Stihl 261 Max Chain Speed

[tractormatt]

Anyone happen to know the max chain speed of a 261 was thinking of getting a 16" bar but i just wanted to check that it will be within the limits of the class 1 trousers (20m/s). I cannot find this info anywhere, would it be simular to the 18.5 quoted by husqvarna for the 346xp

 

Thanks

Matt

[Carlo]

Hi Matt I hope this helps

 

MS 260 max RPM = 14,000

Distance chain moves per rev = 0.115m

14000 x 0.115 / 60 = 26.83 m/s

RPM may vary with bar sizes

 

Martyn

[C.J]

Husqvarna quote 18.5 m/s at max power(9600 rpm)

 

At max speed(13500 rpm) chain speed is 26 m/s:001_rolleyes:

[tractormatt]

ok thanks so it looks like i wil need a higher class of protection, also does anyone know what the warranty is i thought it was 12 months but someone was telling me that if it is just used for domestic purposes it is 2 years but i cannot find this on the stihl site

 

Thanks

Matt

[RobRainford]

When do you plan on sticking a saw at full revs into your leg?

 

Not trying to be stupid but more accidents can tend to happen on rundown. When your moving and not thinking about the spinning chain as much. Although the chain brake should be applied whenever you don't need to be cutting!

[arbogrunt]

this post raises some interesting points. Most chainsaws we use, run at chainspeeds in metres/second in excess of the level of protection in our PPE. The fact is, PPE offers SOME protection....its not a substitute for safe working practice.

If we all wore class 3 protection, there would be more people cutting themselves through fatigue brought on by heat exhaustion. Its a compromise between protection and mobility....be careful out there fellas!

[morten]

Although the MS 261 manual does not specify directly, the chain speed can be calculated from the tech specs section of the MS 261 manual http://www.stihlusa.com/stihl_ownersmanuals/STIHL_MS_261_IM.pdf

 

Here goes:

 

MS 261 Tech specs

 

Max power (ISO 7293): 2.8KW at 9500 rpm.

High speed (no load): 14000 rpm.

Sprocket: 7 teeth.

 

Chain speed calculation

 

Chain: 0.325" => 2 * 25.4 * 0.325 mm => 16.51 mm between drive links.

One engine revolution moves the chain 7 * 16.51 mm = 115.57 mm.

 

at 9500 revs/min => 9500 * 115.57 / 60 / 1000 m/sec => 18.3 m/s.

 

at 14000 revs/min => 14000 * 115.57 / 60 / 1000 m/sec => 27.0 m/s.

 

 

I doubt whether those figures actually does anything for you. But I guess one can conclude that the saw is "rated" at a chain speed of 18.3 m/s, for what it's worth.

Edited January 30, 2011 by morten

[Shiresmill Woodlands]

Hi,

 

The owners' manual states on p.47 under the section sub-headed chain sprocket that the max chain speed of the MS261 is 25.6m/s, but lordy only knows how they caluculated that as it's different to all the other calculations on this post's thread.