Converting a 60" Stihl Sprocket to Roller

[BobL]

I've been messing about working out a way to convert a 404/sprocket to 3/8 roller nose on a Stihl 60" bar.

More details here.

 

[johncinco]

heres what I got back when asking. I never did get ahold of that shop.

http://www.arboristsite.com/showthread.php?t=97257

 

[BobL]

heres what I got back when asking. I never did get ahold of that shop.

http://www.arboristsite.com/showthread.php?t=97257

Yeah - I saw that post but that is for a Hard Nose bar - that's a bit harder that for a sprocket to roller conversion. I could see how it could be done for milling by using a pair of over plate that connects the hard nose to a sprocket. I am even thing of doing that to a hardnose bar I already have.

 

[woodsrunner]

Bob, do you ever sleep? I can't figure out how you have the time to do all the cool things you come up with, much less the brain power to dream them all up. You da man!

Scott

 

[Ed*L]

heres what I got back when asking. I never did get ahold of that shop.

http://www.arboristsite.com/showthread.php?t=97257

I had them do my 60" many years ago. Good guys there.

Ed

 

[BobL]

Bob, do you ever sleep? I can't figure out how you have the time to do all the cool things you come up with, much less the brain power to dream them all up. You da man!

Scott

Cheers Scott. I think it's related to work stress where I head up a unit with ~65 personnel. The more stressful it gets at work, the more I need to unwind so I push things aside to make the time. Other unit heads play golf, go boating, etc, whereas I make stuff and mill - they all think I'm a bit mad but that's OK with me - most of them know I have a shed full of so few of them give me any trouble!

 

[LAndrews]

And Bob doesn't mess around with little saws either. :jawdrop:

 

[Ollbuster]

OK, I searched the net and can't find info on the roller nose.
Exactly how do these work.
I have an 880 and want to try running 3/8 on it once the 404 is used up.

Needless to say Bob has been inspirational and have been following the 880 threads...

 

[BobL]

OK, I searched the net and can't find info on the roller nose.
Exactly how do these work.
I have an 880 and want to try running 3/8 on it once the 404 is used up.

Needless to say Bob has been inspirational and have been following the 880 threads...

Thanks fellas.

With a sprocket, the teeth partially protrude up between the drive links and support the drive link as it goes around the nose. This takes the pressure off the bar rails at the nose so less friction is generated meaning more power goes into cutting. If the sprocket jams the chain just stops.

With roller noses only the very bottom of the drive link is supported to take the pressure off the bar rails at the nose. If the roller jams chain can still goes around and messes up the roller and the chain.

BTW I have found a very good source of hard steel to make the real deal out of, its an old circular saw that I lost a half dozen teeth on by being a bit ambitious when cutting some ally with it a few years ago. Its not quite 2 mm thick (its 1.87 mm) but it should be good enough.

 

[Ollbuster]

Thanks Bob that makes perfect sense with the little I found.
So it looks like the real advantage is you can run any pitch chain on a bar.
Is this it or am I missing something obvious??

 

[BobL]

Thanks Bob that makes perfect sense with the little I found.
So it looks like the real advantage is you can run any pitch chain on a bar.
Is this it or am I missing something obvious??

That's it!

BTW I finished the hardened steel version - some comparative pics and details here.