Power connected components

I am designing a DC quad-copter, I've studied up on the information on how the programming side of things, but am not sure how to power 4 powerful DC motors, 4 servo motors, and a nRF24L01. Each component needs a different voltage, since I don't want to try running 12V through an Arduino 101 I'm looking for a way to send the appropriate amount of voltage to each component. I'll continue to research so i'll try and keep this post updated.

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Now having said that, I am interested in your project. What are the servos for? Frequently Quad-copters use 4 RC hobby ESCs to run 4 brushless motors. Is this what you are doing?

Threads merged.

Again no details provided - "powerful DC motor" is not a datasheet or link to a product page.

One thing that's obvious is the nRF24L01 is not going to be usable for remote control due to its very short range.

By the way the power to weight ratio of the motors is crucial, you are unlikely to find anything approaching the performance of RC BLDCs in standard DC motor formats. For very small the slotless coreless DC motors work, but only because they are 60,000rpm or so.

The servos will be used to rotate each of the 4 brush-less DC motors individually (steering). I have yet to decide on a specific servo motor. I'd prefer to apply the maximum amount of power the DC motor can handle, without wasting power of course, which is stated at 11.1 V. Since Arduino 101 can't handle that kind of voltage itself I need to figure out a set up that will power each of the components.

DC motor (4)

MarkT: One thing that's obvious is the nRF24L01 is not going to be usable for remote control due to its very short range.

I'll have a range extender attached, it'll extend the range to 1.1km. Here.

MarkT: By the way the power to weight ratio of the motors is crucial, you are unlikely to find anything approaching the performance of RC BLDCs in standard DC motor formats. For very small the slotless coreless DC motors work, but only because they are 60,000rpm or so.

Thanks for mentioning this, the DC motor I have in mind is 78.4 grams, which I believe is light enough but I can't be sure. As for the servos, any suggestions?

You will run 4 brushless motors. OK. You would most likley want to run these using 4 brushless motor ESCs. The motors say 80A max. So google 80A ESCs. Hobby King is one affordable source. They will take your 11.1v input, standard servo input and give you brushless motor output.

What are your servos for?

Oh, and you were calling them DC motors. When you say that, everyone things brushed DC motors. Call them brushless motors. Then everyone will know what you are talking about.

Those are big motors. They will turn big props. Those will tear big holes in everything they run into. Have you considered starting smaller? Have you thought through the need for gyros to stabilize the flight?

Where did you read that the 101 cannot handle 11V? The docs say 7--12V on the power jack or Vin as far as I can tell.

A brushless motor is a brushless motor. Calling it just a DC motor confused everyone - this is why we ask, in the "how to post" thread, to give comprehensive details of the hardware involved, to avoid guessing and confusion.

The brushless motors will need to be properly supplied with 11.1V. After looking at this article i'm considering using a shield to protect my Arduino 101 from the voltage, if it'll do what I think it'll do.

MarkT: Where did you read that the 101 cannot handle 11V? The docs say 7--12V on the power jack or Vin as far as I can tell.

The Arduino 101 can have a 12V input, but the digital output is a mere 5V.Info. here. I know this would be an enormous lack of energy efficiency, resulting in a significant loss of voltage in the form of heat, I don't want to risk frying my micro-controller.

vinceherman: What are your servos for? Those are big motors. They will turn big props. Those will tear big holes in everything they run into. Have you considered starting smaller? Have you thought through the need for gyros to stabilize the flight?

Thanks for all the input. The servos will be used to regulate the angle of rotation the propellers will be angled at. (With limits of course to prevent any wire tearing.) I'd prefer to use more powerful motors to simplify the task of figuring out the weight limit, also since this is my first quad-copter it won't be extra-small. As for the gyros, the Arduino 101 is apparently pre-equipped with a gyro which I intend to use if possible.

The battery in mind.

That is not the battery you want. Oh, it could work. But it is intended to be a transmitter battery. A low C application. The skinny size of the wires is a clear indication that it is not intended to be a flight battery.

Most quads do not use servos to control their flight. The motors are fixed to the frame. half the props turn clockwise (CW) and half counter clockwise (CCW). Differential thrust fore and aft controls pitch, left and right controls roll and between the CW and CCW props controls the yaw.

But it can also be done using servos for yaw. Just more complicated.

The classic designs are X-frame (4 rotor), or Y-frame (3 rotor + 1 servo for yaw).

A small buck converter to give 5V for Arduino from the main 11V battery would help isolate it from noise on the supply, the cheap ones on eBay are rather large and go upto a couple of amps, smaller lighter version would be less bad for the mass budget

vinceherman: Most quads do not use servos to control their flight. The motors are fixed to the frame. half the props turn clockwise (CW) and half counter clockwise (CCW). Differential thrust fore and aft controls pitch, left and right controls roll and between the CW and CCW props controls the yaw.

Thanks for the tip, but wouldn't I need the servos to tilt each individual prop so it will be able to preform vertical movements?

Vertical is just all props going full-blast to increase lift at all 4 corners.

4 degrees of freedom, 4 props. I found this nice diagram: http://lhelge.se/wp-content/uploads/2012/06/Control_stable.jpg

Immortal_Conqueror: Thanks for the tip, but wouldn't I need the servos to tilt each individual prop so it will be able to preform vertical movements?

Nope. Just 4 ESCs, 4 motors, 2 CW props, 2 CCW props and creative throttle assignment.

MarkT's diagram does show it well. If I had to guess, I would say that would be for a plus '+' arrangement rather then an 'X' arrangement that is more common. I have one quad that can switch between the 2 modes. It is really just differences in math.

Ah, sorry I meant to say horizontal movements. Or would you just change the rotational speed of the props to move side to side and back and forth? (On the horizontal axis.)

CrossRoads: Vertical is just all props going full-blast to increase lift at all 4 corners.

"Or would you just change the rotational speed of the props to move side to side and back and forth? " Yes. Perhaps slow one blade to tip to that side, then once tipped all 4 fast again to zip along in that direction. Or two to top 45 degrees from what tipping one achieves.

I'm terrible flying mine, not enough practice. Even one that supports first person view with on board camera linked to smartphone. https://www.youtube.com/watch?v=Vo8CbLwWQR0

Typical quads (with fixed motors) use differential thrust to control pitch and roll.
Assume X configuration:
More throttle to the rear motors and less to the front motors pitches the quad forward.
If you pitch a quad forward slightly, it moves forward horizontally.
Pitch it back and the quad moves backwards horizontally.
Roll the quad to the left or right and it moves horizontally left or right.

All with throttle control of the 4 motors.

Yaw is slightly different in that the the differential thrust is between diagonal pairs of motors. Increasing throttle ot the CW motors and decreasing throttle to the CCW motors leaves the overall lift the same, but gives an inbalance in torque. The result is that the quad yaws one way or the other.

This is not to say that your original idea won’t work. It will. Servos to move non-fixed motors can also do some of what you want. But it is more work, more weight, more prone to breakage in a crash.

Unless you are doing something purposeful like the VTOL that shifts into a plane (think Osprey but with 4 props)
pmc_vtol_wire1.jpg

That is essentially my goal, to create a quad-copter that is able to function as a plane as well using 4 props. But what i'm concerned about is if the props in back (during it's plane configuration) will be able to even function correctly due to the air being expelled by the 2 front props. I could offset the props from one another but that'd cause a whole lot more problems to deal with.