Author Topic: Mpx M-Link Servo Move When Rx Is Swicthed On  (Read 2633 times)

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Capitaine LaGaffe

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Mpx M-Link Servo Move When Rx Is Swicthed On
« on: July 30, 2012, 01:15:23 »
Greetings, or rather, Mayday Mayday!

Stupid problem (at least, I feel rather stupid). Radio: Multiplex RoyalPro M-Link, 9ch M-link Rx (fast response on).  I'm trying to set up a new tug with Graupner Voith-Schneider units. With these, the servo travel must not exceed 4mm either way. No problem, easy to limit the travel using the servo calibration in the Tx. But, and this is a big and annoying but, when I switch on the Rx (after switching on the Tx), all servos (all non-digital) travels clockwise to the end point (full 45 degrees) before returning to their proper position, and max travel is at least twice what the VSPs allow (and the limits set up in the Tx). Can't find anything in the manual about this merry servo dance on Rx switch on, nothing about what magic settings may prevent this annoying behaviour and of course, I can't seem to formulate a Google query with a relevant hit among the first few hundred.

Is there anyone who has any idea how to get around this? (That is, how to prevent the servos from making a mighty jerk when the Rx is switched on?) It is rather a show stopper (the only thing broken so far is one servo immediately removing itself by trying to push its arm through the hull: it's a rather tight squeeze). Replacing all the servos with digital ones might work, but inexpensive it would not be.

TIA
« Last Edit: July 30, 2012, 01:17:31 by Capitaine LaGaffe »

mike_victoriabc

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Re: Mpx M-Link Servo Move When Rx Is Swicthed On
« Reply #1 on: July 30, 2012, 05:09:58 »
Is the radio turned on first - then the receiver? I've seen the servo do that if process reversed. I have a F-14 running my voith drives and it appears to work fine without excessive travel.

bourricot

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Re: Mpx M-Link Servo Move When Rx Is Swicthed On
« Reply #2 on: July 30, 2012, 08:16:16 »
Hello

Strange problem, on my Voith I'm using a programmable radio, I'm limitating the travel to 66% from the TX on all servos (non digital) and there is no problem when switching on the RX or TX first ...

Maybe you have to change your name, Lagaffe is not good at all to be serene

Bourricot

Capitaine LaGaffe

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Re: Mpx M-Link Servo Move When Rx Is Swicthed On
« Reply #3 on: July 30, 2012, 09:46:31 »
Is the radio turned on first - then the receiver?
First Tx, then the Rx: by the book. Actually, no problem (or at least less of one) if the procedure is reversed. [Added] Correction, the next time I tried that the servos turned 45 degrees each time I switched the Rx on with the Tx off, that is, after on-off-on the servos had turned 90 degrees clockwise. Ooops!

Switching fast response off didn't help either.

(No such misbehaviour with my old Graupner, nor with the Futaba 2.4GHz car radio (used in a boat – of course), only with the Mpx 2.4GHz and analogue servos.)
« Last Edit: July 30, 2012, 10:33:26 by Capitaine LaGaffe »

Capitaine LaGaffe

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Re: Mpx M-Link Servo Move When Rx Is Swicthed On
« Reply #4 on: July 30, 2012, 09:50:40 »
Maybe you have to change your name, Lagaffe is not good at all to be serene

"Borrowed" from Franquin's Gaston Lagaffe (and yes, his inventions, eh, not always work as intended )