My P-38 for 2015, my "Wicked Woman"

[Mitch]

Okay... I am here in Anchorage... 5 days into the build. I noticed in the build plans it says:

"NOTE! For rubber power free flight, the model MUST be built VERY LIGHTWEIGHT. We recommend cutting holes in the ribs and enlarging the former openings"

Gee... I seem to remember saying the same thing in all my build threads, there must be something to this.

Anyway in addition to that I plan to use only half the wing ribs. Also just the minimal amount of plastic as specified for the rubber powered model.

Without any further chat I will post some progress pictures.

Starting the fuselages


Getting in the second 'halves'


The cockpit nacelle


The mock-up...so far.

Need to get back to the Lockheed factory...

UPDATE: Thought for the week... Make a lot of balsa dust... Meaning, for die cut kits sand the backside of the sheets makes removal a lot easier. Also I will be removing much of the interior wood from the model, by cutting and sanding. If you are flying with rubber, keep your build as light as possible.

[Wildpig]

Looking good !

That's a lot of plastic.


When you get farther along, could you post a picture of how the wing is attached to the cockpit fuselage?
I'm looking for ideas on my Comet P-38.

[BillParker]

From memory, the comet 38's fuse is built up, with a simple flat spot for the wing. The wing leading edge butts up to the front cockpit former, and the fuse just tapers to a point. The wing trailing edge center and the point are roughly in the same place. The cockpit formers are then built up on top of the wing, and then stringered and it stays together... The wing root is covered with a paper fairing that was kind of like news print... Each side of the center fuse is covered with a flat paper, as are both sides of the booms at the wingroot... You're on your own on the canopy glass... Total custom deal...



I've built that kit 10 times, and everytime I've sworn that I'll NEVER build another P-38, but really... The comet kit is probably the best rubber version you can get. I have blowed that plan up to about 12 foot. (wingspan) Now I have to see if I really really want to do it.



96" wingspan...



More:

http://www.parkerinfo.com/ap48.htm

[Wildpig]

Thanks for the answer, Bill

96" wingspan...

[Mitch]

Here I am in Kodiak... home in 3 days. Plastic... Take a look at this:

I will be cutting the air coolers away from the rest of that plastic (as per instructions for rubber power) There two more sheets of plastic with gear doors and bombs, etc.

Nacelle assembly coming along...I forgot my 'blue' bar clamps and am improvising with rubber bands (were in the kit)


Also I did not bring my building board and pins, so I am building up the tail using magnets.

again...also I do not have my dremel tool so I will wait until I have that to cut out lightening holes in ribs.

I plan to make a tube sander to remove inside of fuselage frames after they are finished.

I have the first "L" pieces in the nacelle for mating with the wing. To compare this Guillow kit to the Comet kit would be like comparing this to a plastic model. They are different kits. If I can get this to lady to fly she will be an impressive sight. IMO (in my opinion) the Comet kit is not as nice a scale model, but designed for rubber power. This is a Multi Purpose scale model. I hope it will fly with just rubber.

Mitch

[Steve Blanchard]

Hey Wildpig, Sorry I didn't answer sooner. Just saw the message. The basic comment was from a very well known designer and flyer of rubber powered scale models, Don Srull. He just noted that there are certain designs that would be difficult to model well for scale appearances and be very competitive in flight duration because of an overly thick airfoil such as some of the early Fokker transports. It's not that the P-38 has a very thick airfoil in the actual plane but that Guillow's models all have thicker airfoils than are needed for good rubber flight and duration.
I have built and flown several twins. I have used both counter rotating props and pairs that swing in the same direction. I believe it's a preference. Chris Starleaf is a very accomplished rubber scale modeler in the FAC and he has been well known for his long flying twins using stock props from Peck Polymers. He too has used counter rotating props as well. I think it depends on the set up of the power and thrust adjustments to make these birds fly no matter what the prop choice is.
With regard to length of nacelles and amounts of rubber, it all depends on how creative you want to be. In a short yet fairly chunky nacelle you can get up yo 5.5 times the hook to peg length if you use the Dave Stott sleeved motor peg. For this you slip a sleeve over the motor peg so when the rubber unwinds and can jerk around on the peg without binding up.
Believe it or not the model below which I built from my own plans flew pretty well. The duration was the only issue and I am rebuilding the wing this year to have a thinner airfoil to see if that will help.

[Wildpig]

Thanks for the reply, Steve. I have Martin Simon's book on airfoils for models, I'll check into that to glean some more data.
I've seen Chris Starleaf's models. Beautiful. He can stuff a lot of motor in a B-24 nacelle. Never would have guess 5.5 pth or so could be done. Watch out, Mitch! Brenda might not be power limited on those A-26 nacelles.

That FW of yours looks cool. Nice props.

[Mitch]

I plan on following kit instructions. Using supplied props and rubber. I plan to place another rear peg position forward of those air coolers when I use more loops of tan rubber. I will be home in about 6 hours and will post a few picture updates.

UPDATE: Just got home a while ago... here are some pictures:

Since I was using magnets instead of pins I built the tails up in stages so the magnets would not interfere with each other.


The cockpit nacelle, and stabilizer getting built up, and some reference books.


Still need to add a few more stringers in the tail and longrones in the fuselages


I plan to build the wing this next trip. I will bring my dremel tool to assist with cutting lightening holes... I also will pick up more #11 blades as I only had ONE! I plan to remove some wood from the inside of the rudders and tail (about 1/3) then I will add the extra 1/16 x 3/32 support members.

I plan to first fly this with the props and rubber in the kit as I what to show you what you can expect. I like the grey rubber because it has more torque than tan and will give a short flight but enough power to this girl in the air... I hope.

There are several "L" parts to make the fuselage & nacelle to wing joint. The wing on this model is a scale wing profile. I will take pictures of the construction of all those parts.

I am using all kit parts and kit wood. As I am building this model for the 2015 Guillow Challenge. The plans say for a rubber power model make the model as light as possible. So I will be removing as much as I can. This model is not at all difficult to build the way I am building it. I am building the 'striped down' version of this model as there is a lot more I could do with this kit. But my action 'feature' will see this lady fly... I hope.


Mitch

[Steve Blanchard]

Going quickly Mitch! Looks good so far. I hope you get her up in the air without too much trouble.

Steve

[Brenda]

Thought I would post how my twin is coming along. First photo is fuse squared up. The tic marks make everything so easy it just falls together.



Few stringers here and there. No plastic anyplace. Just balsa. Starting to look like a aircraft now. Just a FYI yes I am building outside in January

[Mitch]

Just got up... at the 'crack of noon'... Looks good Brenda.

For flight time my money would go on the Comet kit. But I building mine for the Guillow Challenge. The real work for me will start when I start 'removing' extra balsa, getting rid of all that extra 'dead weight' I am also straddled with all that heavy plastic of those engine superchargers, but I just want to see mine in the air. Once that is accomplished I will finish my Me109Z! That model is my planned entrant into WESTFAC V. There will be over 25 flying events so I need a few more planes...

I have a few more hours off before I need to get back to the ship... The clock is ticking so I need to get going...

Mitch

[Brenda]

Crack of noon...I remember doing that. The Invader will have some dead weight in the 2 turrets and guns. If I wasn't trying to do ROG I could save a ton of weight as the landing gear is wonkey and has to be altered a tad bit. I just never liked plastic in a kit. I tried using it a few times only to trash the plane because I didn't care about it. The ones I made all the parts out of balsa I would handle with kit gloves as I put so much work into them I was afraid to let it land in damp grass. Long ago I had a Guillows Arrow (think that is what it was called), had a friend tape two bottle rockets to it. Was really cool. Balsa dust weeeeeee.

[Wildpig]

Just got up... at the 'crack of noon'... Looks good Brenda.

For flight time my money would go on the Comet kit. But I building mine for the Guillow Challenge. The real work for me will start when I start 'removing' extra balsa, getting rid of all that extra 'dead weight' I am also straddled with all that heavy plastic of those engine superchargers,........

Mitch

Mitch, there was a version of the lightning that was sold to the British that did not have any superchargers. Maybe that would reduce some plastic usage.

[Mitch]

Just got home, chores are done and dance lesson over... 3 hours at home then back to ship...sail tonight at...

I do not mind the extra plastic in the Guillow kits. Although they add weight I like the scale look. I build Guillow models for the looks and am happy they fly. I do not like the look of the Comet P-38 kit. I will have several non Guillow kits with me at WESTFAC V.

What I know about a British P-38 is they tried to fly without counter rotating props... The plane was uncontrollable. I will also be flying with 2 props rotating in the same direction. My fix is to have adjustable thrust bearings and I may wind the port motor more than the starboard. I noticed that Guillow's plastic cowlings are molded to have right pitch. I will plan to go beyond what they had. The challenge rules allow me to make adjustments to the front end.

I need to gather up my tools and relax a bit before heading back...

Mitch

[Mitch]

Here is my 'new tool' concept for boring out the inside of the fuselages.


NOT RECOMMENDED for heavy duty sanding. The tube is a jam fit over the handle of the screwdriver tool. I can attach some sand paper to the tube and turn the tool by hand or chuck it in a power drill and SLOWLY turn the sanding drum inside the fuselage.

This is VERSION 1.0, if anyone has a better idea I am up for input...

Need to get going...

Mitch