Ive been playing around with my maestro and ive noticed some kind of power failure and it happens with all my other servo controllers too.
When ever i connect power to a board i get about 3-4 frames or 5 minutes of it being plugged in with no movements then everything just dies. I check the battery and sometimes it is dead but other times its still full.
Im using a 5v 3A max UBEC as my power regulator and im wondering if i may need more amps.
Ok i was looking at the pololu stepdowns. Which one would be enough to power my 18 servos? Should i get a 6A or a 9A?
It is unlikely that either of those regulators could handle the combined load of 18 servos. We typically recommend a budget of 1A per servo for standard servos; high torque servos can be many times that. I suggest looking up the stall current for each of your servos and adding the stall currents together to get the combined current load for your system when all servos are running.
Please note that the Mini Maestro servo rails can be segregated into banks of six servo. Each bank of six servos can only handle about 6A, and each header pin can only handle about 3A. If your load exceeds those ratings, you should probably power your servos away for the Maestro board. You can read more about separating your servos into banks in this forum thread. You can see additional pictures showing the cuttable trace locations in the “Mini Maestro Pinout and Components” section of the “Pololu Maestro Servo Controller User’s Guide”. If you power your servos away from the Maestro board, you should be sure you have a common ground between your servos and Maestro.
Ok I followed the links to both the Topic and the thread. Im not seeing anything in the topic about cuttable trace but it shows you where they are. I looked up cuttable trace and only found a short blurry video of how to do it but you cant see whats actually being done.
In the pics for the Maestro it looks like the cuttable trace is in-between each set of servo rails(?)? What exactly do i do to these?
Its obvious ill have to use two or more regulators. Can i still use the same battery or will i need a seperate battery for each. If i need two thats gonna be a killer because my hexapod is so small. After placing the Maestro and the arduino and a wireless head for a PS2 handle that leaves me enough room on the bottom plate for one battery.
Ok found this thread about servo current…
… Looks like each servo draws .21A forced to stall. .21 X 12 =3.28. They might go to .50A but in either case it looks like 9A would be plenty to do what i need.
The current reading you saw in that forum post seems to be for a single type of servo. If you are using the same servo, those current rating might be okay, and you might be able to use the 9A regulator and a single battery.
If you are using a different servo the stall current is probably different than those measurements, so you should either measure the stall current or ask the manufacturer of your servos what the stall current is.
You can cut the + trace between the banks as shown in the picture with a hobby knife like an X-ACTO knife. Simply scoring across the trace until it is severed should work fine.