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Tach, DONE DIRT CHEAP!
Posted: Mon Aug 11, 2008 12:08 am
by Kenny_McCormic
Re: Tach, DONE DIRT CHEAP!
Posted: Mon Aug 11, 2008 2:21 am
by ALOW1
I been hanging around that site for quite some time now, its a great site. Thanks for the link.
Posted: Mon Aug 11, 2008 8:10 am
by burnt_toast
two time! thx now just gotta figure out a way to hook it up to the elite outer pulley
Posted: Mon Aug 11, 2008 2:31 pm
by Kenny_McCormic
burnt_toast wrote:two time! thx now just gotta figure out a way to hook it up to the elite outer pulley
Just use the magnet already in the flywheel.
Posted: Mon Aug 11, 2008 3:38 pm
by burnt_toast
Kenny_McCormic wrote:burnt_toast wrote:two time! thx now just gotta figure out a way to hook it up to the elite outer pulley
Just use the magnet already in the flywheel.
I think there would be interference from the magneto on the actual flywheel side of the engine, plus unsure of clearances without seeing the actual pickup.
I'll get some pics and details up if I do this, specifically on a scoot. Seems like a neat idea
Posted: Mon Aug 11, 2008 4:15 pm
by Kenny_McCormic
I might do this to my go cart as im curious if the motor has any high performance parts in it.
Re: Tach, DONE DIRT CHEAP!
Posted: Sat May 26, 2012 9:17 pm
by mousewheels
Bumping up an old thread.
Searching the 'net, there are lots of references for using a bicycle computer as a tachometer.
From wind power experimenters to scooters.
I have tried to follow this thread in implementation. Picked up an later model Cateye Astrale8 bicycle computer (Ref 1st post - 'instructable' link used a CatEye model). On paper it can register up to 185.0 mph, which according to the tach calibration scheme would cover 18.5k RPM. However, best I can get with the wheel circumference set to the value needed to make 'mph' register as 'RPM/10' is around 6k RPM - 100hz input. A conclusion reached is there is an upper limit to the rate of pulses fed to the computer.
The general idea is attractive if a bicycle computer is already owned. Two attractive features:
- A clock is present in most computers
- Max MPH --> modified, the computer will catch 'max RPM'.
However, there are pickup issues - how to mount the magnet and pickup + finding a computer good for the target RPM range. Three cycle computers I checked used mechanical magnet/reed relays for sensing rotation. This can become a reliability issue when scaled from bicycle wheel rotation (couple revs/sec) to a scooter engine
If you have pulled off this mod and have a 10k/12k etc tach - please post info and cycle computer model.
Otherwise, IMHO - a Trail Tech or Tiny tach around $30 is a much more solid solution.