Logosol M7 with Husq 385XP ---> Sprocket

[IFly2Fish]

I'm having (major) trouble milling on my M7.  I'll start with a question and see if the answer solves (or can potentially solve) my problem.  Here's the question:

Will a worn drive sprocket cause the blade tip to dive when cutting a slab?  The sprocket has been used for some time and never been replaced.

I've looked at pretty much everything else and am close to the "end of my rope".  If specifics regarding the setup are needed, I'll provide, but if I get a "YES" answer it is likely to solve my problem.

Thanks.

[hamish]

No it will not.  The rim sprocket is free floating allowing to align itself with the bar rails.

Check the condition of your bar, your nose, and most importantly your chain.

[IFly2Fish]

Thanks for the quick response.  As I said, I'm using the Husq 385xp...new bar, new chain, purchased from Baileys.  As I cut, the blade tip dives (seriously) causing a twist of the not-so-flat surface.  When the blade exits the log it snaps upwards.  It's obvious there's lots of pressure prior to exiting. 

I've verified that the log does not move, the rail is flat and horizontal to the log bed.  The log bed it perpendicular to the supports.  I've also verified that the saw bar is parallel to and a consistent distance from the two log bed supports.  Using winding sticks I've verified that there is no twist in the rail.

I removed the saw from the sled and installed it in my TimberJig and the bar tip was still pulling downward.

Is it possible the brand new, and I mean NEW, chain is causing the problem?  The bar is new too.  Again, both were purchased from Baileys on their recommendation. 

Thanks for your thoughts!

[Hackeldam Wood Products]

I have the exact same problem. Ripping chain from bailey's. It was suggested to me that the chain needs to be sharpened perfectly and that the bar has no wear when ripping lumber. Although I am sure it was doing with a chain right out of the box. I purchased a grinder to grind the angle of the chains perfectly. I have not had a chance to saw any logs yet though.

[Hackeldam Wood Products]

here is a link to that thread.

https://forestryforum.com/board/index.php/topic,77755.msg1180446.html#msg1180446

[AK Newbie]

Not an expert by any stretch, but I have the same setup as you M-7 with the 385xp, and each time I have issues with the blade diving it's been the chain.  I stop and sharpen the chain carefully and so far each time I've done that, it fixes the problem.  Good luck and let us know what the ultimate fix ends up being!

[thecfarm]

IFly2Fish,welcome to the forum.

[Jemclimber]

As others have said, recheck/sharpen the chain.  A chain is only brand new when it has never been used. As soon as it sees any wood it's not new (because there is a slim chance there was something in the wood/bark right away) and it could have hit something possibly on one side of the cutters which will cause it to cut crooked.  As Hamish said it's not the sprocket. I milled with a 395 and a 066 for awhile on a homemade track type mill, before I got my bandmill, and I've seen many issues. It's the bar, the chain, alignment, or a combination of those 3.  Take your saw off the mill and cut a large cookie that's the length or close to the length of your bar.  Make sure it cuts straight all the way thru.  If it does cut straight, find your alignment issue. Good luck and let us know how you make out.

[IFly2Fish]

Thanks for the responses guys.  It'll be some time now before I run the mill again.  Vacation's done and it's back to work.  It may be a month or two but I'll let you know when I get back to it.

When I say "new" bar and chain...I mean brand spanking new.  I'll throw on a new chain when I get back at it, and let you know how it goes.

[terrifictimbersllc]

First let me say my suggestion seems inconsistent with having a new bar, but......

I wonder whether a bar groove, even if the gap is at spec, which is at the top, can be widened by wear  inside, so that a chain can be allowed to tilt up or down, because there is room for the bottom of the drive link to move sideways inside the bar groove.   Any tendency to cut at an angle to the face of the bar, would be expected to wear the inside of the bar groove to allow more and more of this to happen.  This is something that I would not know how to measure easily, and how this could happen with an almost new bar I don't know. But if you know that you've done a fair amount of sawing with the chain seeming to cut down in  this difficult manner, maybe this has happened. 

If the other side of the bar hasn't been used yet, a test would be to flip the bar to the new side, and try sawing with nothing else perceptibly changed.  A restored ability to cut straight would be a suggestion that your bar groove may be worn wider down inside. 

Maybe others have thought about this problem.   Again, what I am suggesting is a bar groove problem even if it seems to have the right width at the top of the groove (055, 058 063 etc). 

[celliott]

terrifictimbersllc, you may be onto something. Your post just made me have a thought-
IFly2Fish, you said brand new bar and chain. Are you positive the bar and chain gauge match up?

I'm thinking it's a possibility you are running .050 in a .058 or .063 bar, or .058 in a 0.63 bar. That would give some slop. And make sense on brand new cutting gear.