Clutch Engagement Speed - Anybody Tach It?

[Philbert]

I was looking at the service manuals for a couple of saws to check manufacturer recommended RPMs. I was expecting to see idle speed, and maximum speeds, but I was surprised to see chain engagement speeds listed. I was always told to turn it up until the chain starts to move, then back it off a bit.

Anybody tach this speed?

Anybody tach their saws in the wood to see what manufacturer maximum torque feels like, versus subjective feel?

Philbert


Samples From Service Manuals:

Husqvarna 353-----Idle 2700------Chain Engagement 3800------Maximum Torque 9000------Maximum RPM 13000

STIHL 024Super---Idle 2500------Chain Engagement 3600------Maximum Torque 7000------Maximum RPM 13000

 

[lfnh]

Do the same as you. However, ndlawrence has some checking with tach and engagement speeds that seemed to show weak springs. Hopefully he'll drop by and post that stuff better.

 

[testlight]

Maximum torque, just like max HP is at full throttle. I like to keep light pressure on the saw and keep the chain speed and RPM up if I can. It seems like it is easier on everything to me. I don't make the saw work any harder than it has to unless I'm in a hurry, or I can't help it. Which is most of the time in big wood. It seems like max torque happens at less that the RPM's listed, but no I've never tached it and I'm sure the numbers are right for a stock saw.

 

[Philbert]

I checked the chain engagement speed with one saw today (MS 024S) and it was right on, at 3600 RPM. I just put new clutch springs on this saw, and it made me wonder if you could use clutch engagement speed as a test for weak springs.

Any thoughts?

Philbert

 

[PogoInTheWoods]

I checked the chain engagement speed with one saw today (MS 024S) and it was right on, at 3600 RPM. I just put new clutch springs on this saw, and it made me wonder if you could use clutch engagement speed as a test for weak springs.

Any thoughts?

Philbert

Well, if the clutch engages at idle instead of the published engagement RPM, what would you suspect was the problem?

Bad specs?

:msp_biggrin:

 

[Philbert]

Well, if the clutch engages at idle instead of the published engagement RPM, what would you suspect was the problem?

Say the manufacturer's stated idle speed is 2500 RPM, and clutch engagement speed is 3600 RPM. If the clutch engages at 3000, it could mean that the springs are getting weak, even if the chain is not rotating at idle speed. No?

Philbert

 

[hamish]

Yes it would indicate weak spring/springs or other problems. I do a rough check on engagement speed afte rI have set the idle, but to read that 800-1000rpm increase on a tach with your finger on the throttle......well shes alot faster than my eyes.

Warm saw idle set, I will slowly increase the idle speed till the clutch engages then ready where I am at should I suspect something.

Most clutch issues can be confirmet by visual inspection and a lil feeling, shoes that clatter and springs you can compress, overheated shoes, drun wear patterns etc.......

 

[PogoInTheWoods]

Say the manufacturer's stated idle speed is 2500 RPM, and clutch engagement speed is 3600 RPM. If the clutch engages at 3000, it could mean that the springs are getting weak, even if the chain is not rotating at idle speed. No?

Philbert

Perhaps the microscope you use for splitting hairs could also be used to inspect your clutch springs?

But to answer your question, yes, of course -- more or less.

It could also mean your tach is not accurate. No?

Easy, Philbert. Fish will be all over this before ya know it if'n ya keep it up!



Poge