Testing inertia chain brake

[tku]

I've bought an electric chainsaw which the manufacturer advertises as having an inertia brake, however, I cannot get the brake to activate using the nose-drop test as demonstrated in this video. In my test, the bar just hits the wood without the brake clicking on.

 

How hard does it need to hit to activate..?

 

One thing to note... as I want to return the saw I've bought if I can't verify it has this safety feature, I have conducted the test without fitting the chain, so just a bare bar. As far as I can figure, this won't affect the inertial forces so if an inertia brake was present it should be working.

 

I've also been told that all chainsaws must have inertia brakes by law, but I'm not sure that is the case. I have got the sense that a lot of people, manufacturers included in some instances, might be wrongly using the term "inertia brake" just to describe a regular chain brake. 

 

Thanks in advance for any help.

 

 

 

Edited May 20 by tku
Additional information.

[GarethM]

Are you meaning kick back which engage the brake ?.

 

It's electric the chain will only run when you're pressing the trigger, being a electric motor it doesn't freewheel.

[Bolt]

Never really considered this for battery saws, so I just tried it on a Husqvarna battery top handle…. The inertia brake worked as in the vid, with the exception that I had to hold the saw far higher above the log to get the brake to act. 
 

It is possible you are not being ‘violent’ enough. 
 

 

[scbk]

What saw is it you've got?

[pleasant]

All chain brakes work on 'intertia'

 

They are designed to stop the chain in event of kick back and are activated via the chain brake lever coming into contact with the 'knuckles' of your left hand, which with the force of the inertia kick back will push the chain brake lever forward to near immediately stopping the chain from rotating.

 

Not having the chain fitted really isn't going to help you ascertain whether the chain brake mechanism is operational correctly.

 

Generally petrol saws have a mechanical 'band' which grips and then effectively stalls the clutch mechanism to stop the chain rotating. Mains electric saws have a micro switch which immediately cuts the motor power- thus stopping the chain. Normally you will have a reset button to depress to reinstate power to the motor

Edited May 20 by pleasant

[Stubby]

2 minutes ago, pleasant said:

All chain brakes work on 'intertia'

 

They are designed to stop the chain in event of kick back and are activated via the chain brake lever coming into contact with the 'knuckles' of your left hand,

I godda  respectfully issagree with this bit mate . The knuckles of your left hand have nothing to do with it in the inertia sense  of things . As demonstrated in the Husqvarna video above . His left hand is not on the front handle when he drops the saw on the log and the brake engages .

[pleasant]

2 minutes ago, Stubby said:

I godda  respectfully issagree with this bit mate . The knuckles of your left hand have nothing to do with it in the inertia sense  of things . As demonstrated in the Husqvarna video above . His left hand is not on the front handle when he drops the saw on the log and the brake engages .

A fair point, but I was referring to the saw being in 'normal' operating use, and the operation of it thereof.

[GarethM]

Wouldn't electric ones just have a sensor like the ones in your phone ?.

[Stubby]

1 minute ago, GarethM said:

Wouldn't electric ones just have a sensor like the ones in your phone ?.

Does your phone ever " kick back " ? 🙂

[pleasant]

5 minutes ago, GarethM said:

Wouldn't electric ones just have a sensor like the ones in your phone ?.

See my comment above.