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View Full Version : Legality of a home built speedo/odo



FlyingDutchMan
8th November 2005, 12:51
Since my speedo crapped itself (multiple times) earlier this year, I decided build my own electronic one. It works near perfectly, but I'm wondering what mr WOF or COP would think of it. It is very accurate (maximum error of +-1km/h), and the odo counts up nicely too - displayed resolution of 600mm.

I've had a look on the LTSA website and the only applicable thing that I found is that a speedo (if modified) doesn't need to be certified, and must work while the vehicle is moving forward. It does both so is it alright?

Ixion
8th November 2005, 13:00
Well, that's how I read the VIR-M also. I'd be prepared for an argument with Mr WoFman though

WRT
8th November 2005, 13:20
Well done, you gonna post pics of your handywork?

Phenoix
8th November 2005, 14:12
How much did it end up costing you, and is it easily done ?

Thjo to answer your question, no idea

FlyingDutchMan
8th November 2005, 14:22
Well done, you gonna post pics of your handywork?

When I get a digital camera... it seems to be a wee way down my "yet to buy list". I'll give a fairly accurate discription though: 20X4 backlit LCD screen trimmed with black duct taped attached to the bike with black duct tape & #8 wire. Looks better than I thought it was going to.

FlyingDutchMan
8th November 2005, 14:25
How much did it end up costing you, and is it easily done ?

Thjo to answer your question, no idea

Cost was very little... about $5 for a PIC16F628A (programmable microcontroller), LCD screen (freebie, but would cost about $25 from SI components), various small/cheap components. It cost me about $20 once I'd got all the nessary bits. So dirt cheap really.

Its has a fundamental flaw at to moment: It uses an infra-red LED/dector that mounted across the front disk brake counting the holes as they wizz past. Brake generate lost of dirt, and so it stops working after a while (depending on riding its 450km or 50km). Easy to clean though. Tested it with a TV remote to see how "fast" it could measure - 1453 km/h :D

SPman
8th November 2005, 14:36
I think that - as long as it works and can be seen to be working, it should be OK.
If its inaccurate - well - your call explaining to mr Plod.....

Skytwr
8th November 2005, 14:49
From the legal standpoint as long as you can read the display both day and night and it is accurate. The only thing is does it have a memory to retain overal milage covered. this would only be for some one buying the bike later on to know how many ks it has done.

Otherwise all good.


gareth

Motu
8th November 2005, 14:51
Pushbike speedos are legal,so,so long as it looks the part it should be ok...odo is not compulsory.

Phenoix
8th November 2005, 14:56
If its inaccurate - well - your call explaining to mr Plod.....
And that would be the problem. The princable of the speedo works easily, tho what are you using to program the chip ?

skelstar
8th November 2005, 18:36
Had a bit of a brain wave:
1. Buy a 200mV LED digital voltmeter from Jaycar ($30).
2. Get a voltgae/frequency converter (VFC32?)...$30.
3. Opto setup you have already that feeds the pulses into your VFC...easy LED speedo. Might have a go myself.

Admittedly it doesnt do the odo, but kinda cool anyway.

WINJA
8th November 2005, 18:42
Had a bit of a brain wave:
1. Buy a 200mV LED digital voltmeter from Jaycar ($30).
2. Get a voltgae/frequency converter (VFC32?)...$30.
3. Opto setup you have already that feeds the pulses into your VFC...easy LED speedo. Might have a go myself.

Admittedly it doesnt do the odo, but kinda cool anyway.
DO YOU YOU KNOW HOW FAST YOU WERE GOING SON , UMM 100MV ?

skelstar
8th November 2005, 19:10
DO YOU YOU KNOW HOW FAST YOU WERE GOING SON , UMM 100MV ?
Dude, thats the problem with youre stuck CAPS-LOCK is that youre going to be riding in Mega-volts and not milli-volts.:niceone:
With my bike ill be riding in milli-volts for a while I think...

FlyingDutchMan
8th November 2005, 19:33
And that would be the problem. The princable of the speedo works easily, tho what are you using to program the chip ?

I borrowed a ICD2 (in circuit debugger 2) programmer from uni for a couple of months. I could buy one, but I couldn't justify the $160US price tag to myself. If people would like I can post up the circuitry and assembler code I designed & make it freely available. Its pretty easy to change for different wheel sizes etc. It also has a tacho read out with 50 RPM resolution and measures how long the engine has been running for and counts the number of revolutions the engine has done <-- the crowning jewel of uselss info.

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.

Pixie
9th November 2005, 11:39
Cost was very little... about $5 for a PIC16F628A (programmable microcontroller), LCD screen (freebie, but would cost about $25 from SI components), various small/cheap components. It cost me about $20 once I'd got all the nessary bits. So dirt cheap really.

Its has a fundamental flaw at to moment: It uses an infra-red LED/dector that mounted across the front disk brake counting the holes as they wizz past. Brake generate lost of dirt, and so it stops working after a while (depending on riding its 450km or 50km). Easy to clean though. Tested it with a TV remote to see how "fast" it could measure - 1453 km/h :D
Use a reed switch and a magnet,like the cycle computers do.
You can put the magnet in the middle of one of the disc's hollow rivets.
I still prefer a cycle computer to making one myself.Far more functions available.
Cycle computers from $30 to $100

k14
9th November 2005, 12:52
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
9th November 2005, 14:57
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
9th November 2005, 16:38
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
11th November 2005, 01:56
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
19th November 2005, 10:04
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:motu:

skelstar
19th November 2005, 12:02
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:motu:
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
19th November 2005, 13:11
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
20th November 2005, 09:47
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
20th November 2005, 11:43
Snap!...nyah nyah
Fair enough :). Well snapped.

mdb
20th December 2005, 20:46
Does anyone know how accurate a speedo has to be?

Karma
20th December 2005, 20:56
plus or minus 100kph

skelstar
20th December 2005, 21:18
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
30th December 2005, 17:58
What they dont know cant hurt them, eh

Mental Trousers
4th January 2006, 11:32
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
6th January 2006, 14:44
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.

FlyingDutchMan
7th January 2006, 18:39
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.

Thats what I had been using for quite a while until I got the digital one going. Seems by that rule that you can use a wind speed measurer to detrime your speed :laugh: .

F5 Dave
9th January 2006, 08:29
I have a wrist watch & I'm pretty sure that lamposts are a std distance apart. Let's see 10 in 18 seconds @ 40.3M, um, carry the 4, now did I include the 1st lampost into the ten, in which case it was only nine lengths.

Yeah officer I think I was doing 50. (or 212, or 7-1/2kph)

FlyingDutchMan
11th February 2006, 15:57
Well its legal enough for the WOF man to give the bike a WOF.

XP@
1st March 2006, 12:02
I used to have a cycle speedo on my XT, dick smith $20. on my 1st attempt I was told no cos it wasn't lit. so I went to the petrol station next door, purchaced a torch, got the ducktape out of my toolbox, taped the torch on to the bars (direction of the speedo)
And well, Bobs your aunty it passed. Oh and the guy doing the inspection nearly wet himself...

After that I did wire in the most pathetic light off the headlight which took it through a few more wof's.

The WOF form on their computer does require you enter the total distance travelled for the bike. This must be more than the last warrent. So maybe a bit of tape and a marker pen ....

My guess anything is possible ....

for info on selecting a computer...
http://faq.f650.com/FAQs/AftermarketInstrumentationFAQ.htm#Cycle%20Computer %20FAQ

kickingzebra
1st March 2006, 21:29
Just read bike trader about molestrangler discovering Ram air induction, by farting on the carby... Maybe you could make a gadget that would count the farts... Or put a piece of sticky tape there to actually catch a real live one!! Hah...
Sounds like some good indigenuity out there!! Go the duct tape way of life I say!!

El Dopa
20th March 2006, 19:43
odo is not compulsory.

So for certain it is not necessary to have an odo on a road-legal bike?

Krusti
20th March 2006, 19:45
Get a rope, tie knots at regular spacings, throw it out the back......

kevie
6th April 2006, 09:14
When I was restoring my bike my speedo was in a place being reebuilt, the one man band operator had a serious stroke, my bike was ready to put on road ... and no speedo :(
I had debates with my wof supplier who said no speedo no wof, I spoke in length to LTSA and they agreed the law states you must have "a device to indicate road speed" I told them that at 2500 RPM in top im doing 50km/h, at 3000 im doing 70, at 4000 im doing 100km/h ... whats the problem ???? they conferred that yes thats acceptable LOL ... so got the wof.

Speedo finally got reassembled and back in bike .... reads wrong tho :( so hased to come out again and this time sending it to Hastings to be calibrated.... its reading about 20km/h slow at 100km/h

I think the law is basically ... as usual ... open to interpretation lol