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Old Apr 22, 2010, 01:38 PM
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Quote:
Originally Posted by thanhTran View Post
Thanks for explaining that to me. Understand it now.
So what's the benefit of having 6 motors on a tri copter?

Thanks

thanh
More lift and no need for tail servo - yaw is accomplished same way as in quad - by having an equal amont of CW and CCW props and changing speeds between them.

Also you get the flight charactaristics of a tricopter which are better fast forward flight charactaristics (and some say more stabilty). I am not an aerodynamics expert but in my view it has something to do with the rotor-wash from the front propellors interfering less with rotor-wash from the back propellors and creating less turbulence in forward flight.
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Old Apr 22, 2010, 04:36 PM
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Thanks for the info Jussi!

Somehow I was hoping a 6-motor set up could do inverted fly without using variable pitch set up

Does a 6 motor tricopter look like a hex copter? Or does it look like a tricopter with 2 counter rotating props stack on top of each other? When I saw tri copter, I think it's better since it seems easier with orientation, looks cooler, and maybe cheaper due to the fact that it uses only 3 pair of motor & esc.

Thanks

-Thanh
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Old Apr 22, 2010, 05:08 PM
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Hexa = six motors on same plane in a Hexagon configuration!

Y6 is basically a tricopter with 2 counterrotating motors on each arm (upper and lower)

The hammer Y6, is probably one of the coolest Y6 designs around these days:

http://www.rcmovie.de/video/2c797937...utdoortestflug
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Old Apr 22, 2010, 05:48 PM
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Quote:
Originally Posted by 420RcPilot View Post
Hexa = six motors on same plane in a Hexagon configuration!

Y6 is basically a tricopter with 2 counterrotating motors on each arm (upper and lower)

The hammer Y6, is probably one of the coolest Y6 designs around these days:

http://www.rcmovie.de/video/2c797937...utdoortestflug
In a Y design like this, would you happen to know the angles of the arms? Most tricopters I have seen are 120 degrees apart, but this one seems to be different...
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Old Apr 22, 2010, 09:05 PM
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Quote:
Originally Posted by 420RcPilot View Post
A tricopter doesnt need CW and CCW props. The tail motor tilt mechanism provides yaw and counters the rotational torque from props.

On my tri I have EPP1045 CW on left arm and CCW on right arm. Tail is right now a CCW but you can use both directions here!

Regarding PCBs - the layout I just posted is directly based off PUGs design. I just placed motor headers on a row and added headers for motor 5 and 6. Ive been over it countless times and I am pretty sure it checks out! Ill check it once more, and put the files up for grabs...

This is also the PCB design I would put up for production as soon as I have had the chance to build a prototype....components still missing here.

Regards

Jussi
Nice job on getting all six esc/motor connectors in there. One day I might give hex a try myself after getting all my quads in the air flying like I want. Still waiting on the 401 gyros to come in but I also have some ST modules coming in to test which are even cheaper. Thats why I never have any money to buy a nice radio as too much neat hardware out there.
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Old Apr 22, 2010, 09:14 PM
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Quote:
Originally Posted by thanhTran View Post
Thanks for the info Jussi!

Somehow I was hoping a 6-motor set up could do inverted fly without using variable pitch set up

-Thanh
Once I read your post Thanh, I started thinking about a hex doing inverted flying without variable pitch.

Imagine a Y6 configuration, where the top motors run (produce the thrust) when the craft is right side up, and the bottom motors are off, then when inverted, the bottom motors (now on top) turn on to produce thrust, and the bottom motors turn off...
You'd still need one arm to rotate (like a regular tri) to counteract yaw torque.
Would that work?
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Old Apr 22, 2010, 09:27 PM
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Waiting patiently for the file...
Looking forward to trying out the design myself. Does the design have a ISP plug for easy programming?

adrian.
Quote:
Originally Posted by 420RcPilot View Post
Regarding PCBs - the layout I just posted is directly based off PUGs design. I just placed motor headers on a row and added headers for motor 5 and 6. Ive been over it countless times and I am pretty sure it checks out! Ill check it once more, and put the files up for grabs...

This is also the PCB design I would put up for production as soon as I have had the chance to build a prototype....components still missing here.

Regards

Jussi
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Old Apr 22, 2010, 11:05 PM
That tree again!!!!
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Quote:
Originally Posted by outsider787 View Post
...
Imagine a Y6 configuration, where the top motors run (produce the thrust) when the craft is right side up, and the bottom motors are off, then when inverted, the bottom motors (now on top) turn on to produce thrust, and the bottom motors turn off...
...
I've thought about it too. I think it would barely work, or not too well. It would not work as well as a variable pitch set up because the motors have quite some lag & delay from stop to start in order to keep the quad or the tricopter from falling down. It probably falls down a bit before the motors are up to speed. I think the bigger the motors and blades the worse performance would be.

How's your variable pitch set up coming?

I think at sometime I will try a variable pitch set up out. I think flying around without any stunt would be boring. A variable pitch would be nice since we can do tight flip / roll or can fly in much stronger wind.

-Thanh
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Old Apr 23, 2010, 05:44 AM
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Thanks PUG, but its all really thanks to your efforts. You made it easy to modify....

Will put the PCB up tonight when Im off work. Had to make damn sure it was OK. Used most of last night to do that...

No ISP-pins on this one...I tried to make it as small and light as possible. I figured it would make more sense to make a separate board for programming - since the 28-pin package gives us the possibility to remove the chip for programming.

Also the ISP-pins would probably require a 2-sided PCB....adding to cost and complexity. I aimed at a design that could be made with tonertransfer and soldered together by anyone with basic skills....

Anyway - back to business.....
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Old Apr 23, 2010, 07:32 AM
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Once Jussi releases his board layout, I'm diving in and building this thing.

I just have a question about the stability this board provides, and how much flight experience would I need before being able to fly like the pros in the videos earlier in this thread.

Do these quads (and not tri) based on this low cost flight controller fly like a heli, where you're always fighting to keep the thing in one spot?
Or is it almost hands free once everything is trimmed up?

I've never had any heli flight experience, so was wondering if that will affect my flying ability.
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Old Apr 23, 2010, 07:35 AM
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Yeah, I kinda thought that the motor lag would kill the performance of the craft.

The variable pitch is slowly coming along. Mechanical development work is slow enough, and waiting for parts from china only makes it a slower process.
Currently waiting for more parts to test out the arm arrangement, and also working in CAD to design the frame. Will update my thread one of these days with some new CAD pictures.

adrian.
Quote:
Originally Posted by thanhTran View Post
I've thought about it too. I think it would barely work, or not too well. It would not work as well as a variable pitch set up because the motors have quite some lag & delay from stop to start in order to keep the quad or the tricopter from falling down. It probably falls down a bit before the motors are up to speed. I think the bigger the motors and blades the worse performance would be.

How's your variable pitch set up coming?

I think at sometime I will try a variable pitch set up out. I think flying around without any stunt would be boring. A variable pitch would be nice since we can do tight flip / roll or can fly in much stronger wind.

-Thanh
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Old Apr 23, 2010, 09:22 AM
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PCBs

Edit: 18/5-2010. I misplaced comma for value of C1 on Gyro board. Correct value is 4.7 uF. I have edited recap Doc as well. Changes only apply to gyro cap C1 value and size.

Edit: 10/5-2010 - recap on building and programming added. New gyro boards added.

If U downloaded old gyro boards, you can trash them - I had swapped pin 3 and 4 on gyro board. I built and tested new version and it works!


I have removed the old files and put up the new ones - there is nothing wrong ith the old PCB files but I made a few changes and tidyied it up...

Printing and wieving of the .lay-files can be done with sprint layouts free viewer tool. This way you can print to fit your need.

http://www.abacom-online.de/UK/html/...#Layout-Viewer


I have provided gerber and excellon-files as well for those wanting to import design into Eagle with the Eagle power tools.

Design notes:

I tried to make board as versatile as possible. But C4 and C9 have to be tantalum to fit! You can now use 10 mm potis and plastic film caps for C5, C4 and C8. Watch the sizes if you use plastic film caps - they often have very large bodies.

Except for C7 Tantalum is the recommended choice for all caps and especially C9 has to be tantalum according to Kapteins design. C7 is a radial Electrolyte....

All tracks are 0.5 mm and at least 0.5 mm apart. This makes it pretty easy to make with tonertransfer technique....all Holes are set to minimum size 0.6 mm -. you can then drill out to larger size if needed - mounting holes can be up to 3 mm.

IC3 is designed to take a TO220 package, which means that the smaller TO92 package will also fit with some bending of the legs.

R1, R2 and R3 are standing up. LED is designed for 5 mm type. I stacked headers for all six motors in same direction. Potis are uo to 10 mm base with 2.54 *5.08 footprint

I designed so that you can use HK401B or other solution. If HK401b is used then connect signals to Y,P,R and the 3 GND and VVC wires to corresponding pads (vcc 1-3 and gnd in upper right corner of PCB)

I you plan to use the provided gyrostar PCB, then you can omit R1, R2 and R3 (they are on gyro PCB), and connect gyro boards directly to Y,P,R, G and VCC.

V 4.1 part list:

IC1: Atmega48/88/168/328 (28-pin)
IC3: LM317LZ (TO92 or TO220)
DIL/DIP 28 -300 Narrow style IC socket for Atmega

R1: 100 Ohm
R2: 100 Ohm
R3: 100 Ohm
R4: 4.7 Ohm
R5: 10 KOhm trim potmeter (up to 10 mm square with 2.54*5.08 pinout footprint)
R6: 10 KOhm trim potmeter
R7: 680 Ohm
R8: 10 KOhm trim potmeter
R9: 220 Ohm
R10: 68 Ohm (was 39 ohm)
R11: 4.7Kohm - 1206 SMD case. (only for twoside version)

C1: 2.2 or 47 uF tantalum
C2: 2.2 or 47 uF tantalum
C3: 2.2 or 47 uF tantalum
C4: 2.2 or 47 uF tantalum
C5: 0.68 uF tantalum
C6: 0.68 uF tantalum
C7: 100 uF or 47 uF electrolyte or Tantalum
C8: 0.68 uF tantalum
C9: 2.2 uF tantalum or 47 uF Tantalum

Components for Gyro PCB is :

IC1: Murata Gyrostar ENC-03R
R1: 100 Ohm - 1206 SMD
R2: 6.8 KOhm 1206 SMD
C1: 4.7 uF Tantalum SMD C-case
C2: 47 uF Tantalum SMD D-case

You can probably use smaller B-case SMD Caps for C1 and C1 - sizes are max size that will fit.
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Last edited by JussiH; Jun 22, 2010 at 09:13 AM. Reason: Design revised!
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Old Apr 23, 2010, 11:29 AM
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420RcPilot:

You should connect C9's negative pin directly to the controllers GND (pin 8)

Or else you get ground current noise along the blue line that distubs the GND level for the rest of the circuit, and also the effetiveness of C9 is reduced due to the long trace.

Microcontrollers generate a lot of noise, and need decoupling capacitors close to the VCC and GND pins.

Other than that, it looks nice
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Old Apr 23, 2010, 11:32 AM
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Quote:
Originally Posted by kapteinkuk View Post
420RcPilot:

You should connect C9's negative pin directly to the controllers GND (pin 8)

Or else you get ground current noise along the blue line that distubs the GND level for the rest of the circuit, and also the effetiveness of C9 is reduced due to the long trace.

Microcontrollers generate a lot of noise, and need decoupling capacitors close to the VCC and GND pins.
Thanks Kaptein. I will do that - Should I then drop connection from C9 negative to RX GND.

Otherwise it checks out?

Jussi
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Old Apr 23, 2010, 11:48 AM
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Last edited by JussiH; Apr 23, 2010 at 12:30 PM.
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