Hall Effect Sensors - Work with Steel Sheet for wheels?

[Dave Evans]

Hi there,

We're currently modifying our 2007 car to add wheel speed sensors, and would like to check / clarify something about the right set up.

Basically, we're looking at a steel toothed disc ~1.25mm thick and running a threaded hall effect sensor on it. However I'm not sure if this will work, or how well the sensor would pick it up.

I've seen a few teams running this kind of set up, but would just like to double check before anything is made/ordered. I know the other way is to have a 3 or 4 mm thick disc pointing the sensor towards the centre of disc, but our uprights don't have the room in them to get something fitted easily.

Thanks in advance.

[Dave Evans]

Hi there,

We're currently modifying our 2007 car to add wheel speed sensors, and would like to check / clarify something about the right set up.

Basically, we're looking at a steel toothed disc ~1.25mm thick and running a threaded hall effect sensor on it. However I'm not sure if this will work, or how well the sensor would pick it up.

I've seen a few teams running this kind of set up, but would just like to double check before anything is made/ordered. I know the other way is to have a 3 or 4 mm thick disc pointing the sensor towards the centre of disc, but our uprights don't have the room in them to get something fitted easily.

Thanks in advance.

[Christopher Catto]

from what i remember it will work with 2mm thick sheet. if you can, go at least 1.6mm unless there is some reason why not. if you are getting sheet laser cut then by all means try even thinner material but you need to test it for consistency with that particular sensor. if you are trying to save weight I would think more about the teeth not getting bent/damaged by stones or turf.

as always, in theory your thickness might work but it's a good backup plan to have a slightly thicker plate laser cut as well (your supplier should not be charging you more than £3-5 pounds for these things). if things are cheap, that's the way I do it to avoid costs later.

[screwdriver]

Here's a tip:
Try mounting a strip of the metal you want to use and you speed sensor to an angle grinder and look at the signal you get when the metal moves past the sensor with a scope.
If you can identify it as a rectangular signal, it should work. To make sure, look at your controller's specification and verify that the signal can be recognized by it.