point brace/mounting (see picture, purple arrow) and while this bolt does need to be removed when changing over the chain it makes a big difference to the mill stability and stops the saw from rocking front to back and widening the kerf


I don't want to sound too negative but making a carriage out of pine? with the kind of vibe the 075 puts out sounds to me like a recipe for ongoing problems. I imagine the vibe is going to shake the carriage out of true sooner or later. Or maybe you have had it running for a while and I have to eat humble pie?

If you can't make the carriage out of steel or ally I reckon you'd be better off with a basic wooden alaskan and a couple of guide boards or a ladder.

At least the alaskan would stay square for a long time, and you could more easily touch up the chain while the saw is on the mill, and be able to completely fill up the 075 fuel tank more easily.

I have always been pained by the sight of beautiful timber being cut into fire wood and I have wanted a mill for years. I started researching mills and was very unimpressed with what you got when you bought an alaskan or similar mill. Then I bought Will Mallouff's book "Chainsaw lumbermaking". Since then I have built basic versions of most of the simple mills in his book from wood. They worked fine for what they were but I wasn't happy. Then I got my inspiration from a really dodgy mill I saw on utube made with framing pine and nails. Up till then I had been looking at more sophisticated mills and their prices and telling my self that one day I would have one but not for a long time.

Also I'd point out that you are talking to a guy who started building a house when the only tools that he knew how to use were a hammer and shovel.

Originally Posted by BobL

If you want the power head to move as little as possible you are probably asking a bit much to do this using just one vertical connection to the carriage at each end of the bar. The inboard side would benefit considerably from having two uprights.

I was originally going to have 4 posts (threaded rods) but I saw that many of the carriage chainsaw mills only have two so I thought I'd copy that. Now I wish that I had gone for three (2 at the power head as you suggest). Before I add a third post I'm going to try adding a sliding support which was part of my original design. The original idea was four steel 4" pipes with two threaded rods. The threaded rods were only to control depth of cut while the steel pipes dealt with all lateral forces. The mill would have been a lot heavier but a lot more stable if I had done this.

Originally Posted by BobL

Then I would remove the clutch cover and chain brake completely (it's already caused you enough grief). Then make up a flat plate that attaches between the two vertical on the inboard side of the carriage. The plate should have two bar bolt holes that allows you to bolt the saw head direct onto that flat plate. Now also connect that flat plate to the hole in the crankcase left behind from the chain brake.

I'm nervous about removing the chain brake because I like the idea of putting the brake on when I reach in to place kerf wedges or check chain lubrication but I'll have a good look at the saw and your suggestion.

Originally Posted by BobL

I don't want to sound too negative but making a carriage out of pine? with the kind of vibe the 075 puts out sounds to me like a recipe for ongoing problems. I imagine the vibe is going to shake the carriage out of true sooner or later. Or maybe you have had it running for a while and I have to eat humble pie?

My welding skills are non existent. The mounting points for the power head and bar tip were made up for me by a friend. The timber frame is oregon which is a little better than pine but I aggree steel or alloy would be better. This carriage was/is meant to be the prototype and once I am reasonable happy with it I'll hand it over to my friend and say "one like that please"

Also there are several points at where alignment can be adjusted and I insure that the bed is aligned with the saw by cutting off a couple of cms of the mill bed with the saw. The supports that the the log sit on start off as 2x12" pine and will then slowly get shorter as the mill gets moved from place to place.

Originally Posted by weaver

I have always been pained by the sight of beautiful timber being cut into fire wood and I have wanted a mill for years. I started researching mills and was very unimpressed with what you got when you bought an alaskan or similar mill.

I agree, commercial alaskans are over priced (I guess that's because they don't sell many of them)

Then I bought Will Mallouff's book "Chainsaw lumbermaking". Since then I have built basic versions of most of the simple mills in his book from wood. They worked fine for what they were but I wasn't happy. Then I got my inspiration from a really dodgy mill I saw on utube made with framing pine and nails. Up till then I had been looking at more sophisticated mills and their prices and telling my self that one day I would have one but not for a long time.

Also I'd point out that you are talking to a guy who started building a house when the only tools that he knew how to use were a hammer and shovel.

In that case you are doing pretty well

I was originally going to have 4 posts (threaded rods) .
.
The mill would have been a lot heavier but a lot more stable if I had done this.

Sounds good!

I'm nervous about removing the chain brake because I like the idea of putting the brake on when I reach in to place kerf wedges or check chain lubrication but I'll have a good look at the saw and your suggestion.

I understand your concern that a chain brake adds some small safety margin but given the saw is in a carriage it should be even safer than an alaskan. If you are putting the chain brake on to add wedges then you are obviously stopping milling to add wedges. I generally don't stop milling to add wedges, if the saw is on a slope I let it keep cutting on its own or I lean on the saw with my knee/hip/thigh, which leaves my hands free to add wedges. When the saw is running, the closest I get to the moving chain with a wedge is probably 300 mm? The time I stop milling to add wedges is near the end of the log and maybe I get to within 100 mm of the stopped chain. Admittedly the alaskan has a mill rail across the log or cant that sort of protects the user from being exposed to the bare chain.

[quote]My welding skills are non existent. The mounting points for the power head and bar tip were made up for me by a friend. The timber frame is oregon which is a little better than pine but I aggree steel or alloy would be better. This carriage was/is meant to be the prototype and once I am reasonable happy with it I'll hand it over to my friend and say "one like that please"[QUOTE]
Good idea.

Also there are several points at where alignment can be adjusted and I insure that the bed is aligned with the saw by cutting off a couple of cms of the mill bed with the saw. The supports that the the log sit on start off as 2x12" pine and will then slowly get shorter as the mill gets moved from place to place.

I guess this depends how far out it is to begin with but in practice this actually doesn't matter, all you need to worry about is getting the boards parallel to each other - few logs are completely symmetrical to the point where it worth doing this.

Originally Posted by BobL

I guess this depends how far out it is to begin with but in practice this actually doesn't matter, all you need to worry about is getting the boards parallel to each other - few logs are completely symmetrical to the point where it worth doing this.

I wanted a completely flat bed so that I can cut lumber as well as slabs. Down the track I want some sort of circular saw or band saw to mill boards out of cants produced from the CS mill. Plus friends of mine and I are interested in doing a bunch of big timber building so I need the flat bed to be able to cut beams and posts easily.

This is the biggest reason for going for a carriage mill. Looking at all the settup time that Will Malloff goes through to get a cant ready to mill boards looked to time consuming compared to what I can do with a rail and carriage mill.

Originally Posted by weaver

I wanted a completely flat bed so that I can cut lumber as well as slabs. Down the track I want some sort of circular saw or band saw to mill boards out of cants produced from the CS mill. Plus friends of mine and I are interested in doing a bunch of big timber building so I need the flat bed to be able to cut beams and posts easily.

OK - I understand.

This is the biggest reason for going for a carriage mill. Looking at all the settup time that Will Malloff goes through to get a cant ready to mill boards looked to time consuming compared to what I can do with a rail and carriage mill.

I agree making boards with an alaskan is very time consuming. My approach is to use a conventional bandsaw to resaw slabs. It also wastes a little less timber than doing all the cutting with a CS. Of course this needs a decent bandsaw and in feed and out feed system.

Spent the day mostly working on the mill. No pictures because my wife took the camera to Bendigo but I'll take lots when she gets back on Friday.

Had a scare today when I plugged in my angle grinder. Some how it was already on so when I plugged it in it took off. Since it was on the shelf above my head It could have been very messy. Fortunately it wasn't, though the disc that was in it is stuffed.

Mostly been working on how to get the mill on and off and giving the power head extra lateral support.

love ya mill weaver. with a few mods it could be an excellent bit of gear.

bob how can u rcomend removing teh chain break and teh clutch cover from teh saw. seams verry dangerous and a tad stupid to recomend someone dose it.

Originally Posted by weisyboy

love ya mill weaver. with a few mods it could be an excellent bit of gear.

bob how can u rcomend removing teh chain break and teh clutch cover from teh saw. seams verry dangerous and a tad stupid to recomend someone dose it.

Chain brake on a CS is designed to;
- activate on kick back - alaskan and carriage mills don't experience kickback if their noses are protected.
- prevent person cutting themselves while moving around with a running saw. This is not a problem at all for a carriage mill and is also not a problem with Alaskans if saw is started on log rails and turned off before removing from log rails.
- Finally it allows the operator to safely inspect the chain while the saw is running - NO -wait the operator cannot also do this with the chain brake on anyway - so the operator should stop the saw to do that

In short the 3 main reasons for a chain brake on a CS are either irrelevant or make no sense on an Alaskan or a Carriage mill - it's just dead weight.

The main reason for leaving the brake on a CS in a mill is because some idiot will forget to put the brake back on when they go to use the CS in the conventional manner. However, if the bolt cover plate remains firmly fixed to the mill the saw will not operate at all and the operator will be forced to reinstall the brake.