|Apr 21, 2011, 10:35 PM|
Global Hawk EDF FPV "Angel Eyes"
Just wanted to share my adventure in this fantastic "sport" that I discovered right here with ya'll on RCG in the FPV/RPV hangout.
I have several projects going at any one time, but this is surely the topper.
The Hobby King Global Hawk 70mm EDF is my platform, Fast, agile, lots and lots of room for my need for high tech goodies!
I NEVER do a plane or chopper as its designers intended for it to be, gotta put my own touches on EVERYTHING. You may find my builds interesting. Im a tattoo artist, with background of machinest, industrial maintenance tech, master fabricator, and computer tech. I use every bit of creativity I can muster to build some really neat aircrafts. This is the first time I have ever published one of my builds. Hope you like it.
The GH came with fixed gear, the front, no steer! NOT! As I have been working on this I have been trying to utilize all the space posible to house all the goodies going in.
I appreciate a good fast plane as much as the next guy, but landing them is a pain, and the extra weight of FPV gear brings the landing speed up significantly, so right off before I even begin to put this in the air, I decided on rear flaps.
When I cut the airlerons out, I also cut out some flaps, simply done I just took one of my rulers and traced it out on both wings for a matching template. Looks perfect no?
I used the design of the servo pocket for the ailerons for the flaps and routered them in with a dremel and a neat little bit that looks like it was make by a foam airframe builder! LOL
I notched the flaps back unerneath, right up to the surface, creating a nice clearance for the flaps on only the underside of the airfoil. Keeping the top of the airfoil smooth and in shape, the pocket created on the underside should actually help create some life even while they are up, when down! Oh Yeah! Should be able to pick up a cow, well, a plastic cow? The hinges are set at the very top of the foil, the holes are drilled down at a slight angle to go toward the core of the wing, but the pivot point is right at the top without having the hing actually break the upper surface. Looks damned good!
Nice clean tight seam!
You can see I notched it back quite a bit, should make some great lift at full flaps.
Im using a Castle Phoenix Ice 100 ESC, in order to get maximum cooling efficiency, I have made a nice little pocket for it behind the fan in the rear tube, should work well for cooling with minimal drag, Its well over powered, so Im not worried about it much.
The intake tube looks like a good home for cooling the Castle BEC PRO... The Eagle Tree GPS antenna in in the very back, Everything in its place! Safe from damage should it arise....LOL Too bad I wont be able to put EVERYTHING is such well protected locations... You can see from the last photo, i decided to re-route the motor wires, external also gives me easy access to unhooking the pony's should I feel it necessary..... thats good huh!
Put this bird together!
I know I cant access any of these electronics now without major work, but I think Ive done this so well, I should get many many flights without taking it apart! And its pretty good equipment, all tested and re-tested. ITS A GO!
Using the nice robart pinned hinges turned out to be a problem for the airlerons. By the time I had my holes in good, they were very weak, Not willing to put my work and materials on the line for such a whimpy setup, i cut them off and ground down the hinges ( I learned that trying to remove a glued hinge from a foam wing is the recipe for disaster - if that is, you did a good job in the first place! LOL) I decided to replace the ailerons with balsa, The Dubro pinned hinges are glued, and stapled from both sides on the balsa side, and glued, drilled, and screwed on the foam side. Really very well done IMO.
Mock up! without retracts and gear....
|Apr 21, 2011, 10:40 PM|
Nicely done. What do you plan for spars on the wing?
Very much looking forward to seeing this completed. Nothing quite like a scale FPV FPV plane.
|Apr 21, 2011, 10:52 PM|
If the balsa had arrived timely, I was going to put two splits down the core of each wing, one in front of the factory spar, and one behind, and put balsa aileron stock into the split, adding a full half inch to the linear upper airfoil surface, These would have run the full length of each wing acting as spars as well as shape shifters, then a balsa block in the original spar channel.
None of this happend. I am anticipating buying another model to do that with on the side....
I did go with the CF spars included, I know CF is bad for RF, and Im hoping it wont be an issue since there is so little of it, and I have big plans for improving RF performance too. But if its an issue, I will go to splicing together some fiberglass arrow shafts and replace the spars with such.
Im really wanting to try to arch the airfoils, pretty sure that will be an experiment that we will see! LOL I love to try something out of the box.
Thanks for the interest, Dust
|Apr 22, 2011, 12:56 AM|
I dont' think you need to add anything to the airfoils - that gets complicated really quick. I was worried more about flexing from the additional FPV weight - keep the G's down and you should be fine.
Keep us updated eh!
|Apr 22, 2011, 02:54 AM|
Joined Sep 2010
Subscribed Here you can check my first thread hehe http://www.rcgroups.com/forums/showthread.php?t=1425712
|Apr 22, 2011, 03:06 AM|
Joined Apr 2010
|Apr 30, 2011, 11:14 AM|
A little on the wild side, I have decided to try my hand at the Mobicomm vtx/vrx system.
Its the 2 watt 900 mhz system.
I built up the tuning board, not real hard at all, some fine soldering, but most is pretty basic to say the least. The kit was missing a couple parts, the 4 pin board headers, and it had an extra resistor. The instructions called for the soldering of a part in R3, but in the list and instructions, there is not call out for a resistor value for R3. However when the build was done, there was a resistor left over. Thinking they left it off by mistake, I soldered it into R3. Then I looked carefully at a photo of completed board.....R3 left empty! SNIP! THEN I hooked it up to power! WOOO HOOO! It does work, AND it works awsome! I have use the board to tune in the reciever to the actual transmitter for optimum frequency match!
The receiver is nice, it has some cool features besides fine frequency tuning, and a good rssi out (minor soldering adjustment), and for playing around, scan and seek feature! LOL Havent tried it yet, should be fun! I got an antenna that may prove extra fun! (photos taken without rssi and scan/seek mods).
The 2w tx is NOT adjustable, as the FPV model, the extra weight of adjustability is not on it. Since the reciever is tunable, its still a great set up, my FPV heli is 900mhz too, so when Im flying that I can tune the reciever to that tx and have the same benifits.
During testing and tuning the large silvered areas on the back of the tx got very hot, 2 watts would do that. the lower portion barely got warm, but I decided to heat sink both the silver areas, and the lower portion. The silvered areas of the pcb are the same connection, I tested with an ohmeter, and it was zero resistance strait off, no cap drain. So I carefull trimmed down the center solder points on components between the pads, and channeled out a section in the same shape with a good bit of extra depth for clearance and set up a really sweet heat sink!
trying to keep space used to its maximum potential, and improve cooling on high power tx, I opted to mount the tx in the top of the canopy, the heatsinks in the open air, and the antenna (thank you http://videoaerialsystems.com/)
Even though I intend to respect the 400' AGL rule, I put in strobes and navigation lights as a safety offering to the powers that bee. All my lighting came from RAM. I also added some red features to the style for added visibility to other airspace occupants.
Heard of gorilla glue? this was the first test for me...
Using A123 18650 batteries, I built two 3s packs, channeled out a little more foam from the wing area of the fuse and put the packs together end to end in there. I put a popsicle stick wrapped in elec. tape between the packs, then hard wired them in parallel cell by cell, so they are 3s2p, with A123 thats 9.9v nom at 2000mah. this will go through a buck up converter to 12v. I then "welded" them all in place into the fuse with gorilla glue! Yes, dedicated battery pack! The glue will help the airframe strength compromised from extra weight and removed material.
Then I put in 3 sets of 2p A123 26650 batteries. This hard wires into 3s and "welded" to the airframe, again, dedicated pack! This puts my main drive batteries at 9.9v nom, 4600mah not so awsome? Try this combination on this battery give off 140amps continuous 240amp 10 sec pulse peak!!!!! With my 100amp esc, thats 1000watts of power to an edf motor rated at 1000 watts, only 3,300 kv, = 33,000 rpm but put that speed and power behind and 8 bladed 70mm edf fan, oh yeah, this combination is really well done!
All these batteries are good for over 1000 cycles, and have a performance profile that is incredible, LVC is actually as low as 1.6v/cell! 4.8v LVC for 3s packs! Down from 11.1v hot! And the voltage drop is at the end! check out these curves!
Yeah, they charge up pretty dang fast too, so time down in the field is minimal, the dedicated part is nothing! I have batteries to spare! LOL Well worth the quality of the build to stiffen that frame! This whale will be 3.5 lbs rolling down the tarmac! Crazy I know, but I think its gonna go! its really only 500g.s over max rec weight and thats without flaps (though now Im thinking about balsa on them bad boys). This is gonna be a fast plane! This guy is nervous! LOL
last look down the intake before I suck it down the pipe! Once I get the landing gear on, Im going to scale against the wall to get static thrust in the airframe numbers..... where are them retracts!!!!
EVERYTHING EAGLE TREE!
Got the whole eagle tree warehouse over here! In my shop I mean! LOL FY-20a. Running full ET OSD PRO with alt. and airspeed, brushless rpm, the elogger with all its goodies, eagle eyes ground, lots of cool stuff to come! Please subscribe and watch it come to life! Hope youve enjoyed the show so far!
|Apr 30, 2011, 05:03 PM|
http://www.mobicomm.net/ Sorry, no individual links to items...
Its from Mobicomm.
Its the 900Mhz 2 watt VTX
I bought the full set, package deal,
VTX, VRX, and ATV LCD Kit for fine tuning the RX. It was an easy build. Got Ibcrazy antennas for both.
Got all channel access too, both rx and tx.
Edit - while I was typing I went out for a smoke! ya beat me to the answer, but it was in there! Thanks Scrape. LOL
|Apr 30, 2011, 11:39 PM|
Joined Jan 2009
Very awesome looking plane.
will be great to see it fly. Did you use the standard EDF it came with or upgraded it? Heard the standard isn't too hot.
|May 01, 2011, 01:35 AM|
The standard was a 5 blade, and the blades are actually cut back significantly, its a very minimal design. Would take 60,000 rpms at my guess to get a decent push, maybe more?
My rotor came off a Skyworld JP-700, but I think its the same rotor as sold by AEORC.
My housing came from a stock LX 70mm edf. I was building with parts I already had, but the LX housing is rather nice, and the stators have a real good shape, motor mount is 1000 times better than stock design, stock had two holes set right, two holes slotted, and the shaft hole pressed against the bearing race! Two holes slotted? whats up with that? If you cant get your motor in the mount with four screws, just use two in the slotted holes??? OMG!
So, no part of the edf is what came with the build. huh....
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