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zurk
05-29-2013, 11:06 AM
Would like to power
2 x RS-160D controllers, 4 NPC-T74 geared motors with lead acid batteries only due to various factors. Which lead acids and how many ? Also need 12V for the main cpu board (pico ATX) and i also need a single servo motor capable of lifting 2-3lbs. Any suggestions on servo motor and power arrangement (how many batts/what config) ?
thanks.

escott76
05-29-2013, 11:12 AM
Information missing. You need to figure the average amp draw of your platform. This will be dependant on weight, tire size, gearing, voltage to the motors, terrain covered etc. Then figure out how long you want to run. Average amp draw * time you want to run will give you the capacity of the battery needed. Chose batteries from there. Having average amp draw will tell you also what kind of batteries to buy. Hawkers are great for high current but might be overkill (more expensive than needed) if average current demands are low.

Have a look here : http://architeuthis-dux.org/torquecalc.asp for a current calc that may be of some use.

zurk
05-29-2013, 12:17 PM
From the calc :
Torque (per motor) to spin wheels
1224 oz-in


Amps (per motor) to spin wheels
10.854 Amps


Theoretical Top Speed
0.7139 MPH


Total Peak Amps
21.709 Amps


Amp Hours Required - 3 Min
0.7598 AH


Amp Hours Required - 5 Min
1.2664 AH



Assuming I want to run it for 45min - 60 min and its a 340lb platform to move at top speed on a flat surface. does that help ?

escott76
05-29-2013, 12:22 PM
From the calc :
Torque (per motor) to spin wheels
1224 oz-in


Amps (per motor) to spin wheels
10.854 Amps


Theoretical Top Speed
0.7139 MPH


Total Peak Amps
21.709 Amps


Amp Hours Required - 3 Min
0.7598 AH


Amp Hours Required - 5 Min
1.2664 AH




Assuming I want to run it for 45min - 60 min and its a 340lb platform to move at top speed on a flat surface. does that help ?

It probably should help you, now multiply. I find some of those numbers rather odd though, I'd go back and make sure you entered the right thing in the right place.

jwatte
05-29-2013, 01:50 PM
i also need a single servo motor capable of lifting 2-3lbs.

Any servo motor can do this. The question is: How fast do you want the lifting to happen, and how far does it need to be lifted?