Hello everyone,
I need to measure the thickness of a motorcycle tyre tread with extreme precision (microns?) after each 100km journey.
What can you suggest me?
Thanks a lot,
Vincenzo.
I think you need a more expensive sensor
Welcome to the forum
Digital calipers ?
Many have interfaces so that they can be read using an Arduino
Could you give me an example?
If you’re looking for non-contact, I’d think something like very good illumination and two hi-res cameras… followed by some sweet 3D image processing .
I’m not sure what resolution you’ll get, but it could be pretty good, calculating shadows, angles etc.
Keep in mind the tyre temperature is going to affect a lot of things.
Thanks HeliBob.
That attached would work, but I'm trying to find something which doesn't need any human intervention: that's for a statistical project, so...
Set you back a couple of grand though
If only you had said that in the first place ...
ouch. way too much 
I suspect you won’t get reliable micron precision for much less! Do you actually need micron precision?
I need to measure tyre wearing after several trips, 100-km each long. Motorcycle tyres, they usually last 5-10k km, so wearing is faster than cars'.
I guess tread wearing after 100km is in the range of microns, wouldn't you guess the same?
In papers scientists measure wear with weight, but that's not doable for me.
You have many requirements that you are drip feeding. It is generally more productive and less time wasting to post your requirements at the beginning
Budget
Accuracy
Purpose
Restrictions
Environment
Etc etc
How do you envisage positioning the sensor to measure the depth consistently ?
Beg your pardon, my first time here. Slightly edited the first message
I can 3D print a bracket to hold the sensor in place, pointing at the tread. The bracket would be attached to a fixed spot on the motorcycle. Somewhere close to the headlight, pointing down to the tyre. Like a gopro. No need for continuous measuring, only after each trip
But the tyre moves! The distance between the bracket and the tyre will not be micron accurate even after a walk round the garage. The sensor will point at different spots on the tyre which are not calibrated to the original reading unless you do thousands of readings as the tyre rotates and average them. What about suspension?
You are describing an inaccurate setup designed for rough values not a scientific setup designed for micron accuracy
For micron accuracy you need to place the same point of the tyre in exactly the same position relative to a fixed sensor which can only really be done with human interaction unless spending a lot of money. You can’t have bendy, springy bits in between.
I can measure the tread depth at the same point.
I can lift the bike, so the distance won't be affected by suspensions and rotate the tyre to the same point
I can accept the kind of human interaction you're describing: what I don't want is placing the sensor and measuring, as a caliper would require, for example
That's a sketch I drew yesterday about the setting; front view
I suspect you are unlikely to achieve micron accuracy. Basically you have lots of bits between the sensor and the tyre that have tolerances not at micron level and you have a sensor that has being vibrating for a long time.
Getting micron accuracy is going to be difficult with an optimal setup. I would place the best sensor you can find in the garage and have a wheel alignment mount fitted at a known distance. You might then need to calibrate your sensor to the mount which will have spring loaded contact with the tyre to ensure consistent contact pressure.
All the variables will need to be accounted for such as temperature. To get the accuracy you need. Why the scientists use weight etc is you can be very accurate and because you are dividing down from a whole tyres wear inaccuracies are divided. Your inaccuracies will be on a spot test and represented 100% in the results
Oh dear
Conflicting requirements
I see your point, thanks. The setup you described isn't doable for me.
Then, I should go either to the old school caliper in the 6th message (250$) or an high precision scale (~1400$)
Would you say an high precision, analog caliper would work? (same temperature, pressure, measuring spot on the tyre etc.)
I can accept the kind of human interaction you're describing: what I don't want is placing the sensor and measuring, as a caliper would require, for example
As you correctly guessed, I'm not an engineer. Good job.
