Electronic speedo sensor

[ill_will]

There are a few posts on here about conversion to GPS-based and hall-effect based speedometer setups (using propshaft bolts as 'teeth'.)

However I didn't manage to find any information about fitting an encoder directly to the Speedo cable take-off (where the angle drive normally attaches.) This could be quite a clean way to do it, if a suitable sensor exists. Perhaps something like this?

I don't have my car to hand but remember there isn't much space. Has anyone done something similar?

At the speedo end, I'm hoping to keep it looking original but saw there are people who can replace the Smiths innards with an electronic conversion. Does anyone know roughly how much this typically costs? (In UK.)

Thanks for any pointers.

[geni]

Je dispose d'un compte tours Smiths avec l'électronique interne(gradué a 8000tr:mn) ait conçu pour l' Elan
Il n'ai pas encore utilisé ,donc neuf de neuf dans sa boite .
Si cela vous intéresse ,faite moi le savoir .
geni

[HCA]

Smiths make their classic speedo in electronic configuration - you should find one for a tad under GBP300. Try Holden. There are others but will not have the 60s Smiths face.

[RichardHawkins]

Will,

Last time I looked, the smiths speedo has a digital electronic green odometer display. If I remember correctly one of our contributors in California has used a separate drive for his speedometer this consists of a small electric motor that is controlled by a GPS signal. This system allows you to fit the GPS receiver and the drive motor elsewhere in the car, with a speedo cable from the motor to the original speedometer. Hopefully the man from California will be able to give more complete advice.

Richard Hawkins

[phil1800]

The Smith electronic unit is similar to the original, but not more. For me it was a bargain and reasonable compared to the cost of removing the Lotus 5 speed box and fixing the stripped speedo gears.
It works very well and if you are not put off by the looks, I can recommend it.
Philipp

[ill_will]

Thanks for the feedback. I have the early style gauges like on the left in you picture, Philipp.

It looks like converting the 'innards' of an existing speedo and retaining the dial and rotors isn't an option, which is a bit of a shame. I will look into the GPS option though.

Geni - thanks for the offer. I'll contact you separately.

[gjz30075]

Richard Hawkins referes to a unit that drives the original, non modified, speedometer. I have one, along
with 1owner69..., the fellow from California.
https://speedhut.com/categories/speedbox.html

A simpler, cleaner method, I think.

[Foxie]

The electronic unit driven by a magnetic pick-up acting on a driveshaft lug is so simple. No inaccessible angle drives or cables, and so simple to accurately calibrate.