rvnrcer

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I wasn't planning to as there is a really good build thread on here already. I will post some pictures of the engine install as I have used a 1" prop extension to get the engines back more into the cowlings. I didn't want to hack out a big hole in them. Should have it back on my workbench next week. Trying to get my Electra rebuild done first.

SWORDSN

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Always nice to see different solutions to the same problems.....but only if you want to.

70 ragtop

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Well, been quiet here, so I figured I would post a couple pictures of the repairs. It's not pretty, but its getting there

Finished laying up the motor box pieces. The lite ply really sucked up the resin. Wondering if the hair spray trick might elevate that in the future?? Anyways, they came out heavier than I was hoping, but still only about 3.5 ouches per box, and seem like they will be super strong once glued.

Been wrestling with getting the correct angles on the firewalls, or should I say motor boxes. As mentioned before, my YA-38 was badly damaged in a crash, and the right boom at the firewall area was pretty bad, and the left only damaged on the bottom half. Since I'm going electric, decided to save a little weight by not building the strength back into the firewall area with glass and 1/4" ply, but build a couple boxes that tie into the front spar and original firewall area.

Think I finally got the angles right, and made a jig to support the motors in the correct location during assy.

Couple pictures of progress.

SWORDSN

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Your jig looks better than some builds I've seen.

540chevelle

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I would love to join the P-38 Lightning Brotherhood .I am working on a Z-P38 now .I hope to get it flying this spring.

SWORDSN

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Anyone seen the finished cockpit for the YA P38? Or have a picture of it?

kram

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In the winter of 2003-4, I also purchased one of the original CBA-38's from Tim Johnson, who had re-fitted it with DA-50's counter-rotating. I flew it that year and found it heavily wing-loaded and prone to pancaking on the runway when your airspeed dropped to less than 40 mph. I was admittedly intimidated by this characteristic on a 600 ft runway and I've never flown it more than a dozen times. The few unfortunates of you that attended the 2006 Multi-Fly I'm sure remember me trying to land it in a 40 mph head wind that crazy day! I've since done some body work on it and rehabbed some tired landing gear and it's ready to go! It only has to inboard split flaps weakly driven by air system, so that may hurt its low-speed envelope, and I have investigated correct CG all the way back to the designer and maker and have it at supposedly correct 7.5" back from the LE. At 126", it's the largest Lightning I've flown.

panhandler

Count me in Mike

I am in the process of heavily modifying the Nitro 90. P-38
All modifications are from ram3500-rcu kit.

At the moment I am in the detailing stage.
When I first purchased this ARF kit 2 years ago I had no idea I was going to take it this far. But have to say the journey is very exciting.
Before painting I covered the entire bird with liquid sheeting from Wowplanes ( almost no sanding ;}
For power plants I am going electric.
Rimfire 1.20
Phoenix Ice 100 esc's
Gens Ace 5000 mHa 6S1P 60C bats
Robart retracts modified to electric from D&L
Planning on Xoar 16-6 props


Dan

kram

My Feedback: (7)

Also during those giddy years, I acquired my most heart-breaking 38: a Robart-38 all the way from Frank Tiano in Florida. It was beautifully done-up: Sierra gear, the finest electronics, Fuji-50's, a gleaming enamel paint job, and the whisper of Greg Hahn's name attached to it as an early or partial builder. I grew to love the Robart design: uniquely accessible engine and nose cone compartments, a light airframe that floated at low speeds with the flaps down. Unfortunately, the plane was obviously assembled by poorly supervised amateurs: riddled with mechanical flaws. I spent the next 3 years in a race to find and fix them all before one of them did me in. I separated retract air from leaky brake air
systems, I rebuilt loose firewalls assembled pinless with ?Elmer's glue, I re-engineered all the loose and sticky gear door flaps, I vibration-proofed every loose screw on the plane, including servos, I re-manufactured a warped elevator, etc.. Perhaps the worst was an engine-out incident in the 98 degree heat of Iowa Warbirds 2006, where I saved the plane, but came up 100 yds short of the runway in very tall, very hot corn. I still owe a couple of magnificent strangers a steak dinner for braving that jungle to help me retrieve it. Post-incident analysis revealed the cause to be gasoline tanks assembled with glow fuel plugs, which degenerated over time, a flaw which escaped by best attempts at thorough inspection!


My love-hate relationship continued until October 2007, when a routine flight degenerated into a full throttle 45-degree dive over which I had zero control. I think I lost radio contact with it and I blame the whip antenna PCM set-up it came with, although I have no proof. I have no pictures of the incident because the dive ended right in the middle of the Skunk River which runs 1/4 mile from our field. We couldn't find the wreckage except by spotting flotsam debris going downstream. When we saw no more debris floating, we figured that was the spot, and I drug it out of cold 5 ft deep current. I saved the main gear, but lost the nose gear somehow, which was hanging by a thread when I first got to it.

kram

My Feedback: (7)

My fondness for the Robart-38 airframe continued beyond Mama's Boy's death. For a king's ransom, I acquired one of the few remaining Robart kits on RCU Classifieds and I still have the Sierra gear and I got a couple of rear-exhaust souped-up G-62's from Toni-Clark. That and now with 2.4 GHz radio technology, I figure are the basic components of a "bullet-proof" P-38.

And I will build it someday.

And anyone with an ounce of common sense will recognize the cynicism in my voice when I speak the ultimate oxymoron: "Bullet-Proof P-38"

Welcome to the Brotherhood!

kram

My Feedback: (7)

CONFESSION: I have a P-38 I've never flown, which is basically a violation of my "If You Don't Fly It, It's Not Yours" rule. I think it's called an Art Johnson Model and it is at least partly built-up a long time ago. I bought it from Rick Simmons right before we lost him to Dark Ops about 4 years ago. He had it done up in red Yippee trim, but then re-surfaced and painted it right before selling it to me. It has a 93" wingspan and feels pretty heavy, Robart gear and was outfitted with tuned-pipe Moki 1.5's when Rick flew it. It was REALLY fast! I cogitated over the delicate and detailed engine-running instructions he gave me for a couple of years, then decided they violated another basic rule of 38's: dependable engines. Changing them out for OS 1.20-P FS's didn't prove as simple a job as I imagined, but it's done and ready to fly. It has no flaps and everytime I watched Rick fly it, he landed it very hot, so that may be some of my procrastination.

70 ragtop

My Feedback: (24)

LOL, that's just because the plane is so ugly!

Now that I figured out how I want to lay it all out, the other side went pretty quick.

Plan is to glue mounting blocks to the front spar for the motor boxes (watching glue dry now), finish fitting/gluing the boxes, and get everything inside the fuse done. Will then glass the fuse back together with the motor boxes removed. That way, I have really good access inside to seam it. Hope to finish engine area this weekend and the last "big" thing I need to add structure in the nose so the gunner doors can be made removable.

Really anticipating what the weight will be when I get it off the jig! Not worried about repairing/finishing the outside, worried about the bodywork/paint weight though! Time will tell

Mike

70 ragtop

My Feedback: (24)

540chevelle, welcome to the brotherhood, you are #20

Lets see some pictures!

Glass booms, or builtup? What engines?

70 ragtop

My Feedback: (24)

Here is the one from just the pits http://just-the-pits.billr.org/p38pit.asp pix 8&9
Few pix I found online from the precision scale guys. They are good for ideas, last one speaks for itself

70 ragtop

My Feedback: (24)

Welcome Dan, you are number 21

Would love to see some pictures of your build! Good to see another electric P-38..

I'm not too familiar with that motor, but if it is 450KV, on 6S, I'm thinking a 16x6 might not be enough pitch. At 93% efficiency, that is right around 9300 RPM, or 52 MPH. I think I might start with a MA 14x9 three blade for first flight. Same RPM would give you around 76 MPH, and they have great takeoff acceleration


I'm a little worried about cooling the motors as the spinners block the cooling air. I have a few ideas, but haven't decided yet. What are your thoughts?

Mike

70 ragtop

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Kram
That is a beauty!
You building the Robart model yet?

kram

My Feedback: (7)

No

kylelord

My Feedback: (1)

Hey Mike Count Me in
I have a 4+ year ZP-38 in progress. Its all framed up and glassed and waiting for primer.
With my limited warbird experience I decided to get a Ziroli Dauntless going to practice heavy plane flight.
I've also been working with the twinstar, simulator and will have a Great Planes 38 to fly in the spring.
If I'm lucky I'll be able to maiden her in the fall. I"m going to be finishing it with flite-metal in the Pudgy V scheme. My father got me into Thomas Mcguire Jr AFB to get some documentation of the full scale. Amazing to see it it in person!
What club do you fly with in Ct? I've been a member of the Propbusters in Salem until I went to college and joined South County RC in Rhode Island.
Thanks!
Kyle

SWORDSN

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Kram,Those are great stories. You certainly don't discourage easily. I agree with you ,if you have it fly it.

kram

My Feedback: (7)

"Don't discourage easily." That's a nice way to phrase whatever is wrong with me

I've got plenty more stories: like the day I took off the big CBA-38, and I saw the nose wheel roll down the runway as I lifted off.......flew around for 20 minutes trying to plan my landing!

panhandler

I would be happy to post a few pictures. At the moment I just painted the belly so when it is safe to handle I will take some pics and show you how I plan on cooling the electrics.

You are correct on the KV of the motors 450.
The manufacturer suggest a 16-8 prop but we all know this is a starting point. I am coming up with the same numbers as you in Moto calc.
Thank you for the advise and a set of 14-9-3 are on the way. When they arrive I will test and see what the draw is.

Dan

SWORDSN

My Feedback: (13)

Keep em coming

540chevelle

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The p-38 has a pair of counter rotating DA 50Rs for power smart fly radio system robart gear robart wheels and brakes. I am making a mold for the canopy frame now. Few more touches and it will be ready for primer. I will post pics soon. Thanks

Jim Branaum

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That reminds me of an early jet rally I went to. This guy did a touch and go in a Mig-15. When he lifted off the three wheels continued down the runway in perfect formation! The next landing was in the grass....

70 ragtop

My Feedback: (24)

Hi Kyle, welcome, you're number 22

South County RC, is that the club right along RT 95? Nice open space there!

I belong to Quaker Farms RC in Oxford, but do most of my flying on a dead end street right around the corner from work. Half heartedly looking for a new club with a bigger field, but haven't found one close by yet.