Evil Robotics

Weight & Batteries

I found a Torque / Amp-Hour Calculator at Tentacle Combat Robotics. It verifies my horse power calculations were on the right track.

The spread sheet for the total weight is shaping up as follows;

ITEM	QTY.	DESCRIPTION	WEIGHT	EXTENDED
1	1	Electronics (ESC's receiver, wire)	1	1
2	2	battery 10 cell 12 V 2.3 Ah	1.4	2.8
3	2	motor HF drill master 9.6V	1	2
4	4	Wheel 3x.875	0.156	0.624
5	4	wheel hubs Delrin	0.1	0.4
6	4	skirts .050 titanium	0.25	1
7	1	Frame	1	1
8	1	Armor	1	1
9	1	EV Warrior motor	4	4
10	1	friction clutch	0.25	0.25
11	1	weapon bar titanium	2	2

		Total Estimated Weight		16.074

With the amp hour (Ah) calculations I did at Tentacle Combat Robotics, I figure the EV Warrior will take about 3/4ths of the battery capacity. The drive motors will take .37 Ah at 12V and the weapon will take 1.71 Ah at 24V. This would require a center tap on the power pack to supply the 12 volts for the drive motors.

According to the Robot Fighting League rules the weapon will need to be preapproved for tournaments if the spinning mass is over 20% and the rpm's are over 500. Since the EV warrior would be used with a slip clutch but no gears with a one to one ratio, I would expect my rpm's to be 4000 plus. I will need to limit my spinning mass to less than 2.4 lbs. Since the bot is so over weight as it is, It will need to save weight any way possible.

These weight estimates are as low as I can reasonably go. Notice there are only two drive motors in the weight calculations. I am having a hard time justifying the 4 lbs for the EV warrior weapon motor. That motor also means added weight for 24V batteries.

A 3-D SolidWorks assembly will have a more accurate weight estimate.