Sunday, 7 February 2010

R6: Time for the basic Motor electrics

I started on the motor electrics board tonight. Each electrical system will have its own dedicated board making it easier to work on a dn upgrade when needed.
The main motor board has the Sabretooth dual25A speed control, reciever, fusebox, switches and multiblock fitted. Each motor and main battery is protected by fuses, 20 and 25A seems to do the trick. One set of multi blocks allows the motor connection and the other the batteries, either 24v or 12v config.
I decided to assemble the droid and test all the motors and electrics. After an hour or two fitting the feet to the legs and getting them onto the body I was ready to see if I had power and control. This was the point that everything went wrong. Here is the list of all the thing that failed:
The front foot kept tipping.
The main feet kept tipping
The battery boxes are not straight and the gap between the ankle and battery box is to large
The radio does not control the motors correctly.
24v is a joke unless I want a droid that can wheelie

After a depressing couple of hours of removing the battery boxes and getting a better fit I started work on the center foot. The problem is that I can not tighten up the bolts enough to stop the feet tipping. The solution has to be small wood blocks placed accordingly to stop the feet tipping, and heavier bushes placed on the pivots of each foot. You can see in the pictures that the small blocks are not really that noticable.
As for the control or lack of it I eventually found the problem. Working for hours in a cold garage does not help with diagnosing wiring faults. Can you spot the stupid wiring mistake on the board above. It took me two hours to find it. Now everthing drives perfectly.

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