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..and now, for something COMPLETELY Different! http://mowrystrings.luthiersforum.com/forum/viewtopic.php?f=10106&t=26516	Page 1 of 1

Author:	cyborgcnc [ Sat Mar 13, 2010 4:28 pm ]
Post subject:	..and now, for something COMPLETELY Different!
This is my latest endeavor...have been working for quite a few days to try and complete the model, and it is now just about ready to be machined....(Solidworks designed....off course!) It is a frame I will use for a new Quad-Rotor copter I am building...will be primarily used for aerial photography ...another hobby of mine has been RC, primarily model helicopters. The quad will be used with GPS, as well as three accelerometers and gyros. Basically, with a push of a button from my transmitter, it will be able to hold it's altitude, and also use way point navigation if desired. The controller is based on an "arduino" board, which will run code, that will control the speed controllers of the motors. Based on feedback from the sensors.... So many projects....so little time.... See, nothing to do with a guitar....told you it would be completely different!

Author:	Brad Way [ Tue Mar 16, 2010 12:08 pm ]
Post subject:	Re: ..and now, for something COMPLETELY Different!
Very interesting. Looks like a real challange to model. Everything modeled in Solidworks?

Author:	Stuart Gort [ Tue Mar 16, 2010 1:51 pm ]
Post subject:	Re: ..and now, for something COMPLETELY Different!
Check out the brain on cyborgcnc. Marvelous conceptual work there, C! Very nice! Is that the frame of a four rotor deal? Do you know the gross weight of the vehicle? The motor specs? Do you have someone to make the rotor blades? I promise to be expensive !!

Author:	cyborgcnc [ Wed Mar 17, 2010 12:48 pm ]
Post subject:	Re: ..and now, for something COMPLETELY Different!
Thanks for your comments all! -Yes, it is modeled entirely in Solidworks, and Rendered as well with it.... -The frame is initially going to be made out of G-10 (Referred to as Garolite, or PCB material?). It is basically a phenolic, with very high tensile strength. If you ever build a circuit on a copper board, that is the stuff (less the copper off course). Great machine-ability as well. I have all the parts cut already (will post some pics later) and the weight of the frame is about 300 grams. Considering a laser cut version at some point in time out of 1/8 plywood, just for comparison. Motors are going to be 1150KVA Brush-less "Out-runners". Battery is a 3S 11V Lipo, with about a 60 AMP discharge. Controlled via 4 ESC's (Electronic Speed controls), using a Futaba 7 channel radio. The Software will run on a Arduino Board (programmed in the script it uses). Basically, it will have the outputs to the receiver, and the inputs will be from the 3 gyros for pitch, yaw and Roll. Later on, an accelerometer and a GPS unit will be added, so that thing will be able to hold it's altitude. THe software will read the inputs from the Gyro's and then calculate proper commands (pulses) that will be send to the receiver, and then onto the ESC's to control the thrust of each propeller. The "blades" which are actually "propellers" are fixed pitch...and they are standard props as used in many electric airplanes. I want the thing to have some lifting power to lift a camera, so they are 12x3.8. Should provide some good lift, since there will be 4 of them going! So much more to do, yet so little time....

Author:	Stuart Gort [ Wed Mar 17, 2010 2:45 pm ]
Post subject:	Re: ..and now, for something COMPLETELY Different!
cyborgcnc wrote: The "blades" which are actually "propellers" are fixed pitch...and they are standard props as used in many electric airplanes. I want the thing to have some lifting power to lift a camera, so they are 12x3.8. Should provide some good lift, since there will be 4 of them going! So much more to do, yet so little time.... Are you aware of assymetrical thrust and gyroscopic precession as design variables? If not attended, assymetrical thrust in this design they will cause the whole unit to rotate when aloft. Gryroscopic precession will cause instabilty on every horizontal axis. The opposing propellers should be counter-rotating which will alleviate or maybe even eliminate rotational movement but gyroscopic precession will be ever present and it will require a pretty good little program to make this thing fly straight and level. If rotational movement is negligible then the unit MIGHT hover ok....but withour tackling precession the thing will be unstable trying to manuever. I'm a semi-retired propeller designer and did many research projects for aerospace companies. You might be able to fly this by hand but a lot of the directional movements will seem arbitrary unless you understand how these forces are applied to your application. If you do understand them and you are able to compensate by hand....you'll be in the rare company of microprocessors. Usually, stablilization issues stemming from quantifiable variables (like precession and assymetry) are solved with software. Once those issues are addressed the thing can be flown by hand. Also remember. This is a pure static thrust application. Static thrust isn't created by taking a small volume of air and moving it fast...but rather, by trying to affect as much volume as possible. Turning a larger prop slower is far better than trying to turn a small prop faster...to make static thrust (gathering static air and inducing input flow). That's why helicopters have 30" rotors turning at 400 rpm. The same engine in a Robinson 22 helicopter and a Cessna 172 makes 2500 pounds of static thrust and 950 pounds respectively. The thrust is configured to make the wings do the lifting in the Cessna but the Robinson has to lift straight off the ground. Maybe, if you have plenty of thrust, this isn't an issue (depends on gross weight) but it should be understood that the same hp can achieve two to four times the static thrust if efficienty applied to that end. I never dreamed I'd be talking about props here.

Author:	cyborgcnc [ Wed Mar 17, 2010 8:12 pm ]
Post subject:	Re: ..and now, for something COMPLETELY Different!
That is why this thread is COMPLETELY different!!! All excellent points....thanks for that. Props: Two will be pushers, and two will be tractors...in other words, both producing thrust down, but fore and aft will be rotating CW, and the left-right will be rotating CCW. This should stabilize the craft when it comes to rotation. Now, it should be a simple exercise to have the craft rotate, by accelerating one prop, and slowing down the other. Same for forward flight (fore-aft). Basically, the principle of the thing is here: http://en.wikipedia.org/wiki/Quadcopter Everything you stated makes absolutely perfect sense, and the one thing I am struggling with is the amount of weight this thing will be able to lift, given the amount of thrust 4 props will produce. Looking at some manufacturer data, I can extract some thrust numbers (in grams/kgrams) which will be then directly related to the amount of weight (theoretical) this thing will lift. Need to add up my batteries, wire etc etc...and see what I come up with. But then it is all related to the amount of current the battery will pump, etc. Hopefully in a months time, I will have video of this thing flying, or crashing! LOL! Code is not that bad, in fact there are a couple of sourceforge projects, and a couple folks over at diydrones, that are having success. Another thing which I have not done with my CNC machine (yet) is to cut a circuit board, by "isolation" routing. In the old days I used to whip out the etchant solution and copper clad, but we will see how better the CNC machine does with a small bit.

Author:	cyborgcnc [ Mon Mar 22, 2010 8:09 am ]
Post subject:	Re: ..and now, for something COMPLETELY Different!
Well, Finally cut all the parts, and put her together with a little paint.... So much more to do...but I think it came out nice...

Author:	Stuart Gort [ Mon Mar 22, 2010 1:27 pm ]
Post subject:	Re: ..and now, for something COMPLETELY Different!
I'm not getting that photo. Maybe stick a mid-rez .jpg when you get a chance. Otherwise, have fun with it.

Author:	Stuart Gort [ Mon Mar 22, 2010 1:33 pm ]
Post subject:	Re: ..and now, for something COMPLETELY Different!
Zlurgh wrote: I'm not getting that photo. Maybe stick a mid-rez .jpg when you get a chance. Otherwise, have fun with it. nm......now I can see it. Wow! Awesome! What is that frame made of? Seems to me the thing is designed around the idea of possibily reproducing it via plastic injection molding. This is a marketable idea.

Author:	Stuart Gort [ Mon Mar 22, 2010 1:56 pm ]
Post subject:	Re: ..and now, for something COMPLETELY Different!
cyborgcnc wrote: Well, Finally cut all the parts, and put her together with a little paint.... So much more to do...but I think it came out nice... Maybe check out : http://catalog.ides.com/DocSelect.aspx? ... =STD&DC=en That's a plastic injection material with about 1/4 the strength of 6061-T6 aluminum at about 1/2 the weight. If you were going to injection mold those parts at some point that might be a good choice.

Author:	cyborgcnc [ Tue Mar 23, 2010 7:03 pm ]
Post subject:	Re: ..and now, for something COMPLETELY Different!
Sorry about that gents....screwed up the link.... Hope this is working now? I used G-10 (Garolite, Phenolic)...that stuff is strong!! Zlurgh wrote: I'm not getting that photo. Maybe stick a mid-rez .jpg when you get a chance. Otherwise, have fun with it.

Author:	Ziegenfuss [ Thu Mar 25, 2010 7:07 am ]
Post subject:	Re: ..and now, for something COMPLETELY Different!
Hey, You should check out the new ST Microsystems iNEMO board. It has enough peripheral ports to be adding in GPS and comes with a host of 3 axis sensor to allow for the creation of your GPS enabled "hover board". Plus, you get to write in C. I will have to check out the Arduino board though... Enjoy! Stephen

Author:	cyborgcnc [ Thu Mar 25, 2010 8:51 am ]
Post subject:	Re: ..and now, for something COMPLETELY Different!
WOW..that board is sweet!! Well, mine looks a little "simpler" than that one....I cut out the PCB, using a method known as "isolation routing" on my CNC the other day....came out pretty dang good, using a .020 bit to do the routing, and .030 bit for all the drilling.... Like I said, less sophisticated, but she is blinking!! The more I use my CNC machine, the more in LOVE IT!!!!

Author:	npalen [ Thu Mar 25, 2010 9:11 am ]
Post subject:	Re: ..and now, for something COMPLETELY Different!
"GPS enabled "hover board". Wow! Interesting stuff guys and I'm not even into RC let alone electronics to any depth. Nelson

Author:	BobK [ Sat Mar 27, 2010 9:08 pm ]
Post subject:	Re: ..and now, for something COMPLETELY Different!
Not to hijack, but this guy knows how to push the envelop. Bob

Author:	BobK [ Sat Mar 27, 2010 9:11 pm ]
Post subject:	Re: ..and now, for something COMPLETELY Different!
Not to hijack, but this guy knows how to push the envelop. Bob

Author:	cyborgcnc [ Sun Apr 04, 2010 5:55 pm ]
Post subject:	Re: ..and now, for something COMPLETELY Different!
All, We have LIFTOFF!! Could not be happier with the initial code run....basically, a simple program running on an Atmel PIC controller, that reads the inputs from the gyros, and then commands the ESC's to spin-up or spin down the motors. This thing could NOT be possible to control by hand, given the number of motors, but the code sure does keep up with it! Needed to do some initial trimming with my TX before she was stable, but I can almost fly hands off. Hopefully, this will also soon be reality with the integration of a GPS unit, and then an accelerometer, which will provide much better precision for positioning, than the gyros do now... Finally convinced the wife to hold the video camera..... http://vimeo.com/10624120 What do you think?

Author:	JohnAbercrombie [ Sun Apr 04, 2010 6:50 pm ]
Post subject:	Re: ..and now, for something COMPLETELY Different!
cyborgcnc wrote: What do you think?

Author:	Athena [ Sun Apr 04, 2010 10:17 pm ]
Post subject:	Re: ..and now, for something COMPLETELY Different!
cyborgcnc wrote: What do you think? Awesome! I finally got around to watching the video tonight. That thing totally rocks! What's next? A radio controlled super-soaker? ...Ath

Author:	Stuart Gort [ Wed Apr 07, 2010 12:29 am ]
Post subject:	Re: ..and now, for something COMPLETELY Different!
Very impressive!!

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