Rope Length?

[buzz sawyer]

Another thread got me thinking about this.

Has anyone ever researched how the length of the rope affects the effort to pull the starter rope? If the rope is as long as possible, does it give more or less mechanical advantage at the start of the pull - or is this splitting hairs?
I realize there is a minimum length and the circle of rope gets smaller as you pull the rope further.

Maybe I was just up too late last night and the brain isn't in gear yet.

 

[chainsawwhisperer]

The longer the rope , the farther it will be out on the pulley. The farther away from the center of the crank, the more leverage it will have to start
the momentum of turning the engine over. That would especially be an advantage on a high compression engine.
I would also suspect that the longer the rope, the easier it is on the recoil components. CSW

 

[belgian]

The longer the rope , the farther it will be out on the pulley. The farther away from the center of the crank, the more leverage it will have to start
the momentum of turning the engine over. That would especially be an advantage on a high compression engine.
I would also suspect that the longer the rope, the easier it is on the recoil components. CSW

+1 ! This is especially the case with older big cc saws with no decomp.

Fill the pulley as much as possible with rope !

I experienced this myself with an older Solo Rex which is a beast to start.

 

[Nailgunner]

... But not so much that you bind up the spring at the end of the rope

You should be able to pull the rope to the end of it, and not bind up the spring.

With this in mind, yes, fit as much rope as you can. Ideally your arm will run out of travel before it runs out of rope, to save shocking your arm or starter reel.

 

[stihl only]

Just read how a winch is rated and you'll have the answer. They always list a rating for the fist wrap on the drum so they can get better to advertise number!

 

[bump_r]

Just read how a winch is rated and you'll have the answer. They always list a rating for the fist wrap on the drum so they can get better to advertise number!

Yes, but remember that the "effort" and "load" parts of the equation are reversed. With a winch, the spool (drum) is the thing doing the work, on a recoil starer the spool is the resistance. Lower energy required on the first wrap on a winch but final wrap if the recoil rope.

 

[chainsawwhisperer]

... But not so much that you bind up the spring at the end of the rope

You should be able to pull the rope to the end of it, and not bind up the spring.

With this in mind, yes, fit as much rope as you can. Ideally your arm will run out of travel before it runs out of rope, to save shocking your arm or starter reel.

+1 CSW
Buggered recoil springs suck!

 

[RiverRat2]

Good thread!!!!

Yes fill the spool completely !!!!!!

 

[Lakeside53]

Filling the spool only works if you have the correct size rope... and many don't.

Stihl specifies the length in the ipls. This gives a reseve of 1/2 to one turn on the spring. Long ropes mean busted springs.

Always test your installation to make sure you have at least 1/2 turn left on the spring.

 

[Modifiedmark]

I'm thinking the correct diameter is the most important thing, and the major reason the pulley broke on my 925.

 

[buzz sawyer]

Yes, but remember that the "effort" and "load" parts of the equation are reversed. With a winch, the spool (drum) is the thing doing the work, on a recoil starer the spool is the resistance. Lower energy required on the first wrap on a winch but final wrap if the recoil rope.

Good point - that's the comparison I was looking for. By the same token, when the winch drum is full, the load has a better chance of pulling backwards then when it's on the first wrap.

 

[berryman70]

Filling the spool only works if you have the correct size rope... and many don't.

Stihl specifies the length in the ipls. This gives a reseve of 1/2 to one turn on the spring. Long ropes mean busted springs.

Always test you installation to make sure you have at least 1/2 turn left on the spring.

I agree with what you are saying, but most people don't have arm reach to pull to that point. I guess it also depends on the starting technique used.

 

[propliner]

Does anyone have a quick fix for torn second and third finger tendons due to backfire? I'm still suffering, even a year later.

 

[Lakeside53]

Elastostart...

 

[Lakeside53]

I agree with what you are saying, but most people don't have arm reach to pull to that point. I guess it also depends on the starting technique used.

Most ropes are typically 800-900mm... Easy to bottom out if you "long-arm". I don't

 

[Modifiedmark]

Elastostart...

Got my new pully for the 925 and going tomorrow to get a new rope for it, would the Elastostart be a good idea for this?

I didn't measure it yet but the 925 uses a larger dia rope than what I have here to use.

 

[Lakeside53]

Buy the MS660 elastostart... comes with the heavy rope.

 

[Jacob J.]

Does anyone have a quick fix for torn second and third finger tendons due to backfire? I'm still suffering, even a year later.

No quick fixes, but keep working and using your tendons/muscles in that arm. They'll come back twice as strong.

I blew some tendons in my forearms when I was 19-20 cutting timber running those Red-Light 066s..those CDIC coils were infamous for backfiring when hot. Now I have a grip that could crush an abalone shell.

My grandpa however, has a grip that could pulverize a cue-ball.

 

[Modifiedmark]

Thanks, I doubt if they have one in stock, but I'll check tomorrow.

 

[Lakeside53]

No quick fixes, but keep working and using your tendons/muscles in that arm. They'll come back twice as strong.

I blew some tendons in my forearms when I was 19-20 cutting timber running those Red-Light 066s..those CDIC coils were infamous for backfiring when hot. Now I have a grip that could crush an abalone shell.

My grandpa however, has a grip that could pulverize a cue-ball.

I guess nobody says "get a grip" in your family:greenchainsaw: