Question about wiring

[youngti]

Newbe question.  I just received my first prop 1 and have ordered two more and a prop2.  I am working on creating a 3 axis skull, planning to connect the servos using cat5.  I saw a video from Skygod on Youtube and it got me to thinking.  Is there any reason not to take the four servo's Power and ground and combine them each on cat5 line?  I mean I would take say the brown cat5 and use this for all of the four servo grounds.  Not sure how to connect them back to the Prop 1 or 2.  If the +5 are connected to say the red cat5 line and it goes back to the prop 1 or 2, would one P location power all of the servos?

I have to say that I am extremely impressed with the amount of assistance you have provided to the haunting community.  I am a Tech support professional and I have rarely meet somebody as willing to help as you.

You deserve great praise.

[JonnyMac]

I wouldn't use CAT-5 cable for servos.  Why?  CAT-5 is not designed to carry a lot of current and servos can suck up a bunch -- as a few of our customers will attest to.  The other side of the current issue is that the Prop-1 and Prop-2 can only provide about an amp from the five volt supply and yet servos can draw up to half an amp each.  One of our friends, Jeff, was finding that the servo load from his three-axis skull was causing the controller to reset itself (this is a design feature to prevent the EEPROM memory from becoming corrupted).

So...
1) Ditch the CAT-5 cable for #22 stranded
2) Keep the servo connections as short as possible
3) Use an external power supply for the servos (5 to 6 volts with enough current to provide 0.5 amps per servo)
    -- make sure that the external power supply and prop controller have common ground.

[youngti]

Thanks, that answers that.  Do you have any figures on how long you can make the servo connections?  I did read a post in here about problems and length of cabling, but I don't thing anything has been said about the mazimum length.  I'm still learing about a lot of this, with the servo's, you can power them directly?  How would that work, hook a 5v to the power line on the servo and then hook the ground to the Prop1 ground?

Pretty stupid questions I know, but only way I know how to learn.

[JonnyMac]

Personally, I would never go more than a foot or two; you're just asking for trouble otherwise.  If you are going to go longer, definitely use heavy wire to keep voltage losses at high currents as low as possible.  You might even want to go with a 6v supply; the servos will tolerate it and you'll have a little extra head room.

Connect the Px.W outputs to your servo signal line.  The power (usually red) of the servos will go to the positive side of the supply, the ground (usually black) wire of the servos will go to the ground side of the supply.  Connect the ground side of the supply to the GND terminal of the Prop-1/2/SX.

[youngti]

Thanks, thats perfect.