Official FlightLine RC 1600mm P-38 Lightning Thread

[Trobinson99]

That peer thing will get most guys everytime! Glad you found it a awsome plane. Same with me. And yes, I had read about the 4mm, and dialed that in before the maiden. It is needed.

SO the funny thing is, about a week ago I invited my flying buddy over to show the plane and discuss the retract work I needed to do. At the time he commented that the elevator surface was out of trim. I think I had it set to the 4mm spot when I built it, and then re-trimmed it to neutral after his comment, forgetting why I had it out of trim.

[mr.frankenjet]

Nice work Arycon , she looks beautiful. Weathering looks very tempting to me on this bird

[MikeT]

I'm doing the final set up on my P-38 and wondered if the Flap / Elevator mix calling for down is measured from the 4MM up called for in the manual or elevator neutral?

Thanks
Mike

[xviper]

SO the funny thing is, about a week ago I invited my flying buddy over to show the plane and discuss the retract work I needed to do. At the time he commented that the elevator surface was out of trim. I think I had it set to the 4mm spot when I built it, and then re-trimmed it to neutral after his comment, forgetting why I had it out of trim.

I hope you put it back to 4mm UP. People who do not understand the requirements of many twin boom model airplanes, can lead to detrimental comments and a few butt clenching moments for those they comment to. As much as they mean well, they just simply don't know. And then they tell you there's something wrong with the way the plane was designed or that you built it wrong. That, then, transcends into the realm of ignorance.
The UP ELE trim is also a requirement for the LX A-10 Warthog and the R2F Venom. Same goes for the HobbyKing Vampire. That was my first twin boom plane and on the first flight, I plowed that thing into the dirt. I ran out of trim movement on the TX and it still kept going down. If you start off with neutral ELE, you will use up quite a bit of your trim range on your TX.

[xviper]

I'm doing the final set up on my P-38 and wondered if the Flap / Elevator mix calling for down is measured from the 4MM up called for in the manual or elevator neutral?

Thanks
Mike

Yes, since 4mm UP is neutral, that becomes your starting point. I don't use a mix for flap -> ELE. My flap deployment is so slow (~5 seconds per step) that it is extremely easy to manually adjust. In fact, if you set the deployment slow enough, you won't even need any ELE compensation (manual or otherwise) since the plane settles in nicely as it slows down with increasing flap.

[downwindleg]

Hey Brandon, way to go on the strut conversion! I just knew there had to be a plane out there with main gear struts that were the right size AND weren't offset like the real P-38. That has been the main reason I haven't wanted to use the fms P-51 struts-except of course for the nose gear. Thanks and glad your involved on this wonderful plane!

[downwindleg]

Say Brandon, just wondering what if any modifications were needed to fit the fms P-51 and P-40 struts in the "pursuit" of excellance. Forgive the pun, but was there any drilling, cutting, etc. needed to make them work? Thanks

[Aros]

Well done on the weathering Arycon, she looks amazing!

Beautiful work there Brandon on your Cali Cutie...It's great to see your work here on Hobby Squawk!

[downwindleg]

One more time Brandon, I noticed that the connecting rod on the P-40 strut and the retract housing is offset. Presumably because there is no offset on the strut itself, So does that rod with the offset come with the strut or did you have to fab that ? And if so, what material did you use? Thanks Again

[RRHandy]

What size P40 strut are you using. Thanks :shy:

[PlaneCrazy]

What size P40 strut are you using. Thanks :shy:

The FW P51 struts are offset so for scale freaks, they're out...............but................they look awesome, they are more than just wire and are easy to install.............just sayin'

[TwistedGrin]

It's been raining for days now in Fort Worth Texas.....even if it stops for awhile our club field will still be very muddy soft for a long time.....so I decided to follow through with setting up my OD P-38 for the Skidoo graphics I ordered from Callie Graphics......

I took the Canopy into Lowes Hardware for a paint match.....they nailed it perfectly with an eggshell finish Latex base. I spent a fair amount of time applying the stripes and back painting in the tail booms....then painting in the rudder tips with white pin stripes. By no means perfect yet represents very well. I might try to weather this airframe but a little apprehensive about it.......

I can't believe I tacked on all of the decals.....they add plenty of close up fidelity yet barely visible beyond 5ft.

I deployed the Du-Bro 2.75inch diamond wheels and moved one of the stock mains for my nose wheel.....now awaiting the rumored V2 landing gear modification package for the struts although I was prepared to customize all three as noted by previous builders on this thread.

I am pleased with the results of my build....and very excited at how smooth and straight the spinner and prop assemblies are turning.....overall this is indeed an exceptional foamy airframe.

TwistedGrin

[Aros]

Another beautiful sortie job! Love the Skidoo...When I get tired of my current livery I may have to switch her to the Skidoo. Looks great!

[Arycon]

Thanks, everyone. Appreciate the compliments. Many great looking birds here...all around. Cant recall names off hand but My Lil Pig, Putt Putt Maru, Calie Cutie and many others. You guys are all doing fantastic jobs with these planes. I grin like an idiot looking at the pics everyone is submitting.

Twisted, what is your nose strut from? Looks like an oleo P-38 strut with suspension. I know lots of guys are using FMS P-51 struts but I must have missed a post about your mod.

[TwistedGrin]

Arycon - the struts are the stock version for now....I painted them silver with an overcoat of gunmetal silver - then a shadow of silver again. Can't wait to see what the stock drop in version struts may be.....although the Flightline P-40B struts with the FMS wheels would still work just fine as others have vanguarded for us!!

23 Skidoo -
The plane, numbered 162, has the markings that Captain Dahl's plane had while he was with the 432nd fighter squadron. Captain Dahl was a WWII flying ace who flew a P-38 in the Pacific Theater. Five victories were needed to become an ace. Nose art is an American Indian brave, running with his tomahawk. Text on side of plane: "Pilot captain Perry J. Dahl / Crew Chief T/SGT Doyle Dowell". Plane is marked with 9 Victories. 23 Skidoo is a saying from the 1920s, and another way to say 'getting out while the getting's good.'

TwistedGrin

[Shirty]

I hope you put it back to 4mm UP. People who do not understand the requirements of many twin boom model airplanes, can lead to detrimental comments and a few butt clenching moments for those they comment to. As much as they mean well, they just simply don't know. And then they tell you there's something wrong with the way the plane was designed or that you built it wrong. That, then, transcends into the realm of ignorance.
The UP ELE trim is also a requirement for the LX A-10 Warthog and the R2F Venom. Same goes for the HobbyKing Vampire. That was my first twin boom plane and on the first flight, I plowed that thing into the dirt. I ran out of trim movement on the TX and it still kept going down. If you start off with neutral ELE, you will use up quite a bit of your trim range on your TX.

I understand as plane crazy said it might just be the design etc, but I'm still not sure why or why moving the battery aft is not a option? Wondering if you can fill me in please viper?

I obviously don't understand the requirements of a twin (this will be my first), but as above, I don't understand why moving the battery back wouldnt eliminate the need for up trim to fly level? Is it impossible to get this plane into a tail heavy condition then? Is there simply no room to move batteries back? I'm very curious as to why it needs to be balanced with up trim added? If there is room to put your battery back a bit, what happens if you do? Would you still need to dial in up trim to fly straight or woukd moving the battery aft eliminate this? and if moving the battery back stops the need for up trim, then why is this not a good idea?

Also, if you add up trim to balance it to fly straight, wouldn't rolling inverted cause it to dive towards the ground? Ie: up trim is used to balance out a nose heavy condition, and upside down with up trim added, would cause it to dive towards the ground quite quickly - as effectively upside down, it now has down trim added. (To a already nose heavy condition you needed up trim just to fly level). How do you fly inverted with this bird then? Do you have to add almost full down elevator as you fly it to compensate for the up trim you added for normal upright flight? Typically if you have a nose heavy condition and add up trim to fly straight, inverted the plane will be a handful as you will need a lot of down elevator to hold it straight inverted.

Could you fill me in please mate, or anyone who knows? I've just never heard of a plane that needed to be balanced by using up trim to fly straight and level, and I can't get my head around why you would do this, especially if you can move your battery aft to negate this trim requirement and I can only imagine the handling is poor (especially inverted), this way?

Not critising anyone, just truly baffled as I've never heard of this, and can't understand the need to balance it this way and I'm curious as hell to find out why it's necessary, why you dint just move the battery back, and what effect this has inverted etc. as I said, I've never owned a twin, but this would be a huge no no with almost any other plane I own, especially 3D birds and I can't see the principle changing because it has a twin boom? Just very much like to understand this before I maiden mine obviously to avoid any maiden issues.

Thanks. :)

[OV10]

I understand as plane crazy said it might just be the design etc, but I'm still not sure why or why moving the battery aft is not a option? Wondering if you can fill me in please viper?

I obviously don't understand the requirements of a twin (this will be my first), but as above, I don't understand why moving the battery back wouldnt eliminate the need for up trim to fly level? Is it impossible to get this plane into a tail heavy condition then? Is there simply no room to move batteries back? I'm very curious as to why it needs to be balanced with up trim added? If there is room to put your battery back a bit, what happens if you do? Would you still need to dial in up trim to fly straight or woukd moving the battery aft eliminate this? and if moving the battery back stops the need for up trim, then why is this not a good idea?

Also, if you add up trim to balance it to fly straight, wouldn't rolling inverted cause it to dive towards the ground? Ie: up trim is used to balance out a nose heavy condition, and upside down with up trim added, would cause it to dive towards the ground quite quickly - as effectively upside down, it now has down trim added. (To a already nose heavy condition you needed up trim just to fly level). How do you fly inverted with this bird then? Do you have to add almost full down elevator as you fly it to compensate for the up trim you added for normal upright flight? Typically if you have a nose heavy condition and add up trim to fly straight, inverted the plane will be a handful as you will need a lot of down elevator to hold it straight inverted.

Could you fill me in please mate, or anyone who knows? I've just never heard of a plane that needed to be balanced by using up trim to fly straight and level, and I can't get my head around why you would do this, especially if you can move your battery aft to negate this trim requirement and I can only imagine the handling is poor (especially inverted), this way?

Not critising anyone, just truly baffled as I've never heard of this, and can't understand the need to balance it this way and I'm curious as hell to find out why it's necessary, why you dint just move the battery back, and what effect this has inverted etc. as I said, I've never owned a twin, but this would be a huge no no with almost any other plane I own, especially 3D birds and I can't see the principle changing because it has a twin boom? Just very much like to understand this before I maiden mine obviously to avoid any maiden issues.

Thanks. :)

Shirty,
You and I are in the same quandary on this issue and I have had all the same exact questions you took the effort to expound upon but have never gotten an answer when asked in a simple request on earlier posts. I unlike you however do own multiple twins(ya think ;)) and this vague explanation of vipers has me rather perplexed. Looking for the logic in the clarification basis.
Best regards,

[Lon]

Hello Lon,
Back on post 1552 I had asked Aros about the 4mm up elevator being rather contrary to everthing I've practiced regarding control surface neutralization in relation to CG adjustments and asked if it was because the cockpit pod has no room to adjust the battery(s) aft more to zero the need for up elevator to hold level flight but he responded with he didn't know. Same question to you........is there room to move battery aft? Even if it means cutting some foam as long as it doesn't jeopardize the hatch latching mechanism?
Thanx,

Sorry I didn't get back to you on this sooner...To have my CG at 70-71, my batteries are very much forward. Yes, there is ample room to move them aft. I've had the same thoughts as you...But i see the recomendations for the CG in the manual, see videos, posts, all talking and flying with good results, to include the 4mm up ele. Maybe after another weekend of flying her. I'll do some experimenting...But then again"If it's not broke, don't fix it!" :shy:

[OV10]

Sorry I didn't get back to you on this sooner...To have my CG at 70-71, my batteries are very much forward. Yes, there is ample room to move them aft. I've had the same thoughts as you...But i see the recomendations for the CG in the manual, see videos, posts, all talking and flying with good results, to include the 4mm up ele. Maybe after another weekend of flying her. I'll do some experimenting...But then again"If it's not broke, don't fix it!" :shy:

Thanx Lon for confirming the room avail for movement aft of the battery, now I'm really curious about that 4mm up elev as neutral. Makes me wonder how much down elevator ya gotta plow into to hold level flight when inverted. There is this BIG whisper going on in my ear saying "the manuals recommended CG ain't right" and of course we have never seen that before. Optimum CG location is where the airframe holds level flight at neutral elevator. ;)

[MikeT]

Thanx Lon for confirming the room avail for movement aft of the battery, now I'm really curious about that 4mm up elev as neutral. Makes me wonder how much down elevator ya gotta plow into to hold level flight when inverted. There is this BIG whisper going on in my ear saying "the manuals recommended CG ain't right" and of course we have never seen that before. Optimum CG location is where the airframe holds level flight at neutral elevator. ;)

There's been a bunch of flights on this with all the testing flights to production flights by owners. Now I had the same issue on my LX A-10 ( up elevator) and it wasn't a CG issue just a combination of things I never figured it out and just lived with it. Seems like if someone played with moving the CG by battery placement to fix the up in the elevator we would have heard about it by now. Guess you guys could give it a try and see if it solves it.
Just my two cents.

Mike