Shop OBEX P1 Docs P2 Docs Learn Events
Quadrocopter / drone — Parallax Forums

Quadrocopter / drone

BotdocterBotdocter Posts: 271
edited 2010-06-03 23:07 in General Discussion
I am looking for a way to build a quadrocopter using a propeller robot control board.
I am using a memsic2125 accelerometer for balancing.

I need to know what parts i still need and where to get them.

For example: i need motors. As far as i could find they have to be brushless. So what do i need to run them on the propeller?
And how much power do the motors need?

I found these.. Are they powerfull enough?
www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=4700&Product_Name=hacker_Style_Brushless_Outrunner_20-22L

How about remote controll? I have a toy helicopter laying around (3d) can i use that atleast for now? A ps2 controller would be nice too but i think the signal is too weak. Is there any way to boost it?
I need everything to be cheap. Allthough i don't want to underpower it. It needs to carry a small wireless camera.
About 500 grams max.

What sort of batteries should i use?
I need a descend flight time. But dont want to pay above 35 euro/45 dollars.

[url=http://][/url]

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
1 Parallax Propeller Robot Control Board
1 Memsic MX2125 accelerometer/ tilt
1 Parallax Ping))) ultrasonic sensor

a few motors and a whole lot of chaos!

Comments

  • FranklinFranklin Posts: 4,747
    edited 2010-05-31 20:43
    Lets start by defining "Cheap" How much is the maximum you are willing to spend on this complete project?

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    - Stephen
  • BotdocterBotdocter Posts: 271
    edited 2010-05-31 20:59
    About 350 dollar for all the electronics. The body can be seperate.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    1 Parallax Propeller Robot Control Board
    1 Memsic MX2125 accelerometer/ tilt
    1 Parallax Ping))) ultrasonic sensor

    a few motors and a whole lot of chaos!
  • ScopeScope Posts: 417
    edited 2010-05-31 21:22
    Botdocter said...
    I need everything to be cheap. Allthough i don't want to underpower it. It needs to carry a small wireless camera.
    About 500 grams max.

    What sort of batteries should i use?
    I need a descend flight time. But dont want to pay above 35 euro/45 dollars.

    Have you considered this place - they may be able to help you get stuff that works for not much dough:

    www.hobbypartz.com/
  • hover1hover1 Posts: 1,929
    edited 2010-05-31 21:56
    Is it just me or do people do not know how the use google? (First listing)

    ·http://www.google.com/#hl=en&source=hp&q=Quadcopter+site%3Aforums.parallax.com&btnG=Google+Search&rlz=1R2ADFA_enUS371&aq=f&aqi=&aql=&oq=Quadcopter+site%3Aforums.parallax.com&gs_rfai=&fp=2a0dbe5263c501d8

    This thread has been running for a few months.
  • FranklinFranklin Posts: 4,747
    edited 2010-06-01 16:30
    hover1, no, it's not just you but why spend time Googling when you can post to a forum and have someone else do it for you?

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    - Stephen
  • BotdocterBotdocter Posts: 271
    edited 2010-06-01 16:45
    Here we go again!

    I tried doing research. But the info i asked i could not find.

    @hover and Franklin - I do know how to use google, and if you can only make this kind of jibberish.....

    Please Shut Up!!!

    If you don't want to " do the work for me" just don't reply.

    I'm really getting sick of people saying this (expletive)!!


    @Scope - thanx for the link. Very helpfull!

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    1 Parallax Propeller Robot Control Board
    1 Memsic MX2125 accelerometer/ tilt
    1 Parallax Ping))) ultrasonic sensor

    a few motors and a whole lot of chaos!
  • Roy ElthamRoy Eltham Posts: 3,000
    edited 2010-06-01 17:55
    Botdocter: All of the things you ask about are discussed at length in the thread that is the first link in the google search hover1 linked. You really should take a look at it (start at page one and read through all 13 pages). We discuss motors, sensors, R/C recievers, and interfacing with the propeller. There are several folks in that thread (including myself) that are building quadrotor flyers using the Propeller.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Check out the Propeller Wiki·and contribute if you can.
  • BotdocterBotdocter Posts: 271
    edited 2010-06-01 19:55
    Thank you! I tried to follow the linkbut it send me to a empty googke startpage. Maybe because i am on my iphone?
    Anyway i willcheck the link on another computer.

    Thanx again!

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    1 Parallax Propeller Robot Control Board
    1 Memsic MX2125 accelerometer/ tilt
    1 Parallax Ping))) ultrasonic sensor

    a few motors and a whole lot of chaos!
  • hover1hover1 Posts: 1,929
    edited 2010-06-01 20:14
    Hey BotDR,

    It may be too much to fit on the Safari browser. Just go to Google and use "Quadcopter site:forums.parallax.com" as your search criteria. Using "xxxxxx site:forums.parallax.com" is much better than using the Forum search.

    From your first post, it did sound like you wanted someone to give you an entire parts list for a Quad, minus the Propellor Robot control board.

    Do check out the Quadcopter thread:

    ·http://forums.parallax.com/showthread.php?p=890157

    That link should work on the iPhone.

    Jim
  • JasonDorieJasonDorie Posts: 1,930
    edited 2010-06-01 23:11
    That quad on that thread will be quite expensive to put together, as it's built with a 3-axis accelerometer, 3-axis gyro, GPS, pressure sensor, etc, etc...·· You can get away with -just- a 3-axis gyro and have the thing quite flyable, but it won't be "self hovering" without an accelerometer to find "down".

    Making the thing fly with only an accelerometer will be hard, if not impossible.· Accelerometer readings are VERY noisy, especially with motor vibration, and they're not an accurate measure of angular velocity.· For example, if you were hovering, and pushed the thing sideways with your hand, it would read an acceleration in that direction.· Along with the gravity vector, it would now believe it was tilted, even though it was still perfectly vertical.· Gyroscopes don't have this problem.

    For motors, you'll need brushless motors rated at ~1000Kv (also called RPM/Volt), and you'll need motor controllers capable of 10 or so amps of power, depending on how heavy the thing is.· I'm running 18A controllers and rarely use it all.

    On my next quad, I'm trying these:
    http://www.hobby-lobby.com/brushless_skatty.htm
    I've used them before on planes, and they're powerful and light, so they should be ok.· They should draw significantly less than 10A.

    For a motor controller, find a brushless ESC that allows for fixed throttle range programming.· Otherwise, the throttle response will "adapt" on the fly and mess up your balancing code.

    I'm using these:
    http://www.hobbycity.com/hobbyking/store/uh_viewItem.asp?idProduct=5449&Product_Name=TowerPro_n20_Acro_Brushless_Speed_Controller

    They'll handle up to 20A, can be PWM'd at 200Hz (maybe more - I've never tried) and they're dirt cheap.· To program them, I recommend getting the programming box.· Using the throttle and "counting beeps" method takes forever, especially with four of them.

    Jason
    ·
  • JasonDorieJasonDorie Posts: 1,930
    edited 2010-06-01 23:21
    I missed a question - Those 'Hacker style' motors you posted will work just fine. They'll handle ~15A each, and the RPM/V range is perfect.

    To figure out how much lift you'll need, you have to figure out how much total weight you'll be carrying. My batteries are ~150g each (x2 for added time), the motors are ~60g, and the controllers weigh ~20g. Add a little fudge for wiring and propellers, say ~20g:

    4 x (60 + 20 + 20) = 400g for motors + controllers
    2 x 150 = 300g for batteries
    500g for the camera
    = 1200g weight, less chassis and propeller board.

    At 600g thrust for those motors (times 4), you have 2400g of thrust, or another 1200g to play with for the chassis and brain before it won't lift itself. Don't use all of that though - ideally you want at least a 3:2 ratio for thrust:weight. If you don't have that, you won't go vertically very fast.

    Jason
  • BotdocterBotdocter Posts: 271
    edited 2010-06-01 23:33
    Thank you so much!

    That is the onfo i needed.

    One more question though:

    since you build one.. .. Can you tell me what parts i need? I read something about a flight controller? Do i need one? Or is that just the receiver for the rc?

    Is there someone in the netherlands who can help me build it?

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    1 Parallax Propeller Robot Control Board
    1 Memsic MX2125 accelerometer/ tilt
    1 Parallax Ping))) ultrasonic sensor

    a few motors and a whole lot of chaos!
  • hover1hover1 Posts: 1,929
    edited 2010-06-01 23:53
    You implied you where going to use a Propeller Robot contoller board in your first post. That would be your flight controller. Are you looking for autonomous flight control or just a plain R/C control? If it's just plai R/C control, you don't need the Propeller board. If it autonomous, the parts list·Ray put together, would fit your budget ($350.00 for electronics)
    Please visit the other thread. There is much talk about motors, ESC's and the like. There have been a few tested with different weights.
    Jim
    Botdocter said...
    Thank you so much!

    ·I read something about a flight controller? Do i need one? Or is that just the receiver for the rc?

  • JasonDorieJasonDorie Posts: 1,930
    edited 2010-06-02 00:24
    If you've never flown a model helicopter before, I'm not sure I'd recommend this as a first foray into R/C flight - Until the software is "right" it'll be VERY hard to fly. Even when it IS right, including full stabilization, gyro & de-biasing accelerometer, and self-levelling, it'll be harder to fly than you expect. Just throwing that out there - You may want to get a small R/C helicopter and get your brain used to the controls before trying to break your own. [noparse]:)[/noparse]

    When I say "flight controller", I mean the Propeller chip & software. Assuming you want to control it manually, you'll need an R/C receiver and a matching transmitter. If you read through the Quad/Hexa thread, or "Propeller with Propellers" thread in the Completed Projects section, you'll find some useful stuff.

    Jason
  • BotdocterBotdocter Posts: 271
    edited 2010-06-02 22:33
    My previous post didn't come through somehow.

    I have a small rc helicopter and can fly that. It's one of those with 2 propellers above eachother, and that can hover.
    I can fly with that. Is it kind of similiair to fly a quadcopter?

    I do want to fly it manually but also want to have the option to expand later to whatever sensor or so.
    So the propeller will be needed. And i need it to hover when i let go of the controlls so i can manage with the camera.

    I'm not very anvanced in programming spin but hope you can help me a bit. Maybe i can have a copy of your code? Do you have a basic code for remote control? And what sensors do i minimally need to get a stable flight with your code?
    What esc brushless controllers are compatible with proppeller?

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    1 Parallax Propeller Robot Control Board
    1 Memsic MX2125 accelerometer/ tilt
    1 Parallax Ping))) ultrasonic sensor

    a few motors and a whole lot of chaos!

    Post Edited (Botdocter) : 6/3/2010 12:43:50 AM GMT
  • JasonDorieJasonDorie Posts: 1,930
    edited 2010-06-03 01:17
    Any brushless ESC will be compatible with the propeller chip. There's nothing special about them - they're controlled with exactly the same code as servos. The ones I linked can be set to use a fixed throttle range instead of an adaptive one, which is necessary for synchronizing the 4 motors properly. My code is posted in the "Propeller with Propellers" thread, so you're welcome to it. It uses an accelerometer and a gyro, but at present it's not self-stable, so hands-off flight would be short lived.

    Regardless of whether or not you want something self-stable you'll need a controller chip on board to do the R/C input and gyro mixing. A quad rotor is inherently unstable - Without on-board gyros to correct for minor turbulences it's completely unflyable. Mine currently flys like a slightly skittish helicopter, so your coaxial rotor will be about the same, possibly even more stable than what my code will get you.

    That said, my code hasn't been fine tuned, I still get a decent amount of vibration from my motors (which hampers the sensors), and I haven't done much with it since I got it stable enough for -me- to fly it. I don't actually care if it's hands-off or not because I wanted it to fly like a heli, but it shouldn't be that difficult to improve the code once you get something that works.

    I'm currently working on my next one, using all digital components (ITG-3200 3-axis gyro, and a 3-axis digital accelerometer). I hope to have something to show in the coming weeks. I'm going to try to assemble a jig with just two rotors on a kind of "teeter-totter" so I don't have to worry about it crashing, hook it up to a PC, log everything, and start working on a better flight controller. I have the control board working already - I just have to build the test rig.

    I'll post more as I get to it, and you're welcome to ask me questions, either here or via PM. I won't write it for you, but I'm happy to steer you. [noparse]:)[/noparse]

    Jason
  • BotdocterBotdocter Posts: 271
    edited 2010-06-03 03:24
    Ok thank you. I will think about this all.

    Maybe its too simple minded from me but i thought it would work like this.

    Make it hover, in place. That shouldn't be that hard is it? Just calibrate everything to 0 and let the gyro and accelerometer do the rest. Then when throttle is used, the 0-angle is changed to y-30% or x+30%.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    1 Parallax Propeller Robot Control Board
    1 Memsic MX2125 accelerometer/ tilt
    1 Parallax Ping))) ultrasonic sensor

    a few motors and a whole lot of chaos!
  • JasonDorieJasonDorie Posts: 1,930
    edited 2010-06-03 04:33
    Assuming that your gyros don't drift, and your IMU is accurate, that's reasonable. The problem is that something drifting sideways at a constant speed doesn't have any acceleration applied to it, so it can't tell without a GPS or some other frame of reference, so you need to correct to keep it still, and that's assuming that the thing actually stays level, which it wont quite.

    The exception to that rule is the IMU that CessnaPilot is working on, which uses some very crazy math to integrate the readings from 4 accelerometers to accurately model rotational and translational inertia to maintain a real world location estimate. I think I'm going to have to look at his stuff at some point, 'cause it's over my head, but damn cool.

    The reason so many of these things have gyro / accelerometer / GPS / compass / altimeter / PING / IR sensors in them is because that's generally what it takes to make them hands-off flyable.

    Motors and propellers vibrate, and they blow "chopped" air across the arms they're attached to, which also causes vibration, affecting the sensors. Close to the ground you have ground effect turbulence to deal with, and if you're timid with it, that's where you'll be trying to fly. I'd recommend trying your first few flights in the middle of a baseball diamond or parking lot. [noparse]:)[/noparse]

    Note that I'm not trying to scare you off it - I'm just trying to set your expectations reasonably, and that's all. If you can fly your coax you'll be able to fly this thing once it's reasonably well behaved, but it might take a bit of tuning to get it there, that's all.

    Jason
  • BotdocterBotdocter Posts: 271
    edited 2010-06-03 18:05
    I'm thinking of buying this kit. It seems very good and has enough extra weight that it can carry.

    450 grams for complete frame inc. Motors elektronics
    300 grams for double batteries

    still 450 grams to go. I found a small 5mp camera that i'm going to use.

    Atleast then i have a working qc to go from with thw propeller( chip)

    what do you guys think about this set?
    www.cnchelicopter.com/servlet/the-1652/Xaricraft-X600-dsh-D-X600D-aircraft/Detail

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    1 Parallax Propeller Robot Control Board
    1 Memsic MX2125 accelerometer/ tilt
    1 Parallax Ping))) ultrasonic sensor

    a few motors and a whole lot of chaos!
  • JasonDorieJasonDorie Posts: 1,930
    edited 2010-06-03 20:51
    If that thing flies as well as it does in the video, $320 is pretty cheap. It -does- look like it'll fly like a helicopter, so probably not completely hands off, but it looks very stable.
  • BotdocterBotdocter Posts: 271
    edited 2010-06-03 21:15
    It does and it's just updated for better stability and stuff.

    But now i need a proper compatible radio set for it.
    Wich one is compatible? I want to spend max $60
    i think i want 2.4ghz because its faster but i also have a 2.4ghz camera. Will it interfere?

    The radio has to be a set. So receiver and sender.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    1 Parallax Propeller Robot Control Board
    1 Memsic MX2125 accelerometer/ tilt
    1 Parallax Ping))) ultrasonic sensor

    a few motors and a whole lot of chaos!
  • hover1hover1 Posts: 1,929
    edited 2010-06-03 21:38
    I would think a minimum of of $60.00 for transmitter only. Something like this if you want 2.4 Ghz:

    Spektrum DX5e

    Reciever is extra. I myself, would go for a DX7 :

    ·http://www.hobby-lobby.com/spektrum_dx7_transmitter_only_283133_prd1.htm

    If you are going to do any serious Heli stuff you need a transmitter that can support Heli's.

    Here is a 6-channel w/ reciever:

    ·http://www.hobby-lobby.com/dx6i_full_range_transmitter_ar6200_rx_md2_no_servos_3769_prd1.htm

    You would have to go with a 900 Mhz or 1.2 Mhz camera because it will interfere.

    Don't expect a good TX/RX combo for $60.00. The would be the price of a ground based 2-channel system for cars.
  • TimmooreTimmoore Posts: 1,031
    edited 2010-06-03 22:35
    You could try
    http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=8991&Product_Name=Turnigy_9X_9Ch_Transmitter_w/_Module_&_8ch_Receiver_(Mode_1)_(v2_Firmware)

    I have a clone - flysky but I dont know yet how reliable it is and what range you get
  • hover1hover1 Posts: 1,929
    edited 2010-06-03 23:07
    Since you are in the Netherlands, it would be hard to quote prices from here in the US, and frequencies are different between here and Europe, but I think 2.4 is universal now. You even drive your throttle on the wrong side of the box! [noparse]:)[/noparse] (Mode 1, Mode 2)
Sign In or Register to comment.