eagledancer

hey bob
i get what you are talking about on the horz stab... good idea. its basicly what ziroli does with his and that area is solid on the stab should be pretty easy to put 4 ply tabs on the booms and drill through the center section. hmmmm yes bob i do like your idea
my 110 oz servos came in yesterday, guess what i will be doing today lol. also i am planning on using 5 ace noise traps on those long servo leads, and one receiver mounted in the pod. now if that "twin sync" was just availible........

Bob Paris

My Feedback: (13)

Hay Todd,
I'm going with two recievers and two batteries for my airframe. In my F-82 the servo wires became almost a problem for me, and there was less weight with two reciecers and two smaller batteries, then all those freaking servo wires...not counting on trying to keep track of what wire went where. So each receiver will only have six servo's to deal with and no long servo leads.

I was looking at mounting the servo for the elevator on the stab itself aft, but I didn't want part of the servo sticking up out of the top of that flight control. I will modify my sport models to make it easy for me to work on them and I do believe VQ now mounts the elevator servo aft, but they place a bubble over the horizontal stab where the survo sticks out of the top serface. I wonder if I can talk them out of one of their bubble fairings.

A removable stab is a must have for me, or I will not be able to transport the model to the flying field. Ziroli sure has some great ideas for his models...

I have never used an electronic "Twin Sync" in any of my twins. I have found that if your engines are well broken in, and props properly balanced, once airborn and up to flying speed, the engines usually stay close to RPM all themselves. If I can get the engines with in a couple of hundred RPM, I'm happy and the models seem to fly just fine...and to be honest...a little out of sync is music to my ears.

More latter,
Bobby of Maui

Bob Paris

My Feedback: (13)

Hay Buddy,
I just took my kit 100% out of the box, inspected each piece, used a digital postal scale and I now have my dry weight on this kit.

Total weight is 8 lbs 9 oz. Fuel tanks, wing tubes and all controle rods, ect.-(This weight does not include retracts or engines).

Two issues with the kit straight off. One, I only reveived one set of oil cooler boom fairings. Two, the fairings I did receive were warped. There are issues with all the plastic parts, and I will be sending an e-mail with pictures to NP and lets see how their customer service performs.

I have a third issue with the canopy, it is warped, but it is usuable.

All the kit I inspected was made out of balsa and light ply. All the joints looked to have been glued. It is built very light...almost like a larger 3D model, so I am going with .48's for power. This will be more then enough with this airframe built this light and a modified Clark-Y airfoil. I'm at sea level.

The fiberglass work for the engine cowlings is good, and ditto for the nose gun fiberglass piece. I may beef up the cowl bottoms, to give me at least one landing wheels up, for an easy repair. They are lightly made, but I've seen lighter on other kits.

The engine cowls fit good...the gun nose cone...not that good a fit, but livable...and yet, the nose piece is well made.

Here are the pictures of my turbo charger fairings that are warped, a well as the one set of oil cooler fairings warped.

I've more to write on what I found.

Soft landings always,
Bobby of Maui

eagledancer

ziroli mounts the elev and rudder servos in the boom radiators...... you might try that position

Bob Paris

My Feedback: (13)

Hay Eagledancer,
I'm going with the supplied method of controling the rudder and elevator. They use plastic tubes and stiff wire to run down the wing pods to each control and has worked well for me in the past. It's simple, light enough, and keeps the weight forward.

I see that installing the main gear will be a bit of work, but a fine gentelman in an earlier post, Fgpierce, has made templates and has shown the way to do this. I would like to go with 4" main wheels, but maybe some of he wheel will stick out of the fuse. I'm not sure if the retract instilation will cause a problem with assembly of the wing to the pods, but no matter what I do, I will beef up the wing hold downs and convert to 1/4 x 20 plastic screews. I do not like using metal screws and they always turn into a hastle for me.

The Rudder is well built and light. I will need to make an interconnect to get both ends of the rudders to work together. A simple piano wire and brass tube affair will do the trick. When I opened the bag and took out my rudders, some plastic tape was stuck to the covering of the rudders, and this pulled off some color. I'm not sure what it is really...but looks like flat plastic heat shrink covering of some sort.

The nose pod is well built...but very lightly built. As with the booms them selves, both seem very well constucted. All balsa and light ply.

I usually use thin CA glue, and I flow it all over the balsa on the inside of the fuse and wing. It increases strength, and re-inforces brittle wood. It adds little or no weight to the project, but CA glue ain't cheap. I am doing this to my kit.

It amazes me just how light this kit is for its size. Even with retracts and a pound for each engine installed, it will have a very light wing loading for a fighter. My airframe weighs out at 8 lbs. 9 oz. Adding 1 lb. for each engine, and 2.5 lbs. for the retract instilation will give me a GW of 13 lbs. 4 oz. This will give me a wing loading of 28.5 oz./sq. ft. This is still going to be a floater...I may need four wing flaps to slow this model for landing.

I sent an e-mail to Nitro Planes for replacement plastic parts that were damaged and missing.

More pictures guys...

Aloha,
Bobby of Maui

TLH101

My Feedback: (90)

An easy way to to reinforce the rudders, is to cut a slice in the rear edge, with a dremel cutoff wheel. Then insert a thin piece of plywood inside, and maybe a bit of cabon fibre as well.
Also, do not consider using 1 servo for the elevator. You need to use one on each side. That long elevator will twist with only one servo at one end. I know this for a fact. Makes for a strange rolling motion when elevator is applied.
You will also need to figure quite a bit of balance weight into your weight equation. P-38s usually build tail heavy. Especially with those light weight motors.

Bob Paris

My Feedback: (13)

Hay Terry,

Thanks for the information, and I will plan on using two elevator servo's. The kit is set up for two elevator servo's stock built.

I had no idea P-38 models end up tail heavy.

I will go with larger engines before I will will add any lead weight to the nose. I will be beefing up the fuse for the nose gear instilation, so I will add weight forward as it is. I will also place all the retract stuff in the forward nose area. I'm also going with two receivers and receiver batteries...and I can place my gear up into the forward part of each engine pod.

As soon as some one gets their model flight ready...let us know how the model balanced out.

Soft landings always,
Bobby of Maui

eagledancer

i now have the wing "wired" all those servo leads[:-] used 5 ace noise traps i color coded the wires before i threaded them all into the wing made it much easier to figure out which servo lead went where lol. picked up a 4.8v 2700 battery pack, figured i will need it with 11 servos. i am not happy with the fit of the canopy it sits off to the starboard side a touch, i dont think most people will notice it but i know its there and that bugs me. i now have one engine mounted, today will install the other one. my nose cone fit pretty well. i am waiting on a order from tower hobbies to be able to finish this girl. i am going with 4 1/2 main wheels and 3 1/4 nose. maybe later i will install retracts. right now just want to get her flying and get used to twins.
bob i guess your the one that got the green one!!, i was wanting one but they were out of them LOL with me i am always a day late and a dollar short

Bob Paris

My Feedback: (13)

EagleDancer,
Now you know why I went with two recievers and two batteries. If you ever take the time to weigh all those wires and servo lead traps, you will see it is lighter to go with two receivers. I'm waiting for my retracts to make it here and coming from Tomas at VQ (a really nice guy). I will start to cut wood the day they arrive for my retracts, and doing my elevator mod now.

I am very interested in what you use for power and the weight of your engines. I am also very interested in the balance of your airframe, stock built (is it over the 12# given or less)...and if you need to add any lead to find a good balance. TLH101 states," that P-38's usually balance tail heavy."

My delema...K&B .48's weigh more then K&B .61's (Twisters). The power out put is about the same for both engines, accept the .61's swing a larger prop. If you need lead in the nose to balance...I will re-think the engine I will use.

I will be using 13 servo's and plan on using all standard Airtronics 94102's. I've used them for years with excellent results. 4 on flaps, 2 engines, 2 rudders, 2 elevators, 2 ailerons and one retracts. Engine and retract servo's will be half the weight of the standard 102's.

Keep us posted and you just may have the first one airborn and finished.

You used large tires...any reason for the 4 1/2" mains and 3 1/4" nose wheel? I was planning on using 4" mains and 2 3/4" nose.

All my plastic parts were warped-with a couple missing...and hope I get my replacements from NP soon. My e-mail went out yesterday and I will call them tomorrow.

I would also like to find out what kind of covering we have on this model...and I chose the green issue of the kit, because with invasion stripes installed...it will show up better in the air...not that a 90" span fighter will be hard to spot airborn.

Pictures please...

Soft landings,
Bobby of Maui

eagledancer

on the ziroli at 114" span it uses 6" mains and 4" nose, so i figured this should be fairly close for this one (i didnt do any figuring to find the exact size)
i am working on the tail right now, got it figured out my horz stab is already cut, half of my ply plates are cut, i am using 1/8" burch ply.
pics is something i cant do, upgraded my comp not long ago and my camera adapter cord wont plug in [:@]
i am hoping for maiden flight this next weekend

fgpierce

My Feedback: (2)

eagledancer

Good luck being the first. Mine won't fly for a while yet. I'm still messing with bugs in my Dual Ace 46. Throttles were great till today and .... SURPRISE![:@]

Oh well. Welcome to the wonderful world of twins.

Has anyone posted pics of the stab modification yet or did I miss them? It's been fairly hot around here and my AC in my workshop is busted and waiting for the serviceman. Don't feel much like dealing with the heat.

Oh by the way mine is green as well and I'll most likely add the invasion stripes. As big as 90" is I'll still need the contrast.

fgpierce

My Feedback: (2)

Hey Bob

Sorry to hear of the missing and warped parts. If they were f'glass you may be able to gently heat them and straighten them.The plastic is too sensitive to heat and may warp more or worse! Good shots by the way.

How's it going with the 4" main wheels? Are you still going to do the split flaps? Pics?

I'm waiting for the servo wire and plugs to make the harness. I'll only have one hose to each retract as they're Spring air. That makes life a little simpler. May go with 2 receivers as well. Using two receivers went real well in the 80" Bronco I built. We'll see how it goes. There were just too many connections with one receiver. My yellow aircraft P-38 is great as the booms ,wing center section and gondola are made one piece making use of a single receiver a no brainier. Some day I'll get that finished. My friend John dies anytime he comes over and sees it. The P-38 is his all time favorite as his Dad flew P-38's over Germany toward the end of World War II. His Dad loved it!
But then again what"s not to love

Bob Paris

My Feedback: (13)

Aloha Fgpierce,
All my warped parts were made of painted plastic. They were set into the box in a way that created the problem. I didn't use a heat gun on them because NP may want the parts back and I didn't want to damage them in any way. I am going with split flaps and I will make it a four flap wing.

I just started the elevator mod, to make it removeable. I will be posting pictures, and it's quiet simple to do. I will have pattens and line drawings for this mod.

I'm amazed at the size of this airframe...with my usual fighte in the .40~.60 size tops. But i will have to admit...the P-38 has always been a dream for me.

Soft landings always,
Bobby of Maui

BillS

I have wondered if the tank position will be a problem.

Bill

fgpierce

My Feedback: (2)

The 38 Is a BIG plane. I usually fly 1/4 and 1/3 rd scale. I can understand how you would be amazed at it's size.

I'm anxious to see the pics and drawings! I have a large Van just for my trips to the airfield( yeah, the gas is a killer) and I find transportation of this plane is going to be a problem. The wing is tough being 2 piece but the boom / stab area will be very weak and prone to damage when separated from the wing. Then storage between flying sessions will require some sort of spreader bar to keep them securely together. I have to think if the wing could have been shipped at 90" it would have been one piece.

That's one of the great things this hobby has to offer. How many of us would never have the opportunity to see one of these birds fly? How many of us would never be able to live out those dreams?
A great hobby indeed.

Fred

Bob Paris

My Feedback: (13)

Hay Fgpierce,
Your absolutly corect...twenty years ago, all we had would be a Royal kit of the P-38. Believe me...I eyed that kit many times. I did build the Royal B-17 kit, and ended up selling the model to a buddy...and went and bought a second kit of the B-17. I still have the unbuilt kit.

I have built gliders with 100" wing span, but this is my largest powered plane ever. To me it is huge...but what a turn on. I have a 1973 VW van I've had since new, that I use to bring my models to Pu'unana, to fly my models. I could fit my F-82 in one piece into my VW van, if I set up the bed in back...but just... fit it in if I'm carful. there is no way this model will fit with out breaking it down completly.

So for me...modifying the stab is manditory to get this model to the model airport. It's an easy mod really.

I will use one layer of good aircraft quality ply for the center ply wood tonge...no light ply here...and light ply or hard balsa for the filler pices. I may even place the filler pieces in first, sand these to match the conture of the boom, then epoxy the center connector piece of ply (tonge) into the boom. The center ply layer (tonge) will go into both inboard and outboard stab peices (you will have two out board peices and one center stab piece)...epoxie the outboard section permanitly into the tounge and simply slide the inboard section of the stab onto the tonge and hold it in place with two screws/blind nuts on each side. I will glue the rudder to the boom.

I will do a simple mod to the out board stab (you can place ply over the stab inboard ends as it is built and not have to do anything else-just strip off covering and glue two pieces of ply, one on top and one on the bottom-then make room for the tonge). The portion of the inboard center ply will slide into a modified center stab...on both booms. I will use two pieces of ply on each side of the stab that butts up to the booms. After every thing is set up and square, I will drill two holes into each side of the stab next to the booms, install blind nuts to the bottom layer of ply to the inboard stab, and use machine screws to hold the stab firm to the booms. Done deal, and no big deal.

Care must be taken when you cut your stab. I would suggest making a line copy of the stab...just incase you screw it up and need to make a second stab.

I would suggest assembly of the model first, get every thing aligned properly and set, then mark and cut the stab for the mod. You will need to do this anyway to figure out how much stab to cut for the inboard and outboard sections. You will toss out the part of the stab the goes through each boom, for your tonge and filler wood will go through this area of each boom .

It will work...and simple to do.

I read that this model, the P-38 usually builds tail heavy...and I read what Twinman wrote in rcwarbirds, that says the same thing. So I am keeping this in thought, when I mod my aft booms. VQ's P-38 uses a much more complex system to hold their stab into place on their P-38, but since this stab on our kit is made out of balsa...and simply covered, I feel this area may not have to be that built up to work and hold together. Time will tell. And I will keep my model under the speed of sound for the first couple of flights.

And your right...you will need to make a spreader bar to hold the booms and pods together with out damaging the assy. I understand KMP glues the stab into the booms, the same as NP. This to me is very poorly thought out...and why I never bought the KMP P-38.

Keep us all posted.

Soft landings always,
Bobby of Maui

fgpierce

My Feedback: (2)

Hey Bob

Your correct in the KMP and VQ p-38's stabs are glued. That's because the wing is three piece in design allowing the wings, outboard of the booms, to be removable. I'm sure it would fit in your VW bus although the wing tubes may necessitate modification to allow partial removal. Sort of a tube within a tube affair.

What kind of condition is the VW in? Being a body man of 35yrs from the east coast leads me to believe the salt air doesn't do any vehicles any favors![&o] I believe vehicles made here in the states during the 70's were made from recycled steel. I'm sure they use it today but the metallurgy is much better. I used to have to fix 70's Buick's that had Vinyl tops dealer installed . They would use razor blades to cut the top after they were glued on. The Blade would cut through the paint,primer and pickling. Inside of 2 yrs you could put your hand through fist sized holes. A real nightmare for the owner of a 2 yr old loan[:@] It's not too much of a factor here in California but then again I don't see too many mid 70's Buick's. Hmmm....[sm=confused.gif]

I have to say that the Chinese where brilliant in the saying " A picture is worth a thousand words ". That is quite a description! I believe I can understand why it would be best built in. Is the stab actually held in place by being trapped in the boom and locked by the two bolts going into the stab? I think gluing the parts edgewise would be an invitation for failure should a flutter occur. I think a small Dremmel router setup would do a good job making the groove. Maybe something like a rabbit joint cut into the outer stab? What thickness ply? Maybe 3/32 5 ply for the "main" tongues and 1/32 on top and bottom of the inboard stab? I don't think drilling lightening holes would hurt.

Reading this back to myself makes me hope you don't take offense to my comments. I'm just trying to visualize and add my 2 cents

Bob Paris

My Feedback: (13)

Hay Fgpierce,
My trusty ol' VWvan is now in with a friend doing my twice decade rust removal and repaint. Every five years I end up getting some rust work done and a repaint. I live a half a block from the beach...and the salt air takes its toll on older VW's. She ain't bad...just a couple of spots and a new paint and undercoat.

Your absolutly correct, the booms capture the stab, and the screws/lock washers/blind nuts, lock it in. I did plan on having a snug fit for the tonge to stab fit, and planned on making my ply doublers on the stab out of high grade aircraft ply. I hadn't picked out the thickness of the ply yet, but I do tend to over build my models a little, for strength. I've never had one come appart on me in the air, or had any flutter from any mod I have done. I'm not glueing anything on edge wise on my mod to the stab...the out board stab is slotted into the tonge and epoxied in solid. The rudder is glued in per standard build to the kit. As long as there is no slop in the stab, and you have no slop to the movable part of the elevator, you will usually not see any flutter in a flight control. The only time I've seen flutter develope is with a loose fit flight control. If I can hold on to a flight control (elevator, rudder or aileron), and it flops around and not stiff in my fingers...I don't fly that model. I either fix it, or refuse to fly it. Snug controls are a must be, for me.

By the way, I ain't perfect...and if someone can show me a better way to do something...I'm always open to imporve my methods, and listen. I was in aviation all my life, with over 20K hours in mostly helicopters, but I have nearly 5K hours in twins. I'm also a licensed A&P and hold an A.I certificate.

I've given this mod some thought...and I do feel it is a simple mod to do. I am also very interested to find out how this airframe balances out. Nose heavy, tail heavy or nuts on.

Soft landings always,
Bobby of Maui

fgpierce

My Feedback: (2)

Hi Bill
That depends on how you intend to mount your engines. Horizontal is not an issue but the usual inverted mount may be. There are a lot of factors but if the tank centerline is in line horizontally with the spray bar ( centerline) in the carb it should be fine. If a problem does occur I used Perry pump/regulators on my VQ P-61 Blackwidow and it helped tremendously.

I hoped this helps. If not please feel free to ask.

BillS

Maybe I asked the wrong question. If the engines are turned to 9 o’clock how far is the CL of the tank?

Thanks.

Bill

fgpierce

My Feedback: (2)

Hi Bill

9:00 is horizontal. The cylinder head is lying in the horizontal plane. That should put the centerline of the tank at the same level as the centerline of the carb. The hole in the firewall where the fuel tank lines run through it will line up with the center of the tank. When you mount your engine at 9:00 it should be centered over the hole. Then it can't help but be centered with the tank. A carb that lies too far below the line, say 1", will siphon or flood. An engine lying too far above the center of the tank will tend to starve for fuel. The P-38 is normally mounted at 6:00, known as inverted. The cylinder head is pointed downward. My engine will be mounted like this.This will tend to flood or siphon fuel making the engine run rich. Sometimes too rich for the engine to run consistently. A Perry regulator/pump will take care of the problem. It's also a good idea to run a third fueling line to the tank or use a diverter fill valve between the tank and carb.
I prefer my engines concealed as much as possible for aesthetics and this may be a disadvantage. I.E. inverted

You'll find an excellent site that explains far better than I could hope to do here: http://saito-engines.info/body_pumps.html

The pump I refer to is the Blue VP-30 for glow fuel. One possible solution may be the Sullivan adapter # 485. I'm not familiar with option but will personally check into it.
Again, I hope I answered your question or pointed you in the right direction.

shiny side up
Fred

Bob Paris

My Feedback: (13)

Hay Fred,
How are you going to mount your engines. Are you going with inverted engines, or side mounted. I looked at my fuse booms and it looks like the fuel tank sits mighty low for side mounterd engines. I gues I'm going to have to play with it more to make up my mind.
Soft landings,
Bobby of Maui

pettit

My Feedback: (23)

From the poor photographs in the instruction manual, the center line of the fuel tanks are 3" to 4" below the cenger line of the engine.

That's not a little low, that's a LOT LOW!

Baldeagle

My Feedback: (7)

After reading this thread and making it transport friendly. Would it be easier to cut the wing just outside the necels and add wing tubes there so the hole plane would be intact except for the outer pannels. I don't have one of these kits yet but am considering it. What is the distance from one outer necesel to the other.? I know this would be a little tricky to do, cut into the bottom wing , make holes for tube. I would make false ribs out of light ply that fit the tube. That way you can line everything up before gluing. Just plug in your ailerons and fly. Just a thought . Rich

BillS

Maybe the airplane should be relabeled as a ‘master builder’s redesign/bash kit/ARF project.’

And since it is a P-38 it should be for the experienced and skilled twin-engine pilot. In addition to fly a twin one must be a somewhat skilled engine tuner. To tune a twin with grossly misplaced tanks one must be extremely skilled as an engine tuner. On top of all that a P-38 is a death trap with engine out.

There is nothing wrong with any of the above requirements. But one must wonder how long the airplane will survive under actual flight use. The probability of success ranks right up there along with the probability of finding a 20-year-old virgin.

While I hope everyone is successful the deck is stacked. Only the best of the best will be successful with this airplane.

Bill