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Jan 06, 2013, 03:57 AM
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Invertmast, she is shaping up nicely. Remember your going to need a few degrees positive/nose up ground stance for takeoff, otherwise it will want to stay "stuck" to the ground. I have approx. 4 degrees on mine. I wouldn't go more than 5 - 6 degrees positive, unless your going to have a nose strut that is adjustable in flight - to decrease incidence prior to landing, otherwise she may want to bounce like a kangaroo on landing.

Regrading CG - It is a process of checking and double checking on this model. I used to put a few hours into this. It can be tough to get this model to stay level on the balancer. It will still want to tilt or rock slowly fore or aft. Work on getting it to stay still and level on the balancer - but bear in mind Gary Hethcoat had told me: "you know your CG is right on when it tilts either direction equally, just by breathing on it practically".

As you can see, things with a 229 are "different" from most other models. That is true of takeoffs and landings as well.

Mark
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Jan 06, 2013, 04:04 AM
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Do you use the scaled up CG position of Garry's HO-IX or have you just calculated the position?
If you have a calculated position move it more to the front when going for the maiden.

Just to compare the CG-Position.
At my Ho-IX with 3360 mm wing span and 1500 mm length in the center, the CG is at 550 mm from nose to back.

Heiner
Last edited by heiner; Jan 06, 2013 at 04:16 AM.
Jan 06, 2013, 06:55 AM
Designing something...
Thomas,

John's doing it right! I do pretty much the same thing...



Brian
Jan 07, 2013, 12:17 PM
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thtaco's Avatar

Some balance pictures


pictures of horten on balancer.
Jan 07, 2013, 12:25 PM
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thtaco's Avatar

lathe


The lathe looks good in my shop. Now we can make our own landing gear.
Last edited by thtaco; Jan 07, 2013 at 12:40 PM.
Jan 07, 2013, 12:40 PM
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FliteMetal's Avatar
I looked at another Horton CG recommendation last evening. It did not have the scale incidence while on the
ground as noted by the designer the scale position caused the model to "leap" off the ground prematurely
instead of simply lifting off. Their incidence on the ground or angle of attack, which ever you want to call it...
was a 1/4 inch differential between leading and trailing edge...

Just a thought.
Jan 07, 2013, 01:02 PM
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Ed,
The whole ground-stance is another debate in and of itself. Conventionally, an airplane is required to "rotate" to take-off. But the Horton brothers designed this airplane to lift off the ground on its own when at flying speed with no rotation necessary.

Not seeing how the smaller 82" version left the ground with the scale ground stance, I can't say for sure, but we are planning to give it a fairly flat (+2-4*) AoA while it is on the ground and slowly increase the length of the nose gear to try and get it close to the correct ground stance.

Will it be possible. I don't know, but we are gonna try it out!
Jan 07, 2013, 01:37 PM
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John told it before,

you should have 4 - 6 degree angle of attack for taking off. If you have 3 flaps at each wing you can manage landings without a movable front gear leg.

I made almost over 70 flights, I know what a beast the Ho-IX can be.

Heiner
Jan 07, 2013, 07:38 PM
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The wife decided to leave for her parents a day early, so I got the evening to goof off before leaving tomorrow.

I spent a few hours cleaning up the shop since it was a wreck.

Then I chopped out 16 L brackets for servo mounts:


then I bolted up the flap servo's (JR ST-126MG) and the one elevon servo (jR 8711) to the brackets.


Then I installed the elevon servo to its mount plate and made up the linkage. There is VERY VERY little room between the lock-nut/servo arm and the drag rudder. so little in fact, that i had to sand a bit of the bottom edge of the corner of the drag rudder away. Its a very tight fit, but it fits.. barely!


Then I cut out the access panel for the linkage to clear. If I wanted, I could apply some .005" G-10 over the majority of the linkage hole and blend it in to conceal the linkage. but the way it currently is, you can remove the access panel without disconnecting any of the linkages. I like how this is convenient so i'll leave it as is:


since the available mounting area for the elevon servo is limited, I had to route out a bit of the access panel in order for it to fit flush over the aft edge of the servo:



and a youtube vid:
1/5.4 Horton 229 progress 1-7-2012-1 (7 min 41 sec)
Jan 07, 2013, 10:04 PM
Team EJF >>>WHOOSH>>>
AceMigKiller's Avatar
Just caught on to this thread. Amazing job!
Jan 08, 2013, 03:13 AM
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Thomas

I looked at your video and you are nearly there! Just a few comments.

I guess you were using some spare JR 8711 servos. If it is any interest I have JR 8411 servos for all the elevons and flaps on mine. 8711 is way overkill.

Most important though is that you must have more differential with the ailerons than appears on the video. You want about 25% down 100% up. If you have too much down the plane will fly on straight and will not turn as we found out on our first flight.

Heiner is spot on with the need for the incidence angle of fuselage/wing on its wheels to achieve takeoff. I have seen 5 Hortens flying now and they all have around 5 degrees angle of attack. Using the flaps with crow enables landings to be made with this angle.

I know you want to use scale exhausts, but if it were me I would make the first flight with exhaust extensions on. Then at least you can prove everything else works ok before you can try removing them.

Good luck with the first flight.

John
Jan 08, 2013, 09:09 AM
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thtaco's Avatar

120" Giant scale horten in the back of a Hyundai Accent


If transporting your giant scale plane is a problem?
Jan 08, 2013, 06:03 PM
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LuvEvolution7's Avatar
LOL. classic.
Jan 08, 2013, 10:02 PM
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Quote:
Originally Posted by John Wright View Post
Thomas

I looked at your video and you are nearly there! Just a few comments.

I guess you were using some spare JR 8711 servos. If it is any interest I have JR 8411 servos for all the elevons and flaps on mine. 8711 is way overkill.

Most important though is that you must have more differential with the ailerons than appears on the video. You want about 25% down 100% up. If you have too much down the plane will fly on straight and will not turn as we found out on our first flight.

Heiner is spot on with the need for the incidence angle of fuselage/wing on its wheels to achieve takeoff. I have seen 5 Hortens flying now and they all have around 5 degrees angle of attack. Using the flaps with crow enables landings to be made with this angle.

I know you want to use scale exhausts, but if it were me I would make the first flight with exhaust extensions on. Then at least you can prove everything else works ok before you can try removing them.

Good luck with the first flight.

John
John,
The 8711 I got a great deal on ($80) and had it laying around, but I still need another. I had thoughts of getting the Spektrum A6030's for the elevons (2xx oz/in of torque and $75/ea).

But after hearing you had good success with the 8411's, I may just go with the Spektrum A6020's which are Metal gear'd and 146oz/in of torque. and the best part, $38/ea!


The differential and all hasn't really be programmed in yet. I just have the servo hooked up for as much deflection as I can get.. I'll do the aileron differential later on (I've also got the frise hinged elevons, so i may not need as much differential as you guys).

We do plan to fly with the tube extensions on until we get familiar with the airplane. We want to be as success-full as possible and not cut any corners in figuring out the EDF issues, and we can't really determine the cause without being familiar with the airplane to begin with.
Jan 18, 2013, 06:46 PM
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Back home.. for about 2 days.. soo while i've got time and before the wife and lil guy come back, its time to knock some stuff out.

My buddy Tom worked on the main gear doors while I was gone, I think he had fun, but he figured out most of those issues.

I got back to a few packages containing nearly everything needed to finish the prototype:


The I swapped out the JR 8711 elevon servo for a Spektrum A6020.


Then epoxied in the flap servo mounts;



Then made up two of the four Octopus servo extensions. These go into the outer wing panel and consist of about 15 feet of wire. I have two more that run from the Rx to the wing root. Those will consume about 20 feet of servo wire alone.



And the gear for next winter's project arrived from Sierra:


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