Sanwa servos

[John Wagg]

I have 3 Sanwa servo's from a glider I have been given.

They are SM-431 model servos but they don't work with my FRSKY receiver. All my old Futaba etc servos work so are Sanwa different ?

If they should work then have I got the polarity wrong. ?

The plugs have numbers 1,2,3, and #3 wire has a white line down it.

I presume that +ve is the middle wire (#2) and #3 is negative has that matches up with the switch configuration in the model.

QED #1 is the signal ??

Any input appreciated, Thanks.

[Phil Green]

How old are they? Early Sanwa wiring didnt follow the standard neg, pos, signal - and they used all black wire so you couldnt tell by looking 

IIRC they go pos, neg signal so you may have blown them with reverse polarity.

They can be used, in fact they're great servos, but IIRC you have to switch pos & neg around.  I have some here somewhere I'll check.

Edit: Yep, pos, neg, signal. On mine the pos is red, neg & signal are both black.  Lift the little tab, gently pull out the pos & neg, swap them over and push them back.

 

Edited By Phil Green on 20/04/2020 22:16:11

[John Wagg]

Thank you for the reply. I'll double check and swap the wires about. May have damaged one of them that I connected.

Definitely no red wire but one is light blue or faded white. No idea of age.

Will come back with findings.

Cheers.

[Jonathan W]

I think the old Sanwa black plugs with the ribs and pinouts marked 1, 2, 3 were:

1 Signal / 2 Negative / 3 Positive

i.e. the neg & pos reversed compared to Futaba et al. Later Sanwa had blue plugs with "normal" connections.

[John Wagg]

Phil, - I have swapped the wires over as you suggested and success. One servo does't work as I probably damaged that when I first connected it. The other two work fine now.

Jonathon, -You are right and I swapped #2 & #3 wires over to match my receivers. I just assumed that the +ve would be in the middle as per all the other systems I have used. The Sanwa plugs are the "ribbed" ones and I may change these over to Futaba style.

There is also a switch that will need altering but I will fit Futaba style plugs to that.

Thanks very much for your help.

Regards. John

[John Wagg]

I have also got a 35.FM Sanwa receiver which I presume was with the servos?

My son gave me the glider but didn't realise the receiver was part of the package as it all came in a separate box. He had bought a load of stuff second hand of Facebook.

Looks similar to the one in Phil's photo above

So no good to me and free to a good home. PM me if interested.

[Paul Marsh]

You have, if you plugged it in ,you probably fried it. I have a few models the Sanwa 102 servos, and converted to 2.4. Swapped and trimmed the plugs down and as expected work ok. You could buy Sanwa converter leads at one point, Did buy one years ago for a 102 servo which went in a 63 inch Gangster.

Lead

Edited By Paul Marsh on 21/04/2020 11:01:36

[John Wagg]

Yes, Probably fried as you say. Not had the receiver connected so that should still be O.K.

I will snip of the Sanwa plugs on the two good servos and graft on Futaba style ones that I have.

Something to do.

 

.

Edited By John Wagg on 21/04/2020 11:34:12

[Paul Marsh]

The picture above, shows a good example on the polarity for future questions, as these a coloured and obvious.