If you need assistance, please send an email to forum at 4hv dot org. To ensure your email is not marked as spam, please include the phrase "4hv help" in the subject line. You can also find assistance via IRC, at irc.shadowworld.net, room #hvcomm.
Support 4hv.org!
Donate:
4hv.org is hosted on a dedicated server. Unfortunately, this server costs and we rely on the help of site members to keep 4hv.org running. Please consider donating. We will place your name on the thanks list and you'll be helping to keep 4hv.org alive and free for everyone. Members whose names appear in red bold have donated recently. Green bold denotes those who have recently donated to keep the server carbon neutral.
Special Thanks To:
Aaron Holmes
Aaron Wheeler
Adam Horden
Alan Scrimgeour
Andre
Andrew Haynes
Anonymous000
asabase
Austin Weil
barney
Barry
Bert Hickman
Bill Kukowski
Blitzorn
Brandon Paradelas
Bruce Bowling
BubeeMike
Byong Park
Cesiumsponge
Chris F.
Chris Hooper
Corey Worthington
Derek Woodroffe
Dalus
Dan Strother
Daniel Davis
Daniel Uhrenholt
datasheetarchive
Dave Billington
Dave Marshall
David F.
Dennis Rogers
drelectrix
Dr. John Gudenas
Dr. Spark
E.TexasTesla
eastvoltresearch
Eirik Taylor
Erik Dyakov
Erlend^SE
Finn Hammer
Firebug24k
GalliumMan
Gary Peterson
George Slade
GhostNull
Gordon Mcknight
Graham Armitage
Grant
GreySoul
Henry H
IamSmooth
In memory of Leo Powning
Jacob Cash
James Howells
James Pawson
Jeff Greenfield
Jeff Thomas
Jesse Frost
Jim Mitchell
jlr134
Joe Mastroianni
John Forcina
John Oberg
John Willcutt
Jon Newcomb
klugesmith
Leslie Wright
Lutz Hoffman
Mads Barnkob
Martin King
Mats Karlsson
Matt Gibson
Matthew Guidry
mbd
Michael D'Angelo
Mikkel
mileswaldron
mister_rf
Neil Foster
Nick de Smith
Nick Soroka
nicklenorp
Nik
Norman Stanley
Patrick Coleman
Paul Brodie
Paul Jordan
Paul Montgomery
Ped
Peter Krogen
Peter Terren
PhilGood
Richard Feldman
Robert Bush
Royce Bailey
Scott Fusare
Scott Newman
smiffy
Stella
Steven Busic
Steve Conner
Steve Jones
Steve Ward
Sulaiman
Thomas Coyle
Thomas A. Wallace
Thomas W
Timo
Torch
Ulf Jonsson
vasil
Vaxian
vladi mazzilli
wastehl
Weston
William Kim
William N.
William Stehl
Wesley Venis
The aforementioned have contributed financially to the continuing triumph of 4hv.org. They are deserving of my most heartfelt thanks.
Registered Member #2431
Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639
CSU Chico Tilt Rotor Flying Machine, (Airframe and Electronics, 2 of 3.)
Supporting threads: CSU Chico Tilt Rotor Flying Machine, (Programming and CPU, 3 of 3).
PDF's: (soon) gyro accerl mag stm32's IR proximity sensors. U-dar
YouTube: Avatar Scorpion Gunship RC - TwinCopter
Related threads: Differences between good fiberglass, and good Carbon fiber. International Aerial Robotics Competition, Mission 6, 2011. 69mm Electric Ducted Fan, 2.8 lbs Static Thrust... Need help with the STM32F4-Discovery board...
Pics!
please forgive the paper plates, i needed to show the fan placement, but they're not ready yet.
Titanium gear digital servo.
A similar metal gear servo.
Its got guts!!!
37 inches long in this pic. No motors or rotors yet.
Registered Member #65
Joined: Thu Feb 09 2006, 06:43AM
Location:
Posts: 1155
Do you plan to cut holes in the air frame to fit the battery and servos?
Note, loose cable ties and Styrofoam often help PCB survive torsional strains during impact. It would be wise to anchor the main ESC battery connection cable to the air frame so it will pull-free from the battery during impact....
The Oak and the Reed, Jean de la Fontaine (1621-1695)
The Oak spoke one day to the Reed "You have good reason to complain; A Wren for you is a load indeed; The smallest wind bends you in twain. You are forced to bend your head; While my crown faces the plains And not content to block the sun Braves the efforts of the rains. What for you is a North Wind is for me but a zephyr. Were you to grow within my shade Which covers the whole neighbourhood You'd have no reason to be afraid For I would keep you from the storm. Instead you usually grow In places humid, where the winds doth blow. Nature to thee hath been unkind." "Your compassion", replied the Reed "Shows a noble character indeed; But do not worry: the winds for me Are much less dangerous than for thee; I bend, not break. You have 'til now Resisted their great force unbowed, But beware. As he said these very words A violent angry storm arose. The tree held strong; the Reed he bent. The wind redoubled and did not relent, Until finally it uprooted the poor Oak Whose head had been in the heavens And roots among the dead folk.
Registered Member #30
Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706
Maybe I'm missing something, but it looks like the centre of gravity will be a long way away from the centre of lift, especially once you've added the battery pack.
In the above picture of a Boeing Osprey, the rotors are roughly in the middle of the aircraft.
Registered Member #2431
Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639
Steve Conner wrote ...
Maybe I'm missing something, but it looks like the centre of gravity will be a long way away from the centre of lift, especially once you've added the battery pack.
In the above picture of a Boeing Osprey, the rotors are roughly in the middle of the aircraft.
my CG, CL, and CP will all be approximately centered in between the rotors (as in the V-22), the tail only looks heavy its pretty light, and the sensors (MS kinnect and U-dar) are pretty heavy they go in front (with the battery). so it all balances out. its all very Zen.
Registered Member #30
Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706
Well, what is the tail there for? It can't be for aerodynamic stability. If your design needed the tail for stability, it would be unstable in hover mode, when there's no airflow over it. So I suggest chopping it off.
The Osprey (and its RC model version from Rotormast) needs helicopter-style rotors with cyclic pitch control. These can generate a pitching moment to control the vehicle in the pitch axis. A quadrotor does that by having rotors fore and aft of the CG.
You don't seem to have any active control in the pitch axis at all. No matter how you tilt your rotors, the thrust vector will always pass through the CG and there'll be no pitching moment.
Registered Member #2431
Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639
Steve Conner wrote ...
Well, what is the tail there for? It can't be for aerodynamic stability. If your design needed the tail for stability, it would be unstable in hover mode, when there's no airflow over it. So I suggest chopping it off.
The Osprey (and its RC model version from Rotormast) needs helicopter-style rotors with cyclic pitch control. These can generate a pitching moment to control the vehicle in the pitch axis. A quadrotor does that by having rotors fore and aft of the CG.
You don't seem to have any active control in the pitch axis at all. No matter how you tilt your rotors, the thrust vector will always pass through the CG and there'll be no pitching moment. If you look at the you tube clip link above youll see his "twin copter " remain quite usable even when manuevered flat. pitching and rolling seemed to cause problems in narrow office hallways when i was at IARC 2011. for that reason i wanted to use yaw and tilt instead.
yepp as soon as i dont need the magnetometer ill be chopping the tail off (it was mostly for crash protection, and to look spiffy), also i used to much epoxy on one side on the FG. my gaol is to get the total airframe down to 250 grams or less.
As for the pitch and CG comment, i see no problem, i want the sensor plane (the airframe) to remain flat even when the rotors are full forward or aft. the last thing i want is my sensor plane rotating as im trying to update the SLAM model.
This site is powered by e107, which is released under the GNU GPL License. All work on this site, except where otherwise noted, is licensed under a Creative Commons Attribution-ShareAlike 2.5 License. By submitting any information to this site, you agree that anything submitted will be so licensed. Please read our Disclaimer and Policies page for information on your rights and responsibilities regarding this site.
CSU Chico Tilt Rotor Flying Machine, (Airframe and Electronics, 2 of 3).
