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Bonding Magnet into rubber
Miks15 - 26/8/10 at 10:55 AM

Ive got the little magent that come supplied with the acewell speedos. The best place i can see to mount it, where i would also have a place to mount the sensor, is on the rubber coupling i have between my prop and my gearbox,
If i drill i hole smaller than i need so its a tight fit and then bond the magnet in, will this work?


designer - 26/8/10 at 10:59 AM

Will this cause a stress raiser in the rubber coupling and make it fail?


Miks15 - 26/8/10 at 11:06 AM

hhmmm mabye,

its on of these


Daddylonglegs - 26/8/10 at 11:12 AM

Will the flex in the rubber not cause fluctuations in the readings?

Just a thought


Miks15 - 26/8/10 at 11:19 AM

yeh that was something else i thought of, o just cant really see anywhere else suitable to house both magnet and sensor.


Dingz - 26/8/10 at 01:02 PM

I wouldn't touch the rubber bit, they fail quite spectacularly? Can you fit it on one of the bolt heads?


Bluemoon - 26/8/10 at 01:15 PM

The rubber will distort under acceleration/de-acceleration (this is what they are meant to do!) at a guess this will mean the glue will fail/crack as the magnet can not distort..

Also you don't want to put holes in in etc as you as asking for trouble as above.

If you mean on a bolt head then that might be o.k (but I would want to have additional magnets to make the weight equal so as not to put the prop out of balance, i.e. for a 3 legged rubber donut coupling you will need 3 magnets...).

Dan


[Edited on 26/8/10 by Bluemoon]


Miks15 - 26/8/10 at 02:09 PM

yeh i will try and find another place then.

The magnet i have has a threaded part on it aswell so it can be screwed into a boss of somekind, so might look into doing that, mabye and the diff end


britishtrident - 26/8/10 at 03:55 PM

Bonding steel to rubber under tensile stress just won't work, the strain gradient at the interface between the two materials will cause the bond to peel.


Bluemoon - 26/8/10 at 04:40 PM

quote:
Originally posted by Miks15
yeh i will try and find another place then.

The magnet i have has a threaded part on it aswell so it can be screwed into a boss of somekind, so might look into doing that, mabye and the diff end


Diff end is common placment..


vyperstrype - 26/8/10 at 07:00 PM

Hi, If you are running Drive shafts, all i did was drill into the yolk of the Drive shaft nearest the Differential, run a M8 tap down it and screw in using Loctite threadlock, or similar. Then mount an aluminium bracket that bolts to the Diff housing above the magnetic pick up over the Drive shaft. Make sure that you mount the sensor longways over the pick up, or you will get a false reading. This happened to me but i didn't realise until SVA test. The seed worked fine until i reached 42mph and then went staight to 70 mph in one jump. I changed the sensor round to a longways position and it was fine. I hope this was helpful.
Regards Eric.