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Old 01-15-2011, 03:03 PM   #1
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Default Using old servo control boards as actuator driver/motor ESC for PROPORTIONAL control

Here is one little experiment of converting a toy car to proportional control;

Yep, both steering and throttle control are proportional. Steering is spring type, actuator driven;



The idea is to use the servo controller board as H-Bridge ESC drivers for the car motor. The same is also true for the steering magnetic actuator. The steering mechanism is spring centered thus you can actually vary the actuator magnetic strength to define the deflection of the wheels. This can be adjusted further by defining the EPAs and D/R rates on the steering channel at the TX side.

For the Main Motor, i used an old Futaba S3003 servo control board ...





For the steering actuator driver, i used an ESky 8g servo control board.

You need to retain the pots on the servo boards and adjust them for a 0-volt center on the motor/actuator output.







The setup is powered by a small 1S lipo thus a charging port is required;




VIDEOS;

Motor and Steering actuators in action as controlled by a Futaba 2.4Ghz FHSS


+ YouTube Video
ERROR: If you can see this, then YouTube is down or you don't have Flash installed.



Table Top run testing proportional control on both steering and throttle;

+ YouTube Video
ERROR: If you can see this, then YouTube is down or you don't have Flash installed.


Full tests on proportional control on both steering and throttle on the ground;

+ YouTube Video
ERROR: If you can see this, then YouTube is down or you don't have Flash installed.
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Old 01-15-2011, 03:14 PM   #2
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a simple schematic;

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Old 01-15-2011, 03:28 PM   #3
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TX Settings;


Steering EPA at 30% on both sides.

Steering D/R at 40%

Throttle EPA at 30% on both sides. Motor achieving full rotation at such rate thus you only need to spread out the throttle curve on the entire swing of the TX throttle trigger Same case also for the steering.
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Old 01-16-2011, 05:47 AM   #4
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And since we already have the servo control board inside, we can actually replace the steering actuator control with a full blown micro servo using the already existing e-sky servo as motor drivers. This is done by connecting the motor and the pot that is built-in on the servo. Both actuator driven and servo driven steering mechanism can provide full proportional control. However, if you have access to a very small servo for your micro rc car,why not mount that one instead ?




Here she is again in action;

+ YouTube Video
ERROR: If you can see this, then YouTube is down or you don't have Flash installed.



Proportional control tests done on the floor for both steering and throttle ...


+ YouTube Video
ERROR: If you can see this, then YouTube is down or you don't have Flash installed.



and a good ol table top run also testing the proportional control;


+ YouTube Video
ERROR: If you can see this, then YouTube is down or you don't have Flash installed.
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Old 01-16-2011, 01:52 PM   #5
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if im the first, let me say, good job. i was thinking of doing this to a little rc car i have kicking around too!
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Old 01-16-2011, 02:11 PM   #6
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great hack EQMOD!!!
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Old 01-16-2011, 02:41 PM   #7
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That is an amazing hack. Deserves many, many bumps for anyone wanting dNano control and size without the investment. Great job!
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Old 01-16-2011, 05:35 PM   #8
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Thanks guys.

Just to give a comparison and a couple of options too, here are a possible combination of this proportional control mod;

1. Kyosho AM transmitter with magnetic actuator steering. Esky 8g servo as steering actuator driver and Futaba S3003 board as ESC for the main motor drive.

+ YouTube Video
ERROR: If you can see this, then YouTube is down or you don't have Flash installed.


2. Futaba 2.4Ghz + R603GF combo with with magnetic actuator steering. Esky 8g servo as steering actuator driver and Futaba S3003 board as ESC for the main motor drive.

* The programmable TX is actually a better option for the actuator steering as you can vary the strength applied on the magnetic coil by adjusting the D/R rates and EPAs.

+ YouTube Video
ERROR: If you can see this, then YouTube is down or you don't have Flash installed.


3. Futaba 2.4Ghz + R603GF combo with full sub micro servo steering. Esky 8g servo as steering motor driver and Futaba S3003 board as ESC for the main motor drive.


+ YouTube Video
ERROR: If you can see this, then YouTube is down or you don't have Flash installed.



Of the three options, obviously the 3rd one would be the best as it consumes less current than using actuators but it may be hard to access a good micro servo and specifically mount them on a very small scale car. Actuators work well on proportional steering as long as you can properly adjust the D/R rates and Endpoints so that you can maximize the entire steering wheel curve.

Last edited by EQMOD; 01-16-2011 at 05:51 PM.
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Old 01-21-2011, 11:28 AM   #9
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Here is a new one - Small Kart racer with the proportional control steering and throttle.



Specs:

1. 1S Lipo Power
2. 2.4Ghz Efly RX/TX combo
3. 2 Servo Control boards - one for steering and another one for throttling.
4. a couple of centering pots (5kohm)



Using the bulky TX with the programmable TX parameters



With the onboard electronics;



Electronics neatly attached;



Gas time (Lipo charger)



VIDEOS:

Proportional Control Actuator and Steering in action

+ YouTube Video
ERROR: If you can see this, then YouTube is down or you don't have Flash installed.


Table Top:

+ YouTube Video
ERROR: If you can see this, then YouTube is down or you don't have Flash installed.


Floor:

+ YouTube Video
ERROR: If you can see this, then YouTube is down or you don't have Flash installed.
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