P-38 Lightning-Roddie style "plan" rev.C

roddie Tue Mar 06, 2018 2:39 pm

surely to be revised again.. but here's what I've drawn "with corrections" thus-far..

P-38 Lightning-Roddie style.. - Page 6 Plan-p12

roddie Tue Mar 06, 2018 3:55 pm

getback wrote:Hi Roddie , The plane is coming along nicely !! I really like the landing gear you configured on there Good Fun Man . I am sure you know bee sure to fill those extra holes in the firewall good with a fuel proofer.

Hi Eric, I've been thinking about your comment ever since you posted it several weeks ago. It got me thinking about a way to seal the firewalls against fuel/oil-entry into the un-used (optional) engine-mounting holes.

I decided to "laminate" both firewalls with pieces of thin Butyl-rubber.. (bicycle inner-tube material)

P-38 Lightning-Roddie style.. - Page 6 Dsc05415

P-38 Lightning-Roddie style.. - Page 6 Dsc05416

The rubber is adhered to both firewalls using thin/double-sided "film-tape". This should prevent some oil-soaking into the optional engine-mounting holes.. and may also help to dampen engine-vibrations.

roddie Tue Mar 27, 2018 2:00 pm

Ok.. I've got a woody.. Laughing

..

I need to build a pair of Cox/Allisons... and test em' out using my quick-mount.

P-38 Lightning-Roddie style.. - Page 6 Dsc05521

P-38 Lightning-Roddie style.. - Page 6 Dsc04011

This might also be a good opportunity to test my experimental reeds..

P-38 Lightning-Roddie style.. - Page 6 Dsc05522

I don't want finicky engines on a twin though. Easy-starting, stock-engines (product-configured) is my plan. Once it's painted.. I'll have a better idea if standard/mild engines will do the job. Weight (less-finish) is under 10oz. so far..

P-38 Lightning-Roddie style.. - Page 6 Weight15

NEW222 Tue Mar 27, 2018 2:51 pm

Now that reed definately looks interesting. Hopefully it works out well for you. Seems like it is easy enough to make as well.

roddie Tue Mar 27, 2018 5:43 pm

NEW222 wrote:Now that reed definately looks interesting. Hopefully it works out well for you. Seems like it is easy enough to make as well.

Yes.. it will be interesting to see how an engine runs with that one. Nothing ventured.. nothing gained.. or so it they say.. (whomever they are..) Laughing

So.. this afternoon I disassembled several .049 reed-valve engines.. in order to configure a pair with the same parts.

P-38 Lightning-Roddie style.. - Page 6 Dsc05523

Everything needs a good cleaning..

The cylinders have no number stamped.. but both have dual bypass intake-porting, slit-type exhaust-ports and are milled at the top for the spanner. I'm guessing they are non-SPI. I chose two pistons that have near zero-slop in their socket-joint.. but we'll see how well they fit the cylinders.

rsv1cox Wed Mar 28, 2018 8:32 am

As usual roddie, your doing everything right.

I enjoyed the Steve Hinton video, hadn't seen that one. I thought about the P-38's compressability problems as he was coming straight down out of the loop. Thought I detected a split-S there too. Wonderful visibility out of the airplane with the pilot sitting so high.

Enjoy this compressability description:

https://www.youtube.com/watch?v=5J0lEHyKInw

roddie Wed Mar 28, 2018 10:11 am

That was a funny video Bob! Laughing

Thanks also for the compliment.. but I don't always do everything right... Crazy Eyes

I just made something that's pretty cool though.. I'll post photos in the crock-pot thread.. Eyebrows

rsv1cox Wed Mar 28, 2018 10:25 am

roddie wrote:That was a funny video Bob! Thanks also for the compliment.. but I don't always do everything right...

I just made something that's pretty cool though.. I'll post photos in the crock-pot thread..

I did the A/F boil on three Cox engines, one with a red postage stamp back plate, the others with white horseshoes. It sucked the color out of the postage stamp and seemed to soften it, but it did not hurt the white horse shoes. I don't know how it would affect your black back plates, but I don't think you would boil them anyway. I usually clean them separate with Simple Green.

Bob

roddie Wed Mar 28, 2018 11:01 am

rsv1cox wrote:

I did the A/F boil on three Cox engines, one with a red postage stamp back plate, the others with white horseshoes. It sucked the color out of the postage stamp and seemed to soften it, but it did not hurt the white horse shoes. I don't know how it would affect your black back plates, but I don't think you would boil them anyway. I usually clean them separate with Simple Green.

Bob

Thanks for that info Bob.. I won't put any plastic parts in the cooker. Thumbs Up

roddie Wed Mar 28, 2018 3:15 pm

Today was mild enough outdoors.. (mid-50'sF) to get some primer on the model.

P-38 Lightning-Roddie style.. - Page 6 Primer10

P-38 Lightning-Roddie style.. - Page 6 Primer11

P-38 Lightning-Roddie style.. - Page 6 Primer12

P-38 Lightning-Roddie style.. - Page 6 Primer13

I can really see now; the "voids" in the butt-joints where the balsa L/E and T/E pieces were adhered to the central basswood-sheet with thin "CA".

P-38 Lightning-Roddie style.. - Page 6 Primer14

P-38 Lightning-Roddie style.. - Page 6 Primer15

I'll fill/sand.. but I'm keeping this finish as lightweight as possible. I'm resisting the addition of any scale details to the model. It's recognizable as a P38 the way it is. If I could add just "one" dimensional detail.. it would be the coolant-radiator housings on the inside/outside of the booms. I've given this some thought.. but I haven't been able to come up with anything yet.

roddie Wed Mar 28, 2018 3:37 pm

I had a productive day today (hobby-wise) and decided to get working on the engines for this model. I'd "configured them" with like-parts yesterday.. and today it was time to get those parts cleaned-up.

My crock-pot and newly-made "micro strainer-cup" were all set to receive the engine parts. I removed the crankshafts from the crankcases of both engines.

P-38 Lightning-Roddie style.. - Page 6 Prep_f12

P-38 Lightning-Roddie style.. - Page 6 Prep_f13

I'm glad I did this.. because one of the crankshafts had some thickened fuel-residue which was like a blob of hardened-glue.. Shocked

P-38 Lightning-Roddie style.. - Page 6 Prep_f14

The engine parts for both engines fit easily into my 6oz. strainer-cup. I didn't put the plastic backplates in. I'll clean them separately.

P-38 Lightning-Roddie style.. - Page 6 Prep_f15

The little Crock-pot cooker is outside on the deck with undiluted ethylene-glycol.. and set on "high".

P-38 Lightning-Roddie style.. - Page 6 Prep_f16

It's been three hours on the high-setting. I may reset it to "low".. and let it soak overnight.

roddie Thu Mar 29, 2018 1:01 pm

I must say that I'm pretty happy with the results of my first crockpot use for cleaning engine parts. I did not put any plastic parts in the cooker.. only metal.

Here's the first engine to be completely re-assembled. It has an experimental reed installed.

P-38 Lightning-Roddie style.. - Page 6 After_10

The plastic parts (backplate/carb and reed-retainer) were soaked overnight in a small jar containing "Simple Green" RTU spray cleaner. This morning I checked to find that the parts still had a lot of residue that wouldn't brush-off. I decided to try some hot tap-water in another small container with "Dawn Dishwashing Liquid" added. This worked quite well.. but may have been the combination of the two cleaners.

I also discovered that some small dental-flossers work really well for cleaning the ID of the NVA-spraybar. It's actually a little tiny round bristled brush that fits inside the hole in the fuel-nipple.

P-38 Lightning-Roddie style.. - Page 6 Placke10

P-38 Lightning-Roddie style.. - Page 6 Placke11

P-38 Lightning-Roddie style.. - Page 6 Placke12

I followed with a solvent power-flush using a syringe with the needle-end plugged and spray-hole facing down into a cup.

P-38 Lightning-Roddie style.. - Page 6 Syring10

Now that everything is clean as a whistle.. I'll try to run the engine later on this afternoon.

roddie Sun Apr 01, 2018 1:37 pm

Filled, sanded and currently applying the first base-color coats.

P-38 Lightning-Roddie style.. - Page 6 3-fill10

P-38 Lightning-Roddie style.. - Page 6 3-fill11

P-38 Lightning-Roddie style.. - Page 6 4-p38_10

P-38 Lightning-Roddie style.. - Page 6 4-p38_11

It's been a little breezy today. The gallon-jug is in place between the tail-booms, to prevent the model from possibly blowing-off the table..

rsv1cox Sun Apr 01, 2018 2:47 pm

Looking great roddie. Didn't you mention a surprise paint job? Looks pretty close to Blue Angels blue there. Maybe an all blue YIPPEE.

Your going to love the sound when you first sync up those twin .049's.

Bob

roddie Sun Apr 01, 2018 7:58 pm

rsv1cox wrote:Looking great roddie. Didn't you mention a surprise paint job? Looks pretty close to Blue Angels blue there. Maybe an all blue YIPPEE.

Your going to love the sound when you first sync up those twin .049's.

Bob

I'm excited about configuring the engines Bob! I'm working on the "spec" engine tonight actually. The only difference between the twin-engines will be their crankshaft-rotation. I'm hoping that the Perfect-brand #17 fuel-tanks will feed the engines as configured. I still need to leak-test the tanks. The engines will be "stock" configurations.. but not anemic. The cylinders will have dual-bypass intake-porting and non-SPI slit exhaust porting. I wanted to run non-SPI cylinders.. in the advent of fitting my homemade mufflers, with the option of running muffler-pressure to the fuel tanks.

Regarding the "paint-job".. I wanted this model to have a "dark" presence. If I install mufflers on the engines; they will run "quieter/stealthy"... and possibly with the benefit of fuel-injection.

roddie Sun Apr 01, 2018 11:11 pm

Here's my engine bench-run set-up.

P-38 Lightning-Roddie style.. - Page 6 Dsc05610

P-38 Lightning-Roddie style.. - Page 6 Dsc05611

A friend of mine gave me a "spool" of some really good 3M VHB (double-sided) adhesive-tape. I used a strip to mount the fuel-tank to the backside of my bench-mount.

P-38 Lightning-Roddie style.. - Page 6 Dsc05612

P-38 Lightning-Roddie style.. - Page 6 Dsc05613

P-38 Lightning-Roddie style.. - Page 6 Dsc05614

I re-furbished my homemade electric-starter. It was exhibiting some issues. The previous set-up worked.. but the "drive" was out of balance; exhibiting severe vibrations. I had used a small-size "worm-drive" hose-clamp to secure a short length of 5/16" ID rubber-tubing to a "gear".. that's pressed-onto the "540" motor's output-shaft. This has worked QUITE WELL for starting a Cox .049 engine equipped with a Cox "Tee Dee" style aluminum-spinner.. but there was that vibration caused by the imbalance of the hose-clamp. Today I replaced the hose and the hose-clamp with a new piece of hose and two "offset" zip-ties to secure the hose to the motor's output-shaft. Pulsing the starter now; yields much less vibration than before.

P-38 Lightning-Roddie style.. - Page 6 Rebuil18

rsv1cox Mon Apr 02, 2018 7:29 am

roddie wrote:
rsv1cox wrote:Looking great roddie. Didn't you mention a surprise paint job? Looks pretty close to Blue Angels blue there. Maybe an all blue YIPPEE.

Your going to love the sound when you first sync up those twin .049's.

Bob

I'm excited about configuring the engines Bob! I'm working on the "spec" engine tonight actually. The only difference between the twin-engines will be their crankshaft-rotation. I'm hoping that the Perfect-brand #17 fuel-tanks will feed the engines as configured. I still need to leak-test the tanks. The engines will be "stock" configurations.. but not anemic. The cylinders will have dual-bypass intake-porting and non-SPI slit exhaust porting. I wanted to run non-SPI cylinders.. in the advent of fitting my homemade mufflers, with the option of running muffler-pressure to the fuel tanks.

Regarding the "paint-job".. I wanted this model to have a "dark" presence. If I install mufflers on the engines; they will run "quieter/stealthy"... and possibly with the benefit of fuel-injection.

Mufflers???? Where is that XXXXX key. Smile

I used double sided tape on my Mosquito thinking that it might help reduce fuel foaming due to vibration. Not much I think, but it held them in place while I secured them with steel wire passed through the fuselage and backed up on the other side. Later I trimmed the bitter ends and soldered the twists.

P-38 Lightning-Roddie style.. - Page 6 Fuel_t10

I masked off the fuel vents and painted the tanks along with the plane.

Bob

getback Mon Apr 02, 2018 9:07 am

Glad you got the holes fixed so they want get oil soaked Roddie , the satin blue looks good on there >> It won't bee long now!! Babe Bee .049

oldguy Mon Apr 02, 2018 1:22 pm

Cool project, can't wait for the finished product. Want see it fly. Flying

rsv1cox Mon Apr 02, 2018 3:31 pm

I have been meaning to ask. Are you going to bench run those engines first? I would think so. I'm eager to find out how that reed does. I may have missed it, is it your own design?

Bob

roddie Sun Apr 15, 2018 10:14 am

rsv1cox wrote:I have been meaning to ask. Are you going to bench run those engines first? I would think so. I'm eager to find out how that reed does. I may have missed it, is it your own design?

Bob

I missed this comment/question Bob.. sorry about that. Embarassed

By now; you know the answers to those questions.. Smile

I've rebuilt and configured two .049 product-engines with the same cylinder-porting for running in the model. I'd like to think they're identical in terms of performance.. but we all know that no two engines will run the same; no matter how much attention to detail was considered.

The model's "maiden" will have the engine with R/H prop mounted inboard.. and the engine with L/H prop mounted outboard. I hope that my thinking on this is correct. If my critical (inboard) engine quits first, the outboard engine will be torque-rolling the model outward. The reverse scenario would burden the inboard engine with "lifting" the model from a point well outside of its roll-axis. This is in an attempt to prevent an engine-out situation from causing the model to fly inward-circle. Naturally; this can only be accomplished on a "twin" using engines which are capable of running in alternate rotations.

P-38 Lightning-Roddie style.. - Page 6 Dsc05634

fredvon4 Sun Apr 15, 2018 11:43 am

Unfortunately the torque roll effect is not as great as the thrust line effect....

rsv1cox Sun Apr 15, 2018 12:03 pm

I set my LH/RH (3 blade) props the same way roddie but noticed no inclination for the airplane to veer inward when the inboard engine quit which it did on multiple occasions. It just kept chugging along.

That said, I always topped off the inboard engine last.

Of course there are other factors involved, rudder offset etc.

Getting close now and eager to find out how it flys. Practice on a donor airplane first. Smile

Good luck - Bob

roddie Sun Apr 15, 2018 8:11 pm

I appreciate the replies to this thread. I realize that I haven't actually "flown" a model airplane since becoming a member here. Time is running-out on my 2017 AMA membership.. and that's been bugging me. I'll need to get an airplane in the air by 4/30/19.. to get an official flight in. That's a Monday BTW......... Laughing

My P-38 could use some "light-blue" paint applied to its canopy. I could do that indoors with some acrylic-enamel paint, brushed-on. I also need to sand the darker-blue base-color in some spots.. and re-spray them before the clear-coat goes on.

It recently occurred to me, that three out of the last four airplanes that I've built have been USAF interceptors. The F8F-2 Bearcat (Rare-bear), the Lockheed T33 "Shooting-Star" and this Lockheed P-38 Lightning. Also readied for flight are two "stand way-off scale" North American P-51 Mustangs. I really hope to fly these particular airplanes this season.

Ken Cook Sun Apr 15, 2018 8:57 pm

Your really overthinking this. Add more tip weight. 3/4 oz. to start and retract as needed.

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