I am planning to use an adaptor to power 4 servos.

I want to make a servo motor controlled robotic arm. For this I will use an arduino uno, 4xHD-1800A and a 12V 2A adaptor. This way I will have more than enough amp. But will this work? I mean, as I learned, as long as voltage is within the limits, too much amper will not harm. So it should work, but I wanted to ask anyway since I am not that expert in electronics, if at all.

The data sheet specifies the Operating Voltage Range at 4.8 to 6V. You must bring the 12V down to 6V to power the servos.

groundFungus:
The data sheet specifies the Operating Voltage Range at 4.8 to 6V. You must bring the 12V down to 6V to power the servos.

Oh I see. So 12V is too much. Thank you.

Servos take more current than you think when starting.

Plan on 1 Ampere per servo, so 5-6V at 4 Amperes for your setup.

Pololu states 460mA stall at 6volt.

Hope your 'arm' is made from balsa wood (Stall torque @6volt is 1.3 kg·cm).
Leo..

jremington:
Servos take more current than you think when starting.

Plan on 1 Ampere per servo, so 5-6V at 4 Amperes for your setup.

It is hard to find something like that, but I guess I have to.

Wawa:
Pololu states 460mA stall at 6volt.

Hope your 'arm' is made from balsa wood (Stall torque @6volt is 1.3 kg·cm).
Leo..

I will 3d print it, and try to make it as hollow as possible. I don't need much integrity after all.

compnaion:
It is hard to find something like that, but I guess I have to.I will 3d print it, and try to make it as hollow as possible. I don't need much integrity after all.

You can make the "skin" as thin as possible, but will have to have internal ribs to absorb the stress. I am sure you have such design information available.

Paul

Paul_KD7HB:
You can make the "skin" as thin as possible, but will have to have internal ribs to absorb the stress. I am sure you have such design information available.

Paul

I am mechanical engineer, I will find a way. Motor itself weights about 8 g, lets say one is at max 10 cm away from the bottom motor and other is 20 cm away, I will still have 1,3-108-208=1000g.cm. PLA is one though material. 2mm square crossectional 10cm long rod can handle 0.6 kg, and that rod would weight about 0.52 g. So what I will make probably won't even get pass 400g as structure, while it can support all the weight on it.