Why not a HEAT ALERT WARNING?

[Grande Dog]

Do you think the big chainsaw companys don't do it because they would sell less saws per year and dealers would lose the money for labor costs of fitting a new p & c on a burnt up saw?

Howdy,
I just can't imagine a company doing that. All kidding aside, I think this is a good idea, and a good thread. I thought I'd throw in my 2 cents worth. You want the sensor to shut the saw off (saved the saw, lost the house scenario). I started thinking the warning light might be the way to go. The more I thought about it, the more I realized that once I start cutting, I might not look at the powerhead til it runs out of fuel or oil. I think something tactile would be more efficient. Retarding, or a skip a spark ignition would let you know something is up. I'm thinking the best alternative would be something that starts slowly closing the choke, and hold the partial position of closure until you stop and reset it. This way is not only tactile, but will start the cooling before you shut down.
Regards
Gregg

 

[PatrickIreland]

I get your point, Gregg - it's not often I find myself staring at the filter cover or other part of the powerhead while in a cut!
But LEDs these days can be super-bright, flash on their own etc. - so maybe a bright blue flashing one directed towards the top of the bar (or top side if milling?) might be a help?
My electronics mate says that the best bet would be a 1.5v battery (coin cell), a thermistor of the appropriate value mounted in the right place (anyone have an infrared pyrometer?) and an LED that gives a tiny leakage current when the bias voltage is low could well be a dirt-cheap, if not fancy option. If it's any help I'm happy to drill holes all over my junky chink saw to try it out - thermistors are cheap, but a temperature range would be necessary if I'm going to buy a few of them for trials! Are we talking 200c or 400c, etc? Maybe I should just get a 100c one to try, as the head/fins are bound to reach that temperature even under normal use...

 

[Grande Dog]

Howdy,
I would say that when I'm cutting, I look at the tip of the bar (if it's exposed) more than anything else. Secondly, I would say it's the area around the dogs. That's where it would catch my attention.
All though the skip a spark ignition that sends every other spark to the handlebar would do it for me too.
Regards
Gregg

 

[tatra805]

dont remember exactly but you can measure the sparkplug (resistance or inductance??), or the current drawn by the spark and connect it to an indicator. Some sportscars are doing this to adjust their mixture. (thought it was ferrari but it can be audi on the R8 also)

heck you could even route the spark to your wrap handle. bet that would get your attention fast enough