Dreamflight Ahi aerobatic glider - Page 120 - RC Groups
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Feb 12, 2018, 01:22 PM
DWA
DWA
1Corinthians 13:1-8
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I finally got a chance to maiden my Ahi yesterday.
What a pleasure to fly. Can’t wait to get some more stick time with it.

Dave
Latest blog entry: Carbon Fiber Bird
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Feb 12, 2018, 01:27 PM
DWA
DWA
1Corinthians 13:1-8
DWA's Avatar
Quote:
Originally Posted by Phil.Taylor
found this on the vimeo slope soaring group - a swarm of Ahis in Bavaria - looks like fun !

https://vimeo.com/253321954


That does look like fun!




Dave
Latest blog entry: Carbon Fiber Bird
Feb 16, 2018, 07:41 PM
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Bille's Avatar
Quote:
Originally Posted by miksterr
Hi all,

AHI and servos ordered Wondering what receivers are people are using? I am a Spektrum user and see the carbon canopy. Do I need extended antennas to have them exit past the carbon?

Thanks,

Mike.
Here is my setup for the AHI.

I use a Lemon 6 ch receiver with diversity antennas. One antenna goes straight backwards, the other downwards just in front of the receiver. This way the carbon canopy does not interfere with the RF signal. It is best to have the antennas separated as much as possible and at 90° angle to each other.

The servos I use is Emax ES3352, which is exactly the same as the DF servo, but the cable is longer so there is no need for an extension cable from the aileron servos, when the cables is inserted from the back, and I think this makes the cockpit setup cleaner. In The square opening intended for the wires, I have a magnet switch.

I am not fond of NIMH batteries, they are much too bulky and takes long time to charge, so I made my own battery from two nano-tech 750 mAh LIPO combined into a two cell 7.4v battery. It gives me about 4 hours flying time. I had to remove some foam as it is a bit wider than the NIMH, but it is only about half the length, so the CG is spot on without any ballast. The flying weight is 332 g.

To protect the servos from damage, I made servo covers by vacuum forming 0.5 mm plastic plate.

Regards Bille
Feb 19, 2018, 09:26 AM
Registered User
Here are a couple of photos of the bits to make a Madstab mod for my Ahi.

Just got to assemble it all, at last a use for my new 3D printer/laser cutter.
Tailplane is larger than standard one and total weight looks like it will be a few grams more.

David
Feb 19, 2018, 10:42 AM
Gliders ain't drones!
Zenmaniac's Avatar
Nice. Is there any reason that the laser cut parts couldn't be printed instead?

... and would you mind sharing stl files?

-= Dave
Feb 19, 2018, 11:24 AM
Registered User
I just cut and pasted the original .svg drawings into Inkscape which produced a series of gcode files for my Creality CR10 Mini printer with Laser attachment.
I guess you could 3D print the 3 part 5mm plywood part and 3 part bellcrank out of plastic but I do not have the skills or software at the moment.
If someone else knows how to do this then they could produce a kit of parts to sell to would be modifiers.

David.
Feb 22, 2018, 03:03 AM
Registered User
Well I got to try out the Madstab mod yesterday, and all I can say is you must try it.
It was so easy to do the flip. I tried diving a bit and managed 5 consecutive flips.
However before I could try some filming, the Ahi starting twitching, so I landed.
Where the linkage had no slop before, it now moved up and down by a few mm as the thread was no longer tight.
I am now thinking of making the whole bellcrank and thread assembly removable so that if this problem happens again you just screw on a new one to the elevator pushrod.

What was surprising is that I moved the CG back about 7mm as recommended and it flew perfectly, this maybe due to the extra tailplane area or the fact that it is now all moving as opposed to fixed tailplane.

David.
Feb 23, 2018, 08:20 AM
Registered User
fly2bob's Avatar
Just a dab of CA at each end of the thread ought do it.
Feb 23, 2018, 08:42 AM
More Pile-it than Pilot
mdennis's Avatar
Quote:
Originally Posted by f3fisa
Where the linkage had no slop before, it now moved up and down by a few mm as the thread was no longer tight.
David.
What type of thread are you using? It sounds like your thread stretched, typically we use a kevlar thread that does not stretch.
Mark
Feb 23, 2018, 10:12 AM
Registered User
Quote:
Originally Posted by mdennis
What type of thread are you using? It sounds like your thread stretched, typically we use a kevlar thread that does not stretch.
Mark
It was using some strands of Kevlar twisted together, but I have now ordered some Kevlar thread, which looks a lot better.
I have just 3D printed the Bellcrank part using PLA and by using some 2mm carbon tube and M2 threaded tube and rod have made the whole actuating part removable from the elevator pushrod.
I'll publish some pics and .stl files when I have finished.

David.
Feb 23, 2018, 01:45 PM
Registered User
RJD1234's Avatar
Can you provide a video? Like to see how the setup works.

Richard
Feb 23, 2018, 01:51 PM
DWA
DWA
1Corinthians 13:1-8
DWA's Avatar
Quote:
Originally Posted by f3fisa
Here are a couple of photos of the bits to make a Madstab mod for my Ahi.

Just got to assemble it all, at last a use for my new 3D printer/laser cutter.
Tailplane is larger than standard one and total weight looks like it will be a few grams more.

David
Looks like a very good setup.
Latest blog entry: Carbon Fiber Bird
Feb 23, 2018, 03:41 PM
Registered User
I've only copied this setup below, but added a couple of changes.
I'll post some images when I have finished the 3D printing.

https://voltige-planeur-rc.net/2018/...u-need-to-diy/

Feb 24, 2018, 09:11 AM
DWA
DWA
1Corinthians 13:1-8
DWA's Avatar
Crazy!
Latest blog entry: Carbon Fiber Bird
Feb 24, 2018, 02:52 PM
Air is huge!
pgts's Avatar
Wow guys, that's SOOO cool to see you did it!!!
That's the best recompense to my little work.
Thanks again to Steve who helped for translation.

Hope you will enjoy and continue to share!

Stéphane Combet from France


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