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Not Happy - can't calibrate my speedo
nib1980 - 15/8/07 at 03:47 PM

Hi all,

I've finally overcaom all the problems only one left to sort, the SVA documents went in the post this morning. THEN

I sent an email a few days ago to find out how to calibrate the speedo I bought. It's a unique colour and caterham logoed, came with a full set of gagues so they all match. got the response today.

Sorry sir thats a caterham unique gauge only has two calibration settings.

now I can't use it (I think) and any replacement won't match, so I'm not happy, now need to find a solution and I've spent up now.

Any suggestions?




mookaloid - 15/8/07 at 03:53 PM

Is it electronic?

Perhaps one of those speedo healer jobbies would be the answer?

I've no idea what one is but the BEC engine boys use 'em to fix their speedos as far as I understand it.

Cheers

mark


flange nut - 15/8/07 at 03:56 PM

Got any details of what it can be set for, such as pulses per mile? You might be lucky.

Geoff


Guinness - 15/8/07 at 03:58 PM

I guess it is one of the bright yellow Caterham ones from the sounds of it.

So I'd guess it is electronic, rather than cable driven? If it is, you'll need an electronic speedo sender unit for the gearbox (guess you are using a type 9). That should give you a pulse for every time something happens (output shaft rotates?). Feed that pulse into a speedohealer, and from there into the back of the speedo. (Speedohealer were pretty helpful to Jambojeef and even made him one with custom made range adjustment.)

Once the speedo healer is in, you can change the speed of the pulses in to match what your dial expects to see. Unfortunately it sounds like you'll have to do this on a rolling road.

Failing that, get another adjustable speedo and take the guts out of that and put it inside the Caterham face / bezel?

HTH

Mike


mark chandler - 15/8/07 at 04:11 PM

You do not need a rolling road to calibrate, just find someone with a GPS system and sit them in the passenger seat !


BenB - 15/8/07 at 04:29 PM

Speedohealer should do it.....

For getting the speedo reading right I just waited until rush-hour and drove down roads with speed cameras. Most people slow down to 2mph below the limit!

Compare, adjust, repeat....


nib1980 - 15/8/07 at 05:14 PM

hmm interesting, two ideas I like, take guts out of new one, and speedo healer I'll look into it

how much are they normally?

many thanks

[Edited on 15/8/07 by nib1980]


nib1980 - 15/8/07 at 06:27 PM

quote:
Originally posted by flange nut
Got any details of what it can be set for, such as pulses per mile? You might be lucky.

Geoff


yeah it can only bet set to 8380 and 8790 pulses per mile, I'm using a hall effect sensor on a cable drive from my 4 speed ford box.


jambojeef - 15/8/07 at 06:33 PM

As Mike mentioned, speedohealer are the dawgs, its not exactly cheap but they reply to all emails within 24 hours and are very helpful.

www.speedohealer.com

I got the extended range one since I needed 315Hz for 30 mph and only have 2 pickups on my prop!

Geoff


nib1980 - 15/8/07 at 06:37 PM

quote:
Originally posted by jambojeef
As Mike mentioned, speedohealer are the dawgs, its not exactly cheap but they reply to all emails within 24 hours and are very helpful.

www.speedohealer.com

I got the extended range one since I needed 315Hz for 30 mph and only have 2 pickups on my prop!

Geoff


so if can work out what pulses I am getting from the hall effect sensor, and I know what pulses the speedo wants to see, and send them an email do you hink they can help?


jambojeef - 15/8/07 at 06:59 PM

Yeah you could do.

I borrowed a signal generator from work and just picked a speed and read off the dial how many Hz it was - any speed will do since its al linear and all.

Then I made a little spreadsheet and bashed it all in - here it is if its any help?

Geoff


nib1980 - 15/8/07 at 07:22 PM

excellant I'll try and contact them 2moro.

Many thanks