Official Freewing B-2 Spirit Bomber 86" Twin 70mm EDF Jet

[avanti127]

I epoxied the servo horn and put a piece of plastic to reinforce it. Maybe it will do for now. Not sure how I feel about it. If it fails the aircraft could be lost. Ill keep on with repairs until I have another option. Or I may just store it away until parts are available.

Personally I would not consider this risk. Epoxy Vs. $700, $700 and waiting for the right parts is the best choice.

[MeyerVW]

I epoxied the servo horn and put a piece of plastic to reinforce it. Maybe it will do for now. Not sure how I feel about it. If it fails the aircraft could be lost. Ill keep on with repairs until I have another option. Or I may just store it away until parts are available.

[GliderGuy]

Yepper….gotta figure this out. Folks will need replacements, obviously.

-GG

[Evan D]

The servo arm is a specialty item, very different than any other arm I've seen. I would think there would be a way to do a ball on either side of a normal arm but it wouldn't be the same as the stock setup.

[MeyerVW]

Are you talking about this servo horn .......................................?



Can you not just buy this servo that comes with several arms and transplant the double ball thing onto the appropriate arm?
https://www.motionrc.com/products/fr...ad-md31092-400
Sure, you'll have to buy the whole servo just to get that arm, but for 11 bucks, you'll have a spare servo.

Or is it the other end of the rod that's broken - the part on the rudder itself. You've used 2 different terms in your posts ..........................
"rudder control horn" and "servo horn". Which one is broken? If you're looking for the part on the drag rudder, they have stock on those as well for 7 bucks.

Yes thats the one. Its the servo horn for the rudder. Im not sure why the special servo horn buts its offset by alot. So I have not tried using a regular horn. I do have some spare servos so I should have a horn to try it. After looking at the photo there is no good way a regular horn will work. The inner ball and socket would hit the edge.

[xviper]

Surprised that the servo horn is the weak link in that system. And the one part thats not available, that I see. Ill call and ask them if the horn is availble. I just dont see it online.

Are you talking about this servo horn .......................................?



Can you not just buy this servo that comes with several arms and transplant the double ball thing onto the appropriate arm?
https://www.motionrc.com/products/fr...ad-md31092-400
Sure, you'll have to buy the whole servo just to get that arm, but for 11 bucks, you'll have a spare servo.

Or is it the other end of the rod that's broken - the part on the rudder itself. You've used 2 different terms in your posts ..........................
"rudder control horn" and "servo horn". Which one is broken? If you're looking for the part on the drag rudder, they have stock on those as well for 7 bucks.

[MeyerVW]

Anyone have a rudder servo horn, or a complete right outer wing, they would sell?

[MeyerVW]

Surprised that the servo horn is the weak link in that system. And the one part thats not available, that I see. Ill call and ask them if the horn is availble. I just dont see it online.

[GliderGuy]

When you find out about the horn, let us know. Sounds like it might be a good idea to have a spare on hand.

Thanks!

[MeyerVW]

MeyerVW….That does suck!

Is it not possible for someone to 3D print one for you?

Also, for what it’s worth, I once made a temporary horn fix for a different bird by using a thin carbon overlay onto the pieces and JB Kwik epoxy. Got me going while I waited for a real spare. Might take a bit of Dremel grinding to shape once the epoxy cures.

-GG

I can repair most of the damage pretty easy. Its that special control horn they used that's killing me. Its going to be an expensive horn. With the horn broke like that I am not sure how the servo is either. I will have to test it and see if the gears are OK. My nose wheel is also not centered so I will have to inspect that servo too. Not sure if there is a 3d printed one out there.

[GliderGuy]

MeyerVW….That does suck!

Is it not possible for someone to 3D print one for you?

Also, for what it’s worth, I once made a temporary horn fix for a different bird by using a thin carbon overlay onto the pieces and JB Kwik epoxy. Got me going while I waited for a real spare. Might take a bit of Dremel grinding to shape once the epoxy cures.

-GG

[MeyerVW]

So I flew today with the adjustment on the ailerons. I took out 10% and I did not notice the aircraft fluttering from the gyro gains. So I like it. Unfortunately during landing a crosswind hit me and rolled the aircraft onto her side just as it touched down. Some damage but no spares available to repair it. It broke the rudder servo horn and you cannot get them separate. So an expensive aircraft will now just sit there until parts become available. Sucks.

[GliderGuy]

Mshagg - I settled on 50 mm wide top to bottom and 65% or 70% travel in the TX.

They close alternatively with a slight tap at full rudder. That’s as close as I could get.

It appears to me that they blow down some in flight. They don’t look 50 mm wide in flight. Maybe the drag isn’t so much after all.

-GG

[mshagg]

So Q for those of you that have been flying her, let's say the clam shells don't close precisely at the TE when moving the sticks around left right aileron or left right rudder...Would you say there is some wiggle room in the sense that if you aren't jamming the sticks to their end points drastically (and why would you ever do that?!) it shouldn't really effect flight performance or am I totally off my rocker here? I am just trying to gauge how much time I want to spend getting these clam shells dead nuts perfect. Appreciate any comments.

I left the clamshells as they were from factory and just double/triple checked travel and neutral positions were even. I think that's around 70mm gap between upper/lower with sticks neutral. With 100% roll and 65% yaw on the tx they 'tap' together nicely at full deflection. Flew great like that. Avoids the potential for overdriving a $10 servo at full roll/yaw (although acknowledge that's an unlikely control input configuration) and introducing a bunch of slop in the ball link from popping it on and off trying to get it right.

So if yours are somewhere between stock and the setup recommended by Mr Solt, I think it's safe to assume it will fly fine so long as everything is even.

Interested in people's thoughts about different travel settings for the clamshells. On face value I'd guess it has better yaw stability the further open they are at nuetral, at the cost of some drag.

[GliderGuy]

Winds were very light but shifting due to passing thermals. Out of 11 B-2 flights, about 1/2 were light crosswind 90 degrees. By golly, she did OK! Winds were calm to 2 knots maybe 4 knots max. The stronger cross wind I just waited it out in the air to calm.

I had one bounced to a go-around landing.

Ya know….It is simply gonna happen. Don’t be scared of her….it’s just something that’ll happen regardless of how hard you try.

Make up your mind that bounce = go around BEFORE you fly her even once. You’ll be fine.

-GG

[davegee]

Hi Davegee-

Be careful! You cannot have both “IDLE POWER” and “MINIMAL ENERGY”. These are mutually exclusive.

Best to hold her off with ZERO power as long as you can while only a few inches high. Any throttle amount adds energy.

Bring it in like a glider! You can make VERY smooth landings without any power. BUT….you gotta work at it and practice. No need to drop her in. In fact DON’T!

Yes, you can make very smooth, minimal energy landings from a few inches high without bouncing. You don’t want a bounce. Land her like a full scale Piper Cub and NO power. She’s not your average high wing loading EDF jet that needs power to landing.

It’s a learned skill. Ask any RC or full scale glider pilot.

-GG

Edit: With my CG (slightly nose heavy when lifted on the marks), she touches slightly mains first…slightly nose high even with a lot of nose up elevator. Courtesy of the slow airspeed, of course.

Thanks, GG. I could have phrased that a little better, but what I mean is pretty much what you are saying. By "idle" power I'm saying my throttle is all the way back to the stop. I think with air flowing through the motors in the air the fans will still be turning a bit. But yes, I am "floating" it in with power all the way back to the stop, and holding it off in a slightly nose high attitude until it gently touches down. I'm getting pretty smooth landings so far (having only recorded 2 of them!) but your point is well-taken. The landing I got this morning was very smooth, and then I lowered the nose to roll out. Still, with the condition of our runway with lots of cracks in it, I think it will be hard not to have it bounce just a little bit on the roll out. But since I don't have access to a really smooth road or runway to test that out, I can't really prove it at this point.

Cheers

Davegee

[GliderGuy]

#1 When moving ONLY the aileron, the clamshells only open and close a little bit.

#2 When moving ONLY rudder the max stick throw, the clamshells will move enough to close fully on one side while being max open on the other side.

I’m with Evan. In # 2…If they don’t fully close but are symmetrically almost closed on each side as you fully move the rudder stick, you should be OK.

#3 Fully move the aileron stick AND fully move the rudder stick???
Some have addressed this in the prior posts as a potential for servo overdrive. I am never gonna do that, so it is a non-concern for me. I choose to never do #3. No sleep lost.

-GG

[Evan D]

I think you’d be ok… as you say you don’t fly around with full rudder anyway.

[Aros]

So Q for those of you that have been flying her, let's say the clam shells don't close precisely at the TE when moving the sticks around left right aileron or left right rudder...Would you say there is some wiggle room in the sense that if you aren't jamming the sticks to their end points drastically (and why would you ever do that?!) it shouldn't really effect flight performance or am I totally off my rocker here? I am just trying to gauge how much time I want to spend getting these clam shells dead nuts perfect. Appreciate any comments.

[Evan D]

Slightly tail heavy to the marks. Flying off grass dragging tips may not be an issue. Since they are open they hit first.