S3154
Okay, after extensive testing I was able to determine the max rotation for the servo. I can get a total of 120° out of the digital micro servos I purchased. After weighing the variables, a full 180° but having to use analog servos or 120° with digital ones, I decided that the benefits of using a digital servo far outweighs the benefits of the analog ones. I also realized that this would be the best option anyway considering the shape of Megatron's arms. technically they should only be able to swing forward and back, if he tried to raise them to the side, the shoulder mounting points don't have the necessary gaps needed to allow his arm to bend that way. This could also mean I may have to abandon a transformer design since the artists built them to look cool, not to actually be functional. Anyway the two images below give a perfect example of the range of motion the shoulders and hips will have. as you can see the hips are about right where they should be in terms of how far they can bend. The arms are missing a significant chunk of how far they should be able to bend. But I think the end result will still be something that looks good. I especially like these servos I bought, so I think a little sacrifice is worth it in the end.
I also figured out the values for the pulse signal. The time spent low does not matter. When the servo sees a "low" it is basically off. 800 µS instructs the servo to turn all the way to one side, and 2180 µS will have it turn all the way to the other. There is a bit of buffer on each side, I assume that's there to prevent the gears from getting stripped easily. Each degree is about 11.5 µS, though You'll need to round it to the nearest whole number since you cannot use decimals with the delay_us() function
Anywho, I think I'm going to stick with the Futaba 3154 micro servo. I'll also need to buy 6 larger servos for the rotational component. For those I'll need to disassemble the servo, and remove the motor+pcb inside so I can properly center it within the frame. So in total I'll need to buy,
Futaba S3154 Microservos: 20
Futaba S148 Robot Servo: 6
The S148's will be used to control the spin compoent of the arms. Each arm will have two spin motors, and each foot in the legs will have one. So I'm looking at a total of:
$84 - Arm/Leg spin servos
$580 - Arm/Leg Bend + torso and head servos
$93 - PCB Fabrication
$12 - 13 PIC16F1825 Microcontrollers
$5 - Various Caps, switches, resistors and buttons
$??? - Cost of manufacturing robot's frame
Arms and legs are gonna be easy, I can use threaded braces to link them together. the torso is gonna be hard, that will be a custom job. But I'm going to save that part for last.
I also figured out the values for the pulse signal. The time spent low does not matter. When the servo sees a "low" it is basically off. 800 µS instructs the servo to turn all the way to one side, and 2180 µS will have it turn all the way to the other. There is a bit of buffer on each side, I assume that's there to prevent the gears from getting stripped easily. Each degree is about 11.5 µS, though You'll need to round it to the nearest whole number since you cannot use decimals with the delay_us() function
Anywho, I think I'm going to stick with the Futaba 3154 micro servo. I'll also need to buy 6 larger servos for the rotational component. For those I'll need to disassemble the servo, and remove the motor+pcb inside so I can properly center it within the frame. So in total I'll need to buy,
Futaba S3154 Microservos: 20
Futaba S148 Robot Servo: 6
The S148's will be used to control the spin compoent of the arms. Each arm will have two spin motors, and each foot in the legs will have one. So I'm looking at a total of:
$84 - Arm/Leg spin servos
$580 - Arm/Leg Bend + torso and head servos
$93 - PCB Fabrication
$12 - 13 PIC16F1825 Microcontrollers
$5 - Various Caps, switches, resistors and buttons
$??? - Cost of manufacturing robot's frame
Arms and legs are gonna be easy, I can use threaded braces to link them together. the torso is gonna be hard, that will be a custom job. But I'm going to save that part for last.