Official FlightLine RC 2000mm B-24D/J Liberator Thread

[WrightBrosRC]

Hey there fellow B24 pilots! I had what I thought was a flap servo failure recently. No noticable problems for numerous flights and then the surprise single flap deployment on final :Scared:

Recovered safely and landed without flaps. Ground testing revealed the servo operated normally until some gentle pressure was applied to the flap with my finger and then it would fail intermittently. My flaps deploy using the xmitter speed reduction. I still don't know for sure if operating them slower causes other issues such as this. When I return the flap servos to full speed the servo has no failures but still no difinitive proof that one causes the other. Slowing the operation speed may only reveal the servo is getting weak and not be causing or attributing to the failure.

For my own peace of mind, I am choosing to replace the flap servos with an option that works smoothly with the reduced speed and re-test.

I have only read of Hugh having a similar concern in the past. This doesn't appear to be a frequent failure. Has any else had similar experiences?

-Den

[Hugh Wiedman]

Hey Hugh, I saw that article as well and had the same thought, I know her, at least through her dad and HobbySquawk!!

My wife has been in that magazine several times, a lot more than I have and she barely flies. But she does take some mean pics though

That's her with the camera, there are variations of this shot and sometimes its printed in reverse!

Grossman56

How cool, clearly your better half.:Cool:

[Grossman56]

Hey Hugh, I saw that article as well and had the same thought, I know her, at least through her dad and HobbySquawk!!

My wife has been in that magazine several times, a lot more than I have and she barely flies. But she does take some mean pics though

That's her with the camera, there are variations of this shot and sometimes its printed in reverse!

Grossman56

[F106DeltaDart]

Brought out my B-24 to Warbirds Over the Johnson Space Center this weekend, and flew it in some pretty nasty crosswinds. I got a few photos next to Mike Liable’s beautiful scratch built nitro powered B-24. Unfortunately, the big B-24 was grounded due to the intense crosswind. In an interesting twist, my B-24 ended up being awarded “Best Multi Engine” the event, since I was one of the only multi engine pilots to brave the winds.

[cclark8871]

Just ordered and received my model Friday. Plan on starting on it soon, as I will use some of the model as a test bed for finishing up my Jack Stafford B24 Ive been hoarding away. I must say the detail and assembly instructions of the Motionrc model is pretty good and the manual is well layed out..

[theoldALFER]

Me, too :Cool:

[MikeT]

I also saw it in MA. Congratulations.

Mike

[Hugh Wiedman]

Wow, thanks, I'll let my daughter know she's almost famous. Happy Easter to you and all the Squawkers as well.

[Hardway]

Happy Easter Hugh!!! ;)

[Hardway]

I do, and I saw the article when it came out!!! Told my wife, HEY LOOK, I know that guy (from here at least) …… :Cool::Cool::Cool:

[Hugh Wiedman]

Finally got around to looking at the April edition of Model Aviation and went to the table of contents page and there was a picture of my daughter holding one of my B-24's. At first, I thought what the hell, where did they get that, then I remembered I submitted a short article and pictures for the District News way back last May when our club held our annual Warbirds festival. Sure enough, went to that page and there was my "article" with other pictures. Another club member who has had his articles published and who the editor had asked him for more articles submitted a great write-up with photos, but they never published it. I submitted mine just for a short District article and told them to watch out for the real article, never thinking they would publish mine. My daughter got a big kick out of it, but I didn't have the heart to tell her that I don't think many people actually read this publication any more.LOL

[WrightBrosRC]

Coated both my Silver and Olive B-24's with the water based exterior Gloss Spar Urethane. Love the hard "shell" it gives and especially the shine. The CG on the Silver did not change at all, 76mm, but the CG on the Olive did and I had to add 1 ounce in the tail of all places to get it back to 76mm, why one and not the other, no idea. I checked the CG twice on each plane before and then 3 times after (because of the difference in the one and not the other) but that's what it is. Used the Great Planes CG Balancer and it's always been pretty good for me, so I have no reason to question the results. We'll see for sure next time I fly each one. :Sweating::Thinking:

You have a nice pair! :Cool: Beautiful work Hugh!

[Hugh Wiedman]

Coated both my Silver and Olive B-24's with the water based exterior Gloss Spar Urethane. Love the hard "shell" it gives and especially the shine. The CG on the Silver did not change at all, 76mm, but the CG on the Olive did and I had to add 1 ounce in the tail of all places to get it back to 76mm, why one and not the other, no idea. I checked the CG twice on each plane before and then 3 times after (because of the difference in the one and not the other) but that's what it is. Used the Great Planes CG Balancer and it's always been pretty good for me, so I have no reason to question the results. We'll see for sure next time I fly each one. :Sweating::Thinking:

[WrightBrosRC]

Got some more flight time on the Dragon. Speaking of flight time.. 12 to 15 minutes? Easy enough to get the hours for your rating ;)

[Hugh Wiedman]

My flaps on the L-39 does this from time to time and I've narrowed it down to something in the control box that doesn't like a slowed down flap deployment. When I reduce or eliminate the flap activation delay, never a problem again.
I don't know how other feel about this, but I think this is wrong. If your flaps are at full deployment (ie, for landing), the servo arm should be near one end of it's travel. The way you have it, you are not using the broadest span of the servo's travel. You are using less than 1/2 of your flaps servo's travel. On all of my planes with flaps, "0" flaps (ie, flaps even with the wings) sees the servo towards (but not completely) one end of its travel, just as full flaps is near the other end, with take off flaps somewhere in between (and not necessarily at 90 degrees depending on how much take off flaps you like). This may or may not be the cause of your flaps occasional "sticking". I'd start by disconnecting the rods and cycling the flaps to see if you can duplicate the sticking. In that scenario, you can also manually move the flaps to see if there is any impedance to their smooth operation - fix as needed. If the disconnected servo still sticks, then I would suggest that there may be a problem in the control box, perhaps a bad ground or other connection.

Thanks xviper and WrightbrosRC, those are some great suggestions to get me heading toward a solution. I'll let you know if I find anything. Thank God this forum exists so I can get the help from RC brainiacs like you guys, I really appreciate your help.:Cool:

[WrightBrosRC]

Anyone having any problems with their flap servo's on the B-24's? From virtually day one, one of the flap servos gets stuck in the down position about 1 in 4 flights. After it comes in, I give a little push and it goes back up. I have never been able to get it to stick on the ground, even thought I "recycle" the flaps about 20 times and they work perfect. I always forgot :Silly:which one it was by the time I got it home to replace it, then last week it did it on 1 of the 5 flights I did, and it was the right flap-OK, now I wrote it down. Darned if the very next flight 20 minutes later, the right worked perfect and the left got stuck in the down position. It's not that big a problem, just have to make sure I don't extend the flaps during flight to retrim it, and extend only when I'm getting ready to land. My first thought was that maybe the servo arm was in an "extreme" position on full flaps, but no, its exactly at a right angel (90 degrees) at full extension, giving it the best and easiest possible leverage when fully extended. I'm baffled (more so than my normal insanity). :Thinking: I'm using the 4s 4000mah Admirals and get about 7-8 minutes flying time and still come in with 40% battery power. Can't figure out why they get stuck only when flying.

Hey there Hugh, I have two thoughts from what you have shared. Both seem to point to the servo as the problem. You said you could not create the problem on the ground via cycling the flaps. Also you said that some pressure on the flap/servo makes it function again. I would recommend more ground testing while placing some simulated wind pressure on the flaps during deployment. My guess (its just a guess, lol) is the feedback loop which maintains proportional control within the servo is having a problem.:Confused: xviper is correct about the possible speed sensitivity issues too. They may be related.

I'm not an expert, but I did stay at a Holiday Inn Express last night. LOL Good luck with your testing. I'm curious to find out when you nail it down.

[xviper]

Anyone having any problems with their flap servo's on the B-24's? From virtually day one, one of the flap servos gets stuck in the down position about 1 in 4 flights. After it comes in, I give a little push and it goes back up. I have never been able to get it to stick on the ground, even thought I "recycle" the flaps about 20 times and they work perfect. I always forgot :Silly:which one it was by the time I got it home to replace it, then last week it did it on 1 of the 5 flights I did, and it was the right flap-OK, now I wrote it down. Darned if the very next flight 20 minutes later, the right worked perfect and the left got stuck in the down position. It's not that big a problem, just have to make sure I don't extend the flaps during flight to retrim it, and extend only when I'm getting ready to land. My first thought was that maybe the servo arm was in an "extreme" position on full flaps, but no, its exactly at a right angel (90 degrees) at full extension, giving it the best and easiest possible leverage when fully extended. I'm baffled (more so than my normal insanity). :Thinking: I'm using the 4s 4000mah Admirals and get about 7-8 minutes flying time and still come in with 40% battery power. Can't figure out why they get stuck only when flying.

My flaps on the L-39 does this from time to time and I've narrowed it down to something in the control box that doesn't like a slowed down flap deployment. When I reduce or eliminate the flap activation delay, never a problem again.
I don't know how other feel about this, but I think this is wrong. If your flaps are at full deployment (ie, for landing), the servo arm should be near one end of it's travel. The way you have it, you are not using the broadest span of the servo's travel. You are using less than 1/2 of your flaps servo's travel. On all of my planes with flaps, "0" flaps (ie, flaps even with the wings) sees the servo towards (but not completely) one end of its travel, just as full flaps is near the other end, with take off flaps somewhere in between (and not necessarily at 90 degrees depending on how much take off flaps you like). This may or may not be the cause of your flaps occasional "sticking". I'd start by disconnecting the rods and cycling the flaps to see if you can duplicate the sticking. In that scenario, you can also manually move the flaps to see if there is any impedance to their smooth operation - fix as needed. If the disconnected servo still sticks, then I would suggest that there may be a problem in the control box, perhaps a bad ground or other connection.

[theoldALFER]

Thanks guys.
Boomer, I’ll “tighten up” my aileron’s tension - good idea. :Cool:

[boomer108]

I'm fairly sure the little bit of roll I had on take off was attributed to being out of trim. I haven't noticed any regular problem?

I don't know if this could be your problem but when I first started flying I would sometimes experience the same problem. I came to find out that I was inadvertently pulling a little right aileron when I was pulling up elevator. So tightened up the stick tension and haven't had a problem since.

[Hugh Wiedman]

Anyone having any problems with their flap servo's on the B-24's? From virtually day one, one of the flap servos gets stuck in the down position about 1 in 4 flights. After it comes in, I give a little push and it goes back up. I have never been able to get it to stick on the ground, even thought I "recycle" the flaps about 20 times and they work perfect. I always forgot :Silly:which one it was by the time I got it home to replace it, then last week it did it on 1 of the 5 flights I did, and it was the right flap-OK, now I wrote it down. Darned if the very next flight 20 minutes later, the right worked perfect and the left got stuck in the down position. It's not that big a problem, just have to make sure I don't extend the flaps during flight to retrim it, and extend only when I'm getting ready to land. My first thought was that maybe the servo arm was in an "extreme" position on full flaps, but no, its exactly at a right angel (90 degrees) at full extension, giving it the best and easiest possible leverage when fully extended. I'm baffled (more so than my normal insanity). :Thinking: I'm using the 4s 4000mah Admirals and get about 7-8 minutes flying time and still come in with 40% battery power. Can't figure out why they get stuck only when flying.