pcf_mark

I am trying to join this brotherhood. My Ziroli P-38 is coming along nice but I have stopped with the flaps. From what I have read fowler is the way to go. I see several designs and the version by Kram looks the most robust, lowest weight and with the least amount of intrusion into the wing design / structure. Does anyone have any actual flying experience with different fowler designs? I see various posts of building but not too much on successful flying.

Thanks in advance. Going back and adding or changing that later would be a huge hassle!

Fili

Hello? Anyone here? I'm also trying to join the Brotherhood. I'm knee deep in my Ziroli P38 build.

kram

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Fili:

Building a Z-38 pretty much makes you a Brother, I’d say.

Flying it means yer a lifer

There's a lot of good info buried in this thread which can be useful to you

Please post pictures and feel free to ask advice. Lord knows that’s one thing we love to give away!

Thread seems quiet lately, and that correlates with my general feel for the Brotherhood: 38’s are complex builds, ARF surge seems to have stopped, and they are often exciting, but short-lived models, then guys move on to more reasonable, safe projects. Maybe there will be a cyclic resurgence when the vaccine opens things up.

I am more pathologically afflicted: despite several mishaps, I still own 2 flying 38’s and 3 others in varied forms of development. Experimenting with electric twins lately, so I’m thinking of converting an older VQ-38 I bought to electric.

Seminal Advice: ENGINE and GEAR failure are by far the leading culprits in P-38 loss. Take care of that and they’re not that hard to fly. For yer Z, get Sierra gear if you can afford it.
Makes a huge difference!

mt

Fili

Thanks! I built the Royal P38 many moons ago, they’re so different in the sir! I lost her having too much fun, ran her out of fuel. Those were the days of no timer on the radio.

Anyhoo, I’ve built several twins. Engine reliability is a big thing... we’ll see!

Fili

( sorry about the last post, I typed that on my phone...)

I have an older friend who loves to cut kits. I recently finished rebuilding my Z B25 from an incident when he announced he had cut me a Z P38 with hopes of me building her and finishing her as "Yippee. Reluctant to built yet another twin, I started her as he recently turned 82 and I would really like him to see this thing fly.

Not sure what engines yet, and yes, sierra if I can sell the kids to afford them. Lol

kram

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Very Nice!

Looks like most of the actual building is done

I had to retro-build Fowler’s on my CBA to tame the beast. (That took me 2 months!) but my experience with Ziroli airframe is that it lands nicely with split flaps

I have a prejudice towards Zenoahs and OS for my twins, due to reliability, and of course you’ll need weight up front anyway, but I do have counter rotating DA’s on the CBA and with a little help from the boys in Arizona and Viton tubing, they have been 100% reliable

308jockey

Evening everyone,

I've been lurking around here and finally got a P-38, in this case a Royal kit. I have a pair of OS 61 FX engines that should pull it around just fine but I'm wondering if I could set this plane up as an electric. I've got several electrics so I'm not new to that game and also have a couple of twins but don't know if the Royal kit is big enough to install everything I would need for this plane. What motor would be enough to fly it with power to spare? Will I be able to use big enough batteries to get an 8+ minute flight? I'll be installing retracts too, probably electric. This kit has never been unpacked so I haven't looked over the plans to see what the dimensions are but it's an old design and I doubt electric was on anyone's mind at the time. I can run the OS engines and they've always been reliable but electric is intriguing. It would definitely be easier to set up counter rotating props. Will it work? Also does anyone make fiberglass replacement parts for things like the cowlings and other detail parts? Fiberglass Masters maybe? Thanks.

Rick H.

kram

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Interesting project and questions

I do love the 61FX as a reliable motor. I put about 140 flights on a VQ-38 with them, never suffered an engine-out

I must recuse myself from serious discussion about the Royal-38 kit and electrification of P-38’s, however, having no hands-on experience with either.

there are good threads by reputable guys on RCU about e-38’s. They loved them: not sure how they turned out. Need to do do some research and inquiry.

E-motors do suffer failures, of course, although I haven’t suffered one on my 82” Otter YET, and I’ve been very impressed with precisely matched rpm’s and battery life, easily getting 10 minute flights

Otter is not a 38, though. Not even close!

mt

kram

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Yes, reversing rotation for an e-motor is ridiculously easy: just switch 2 of 3 motor wires.

As with combustion motors, finding high-quality reverse props is the hard part!

Fili

here’s my Royal P38. I think from around 99’ or so. Two OS SF .46’s in her, she was fast! I think I got fiberglass cowl for her at fiberglass specialties.

70 ragtop

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Good to see some life here again, and some great looking projects
For those asking to join, if you love the P-38 ( or even if you just like it), consider yourself a member!

I've got a few twin electrics, and still think the Yellow P-38 is the perfect electric warbird. Here's a video of my Yellow P-38. First flight in a year, weak batteries, and I forgot to set the timer....so I landed early. Batteries are 5 or 6 years old now, and the plane is clearly slower than it used to be, but it still hauls, and is a blast to fly

Fili

Love the video Mr 70 Ragtop! Thanks for the ok to join the Brotherhood!

kram

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Could you please give us basic specs on your Yellow e-38?

Weight, motors batteries, ESC's?

Thanks,

Mark

70 ragtop

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Hi Mark

Right now it's flying with Scorpion SII-5535-190KV and Vario 19.9" adjustable pitch props. ESCs are Castle Edge 120s Gens Ace 5300 with 10 cells per side (10S). These are 5-6 years old now, but they still do fine in this plane
Weight has got to be around 37-38 since I put the heavier motors in it. The motors were a pound heavier, plus lead in the tail to balance it. If you'd be happy with 18" three blade props, a few good 160 size motors should work fine. I actually think a 160 size motor is the perfect size motor for this plane. Only catch is the typical KV is around 240-245, which means you need to run a little smaller diameter with less pitch.. That said, I flew with that setup for a while, and it flew great.

Here's the thread for it, shows all three setups I've run https://www.rcgroups.com/forums/show...and-conversion

BTW, the Iowa P-38 is jigged up on the bench, and I started tacking it together...just need to wrap up a couple long term projects before getting serious

sudstad

Iowa P-38?

pdierking2

hi I am currently in school at UAB and am currently working with a group to design a uav aircraft to be flown in an AIAA competition. We are designing this aircraft from scratch and are looking at modeling it after a C-130 because of the missions that are to be done. Because of this the aircraft is designed to be quit long reaching 53 in. An idea we had to help reach items in the front of the aircraft is to make a removable nose cone that is attached to the fuselage and has the ability to raise up and latch back in place when positioning is done. I am just curious if anyone has any idea if this is worth exploring or should this idea be scrapped quickly.
Thank you for any advice.

grego351

Hello 70 Ragtop,

I am currently working on three P-38 projects as I am really hooked on this aircraft and it all started innocently about 18 months ago when I decided to 3D a 1.6M wing span P-38. Enter P-38 project number 1. The plane is printed now and being slowly assembled and I have a reasonable electric setup planed. During the time I worked on this I always wanted a bigger scale P-38 and so I have now taken over a scale build but it will be a while before I finish the sanding, glassing and painting. So enter P-38 number 2 which is about a 83" wing span scratch build off the plans. Just a few weeks back in searching for other things I came across what apears to be an even larger old ARF kit. Thee is no manufacturer marketing but it seem to be a scale like P-38 with 90" wingspan and is to be my quicker path to the air and test bed for the scale project. So enter P-38 number 3.

At the moment I am restling with what electric motor, prop and esc's to use and have spent quite a bit of time reading this brotherhood thread and other including your yellow aircraft P-38. The kit is about a 1/7th scale so from original 138" prop dia , a 20" bladed prop like your currently flying would be ideal if I could only find a place to buy it from. I sent a quick email off to remosa germany but what I am not sure about is the exact model of hub your using? Is it the 16D and if so which particular 16D model My prefernce is to attach such a hub using the typical prop adapter and nut but if you had some photos of the way you have attached the scorpian motor that would be great. I should have started with what propeller I can source first becuase this seem to be a sticking point. A good price and close to scale setup would be perhaps using an 18 x 10 3 bladed prop but I cannot find the right brand and shape in 18" dia. Can you tell me what brand of 18" prop you used previously with the Tacon 160 motors. I must admit for the lighter ARF p-38 I am building the tacon 160 ( 5335 245KV I think) is lighter. Right now I can get at least the master airscrew 16 x 10 and run a counter rotating setup but it just doesnt look big enough. I could run these props with a scorpion S-4025-12' (440KV I believe) and the number do seem to come out ok in eCal. Anyway I hope you can share some more infor on the props you used in the earlier 90" P-38 with Tacon or even the earlier scorpion motors. Just another data point if I was to use the same setup your flying now there is only 2 to 2.5" clearance to the ground under the prop arc. I am not sure if this is enough. I will try to attach a couple of photos of my 3 x P-38 build at the moment but I dont think RC universe will allow me.

70 ragtop

My Feedback: (24)

Hello
I used the same Ramoser 16D light hubs for both 17.9 and 19.9" blades. The blades 456-16 and 456-16-L for the 17.9" and 505-16 and 505-16-L for the 19.9".
The Scorpians have a long shaft with threaded end, so simply purchase hub with hole to fit motor shaft, and secure with nut. One the Tacon, I used prop adaptor bolted to bell end. The 5030 Scorpians used a spacer/collet setup, but still a threaded shaft. Ramoser sells shaft adaptors for their hubs if that's the way you want to go. I believe I "roughed up" the back side of the hubs, and I wasn't shy about tightening up the nuts, as hubs will slip if not tight. Be sure to use lock Loctite on the CCW motor

For the 83 and 90" models you mentioned, the S-4025-12 . A lot depends on how you want it to perform, and what it weighs. I tried lots of props on those motors on my green 90" P-38, which weighed roughly 22-23#. The Master Airscrew 16x10 is a good fit, pretty good around setup. It is high on amps on the ground, but they unload a lot in flight. I ended up flying APC 15.75x13s for a while. They are glow props, so they do pull a lot of amps, but they also pulled the plane around really nicely
I put the Tacan 160s and 18" Vario props in the green plane on 10S, just to try out the combo, and it was massively overpowered. Same setup flew the 36+ lb Yellow great
I later fit the same APC 15.75x13 props to the Tacons, and it was a blast. Too fast for scale, but it was sport scale anyways

As far as the 19.9" props, I added an extra pound of motor, and another half pound of weight in back to be able to spin the 20s. I still ended up trimming the cord some to give them a little different profile, and lower the amp draw. The setup overpowers the Yellow P-38, and I have the props dialed back. Pretty sure they could easily spin the 19.9" props with a 20 pitch with no problem, but it's already plenty fast. I found myself overflying our field pretty quickly with them set at 16 or 18 ( don't really remember). I think they around 12 pitch now, and that's a pretty good setting
As far as the 138" model, couldn't tell ya. At that size I would look at what's being used in converted 80-90" warbirds

These pictures are from the Yellow thread on RCG, there are a bunch more there
Lets see some pictures of the builds!

grego351

Thank you for the detailed information on the Varioprop hub used and detailed electric drive and prop information. Fantastic data. By the way in one photo of the Tacon 160 showing the prop adapter is that the one that comes with the motor? In the email I have just received from Ramoser they asked if the Tacon prop shaft was at least 30mm long to take the 16D hub? I think I will start with the 16 x 10 prop for now based on limited battery choices and while I wait for the parts from germany. I have done many calculations in Ecalc by the way now and whilst I would like to use the Tacon 160 it seems thats the combination of varioprop 17.9 x 12 with 10S pushes the motor well past its power ( wattage ) rating. I am seeing about 2800-3000 Watts on a 10S battery which it over the motor 2700 limit. However, if I coudl only find an 8S lipo equivalent in battery around 5000-6000Mah all of the numbers come out great. But it seems no one sells many 8S batteries these days I only found one Turnigy Nanotech 8S @ 5000 MAH which might do. In order to use a 10S system (like you have now e.g Gensace 5300 10S I would have to go with the Scorpion II 5535-180 motors and these are considerably heavier and almost $400 US each (4 times the price of the Tacon) Although with the Scorpion 5530-190 at least I have the choice to run either 18" or 19.9" varioprops. I did find one interesting corner case were I could use 10S with the TACON 160 and the 16 x 10 master arscrew 3 balded prop, That produced a good flight time in Ecalc but a very fast pitch speed. Question.When you ran the TACON 160 with the 17.9" x 12 varioprop on the 16D hub and the gensace 10S 5300 per motor Did it over heat or is Ecalc showing the high current on the ground (~80+ AMPS) and 3000 Watts ( over the 2700 rating). Could really benefit from your observation of this battery pack and motor heat observation after flying the Tacon 160 @ 10S here. Did you use the Tacon and 17.9" prop for many flights or was it a once off and you went back to that 17.75 x 13 you mentioned.? RIght now for the 90" plane I am building the TACO 160 with Variopro 17.9 and limtiing the pitch to around 10.5 might work on 10S. But I need to know how many flights you made with this combo as I suspect the motors might burn out based on ecalc data, Thank you again 70 Ragtop for the help and advice

70 ragtop

My Feedback: (24)

No worries, happy to share

I flew many flights with the Tacon 160s and Vario props in the 36+ pound Yellow P-38. If flew very well with that setup, but it’s not super efficient. The RPM is too high to take advantage of the variable pitch, a lower RPM/higher pitch setup would be better
I looked for a similar sized motor(5335) with a KV around 190-210, but never did find what I was looking for what I as willing to spend at the time. I think that size with a lower KV would be the perfect motor to spin those props in a 35+ pound twin

To answer your question, it is over amps on the ground, but unloads quickly in flight. Pretty sure I shared that info, and posted ESC downloads to match flight videos in the RCG thread.
Our home PC died a few years ago, so I lost all of that info, what’s posted in the thread is what I have. That is the stock prop adapter, and they are too short. I used red Loctite to make sure they stayed put, but yes, they’re too short. I think I may have machined the face some as well as I remember a problem getting props to spin true. There are clearly better 160 sized motors available, I was just being cheap

The 5535 are a lot of motor, a better fit might be the 5525, closer to 160 size. I plan to reuse the 5030-220 I originally had in the Yellow in a BertBaker P-38 build. Same size as a Yellow, but I think it will be a good bit lighter. They actually flew the Yellow really nice, they just ran out of ump pulling thru the top of a loop..... you could say they flew it scale, but it was a pretty light weight setup with great cooling
I say mine is 36+ as that’s what is was when I was still detailing it with the 5030s in it. It got heavier with the 160s, and a lot heavier with the 5535s. IMHO, I wouldn’t go with such heavy motors in a 90” P-38.

Hope info is helpful
Mike

jmdunstan

I am planning a Ziroli P-38 build, and would appreciate any advice on servo selection. Specifically, would Hitec HS645MG servos be appropriate for all control surfaces? Also, I would appreciate advice on gear door operators - air cylinders or servos?
Thanks

WWIIP38

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Built a Yellow Aircraft P-38 in the '90's. Had 2-Moki 2.10's

70 ragtop

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I haven't built a Ziroli yet, but 645s would be my choice ( with two on elevator). As far as doors actuators, if it were my project, I would do air retracts with air cylinders on the doors with a UP3 valve.....just my 2 cents

FlyerInOKC

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Back when the earth was young and still cooling I had a Jr. High teacher Mr. Winger. He was a former Squadron Commander and Colonel in the USAAF who's squadron had been tasked to photograph Normandy before the June 6th invasion. His squadron was outfitted with P-38s with cameras replacing two of the machine guns in the nose. In all their sorties they only loss one man, he did his victory roll over an antiaircraft gun. Dragging war stores out of him was a chore so I don't know much. I have been considering a future P-38 project at some point but I have some limitations in storage and transportation. I would like something in the 80" to 98" wingspan is there a kit, plan, short kit, you guys can recommend?

WWIIP38

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It's hard to find a P-38 kit that size any more. Legend Hobby sells an ARF. Old Royal kits were 74", a box of balsa, and a lot of work. Motion RC sells the Fiightline foam ARF's which are nice but smaller.