Modify RC Servos for Continuous Rotation and External H-Bridge Control
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- Опубліковано 10 вер 2024
- In this video I show how to modify RC servos so they can spin continuously. Two ways are presented: the first way allows the servo to still be controlled with a servo signal. The second way allows for controlling the h-bridge externally so you have better control over the motor. I also explain some the theory behind the h-bridge and how to use PWM signals to control it. Lastly, I show how to mount an RC airplane wheel to the servo so it can be used to power small robots.
This video is part of a series showing how to build a balancing robot:
Part 1: [THIS VIDEO] Modify RC Servos for Continuous Rotation and External H-Bridge Control
• Modify RC Servos for C...
Part 2: Building a Robot Chassis with Brass Square Tube, a Dremel, and Solder
• Building a Robot Chass...
Part 3: First Steps with a GY-86 10DOF Sensor: MPU6050, HMC5883L and MS5611
• First Steps with a GY-...
Part 4: 6DOF & 9DOF Sensor Fusion with Madgwick's Filter, MPU6050, HMC5883L (GY-86 Module)
• 6DOF & 9DOF Sensor Fus...
Part 5: How to Use CC2500 PA LNA 2.4GHz Wireless RF Modules
• How to Use CC2500 PA L...
Part 6: GPU-Accelerated Data Logging and Telemetry
• GPU-Accelerated Arduin...
Part 7: How to Tune PID Control Loops Visually
• How to Visually Tune P...
very nice and detailed video!
Thanks!
nice keep up the good work
Can I use a stepper motors instead
Great tutorial sir!
I have a question. Why did you choose modified servo over regular geared DC motor?
Thank you.
I just find servos to be a little easier to work with. They are trivial to mount, come with an h-bridge, and decent servos have good gears with little slop.
Do they have any other benefits such as torque or stability? Because I know DC motors are not very stable, with the same power source one can rotates faster than another. Thus, they usually require encoders.
Great job on the video. Will be watching the series and likely building a very similar one using your example. Please confirm the 2.2K resistors for the servo micro-controller voltage reference was no longer needed once you modified to control the H-Bridge directly.
When controlling the H-bridges directly, the microcontroller (and therefore the potentiometer which precedes it in the signal flow) are irrelevant. So you won't need the resistors.
Can you tell me specifically the speed of servo for a balancing robot? like 0.1s for 60 degree?
There is no exact speed requirement, but the faster the better (assuming you have enough torque.) The servos I used are rated at 0.05s and 97oz-in when powered with 7.4V, but I was using a 6V battery. 0.1s is probably good enough but it may not balance as smoothly.
Can you recommend on a chipper servo from ebay please?
I have not taken apart any no-name eBay servos. Look for servos where the output gear is a circle (not a lightened D shape.)
Why you didnt just buy 360 angle servos?
I didn't look into it back then, but I'm guessing 360 degree servos with a similar speed would have been a little more expensive. Also, by controlling the h-bridges directly, I reduce latency.
@@upgrdman alright sounds good, I was just wondering. Your tutorial videos are awesome!
If you're using your own h-bridge why can't you just forget the entire printed circuit board? You've basically turned this into a simple D.C. Motor and gear set up.
I'm using the h-bridge on the servo's PCB, but I am controlling it from my microcontroller.
I misunderstood you. Sorry.