I'm trying to design/build a desktop robot arm from scratch as a fun 3D printing + Arduino challenge, and I'm fairly new to large-scale power supplies. Particularly, I have several different types of servos used in the arm (some joints need more power, some need to be lighter weight, some in between) and they're all a slightly different voltage. I'm using:
1x SG90 (standard cheapy RC servo for one of the low-load wrist joints)
~ Voltage: 4.8 - 6V
~ Max current: 1.6A
3x MG995 (medium servo for other wrist joints and claw)
~ Voltage: 3.0 - 7.2V
~ Max current: 1.5A
2x DS3218 (medium-beefy 270deg for elbow and yaw joint)
~ Voltage: 4.8 - 6.8V
~ Max current: 2.2A
1x D3625 (big boy for main shoulder joint)
~ Voltage: 4.8 - 7.2V (9V max)
~ Max current: 30.0A ( )
All driven by a PCA9685 16-channel servo driver, which is controlled by an Arduino Nano. All servos claim to run on at least 5V, and I have a 5V 10A wall adapter power supply (previously used on an LED strip project with amazing success) which works great for any ONE of the servos, but as soon as I start hooking up more at once it starts giving out under smaller and smaller loads until it essentially doesn't work at all.
Any ideas on why this is or what I should do instead? The project can be either battery or wall powered; doesn't make a big difference to me.