Legality of a home built speedo/odo

[k14]

Yeah get a hall effect sensor and magnet. I use one a bike speedo on my race bike and its sweet as. Just lockwired the magnet to the disc and it seems to be pretty accurate.

Sounds like a pretty cool project mate. Does it run on 12v from the battery? Or does it have its own battery?

[Pixie]

Yeah get a hall effect sensor and magnet. I use one a bike speedo on my race bike and its sweet as. Just lockwired the magnet to the disc and it seems to be pretty accurate.

Sounds like a pretty cool project mate. Does it run on 12v from the battery? Or does it have its own battery?

They are actually reed switches which are magneto-mechanical,you can hear them click as the magnet asses them if you have good ears

[FlyingDutchMan]

IMHO reed switches are crap. They have moving parts (the root of all evil in the electrical world). Plus you only have one pulse per revolution, and currently I have 15 - much better resolution.

[Aiolos]

If people would like I can post up the circuitry and assembler code I designed & make it freely available.

Please do.
The RGs speedo is out by nearly 15 Km/h (Factory error compounded by smaller tyre on the front) So this could be just the thing.
How does the tacho work?

[Pixie]

IMHO reed switches are crap. They have moving parts (the root of all evil in the electrical world). Plus you only have one pulse per revolution, and currently I have 15 - much better resolution.

Well my reed switches have been operating for 5 years,1 cycle every wheel rotation for 70,000 km with no problems.
Reed switch life is measured in hundreds of thousands if not millions of cycles.
Your opinion has little to do with the real world of electrical technology and your home made tech will fail from environmental degradation before a good cycle computer will.
As for resolution-who needs better than 0.9 kmh?
Don't try teaching granny to suck eggs

[skelstar]

Well my reed switches have been operating for 5 years,1 cycle every wheel rotation for 70,000 km with no problems.
Reed switch life is measured in hundreds of thousands if not millions of cycles.
Your opinion has little to do with the real world of electrical technology and your home made tech will fail from environmental degradation before a good cycle computer will.
As for resolution-who needs better than 0.9 kmh?
Don't try teaching granny to suck eggs

No offence but in the electrical/electronics world mechanical switches ARE the root of all evil. I constantly have to fix reasonably complicated scientific instruments only to find that switches have become tarnished and have failed. Im not saying that you are wrong, your reed switch has been working for ages, but at least give the guy some credit .

[pyrocam]

for the lazier or less electronically minding. you can take a pushbike catseye device and fir it on easy enuf. $25 for one without a backlight

[Pixie]

No offence but in the electrical/electronics world mechanical switches ARE the root of all evil. I constantly have to fix reasonably complicated scientific instruments only to find that switches have become tarnished and have failed. Im not saying that you are wrong, your reed switch has been working for ages, but at least give the guy some credit .

Snap!
I've been an electronics tech For 25 years and have been in the lab analyser/scientific instrument feild for 19.
You should know that a reed switch is glass encapsulated and thus does not suffer the problems of conventional switches nearly as badly.
They are still the prefered position switch for pneumatic actuators in the equipment I service,I have had plenty of hall effect position switches fail,but never a reed switch.
What is more important than the type of switch used as a wheel pick-up on a bike is how well the environment is kept out of the package ,ie how well the wires are sealed.
nyah nyah

[skelstar]

Snap!...nyah nyah

Fair enough . Well snapped.

[mdb]

Does anyone know how accurate a speedo has to be?

[Karma]

plus or minus 100kph

[skelstar]

Does anyone know how accurate a speedo has to be?

Hey mate. I think it has to be between 5%-10% high. ie you think youre doing 100km/h but youre really doing around 96km/h.

[froggyfrenchman]

What they dont know cant hurt them, eh

[Mental Trousers]

My next project will be far superiour: rip out the bikes entire wiring and replace it with a CAN bus, electronic fuel injection and new electronic ignition. At the same time I'll be replacing the speedo/odo/tacho/temp/etc bits and pieces. LED lights (except head lights) and it'll look fair bling, lose some weight, and hopefully make a few more HP along the way.

That sounds like fun. After reading a thread in the General Bike Stuff forum about GPS speedo's, I'd say you should integrate one of those into the whole thing.

[F5 Dave]

Not sure if the regs are the still the same, but a friend of mine used to do WOF stuff & he was going to fail some vehicle for not having a speedo & the guy argued that it had a tacho & he knew how fast he was going from that. So he called ‘the man’ & was told the vehicle required an instrument for determining the speed of the vehicle’. Pass.

I’d love to put a digital speedo on my YZF, but too much like hard work & I have far more pressing projects.