Revving up saw before cutting?

[gman98]

Hello guys.  I'm reading some places that it reccomends that you have the chain moving and the rpm's up before you touch whatever you are cutting.  What is the purpose of this?

Thanks

[DelawhereJoe]

Are you talking 1/2, 3/4 throttle or you talking red line ?

[Ianab]

I'd think it would be easier on the clutch to have the chain moving at cutting speed before it touched the wood. Otherwise you have the clutch engaging with the load of the cutters dragging on it. Going to wear the clutch slightly more. I'm talking about 1/2 throttle for a split second, just to get the chain up to speed, then going to full power as the saw bites in.

Having said that, if I'm making some more "technical" cut where the saw has to be positioned exactly I may rest it in place, adjust the position exactly, and then hit the throttle once I'm happy with the position and angle. But even then I try and keep the pressure on the bar to a minimum to make it easy for the chain to start.

[joe_indi]

The technical guy will tell you that you need to rev up the saw to a speed beyond the rpm at which its working power is rated.
When the chain comes in contact with the wood, the rpm would then drop to the rated rpm for maximum power.
Eg. Saw is rated for X bhp @ 10000rpm.
Maximum rpm is 13500rpm
When it touches wood @ 13500rpm the rpm drops to 10000 where the power is at the maximum.
Having said that, you are not going to need X bhp all the time, maybe less, so at times something above midway works fine, but never be in contact with the would at idle and try to throttle.
That is somewhat like having the brake on, and if it is a poweful saw you get pulled forward and lose control.

[CTYank]

Hello guys.  I'm reading some places that it reccomends that you have the chain moving and the rpm's up before you touch whatever you are cutting.  What is the purpose of this?

Thanks

As Ian noted, it's mainly about clutch-saving. Chainsaw clutches don't have friction-facing anywhere near as durable as automotive clutches. Obviously enough, getting engine speed up gets the clutch solidly engaged- it is dependent on speed for centrifugal force.
Don't be influenced much by vids that show the saw up to screaming rpm before entering the cut. You just want the chain spinning as the engine soars off to full speed in the cut. Normally a few milliseconds delay between opening throttle wide and entering the cut will do just fine, giving max mechanical longevity too.

[ZeroJunk]

You will find that if the chain is not moving when you set it on the wood being cut you may have a hard time getting it moving if you have any pressure on it at all.

[Ada Shaker]

It just gets through the bits of stone, nails and barbed wire that may be embedded in the wood a lot easier. If you go to slow the teeth may grab hold and pull the saw in. ;D

:P I think there's less pull on the saw if the revs are kept up high which equates to better control of the saw. Going slow tends to pull the dogs in and may stretch the chain further I think.