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Foamboard Grumman X-29 w/ 50mm EDF

#1
Hi everyone!

I'd like to show you all my new X29 design:

IMG_20160109_120506_70p.jpg

So I finally got to take her out for a maiden flight, and I didn't crash and burn!

She was tail heavy on the first launch, but I got it right on the second launch. Unfortunately, she was really underpowered with a 50mm Dr. Mad Thrust EDF and a 3S setup. She couldn't fly at all until I removed the top hatch that gives access to the receiver and ESC. With all that extra inlet area the thrust was just enough to keep her in the air.

I'm only using two 9g servos to actuate the control surfaces. I've got each servo controlling an elevon on the wing as well as at the back of the wing strake. She was very stable in the air and this control setup actually worked really well! I just need more POWER!

I don't have a thrust tube right now, so that will be my first change. I'm thinking about trying a 4S, but I don't know of my EDF can handle it. What do you guys think??

This is what I've got in there right now:
http://www.hobbyking.com/hobbyking/..._Thrust_50mm_10_Blade_Alloy_EDF_400 0kv.html

I designed this plane using Sketchup and I'll be making an article with plans once I get the power issue straightened out.

Some specs:
LOA: 36"
Wingspan: 23"
AUW: not sure, probably 700g?
CG: where the LE of the main wing meets the fuselage.
Max speed: ~25mph

Here is the vid!

 

wilmracer

I build things that fly (sometimes)
Mentor
#3
Very nice! Looks quite stable, which is always a challenge with the x-29. Did you use any stabilization? I built one years ago and could never get it flying right.
 
#4
Thanks guys!
Wilmracer: nope, no flight controller, just an HK-T6Av2 receiver and Flysky i6 transmitter. The battery is up forward, between the intakes, velcroed to the floor. I was pleasantly surprised with the stability, and the stall charteristic. It seemed to have a high-alpha mode that it would lock into at low speed, and then a little down elevator would drop the nose a bit and she would gain speed. But yea, it flew well hands-off, just really underpowered.
 

wilmracer

I build things that fly (sometimes)
Mentor
#5
Nice. Yeah, hands off isn't a term I would have used to describe mine. Did you actuate the canards? The jetset44 plans I used had actuated canards, aft strakes, flaperons, and rudder and use linkages to slave the strakes and canards and mixing to blend in flaperons with elevator input. I had a gyro on pitch to help with it getting super pitchy at certain speeds and AOA and porpoising in general.

Good luck with upping the power system. Looks like a nice flyer!
 

earthsciteach

Moderator
Moderator
#8
Nice job! I am very surprised that it is that stable.
The 3300 kv Mad Thrust edf is rated for 4s. Heck, I'd drop a 4s in yours and see what happens. But, that's just me and I am not saying its the "sensible" thing to do.
 
#9
Saiga: I think I'd be happy enough with another 30% thrust. I added a thrust tube and some initial testing with the "hand dyno" indicates this made some improvement. Here is a pic...

IMG_20160111_224715.jpg

I'd probably need double the thrust for vertical capability though. To get that much extra I think I would have to get these:

64mm EDF
60A ESC
1800mah 4S Lipo

Those parts add up to about an additional $70. So we'll see!

EarthSciTeach: I like your idea... drop a 4S in there and let 'er rip! :D
Of course it would just be a quick flight and then check the motor temp... right...
 

Jaxx

Posted a thousand or more times
#11
Centus,

Very nice work! I would try scaling it up to fit a 64mm EDF. With that 10-blade fan, I believe a 4s would burn up that motor. How long have you been using Skechup?
 
#12
Crash: Thanks man!
Jaxx: Yea, it might fry the motor. Maybe I'll grab a FrSky temperature sensor and get telemetry going on my i6... :)
I've only been using Sketchup for a couple months. I got started using Jason Anderson's tutorials on YouTube. I'm an engineer by trade and have experience with AutoCAD and Rhino so I think that helped to pick it up quickly. That being said I think it is great free software and pretty user friendly. The flattery plugin was awesome for making the plans. Do you use Sketchup too?
 
#13
I've only been using Sketchup for a couple months. I got started using Jason Anderson's tutorials on YouTube. I'm an engineer by trade and have experience with AutoCAD and Rhino so I think that helped to pick it up quickly. That being said I think it is great free software and pretty user-friendly. The flattery plugin was awesome for making the plans. Do you use Sketchup too?
Hey, I know this comment wasn't directed at me but I would like to ask a question. I use Sketchup pro-2016, and Jasons tutorial's, but I cannot figure out how to turn everything on the file to a PDF. It will only let me turn what is visible on the screen at the time of export. Any help is much appreciated!
Colin
 
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#14
Sure Colin, here is how I made .pdf's from Sketchup:

1. Arrange the pieces in Sketchup how I'd like them to appear on the pdf
2. Select all of the pieces you wish to export and make them a component
3. With the new component selected, use the flattery plugin to export to .svg (see picture below!)
4. Open the .svg with Inkscape (also freeware!)
5. Inkskape can be used to edit the .svg if you wish. I usually just open the .svg and goto "Save As", and pick .pdf.
6. Then I print the .pdf using PDF X-change Viewer.

It is kindof a roundabout way to do it, but at least it is all free software. Good luck!

Here is a picture of the "SVG output" button in the flattery plugin. Also in the picture is my sketchup model of the X29 v2.0, which I've been working on.

x29_v2_sketchup.png
 

Jaxx

Posted a thousand or more times
#15
Jaxx: Yea, it might fry the motor. Maybe I'll grab a FrSky temperature sensor and get telemetry going on my i6... :)
I've only been using Sketchup for a couple months. I got started using Jason Anderson's tutorials on YouTube. I'm an engineer by trade and have experience with AutoCAD and Rhino so I think that helped to pick it up quickly. That being said I think it is great free software and pretty user friendly. The flattery plugin was awesome for making the plans. Do you use Sketchup too?
I've been wanting to get start playing around with Sketchup for quite some time now, but can't seem to find the time. In all honesty, I'm a little intimidated as well. I have no CAD experience.
 
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#16
Well, let me just say this: I tried using Sketchup at first last October because I wanted to make a DTFB design of this X-29. I went in cold with no instruction, and found it to be very frustrating because it didn't work like Rhino or AutoCAD. It is quite possible that my previous experience with CAD actually hurt my adoption of Sketchup in this case.
It took until December, when my wife was on business travel, when I decided to give it another shot. So after work I cracked a beer and sat down with Jason Anderson's tutorials. It was important that I was actually working on a plane design while watching, instead of just watching the tutorials and trying to remember everything when trying to design the plane later on. Anyway, it took probably 3 nights of 2ish hours each to get through all the videos, but it was a very rewarding and fun experience.
Anyway, I think that the Sketchup/flattery method of designing DTFB airplanes is a great combination of accessible (free!) and powerful. If you do decide to get started with the tutorials and have questions or need help feel free to PM me and I'd be happy to help out.

Good luck and have fun!
 
#17
I feel like my AutoCAD experience also hurt my initial use of sketchup. I still find myself trying to so thing as though it was AutoCAD sometimes.

I would rather use AutoCAD but the cost is prohibitive. Using AutoCAD with a tool like flattery would be much better.
 
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Jaxx

Posted a thousand or more times
#18
Well, let me just say this: I tried using Sketchup at first last October because I wanted to make a DTFB design of this X-29. I went in cold with no instruction, and found it to be very frustrating because it didn't work like Rhino or AutoCAD. It is quite possible that my previous experience with CAD actually hurt my adoption of Sketchup in this case.
It took until December, when my wife was on business travel, when I decided to give it another shot. So after work I cracked a beer and sat down with Jason Anderson's tutorials. It was important that I was actually working on a plane design while watching, instead of just watching the tutorials and trying to remember everything when trying to design the plane later on. Anyway, it took probably 3 nights of 2ish hours each to get through all the videos, but it was a very rewarding and fun experience.
Anyway, I think that the Sketchup/flattery method of designing DTFB airplanes is a great combination of accessible (free!) and powerful. If you do decide to get started with the tutorials and have questions or need help feel free to PM me and I'd be happy to help out.

Good luck and have fun!
Thanks! I really appreciate you willingness to assist.
 

erice3D

Junior Member
#19
Great build.. I built an 80% viggen over the summer. I also used the Dr. Mad 50mm 4800kv 3s version.
I tried it a couple years back on a delta with no luck on 3s but it was way under the 18a it rated for. So I decided to go for 4s it only draws 18a with the air frame and battery @ 14.5 oz. Its not a rocket ship but I would say in the 50+mph range with an output diameter of 50mm as they are really 55mm edf units. I was getting about 15oz of thrust. Hope to see plans for your bird..
 
#20
Erice3D: Nice! I'm definitely going to try a 4S based on your experience. Also, this past Saturday I flew the X-29 with the new thrust-tube and I was surprised with how much better it was! Last night I got 75% through building the v2.0 with changes to the design based on what I learned from the v1.0. The fuse on this one is alot stronger and stiffer, also the inlets are larger and come off the ground a little so hopefully they scoop less dirt upon landing!

I will most certainly be posting the plans and build instructions to this version as soon as I can verify that it flies well.