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Steve Riese
05-31-2016, 4:41 PM
Hi, I'm new to the forum and have found some great tips, but still have a two questions.

Every DIY Alaskan Mill I've seen has two support points for the chainsaw, one near the motor and one near the tip. Those supports are either done via clamps and a bracket or via holes drilled through the bar and threaded rods. My setup uses the threaded rods.

My saw is a Stihl Farm Boss with 25" bar. I've learned from other posts here that the Farm Boss motor (I think it is around 50cc) may be too small for serious milling. That's okay, as I'm more of a tinkerer experimenting with mostly 12" to 16" logs. The 25" bar and chain were both new, with a few minutes of warm-up running and cutting to break them in.

After building the mill, setting up the guide, and cutting into the fist log, the chain started to bind. I took off the 25" bar and put the original 20" bar back on just to check that it wasn't the engine, and it ran fine. The chain on the 25" bar is now hard to pull around by hand, whether the bar is on or off the saw. The only thing I can think of is that the weight of the motor, and the eccentric placement of that weight relative to the axis of the bar, has somehow twisted the bar. But every Alaskan Mill I've seen has the bar supporting the weight of the motor in the same way.

First question: Is the bar rigid enough to support the weight of the motor without twisting the bar?

Second question: How should I proceed to "un-bind" the chain? There are lots of tips for cleaning, filing, oiling, etc., but this is new territory for me.

I can post some pictures later this evening if that would help.

Thanks for any advice you can provide.

-Steve

Steve Riese
05-31-2016, 11:46 PM
Some pictures to help explain my experiment. The middle picture gives a good perspective on how the weight of the motor might cause the bar to bow and twist.

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david privett
06-01-2016, 7:07 AM
the blocks that hold the saw must be perfectly square or it will pitch the bar, use a metal straight edge to verify bar is straight before assembly then after assembly, once assembled the blocks look big enough that the weight of the engine I would think not be transferred down the bar causing a flex. as far as cleaning the bar they make a tool for that it is just a flat piece of metal with a hook on the end that fits in the bar the hook scraps out the junk that ends up in the drive link guide channel. try that first on some saws it also cleans out the oil passages from the saw to the bar. also make sure your oiler is set to max.

Steve Riese
06-01-2016, 1:08 PM
"they make a tool for that"

Some of my favorite words ever... :)


the blocks that hold the saw must be perfectly square or it will pitch the bar...

Thanks David. I didn't realize that, although now it makes perfect sense. I think I'll re-cut the stacking faces of the blocks and see if that helps. But first, a trip to our local tool/hardware/feed/apparel store (Bomgaars) to pick up a new tool!

Steve Riese
06-03-2016, 12:21 PM
I think the problem with the chain is oil. Spent some time with the chain and bar last night. There looked like there were some burrs on the inside of the groove, at the top of the rails. The sketch below is exaggerated, but it shows the location. I got rid of the burrs, and the chain pulled around smoothly. But after a minute of running, it bound up again and the burrs returned.

The oil hole is clear, but there isn't much sign of oil. No initial spray when the trigger is pulled. When I put the 20" bar and chain back on, it all worked well - oil spray as expected. So looks like something in the 25" bar. Hope to take it into the shop today and have the Stihl guy look at it.

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david privett
06-04-2016, 7:44 AM
I bought a Forrester brand I think, 20 inch bar for my husky and during the manf. process they did not drill the oil passages out . took me awhile to figure that out . Some careful drilling got it to work and still am using it. and as far as the burr goes watch your chain tension, of course it has to have oil. but I see you show the burr on the inside of the drive link channel, I would think that could only happen if the chain is pulling to the left, do you have a chain sharpener to touch it up.

Steve Riese
06-04-2016, 8:30 PM
Thanks David. I ran the motor without any bar attached and oil came out normally. I then put my 20" bar back on and have been using it all afternoon with no problem. But no luck when I put the 25" bar on, even after I flipped it upside down (I learned today that it is reversible). There was some evidence that oil was making it to the bar, but nothing beyond that. The oil residue after a minute of the 25" bar looked black-gritty dirty, making me think it is still rubbing the wrong way somewhere.

If you look at the center picture above, you can see that I put the outer hole in the nose piece of the bar. I'm wondering if the fact that it is a separate part somehow caused a slight misalignment between the tip and the remainder of the bar. Should I have put the outer hole in the main part of the bar itself?

Another thing I learned is that the Stihl manual says that the Farm Boss can take up to a 20" bar. That's what came with it. The salesman said that the saw is powerful enough to take a larger bar, but I didn't tell him I would be milling with it. Not sure that matters. I've read elsewhere that the Alaskan Mill requires a fairly large engine--90 cc or so. The Farm Boss is about 55 cc. But that shouldn't keep it from turning a 25" chain.

Appreciate your ideas. I'll keep experimenting.

Bradley Gray
06-04-2016, 10:37 PM
Sound like your bar is getting hot from not getting enough oil or some other cause. Are you running standard chain or chain designed for ripping?

Steve Riese
06-05-2016, 5:33 PM
Sound like your bar is getting hot from not getting enough oil or some other cause. Are you running standard chain or chain designed for ripping?

Thanks Bradley. It's a standard chain. Both bar and chain are Stihl, so I didn't expect any compatibility issues. Since the saw works great with the 20" bar that came with it, the possibilities as I see them now are:

1. The 25" bar is bad and blocking the flow of oil.
2. Something I did while drilling the holes in the 25" bar is blocking the oil.
3. When I first used the Alaskan Mill, something in the way the bar was twisted caused a problem with the groove and flow of oil.
4. The Farm Boss just can't handle a 25' bar, and Stihl designed it to not work.

I'd be really surprised, and quite disappointed, if it was #4!

david privett
06-05-2016, 7:10 PM
I have a old mac 650 it is a 60 cc saw and I run a 24 inch chain I think the saw is rated at 4 hp, so your are in the ball park, look at the bar and see if you can figure out the oil path and run some fine wire thru the oil path to make sure it can flow, remember the bar is reversible so there are two independent paths . I wish I could tell you what to look for but I do not have a sthil bar to look at.

Steve Riese
06-06-2016, 8:51 AM
...look at the bar and see if you can figure out the oil path and run some fine wire thru the oil path to make sure it can flow...

I think that is the next step. The bar is a Stihl "Rollomatic" and I'm not sure what internal mechanisms it might have. The hole that goes from the outside of the bar into the channel is clear. And I used some high pressure air to blow out the channel, but I really don't know what lies beyond that. Time to get out a bright light and a magnifying glass!

James White
06-25-2016, 6:50 AM
Another thing to check would be to make sure the gauge of the gain guides is correct for the bar. If you have a pair of dial calipers you can measure the guides of both chains and the kerf of the bars. Other than that. Since you are new to chainsaw milling. It may be possible that you over reved the engine in the cut and heated the chain and bar and have galled the bottom of the chain where it rides on the bar. File the bar clean and try a new chain.

James

Steve Riese
07-10-2016, 1:45 PM
Thanks James. I finally got back to this project yesterday. Tried a new chain and it worked okay for a few minutes doing some non-mill work. Then it started to bind again. On top of that the bar was extremely hot. Lots of friction.

It dawned on me that one reason the 25" bar doesn't work on the MS 271 Farm Boss is that the engine doesn't pump out enough oil. When I read that the MS 271 takes up to a 20" bar, I assumed that it was because of engine power. And since I got good power initially, I figured that if I took it carefully I should be okay.

More research... I'm trying to find out now if longer bars take more oil (sounds reasonable), and if the MS 271 Farm Boss pumps out enough oil for a 25" blade. Good thing this is all just a hobby for me!

-Steve

John TenEyck
07-10-2016, 5:42 PM
Are you sure that bar is compatible with your saw? The oil hole on the bar has to line up with the exit hole from the saw. Beyond that, turn up the oil flow wide open if it's not already. There should be an oil adjustment screw, usually on the bottom of the motor. Even at full flow that saw will be challenged to adequately lube a 25" bar, and the saw itself will struggle for milling anything much over 10 or 12" in hardwood. Of course, in 12" wood you could use the 20" bar. Going to a lower viscosity oil may help increase the flow of oil. If you are using Summer grade oil try Winter grade instead, or straight 30 wt. motor oil.

You also said you are using standard chain. That's a poor choice for milling as it will create big strings of spaghetti that will bind up in the clutch. Grind the teeth to no more than 15 degrees, or buy a ripping chain. They will cut more slowly, but they will make chips instead of spaghetti. Finally, the chain has to be sharp, sharp, sharp.

John

Steve Riese
07-10-2016, 6:40 PM
John, great points -- thanks. Since this is a first time experience for me, I'm sure I still have more to learn. The guys at the store are helpful and have been through the basic Stihl course, but unfortunately didn't get the expertise to deal with these kinds of questions.

Starting with oil hole alignment... The bar is a Stihl, as is the saw, so my expectation is that they would align. But, I'll check closer. The fact that I didn't see any oil spray might be a clue that Stihl 25" bars don't go on the mid-range Stihl saws.

**Evening edit: the holes seem to align quite well. If I can get the right lighting, I try to take a couple pics.

I don't think there is an oil flow adjustment. If there is one, it is not advertised in the manual. Elsewhere someone suggested I might need to add an external oiler. Not sure I'm ready for that. I'll look on the bottom of the motor as you suggest.

**Evening edit: several online sources indicate that the MS 271 Farm Boss oil flow is factory set and cannot be adjusted. Apparently this is a change from previous models. I did look at the bottom of my MS 271 and could find nothing that looks like a set screw.

If the motor and oiler were not meant to drive a 25" bar, then I'm likely facing a long-term headache if I keep trying. I'm going to try a 20" bar next, before trying to fix the 25" bar problem. I was wrong up above when I said that the original bar was a 20". It's actually a 18", and the manual says it can take a 20" bar. I found an Oregon bar/chain combo for about half the price of a a Stihl 20" bar without chain. I need to make sure it fits and that the oil holes match up. The guy at the store said to bring it back if it didn't.

**Evening edit: It didn't fit. Might have to spring the big bucks for a Stihl 20" bar and chain. Ouch!

Other have suggested a rip chain as well. Didn't know they cut more slowly, although that is okay given that this is basically just a fun experiment. Don't think that I'll convert a cross-cut chain into a rip chain by grinding. Probably order one online. But I want to get the setup working first.

Sharp, sharp, sharp -- I agree! A while back someone suggested to not wait for the chips to become sawdust to sharpen. He recommended sharpening with every tank of gas. That's what I do now, and wish I had stared doing that 20 years ago.

Thanks again for your tips. I'll report back on progress as my day job allows...

-Steve