What causes thrown chain?

[BryanEx]

My cutting needs are a little different than most here given I run a maple syrup operation. Most cutting is about releasing the canopy and/or maintaining sap lines. I'm often using a saw to clear underbrush or to reduce branch piles to a workable size for removal. During this process I often throw the chain off the bar and have been trying to figure out what exactly happens in the process. Near as I can figure is that the chain gets a pinch and twist right near the tip of the bar and as it rounds the nose jumps the track. I never throw chains cutting real wood but sticks and brambles can frustrate me to no end repeatedly putting the chain back on. Once I have an opening I turn to my clearing saw (basically a trimmer with a circular saw blade on it) but I still need an opening in the bush to get started. Is there anything that can be done to reduce derailed chain while cutting up sticks-n-brambles?

I use a Poulan P3818AV with Oregon bar and safety chain for my more abusive cutting like brush, rocks, dirt, and old wire fence.

 

[Oldtimer]

Run a good bar, one with less rather than more wear.
Tighten the chain until you can just pull 3/16" of slack at the center bottom of the bar. Needs to be on the verge of being "too tight".

 

[oscar4883]

Running the chain slightly tighter than normal, and trying not to cut at an angle should help some. I may be totally off here, but I believe bow saws excell at what you are trying to do. Some real gurus over in the chainsaw section whomay be able to help.

 

[tree md]

What I have found sometimes happens when cutting down brush is a twig will find it's way between the chain and the bar and throw it. Not hard for it to happen when you have multiple small twigs making contact with multiple points on the bar. It's really hard on a bar and chain.

 

[BryanEx]

Running the chain slightly tighter than normal, and trying not to cut at an angle should help some.

I've been experimenting with different tensions but to no avail. I'm convinced the main problem is that the material I'm cutting is only marginally larger than the chain depth so any pinching or leverage, no matter how slight, is all on the chain and not the bar itself.

 

[vincem77]

Are you setting the chain tension without lifting the bar up at all? That may make it seem tight before you start cutting.

With the clutch cover nuts hand tightened adjust the chain tension. Then lift up the bar and you should notice extra slack in the chain. Take out the extra slack and tighten everything up.

I prefer to hold the saw in my left hand and rest the bar on a log in order to lift it some. With my other hand i set the tension and tighten the nuts.

 

[daytondedrick]

Its no secrect that cutting releases tension and compressional forces, the small stuff can exert that force directly to the chain rather than the bar and chain like bigger stuff. The only real way to prevent it is to cut each twig/branch/sapling individually. But, if youre like me, you see several small cuts as one and feed the chain in there full throttle. Thats what usually happens to me as I see it.

 

[KD57]

What I have found sometimes happens when cutting down brush is a twig will find it's way between the chain and the bar and throw it. Not hard for it to happen when you have multiple small twigs making contact with multiple points on the bar. It's really hard on a bar and chain.

I agree, cutting multiple small diameter brances at once will do that. Running a chain a little too tight helps, but I haven't found a solution to the issue. It will throw every time if the chain is just a little loose.

 

[rarefish383]

What I have found sometimes happens when cutting down brush is a twig will find it's way between the chain and the bar and throw it. Not hard for it to happen when you have multiple small twigs making contact with multiple points on the bar. It's really hard on a bar and chain.

Tree MD is right, cutting brush is a sure fire way to throw a chain. I don't mean limbing up brush, but cutting through the small twigs. As you cut through the pile any thing with tension on it will snap up and flick the chain sideways or get under the chain as mentioned by others. Keeping it a bit tighter will help, but it's not really made to do that kind of cutting. Repeated chains throws will eventually bur up the drive links and and damage the bar too. No real way to prevent it, Joe.

 

[bsearcey]

Use a bush axe.

 

[webie]

Since I have been brushing for years with a chainsaw , the best set up I have found is the shortist bar you can get , safety chain with the extra guard humps in between the cutters work better than other types and a rim sprocket for your chainsaw drive clutch . Keep the chain plenty tight and then I still throw one once and a while . Also the newer the bar and chain set up seems to be better also , rather than a worn out bar and chain , I think because there is less chain slop and less chance of snagging brush with the saw chain .

The best saw I have for brushing is my MS180 with the tooless chain adjuster at least I can put the chain back on again in the thick of things .

 

[BryanEx]

Great advice and feedback... thanks everyone. I haven't thought of trying a shorter bar but that suggestion makes sense and it's one of the few I haven't tried yet. My clearing saw is certainly the tool for this kind of work but until I've opened up enough elbow room it just becomes a tangled mess around the shaft and often myself.

 

[treesquirrel]

Sounds like a job for some goats.

 

[RedlineIt]

I run into this mostly while retopping hedges, wading through cutting alot of two, three inch stuff but lots of twigs too.

Best i've figured out is run the chain rediculously tight.

As I figure it, as the chain rotates it tries to describe a circle, only the bar and tension keep its shape, so any slack at all allows a twig to get in the gap, gets pulled into the nose of the bar and then derails the chain.



Short bar, tight chain seems the way to go, then some flat file maintenance to the bar when you're done as you'll have burred up the tip.

RedlineIt

 

[BryanEx]

Sounds like a job for some goats.

According to some of the university extension research, goats are beneficial to a maple syrup operation at a rate of 20 goats per acre... once every decade.

I need to work a little bit faster than that.

 

[treesquirrel]

According to some of the university extension research, goats are beneficial to a maple syrup operation at a rate of 20 goats per acre... once every decade.

I need to work a little bit faster than that.

LOL

There is a local lake here and the earth dam slopes are so steep they keep a big herd of goats there to keep the vegetation under control. Been doing it that way for since I remember. Kinda cool.

 

[tree md]

LOL

There is a local lake here and the earth dam slopes are so steep they keep a big herd of goats there to keep the vegetation under control. Been doing it that way for since I remember. Kinda cool.

You must be somewhere in Cumming, GA. :hmm3grin2orange:

 

[treesquirrel]

You must be somewhere in Cumming, GA. :hmm3grin2orange:

I grew up in Lawrenceville. Yes, you know I am talking about Buford Dam on Lake Lanier.

I remember as a small boy when my grandfather showed me the goats.

 

[a. palmer jr.]

All good answers here and I might add another: be patient when cutting brush. Sometimes I find myself hurrying through it, cutting at different angles when I should be taking my time and not abusing the saw.

 

[randyg]

All good answers here and I might add another: be patient when cutting brush. Sometimes I find myself hurrying through it, cutting at different angles when I should be taking my time and not abusing the saw.

Many good points but this last was closest to hitting the big nail on the head. Before I got chipper, I stacked all the branches into the dump trailer till the pile got so high they were falling off. Then I would throw a rope over the top, cinch it down, and jump up in there (PPE for sure) with a 372 w/32" bar on and make cross cuts every 6" - 10". Could do this 3 or 4 times before I had to go dump. I found that when cutting multiple groups if you make the cut close to the saw head, the chain will pull the wood up to the dogs and make the cut. Further out on the bar and the bar might jump up and down and starts this rythum with the chain (tight loose tight loose). This happens when trying to cut a small sapling 2' above ground rather than 2". This can jump the loop off the nose of the bar but for me the very worst was when one branch would get in the pile sideways. If the chain was the slightest bit loose when I hit that one, off it would come.