Just a general out look of the build.

 

I'll see what I can do, it's a bit hard with the car not being very high off the ground.

 

I am still working on this, I have made a new speed sensor ring from plastic with five counterbores to accept magnets.
Still waiting on magnets from eBay, once they are pressed and glued in I can re assemble and re full the gearbox, then that's the car back on the road for a good shakedown

 

In the green

 

If I had not already bought a 6 speed, I would have defo tried to twist your arm to do this conversion for me

 

You'd probably break my arm

 

Is that ring and are the magnets going to be rotating? If so I'd be a little unsure of the strength of the glue to hold the magnet elements in place.

 

Yep, spinning round at driveshaft speed.
I'm pretty sure it will be fine, as I said the magnets will be pressed in with glue, not just glued

 

If you want I can spin it up in the lathe to see if they fly out? Just to put your mind at rest

 

With heat expansion of the plastic & glue bond I personally wouldn't trust it. If possible I'd see if you can drop the magnets in from the inside of the ring so that there is a solid plastic edge stopping them coming out. Also, you may not need them visable as they will obviously work through the plastic.

That will depend on the measuring range of the sensor and the mounting gap from the target.

 

I was going to put a sleeve over the whole lot once they were in, need to see if I can get them deep enough first though, not a lot of space!

 

Cool!

 

Sleeve it with this alu ring loctited over it?

 

You may find an aluminium ring will reduce the magnet strength somewhat. Aluminium can be used as a magnet shield.

Certainly worth a go though!

 

cool banana's.

wonder whatt he final cost would work out compared to a 6 speed switch?

 

Gearbag £250
Clutch was in stock
Made the flywheel at work
Rear diff £110
Prop £90
Gear shift remote £25
Cv joint, welding supplies, brake fluid, paint gear oil and other bobbins £100?
So £575 plus lots of time.
If I sell my mintastic five speed with rear diff and near new uprated clutch for £400 then it's only cost £175 plus my time.

 

Rare earth moly what's it's I've bought, hellish strong magnets. Alu is .5mm thick. I'll test the attraction with a bit of mig wire. The reed switch doesn't need much

 

I would estimate that the magnet may lose up to 3/4 of it's strength & range if an aluminium cover is put between it and the target.

We have some rare earth magnets here at work and aluminium sheet and I have just tried this.

 

Cool, the audi ring was not very magnetic at all, so hopefully my combination of rare earth magnet and thin aluminium will be just about right. We will see as soon as Royal Mail eventually turn up, hopefully tomorow.
Away to go and mess with magnets myself now!

 

Good stuff. I love a good bodge/modification!

 

sounds like if you have the capability to do it yourself then cheap upgrade option, i'd guess if paying someone then not, but fair play for doing it chap

 

What would you roughly say the hours worth is? If you did it again I mean

 

Engineering solution!

 

Difficult to say as I do an hour or two here and there. Probably 60-80 hours at a guess including making the flywheel and all the other custom machined parts.

 

I would used a cable tie to hold the magnets in
Joking aside, what an awesome build and some great, out the box, engineering
Will continue to watch with interest

 

Lol if only it was that simple, there's about a half mm gap between that ring and the magnetic pick up

 

Regarding the strength of the magnets...

You say the Audi magnets are not that strong and you've bought strong magnets. Might seem like a good idea, but what about the fact you're effectively enlarging the magnetic field between the magnets? I know how strong those magnets are, just thinking it might pick up wrong in regards to your calculations regarding speed?

Love the project though.

 

It might do, just have to try it, we could discuss it all day until we are blue in the face, but no one will know until we actually try it!
But yes I suppose magnets that are too strong will just keep the reed switch closed all the time. I guess we will find out this week

 

That's right, nothing ventured nothing gained especially with a build that's outside the box, sometimes its trial and error just to find what works right for you.

 

Installed the ring, re assembled front diff casing, filled with oil.
Speedo works, but reads double. I think it will be ok once the cars in the ground as I'm sure the rear wheels aren't turning, hence the double speed through the differential. There's no driveshafts in the front just now, so driveshafts in, wheels in and she's good to go.
Working on the pitch stop just now too, making one from scratch to suit the audi box, this won't stop me running the car in te meantime though.
The fact the speedo works and reads high must suggest it's seeing every magnetic pulse, I was concerned it wouldn't pulse at all so must be working. Find out over the weekend I suppose