gearwheel encoding

[Todd Knighton]

khearn at scuacc.scu.edu wrote:
> 
> I seem to recall some discussion on gearwheel encoding some time
> ago, and I'm sorry for bringing it up again but...
> 
> I want to put a 60 tooth wheel (with 2 missing) on the crank shaft of
> a motorcycle engine that goes up to 12000 rpm.  My problem is this, I
> don't know what the min. diameter of the wheel should be.  At 3deg. per tooth
> edge, the tooth length gets quite small as the diameter goes down.
> 
> I am using a Siemens hall effect IC to pick up the pulses, which I estimate
> will be fast enough at static speeds.  However, at hard acceleration or
> deceleration, I assume that there will be more opportunity to miss teeth
> or add more, if the teeth are very small.
> 

	The older motronics used to use 129 teeth, or up to 132 tooth
flywheels, that we're approximately 3mm teeth with 3mm gaps, or for you
americans out there about .120-.125" (1/8")
	This would get you down to a 4.77" diameter flywheel, using the 60
tooth system.

-- 
Todd Knighton
Protomotive Engineering
knighton at net-quest.com