chain de-railing

[normandylumberjack]

Hello chaps,

 

I was knocking the top out of a conni hedge today, and my ms192t threw a chain, i checked it over and no damage to saw or drive links so fitted the chain and carried on. about an hour later it de railed again this time chewing about 10 drive links.

 

I have had chains de-rail before but never twice in one day, any ideas why?

 

It was a new bar and chain, both stihl, about 10 hours cutting on both. Chain was tensioned correctly, chain was sharp, oiling well.

 

The one problem i did encounter was small branches being pulled in and around the clutch and needing clearing often.

 

Anything to worry about?

[treequip]

Twice in a day is unusual but probably a bit of bad luck, bits of conny twig pulling the chain out of the grove.

[Le Sanglier]

When you say chewed drive links do you mean they are burred and will not fit back in the guide rail? If so put the chain back on very loose, run it for 30 secs or so and the burring will wear off, tighten chain again, continue work.

[tree_beard]

How worn is the sprocket?

[Stephen Blair]

To me there's is only 1 thing, and that's the chain is too slack.

I adjust a chains tension depending on what I am cutting.

If I am reducing a large privettes hedge with a 46, I will tighten it right up and still expect it to be knocked off the rails, always check the cir clip hasn't been knocked off, this usually happens if you get a tangle, with say string.

The saw might run at first without 1 but eventually it will all end in tears and then you have to search for it around your feet unless you array spares, which I do, every vehicle has spare circlips, roller bearings and a washer in them.

[Le Sanglier]

It happens on conny topping because as you cut through the weight of the top presses down on the chain pulling it out. Step cutting will prevent it but doing it 10000 times a day wears a bit thin.

[Stephen Blair]

If the chain drive links have burrs on them and say a kink, put the chain over your knee and bend it back.

A flat file will take the burrs off but if you are too impatient, stick the chain on but put the 3-4 burred links on the sprocket, you shouldn't need to slacken the chain, but this will cause extra heat and I would recommend tightening the chain after the whirry noise stops:biggrin:

[geoff]

It happens on conny topping because as you cut through the weight of the top presses down on the chain pulling it out. Step cutting will prevent it but doing it 10000 times a day wears a bit thin.

 

This and mr Blair's posts.

[treequip]

When you say chewed drive links do you mean they are burred and will not fit back in the guide rail? If so put the chain back on very loose, run it for 30 secs or so and the burring will wear off, tighten chain again, continue work.

 

Its rough but it is effective, give the bar a gobfull of oil to help a little:thumbup1:

[Rob D]

When you say chewed drive links do you mean they are burred and will not fit back in the guide rail? If so put the chain back on very loose, run it for 30 secs or so and the burring will wear off, tighten chain again, continue work.

 

 

 

IMO I wouldn't stick the chain back on with burred drive links - they will quickly claw out the bar groove and start causing chain slop - you'll end up needing a new bar as well as a new chain...