Board logo

How do you secure your speedo sensor magnets ???
Antnicuk - 20/6/11 at 08:53 PM

Since building the car i have been through 8 speedo sensor magnets. I have tried chemical metal to secure them to the prop shaft, and araldite but still they keep disappearing! I am considering welding them on next! any one got any suggestions? can i buy grub screw type ones that i can tap a hole in and screw it in?


Ben_Copeland - 20/6/11 at 08:56 PM

Araldite work for me. Make sure the surface is clean and de rusted. Blob of glue first, set magnet in. Another blob on top and levelled off. Never lost any, apart from when the sensor dropped and knocked a few off !!

Some people have drilled a hole and glued them into that.


gingerprince - 20/6/11 at 09:01 PM

I've lost a couple myself, epoxied on. Rang ETB to get some more and asked what they recommend. Suggested chemical metal, and a turn of gaffer over the top.


daniel mason - 20/6/11 at 09:06 PM

i am using a speed sensor which detects the bolt heads on the prop this time instead of a magnetic one! plus there is 6 per rotation and not just 1 so caliberation should be closer


bigfoot4616 - 20/6/11 at 09:08 PM

i use araldite and i don't think i lost any last year. so far this year i've lost one at rockingham and one at croft last week. the croft one barely managed 5 laps.
mine are slightly recessed into holes and i got some fresh araldite to see if thats any better. not sure if it has a shelf life but my old stuff has been in the garage for a lot of years.


myke pocock - 20/6/11 at 09:19 PM

Anyone ever tried VHB tape (very high bond) ? They use it in sign making etc.


watsonpj - 20/6/11 at 09:20 PM

I drilled holes the right size in the prop flange and araldited them in then tape over the top with a coating of araldite for good measure. They are not going anywhere


Antnicuk - 20/6/11 at 09:21 PM

i have just looked on the koso dealer website and they have m6 and m8 bolts so i have ordered a pair of them. I will try fitting them somehow. I tried putting the magnets in the yoke of the spline that goes into the gearbox and fitted the sensor to the end of the box, that way they should never move any closer together (problem with a live axle). I find i have to put the sensor so close to the magnet to pick up a signal that they get knocked off. I am hoping that the bolts, being bigger will have a stronger signal. Also the magnet seems to be in the centre of the bolt head so i maybe able to weld it on without effecting the magnetism. I also dont fancy drilling a hole in the yoke.


whitestu - 21/6/11 at 06:42 AM

I tried with epoxy and it came off.

The locost solution that worked was epoxy and a cable tie.

The cable tie and the magnet were glued on, with the head of the tie on the opposite side of the prop to the magnet under the assumption that it will help keep it in balance a bit.

Been on for several years now with no problems.


Stu


indykid - 21/6/11 at 08:13 AM

Mine are epoxied on, then a layer of speed tape/foil tape over the top. I initially had 4 with just epoxy and lost 2 in the first week.

The other 2 are still there 5 years later


DaveFJ - 21/6/11 at 11:04 AM

mine are epoxied on using araldite standard as it is generally better than the rapid in my experience.....

I was absolutely scrupulous about preperation and roughed up the surface with wire wool then cleaned very carefully with MEK solvent (acetone based nail varnish remover is pretty mush the same stuff). Used quite a lot of glue so it actually covered the magnet in a little coccoon - not just on the base.

now been on for 3000 + miles with no issues at all.....


lotusmadandy - 21/6/11 at 12:33 PM

Mine is fitted on the n/s rear drive flange.

I drilled and then tapped the hole to m6,then screwed the
supplied bolt with a magnet fitted in the head,into the hole.

Three years down the line and it's never been touched.

Andy


bigfoot4616 - 22/6/11 at 07:02 PM

quote:
Originally posted by Antnicuk
that way they should never move any closer together (problem with a live axle).


to stop that happening on my live axle the sensor is fitted to a bracket welded to the diff housing. the magnets are fixed to the diff flange