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Magnetic speedo on live axle
the moa 2 - 20/2/05 at 11:23 PM

Hi guys

Ive already posted this in the luego area but i thought maybe other locost live axle builders may be able to help.

I have a luego locost chassis and have a electric magnetic speedo and need to know where to fit it due to the fact that the prop and rear diff are always moving.

Any help much appreciated


clbarclay - 20/2/05 at 11:33 PM

If like the bicycle type, it would probably fit best to a wheel.

If the sensor is the type with 2 coils (on producing a magnetic feild the othewr measuring the feild as it is destorted) then the best place for these is through the axle casing and reading the pulse from the teath on the ring gear.
This not easy though if the axle casing was never designed to take the sensor.

The second type is the same as comonly used for measuring rpm of the flywheel.


mookaloid - 20/2/05 at 11:45 PM

Is that a type 9 box you are using?

If so I have seen them with sensors that go into the speedo drive - may be one of these is the answer?

HTH

Mark


albertz - 21/2/05 at 07:48 AM

I recently bought a speedo and magnetic sensor from lowtension and the guy there told me that the sensor will work with anything up to 20-25mm clearance.

Therefore, i plan to mount it on the prop where it enters the gearbox, hopefully the movement there will be within these tolerances.

I too, would appreciate the advice of others on where to place the magnets. Also, how crucial is the spacing between the magnets (4 magnets in my case)?

Sorry for trying to take over the thread


Jon Ison - 21/2/05 at 02:22 PM

not very clear, its an old pic, but this is how i mounted my speed pick up, you cant see the magnets, there was only two, but they where stuck to the prop flange in a puddle of araldite, scuse speeling,

http://www.locostbuilders.co.uk/photos.php?action=showphoto&photo=prop.jpg


the moa 2 - 21/2/05 at 09:52 PM

Tried to work out photo i was upside down and everything but still cant quite see where the speedo sensor was.

Just to clarify what type of speedo i have its a tiny thing about 3cm by 1cm which is threaded in order that i can mount it to something i then have 2 tiny tiny magnets about 3mm diameter which i need to mount 180 degrees apart on something that rotates with the drive of the vehicle and is about 1-1.5 cm distance from the sensor.

I too was thinking of putting it at the front near where the prop splines into the type 9 gearbox but am still worrying about the movement or my second idea which my dad thought was to glue the sensor onto the escort axle just behind the flange and put the two magnets on the flange.

Any other help would still be useful and more pics would be especially good.

Why cant you search for stuff in the photo archive that would be so usefull . dont ya think ?


Peteff - 22/2/05 at 12:51 AM

Weld a bracket to the axle or bolt one to the trailing arm bolt and mount the magnets on the brake drum flange.


stevebubs - 22/2/05 at 01:02 AM

quote:
Originally posted by albertz
I recently bought a speedo and magnetic sensor from lowtension and the guy there told me that the sensor will work with anything up to 20-25mm clearance.

Therefore, i plan to mount it on the prop where it enters the gearbox, hopefully the movement there will be within these tolerances.

I too, would appreciate the advice of others on where to place the magnets. Also, how crucial is the spacing between the magnets (4 magnets in my case)?

Sorry for trying to take over the thread


That's what I did with my ETB sender and it works fine. I know several other cars with a similar setup.

Spacing isn't too crucial (it doesn't need to be exactly 90 degrees) but does need to be approximately correct.

[Edited on 22/2/05 by stevebubs]


the moa 2 - 22/2/05 at 11:50 PM

Heres what i plan to do now and im quite happy with it please tell me what ya think .
I was gonna just glue it to the prop and then glue the 2 magnets on the flange .

If you cant work out the photo its a picture of the prop at the back of the car connected to the escort live axle.

Mine is also the etb sender.

speedo on axle
speedo on axle


speedo on axle 2
speedo on axle 2


indykid - 23/2/05 at 09:49 AM

looks about right.

the sensor looks a bit far from the magnets in the 2nd pic, but esy way to check is to stick a multimeter with continuity tester on the tails and see how far away it can be and still beep.

i worried about getting the smiths reed switch 3-6 mm from the magnets as stated in the lit, but it switched up to about 15mm away.

hth
tom


the moa 2 - 24/2/05 at 09:26 PM

Glad to hear someone else approves.

What are peoples views the best glue to use surely arledite isnt enough ?


Humbug - 24/2/05 at 10:09 PM

You could make a small u-section bracket/holder for the sensor (coloured black in my picture) and both glue it and hold it on with a large jubilee clip (shown white) - I found some in B&Q with about a 4" diameter which I used to hold the brake pipes onto the axle with. If you positioned the sensor on the side of the axle instead of the top there looks to be more of an overlap with the prop flange - that would make it easier to line up with the magnets. Rescued attachment speedo-on-axle-2.jpg
Rescued attachment speedo-on-axle-2.jpg


the moa 2 - 25/2/05 at 12:02 AM

Isnt that a bit OTT or have people had experiences of things flying of when just glued on?


Humbug - 25/2/05 at 06:57 AM

Maybe a little OTT, but you seemed worried about the araldite and the jubilee clips were only £1.79 for 2, if I remember rightly.


indykid - 25/2/05 at 10:07 AM

i'd be worried about the jubilee clips riding towards the diff flange with vibration.

if you're worried about it dropping off, which i can't see happening, wrap some insulating tape round and superglue the loose end down.
tom


Peteff - 25/2/05 at 10:35 AM

JB Weld the magnets onto the diff flange. You could drill a recess and put them flush with the surface if they're not too big. I'd weld a bracket on the housing for the sensor and with a nut either side you could adjust it for distance.


jmbillings - 25/2/05 at 03:39 PM

Fitted our magnets to prop with araldite, sensor just above.
Sensor died due to up and down movement. Bought cheapy bike-computer sensor from Halfords, mounted to side of prop. Fine ever since