Baileys LP chain broke on first day!

[madrone]

I was all excited to get my mini mill and LP ripping chain going today to speed up the process I've been making with the Alaskan. Things seemed fine, the cut was smooth and fairly quick but on the third cut slabbing off the edge of a douglas fir tree, the chain broke.
I'm running a 20" bar on a 660, 7T sprocket and was only taking off about 4" from the bark side of 14" cant. I didn't see anything in the bark or wood to snap the chain so I'm guessing I did something else wrong or the chain was defective.
The only thing that seemed odd was after making the first pass the chain was very loose after it cooled down. I figured its normal on a new chain so I tightened it up. Then after the second cool down it was loose again, so I tightened it again. The next cut was going fine then, snap.
I checked the bar and oil was getting to it.
Any ideas?

 

[BobL]

I was all excited to get my mini mill and LP ripping chain going today to speed up the process I've been making with the Alaskan. Things seemed fine, the cut was smooth and fairly quick but on the third cut slabbing off the edge of a douglas fir tree, the chain broke.
I'm running a 20" bar on a 660, 7T sprocket and was only taking off about 4" from the bark side of 14" cant. I didn't see anything in the bark or wood to snap the chain so I'm guessing I did something else wrong or the chain was defective.
The only thing that seemed odd was after making the first pass the chain was very loose after it cooled down. I figured its normal on a new chain so I tightened it up. Then after the second cool down it was loose again, so I tightened it again. The next cut was going fine then, snap.
I checked the bar and oil was getting to it.
Any ideas?

How old and worn is your sprocket?

 

[madrone]

How old and worn is your sprocket?

Hi bob, I just bought the sprocket to fit the chain so it's brand new. I had an 8 T on with a 32" bar before.

 

[Brmorgan]

Personally I'd say keep the 8T on a 20" bar, lots of power to spare for that. As for the chain, maybe one of the rivets on the joint link failed? I run Oregon LP on my 660/25" and have cut a few hundred BF with nary a problem so far. Strange.

 

[BobL]

Can you post a picture of the break and also close up of one of the cutters?

The stretching you report is normal but I am still surprised it broke in douglas. I have used low profile to cut timber that is twice the hardness of Osage and yes it stretches (a lot) but otherwise no problems.

Do you also remember what you were doing when it broke. Was it at the start or at the end of the cut? If low profile chain comes of the bar and you don't notice it, even for a few seconds, the sprocket can mince and break that chain.

 

[pa.hunter]

lp is alot lighter chain than regular ripping

call them they will make it right , i use both with no problems , i like them and they stay sharp and last long time and all i cut is hardwoods , show some pictures of it and cutters

 

[Crofter]

Have a look at the inside of the drive links up between the tie straps. It helps to bend the chain the other way than normal. This exposes the contact area with the roller nose sprocket teeth which is different than where the drive sprocket contacts the drive tangs. The shape of the low pro drive tang makes a different contact with the roller nose sprocket than the larger drive tangs of the full size chassis of the 3/8 chain and the sprocket tends to carry the low pro chain on the tips of its teeth jameed up btween the tie straps instead of bearing on the sides of the nose sprocket and the flanks of the drive tangs. It makes for pretty small contact area compared to the rear sprocket.

 

[MJR]

Ha Bob I like your question about – Do you remember what you were doing when the chain broke?

My money is on - ……. his pants!

 

[madrone]

Actually, no laundry was necessary for the incident.
At the time I was in the middle of the cut, standing there slowly assisting the mill while it moved fairly quick down the slab. When it snapped, the saw reved a bit but the chain just hit the ground with no fanfare.
I thought the baileys LP was designed to run with typical 3/8 7 pin sprockets and tips?
Here are some pics

 

[BlueRider]

According to Bailey's web site LP chain is not recommended on bars over 18" or saws larger than 45cc. You exceeded both of these recommendations and broke the chain and you are wondering why? And if exceeding the cc recommendation by double wasn’t enough you added a new sprocket which was the equivalent of using an even bigger saw. The chain was not defective you simply stretched it beyond its limits and it broke.

There is a reason why they make chain in .63 gauge; it is for the larger cc saws. With a 660 you should try to use only .63 gauge chain, it can still be .375 pitch if you choose but you should stay away from the smaller stuff particularly if you want to use a 7 pin. When switching to a shorter bar you should have gone to a larger sprocket to increase you chain speed (which would have reduced the torque).

 

[Grande Dog]

Howdy,
Since the Logosol Mill came around, people have been running similar set-up's as you've described. The LP chain can't handle the full torque of a large powerhead especially when you have transitional wood. In these cases soft wood like fir can have big differences in hardness from sapwood to some really hard pin knots. The chain can only handle so much resistance to the torque of the saw. If you feel that it was a product issue rather than cutting condition situation, we have no problem replacing it for you. Just give us a call.
Regards
Gregg

 

[madrone]

According to Bailey's web site LP chain is not recommended on bars over 18" or saws larger than 45cc. You exceeded both of these recommendations and broke the chain and you are wondering why?

My Baileys catalogue recommends the LP chain for bars 20" or less and says nothing about cc's. I didn't check the website for more info. I appreciate the rest of what you said and see that I just overdid the chain. I would have gone with the .63 but it's just not used much around here and I would have needed a new sprocket as well as bar tip. I'll try ordering the conventional 3/8 and see how it does. I have not had any problem with stihl RSC 3/8 .50 ground to 10º on the Alaskan. I'm gonna put that chain on now and finish the project.

Oh, in addition, it turns out the Granberg mini mill I bought is defective. The guide on the mill that runs on the V rail is not perfectly parallel with the guide rail that slides on the board. Seems to be some warpage on the rail that leaves about 1/4 inch rocking and makes it hard to make a perfectly straight cut. I talked with baileys and they are going to replace it. I doubt this affected the chain breaking.

I really appreciate the folks at Baileys and never meant to imply that they sold anything other than quality stuff.

 

[BobL]

According to Bailey's web site LP chain is not recommended on bars over 18" or saws larger than 45cc.

FWIW I'm using the LP on a 20" bar with a 50cc saw and have milled about 20? logs with it no problem. Bit of a difference using it on a 660 though. I though there were some others on this site using in on longer bars?

 

[madrone]

I'm going to go see if I can have it fixed at the dealer as I have no LP dls. If so I'll try it out using the 361 tomorrow.
Thanks for all the input guys. It great to have such a great resource. I couldn't be doing half the wood things I do w/out this site.
-Mark

 

[Zodiac45]

Madrone, I'd go ahead and replace it. Looks like a pretty clean break for sure. One question. Was the saw oiling well? Chain looks a little dry but that could just be you cleaning it for the pix? I think Grande Dog is probably right about the wood having allot of transitional hardness versus the torque of the big saw. That and you mentioned quite a bit of stretch right off the bat must have overstressed it.

 

[rmh3481]

You sure there wasnt a piece of metal in that wood? Could be an old piece of wire fencing or a big bolt? Just look before you go back to it.

Best wishes,
Bob

 

[madrone]

You sure there wasnt a piece of metal in that wood? Could be an old piece of wire fencing or a big bolt? Just look before you go back to it.

I finished the slabbing today and found no metal in the wood. I doubt there was any cause this log was from about 25' up. Unless it was a bullet which is always possible. I think I just over-stressed the chain.
Zodiac, yes the saw was oiling well as far as I could tell at the time. The oil tank was close to as low as the fuel which seems normal. There is always a chance the hole in the bar plugged up without me noticing but I do clean the bar often.
I removed the broken dl from the chain today and the chain must have stretched a lot because it still fits the saw. Tomorrow I'll try it on the 361 and let it stretch in slowly.
I'll post back with an update.
Thanks all,
Mark

 

[glennschumann]

Looking at the picture, it looks like the bottom of the drive links are a bit worn... as if they have been bumping into something. The wear I see on my chains never seems to be like that, but I did acquire an old bar where the chain wouldn't go around easily. Turns out that bar had a misalignment of the rails where the tip and bar met. The tip was a bit loose, and the rails on the tip a bit bent, so the chain was catching up there. Fixing the rivet and aligning the rails fixed that problem. I also had one bar that I modified to fit another saw by cutting the other end a bit shorter. I had the same hang up issue until I flared the slot where the chain entered the rails from the sprocket.

I only mention this because it looks like your drive links may be hitting something from the wear I see.

Just my 2 cents.

 

[BobL]

Looking at the picture, it looks like the bottom of the drive links are a bit worn... as if they have been bumping into something. The wear I see on my chains never seems to be like that, but I did acquire an old bar where the chain wouldn't go around easily. Turns out that bar had a misalignment of the rails where the tip and bar met. The tip was a bit loose, and the rails on the tip a bit bent, so the chain was catching up there. Fixing the rivet and aligning the rails fixed that problem. I also had one bar that I modified to fit another saw by cutting the other end a bit shorter. I had the same hang up issue until I flared the slot where the chain entered the rails from the sprocket.

I only mention this because it looks like your drive links may be hitting something from the wear I see.

Just my 2 cents.

Yep I agree, That is an unusual wear pattern especially given that this chain has been used to cut only 2 and a half slabs.

Look at this magnified image of the drive link that broke, and in particular at the red arrows.

The bottom tips of the drive links have a pronounced wear ridge and appear not to entering the sprocket slots correctly or hitting something somewhere along the chain path that pinches the bottom tip of the drive link.

The drive link tip wear is also matched by two opposite patches suggesting the drive link is rocking somewhere. This rocking could easily explain the excessive stretching and ultimately breaking of the the chain.

After 2.5 slabs I would expect a totally clean drivelink and virtually zero wear on the edges of that link. Most of the wear that does occur usually happens in the inside part of the half moon curve of the link

Something could be jammed inside the sprocket, bar groove or tip. You really need to get this checked out before using any other chain on your setup. I'd be using my magnifying glass or putting on my head magnifier and inspecting the chain path very closely.

 

[Brmorgan]

A long time ago, when I was much younger and had practically no experience with chainsaws, I tried running .404 chain with a 3/8 sprocket (like I said, no experience and didn't know there were different sizes!) and the resulting damage looked exactly like this. I quickly realized something wasn't right but I couldn't see a problem and made a bunch of cuts anyway. Didn't take long to do a number on the drivers and sprocket.

Since you said you got a brand new sprocket, maybe the bar tip isn't the same pitch as the chain? Not to infer that you don't know what you're doing or anything, but we've all made dumbass mistakes like that before. 3/8 chain WILL go around a .325 bar nose, but not smoothly, and will cause wear like that. The damage that the top arrow in Bob's magnification is pointing to looks like a sprocket point is contacting 1/8" or so before the gap between the drivers where it should.

Glenn's suggestion for checking the bar/nose joint is a good one. Also check that the rails of the nose haven't separated, allowing the drivers to run beside the sprocket instead of on top of it. We had a saw at the mill do that, but the tip got so hot it blued the steel in a couple minutes. But I'd imagine you would have noticed if that happened.