Hi Guys,

Had a search but can't find the answer..

I have an acewell 7659 with a digital speedo.
The magnet is mounted on the prop with the sensor next to it (seems to be within the measurement tolerances.

However,

I don't fully understand the calibration settings.

There is:

SPD cXXXX = where c is the circumference i believe.
SPD P-001 = signal divider for the engine?

So i've currently got the first setting as around SPD 0200 and SPD P-001 which seems acurate(ish) up to about 20 and above this speed, the speedo stops reading anything at all and just sits on 0 MPH.

I have tried the speed setting at 500, 800, 1500 etc and this will cause the speedo to massively over-read.

Any ideas?

Regards,
Andy

Have a look at this http://www.locostbuilders.co.uk/forum/5/viewthread.php?tid=181887

There is a reply from russbost which explains the correct way to set up. Although I do have a different dash. Best u2u Russbost as he is the man for Acewell knowledge!!!

Hope that helps

Andy

[Edited on 30/7/13 by AndyW]

The "P" screen should be set to 001, you only need to change this if you're using an OE gearbox sensor. The "c" screen is indeed the circumference, typical circumference on a locost would be around 1500, but you'll need to divide this by your diff ratio as you're using prop mounted magnet, so probably around 400 - 450.

If it's reading ok at low speeds then going wrong at around 20 mph you have the sensor mounted wrongly - it's essential that the magnet does not go down the centre line of the "barrel" of the sensor - that will give exactly the symptoms you describe, at each end of the plastic barrel there is a line cast in the plastic, the magnet should run along one of these lines or further to the end of the barrell, it must not pass between the lines.

thanks russ, i'll have another look at how i've mounted, i'm pretty sure it must be that....

A quick question regarding your original post, i do seem to remember a resistor included but have no idea where it is now....
Do you know what rating a resistor it is for the RPM smoothing?

Regards,
Andy

IIRC it's 1 meg ohm