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Posted (edited)

So, what's cookin'? Any progress?

I'm working on the cockpit controls of my P-38. Fitting all the working levers and buttons is a challenge. Also working on the right hand engine/landing gear/prop pitch mechanism.

I've been trying to dig up diagrams of the P-38 landing gear actuators and their locations, but so far have been unsuccessful. I may have to make up my own design in this area. Same with the flap guides.

I'll start a WIP thread once I get a little further along.

I just got all of the parts for my flying saucer, starting to figure out how to make it spin and have flashing lights

Awesome!

Edited by dhc6twinotter
Posted

And I made coupling for potentiometers for rudder and elevator, placed linear actuators controlling pneumatic switches in different way and now there is no stress on them. All RC stuff still on it's way, I hope. Also seems like I need some 60 pcs of 15068 to make symmetric tailplane and I'm checking it daily at BL, there was no single place having such quantity. Surprisingly, I checked right now once again and there are some, though 2.5 times more expensive. I still got plenty to do except of tailplane, so I'll just hope that price will go down a bit eventually.

Posted

I was unable to find it at LEGO - can't see it in Pick a Brick even if I set region to UK, Denmark, USA, Germany. Please tell me where should I look :) And chances are I can work around shipping problem :)

Posted

I've been trying to dig up diagrams of the P-38 landing gear actuators and their locations, but so far have been unsuccessful. I may have to make up my own design in this area. Same with the flap guides.

A P38 Awesome!

I found this for the flaps

nasm_p-38_03.jpg

http://static.rcgroups.net/forums/attachments/1/4/6/2/a2759239-214-P38%20flap%20track.jpg?d=1253048347

and

http://static.rcgroups.net/forums/attachments/2/3/7/5/7/0/a2759557-225-Flap%20Track.jpg?d=1253060878

I'm actually working a bit on a fowler flaps extension but I haven't found something great yet.

Good luck! I'm looking forward to see your job

Posted (edited)

A P38 Awesome!

I found this for the flaps

http://static.rcgrou...pg?d=1253048347

and

http://static.rcgrou...pg?d=1253060878

I'm actually working a bit on a fowler flaps extension but I haven't found something great yet.

Good luck! I'm looking forward to see your job

Thanks for the links! I've seen the picture and the image in the first link, but I haven't seen the image in the 2nd link, and it's a much better diagram. I've been planning to use a dual slide like those links show, but the part I'm stuck on is the combat/maneuver flap position that the newer P-38s have (J or L variant and onwards--can't remember which). It's sort of a "hybrid" split and fowler flap. When combat (or some places call it maneuver) setting is selected, the flaps just drop a bit and don't slide back. When in landing configuration, the flaps slide back and down.

I'm going to try a pneumatic flaps system that still allows for incremental adjustments, but I've yet to test it. I want to get the cockpit and landing gear sorted out before I begin working on the flaps.

EDIT: I'm looking at the diagram in the first link again, and it has a maneuver setting labeled. According to the diagram, the flaps do move back when maneuver setting is selected, but that's inconsistent with what I've read elsewhere. I think I have more research to do.

Edited by dhc6twinotter
Posted

I was unable to find it at LEGO - can't see it in Pick a Brick even if I set region to UK, Denmark, USA, Germany. Please tell me where should I look :) And chances are I can work around shipping problem :)

Go to: customer service, bricks and pieces, I want to buy a piece.

Posted (edited)

Thanks for the links! I've seen the picture and the image in the first link, but I haven't seen the image in the 2nd link, and it's a much better diagram. I've been planning to use a dual slide like those links show, but the part I'm stuck on is the combat/maneuver flap position that the newer P-38s have (J or L variant and onwards--can't remember which). It's sort of a "hybrid" split and fowler flap. When combat (or some places call it maneuver) setting is selected, the flaps just drop a bit and don't slide back. When in landing configuration, the flaps slide back and down.

I'm going to try a pneumatic flaps system that still allows for incremental adjustments, but I've yet to test it. I want to get the cockpit and landing gear sorted out before I begin working on the flaps.

EDIT: I'm looking at the diagram in the first link again, and it has a maneuver setting labeled. According to the diagram, the flaps do move back when maneuver setting is selected, but that's inconsistent with what I've read elsewhere. I think I have more research to do.

Hey I just found some gold :)

Here you will find the erection and maintenance manual (page 1) and the service instruction (page 2) of the P38 (you just need to register). Lots and lots of technical diagrams and informations. I hope it helps hehe

EDIT: Don't download the 16 pdf of the first post but the 2 pdf post #9.

EDIT2: Page 115 you have diagram of the main landing gear with its actuator

How big is your moc?

Edited by hysot
Posted

Hey I just found some gold :)

Here you will find the erection and maintenance manual (page 1) and the service instruction (page 2) of the P38 (you just need to register). Lots and lots of technical diagrams and informations. I hope it helps hehe

EDIT: Don't download the 16 pdf of the first post but the 2 pdf post #9.

EDIT2: Page 115 you have diagram of the main landing gear with its actuator

How big is your moc?

Thanks for the links! For some reason the pdf in post #9 won't open for me (says there is an error or something), but I just downloaded a pdf from page 2 in that thread. It has some excellent info. Thanks for the link!

I've had another look at the first link you posted in your previous post here. I saw that picture several days ago, but I assumed it was for an RC plane and dismissed it. However, after digging around a bit more, I've found the source of that picture, and it appears to be from the actual P-38 plans. If that is the case, then it appears the combat/maneuver flap setting is not a "hybrid" split/fowler flap, but just another setting on the fowler flaps. So, it seems my earlier sources were incorrect, and the combat/maneuver setting does move the flap back and down. This should make things much easier to build with LEGO (still a fun challenge though).

I also spent an hour or so studying the landing gear diagram last night. It took me a while, but I figured out the location of the landing gear actuators and how they worked.

As for the size of the plane, I'd like to make it smaller than the Piper Super Cub I built a couple years ago. If I can keep the overall length down to under a meter, than I'll be happy. Smaller the better, but scaling the cockpit down is a challenge, especially with all the linkages for the working levers and buttons (rudders, elevator, ailerons, flaps, prop pitch, throttle, dive flaps, radiator shutters, bomb/fuel tank release, and landing gear). Nice thing about the P-38 is that I do have some space under the cockpit to use, so long as I leave enough room for the nose gear. I don't want the cockpit section to be any wider than 11 studs, and the booms about 9 studs at their widest points. Main landing gear will probably use the tires from the mobile crane.

Thanks very much for the help!

Posted (edited)

Thanks for the links! For some reason the pdf in post #9 won't open for me (says there is an error or something), but I just downloaded a pdf from page 2 in that thread. It has some excellent info. Thanks for the link!

So download the pdf number 5 of the post #1. You'll have the landing gear diagram I was talking about.

Your project seems to be awesome. I have a project like yours in mind but not the same airplane, probably a Bronco or a plane inspired from it

Edited by hysot
Posted

Yup, I've been building! I have a WIP thread started, but haven't posted it yet. I want to get get a bit more built before posting. Main landing gear is done I think, but I still need to figure out how to build the sequencer for gear and bay doors. Landing gear locks in both the up and down position. One of the fowler flaps with slide mechanism is built, but I still need to figure out if I'm going to motorize or use pneumatics on the flaps.

I'm currently working on the variable pitch mechanism. I'm using mini-turntables for the propellers, which means the old system I used on the Super Cub doesn't work. I've got the gearing sorted out, but the rest is kicking my butt. :laugh:

I'm out of town currently, but I'll try to have a WIP post up on Tuesday or Wednesday

Posted

Yup, I've been building! I have a WIP thread started, but haven't posted it yet. I want to get get a bit more built before posting. Main landing gear is done I think, but I still need to figure out how to build the sequencer for gear and bay doors. Landing gear locks in both the up and down position. One of the fowler flaps with slide mechanism is built, but I still need to figure out if I'm going to motorize or use pneumatics on the flaps.

I'm currently working on the variable pitch mechanism. I'm using mini-turntables for the propellers, which means the old system I used on the Super Cub doesn't work. I've got the gearing sorted out, but the rest is kicking my butt. :laugh:

I'm out of town currently, but I'll try to have a WIP post up on Tuesday or Wednesday

I plan on using the force of the wheel going down to open and keep the doors open until the undercarriage is retracted.

Posted

I'm virtually building in ldd. Forgot to take my laptop with me when i was away on business this last week but I'll try and get some building time in tomorrow and post an update

Posted

Yup, I've been building! I have a WIP thread started, but haven't posted it yet. I want to get get a bit more built before posting. Main landing gear is done I think, but I still need to figure out how to build the sequencer for gear and bay doors. Landing gear locks in both the up and down position.

I wouldn't use a sequencer as on the P38 the doors stay opened when the gears are down. I would try to use connecting rods pushing or pulling the doors when the landing gear is lowered or retracted. Yeah it might be tricky...but i would give it a shot.

One of the fowler flaps with slide mechanism is built, but I still need to figure out if I'm going to motorize or use pneumatics on the flaps.

I'm curious to see how you did yours. I made two version few days ago. They are not awesome but they are working. If you interested, I can post some pictures. One is working with small LAs and the other with gears/liftarms.

I'm currently working on the variable pitch mechanism. I'm using mini-turntables for the propellers, which means the old system I used on the Super Cub doesn't work. I've got the gearing sorted out, but the rest is kicking my butt. :laugh:

Really! how come it doesn't work? (nice plane btw)

I worked on two versions of a variable pitch propeller last week (6 blades and 3 blades). I got inspired by Andy G's work.

The 6 blades propeller (I mounted short blades)

The 3 blades propeller

The pitch would be controlled by mini LA if motorized or just a handle in the cockpit if not.

Posted

I plan on using the force of the wheel going down to open and keep the doors open until the undercarriage is retracted.

I wouldn't use a sequencer as on the P38 the doors stay opened when the gears are down. I would try to use connecting rods pushing or pulling the doors when the landing gear is lowered or retracted. Yeah it might be tricky...but i would give it a shot.

A system like that would be easier, I think, and I may end up going that way. On the other hand, a pneumatic sequencer would be a bit more realistic as the real p-38 has an actuator for each bay door set. Plus I think it may be fun to build. Not sure which way I will go on this.

I'm curious to see how you did yours. I made two version few days ago. They are not awesome but they are working. If you interested, I can post some pictures. One is working with small LAs and the other with gears/liftarms.

The flap I built uses two tracks (just axles) per side. It's pretty much the same track layout as the real P-38. It took a bit of figuring, but I'm very happy with how it works. If I can figure out how to use a single pneumatic cylinder mounted behind the cockpit to give me incremental control of the flaps, I may go this route to lower the flaps. If I can't figure that out, I may go with 2 mini-LAs per flap, or a simple worm gear and lever setup.

Really! how come it doesn't work? (nice plane btw)

I worked on two versions of a variable pitch propeller last week (6 blades and 3 blades). I got inspired by Andy G's work.

The 6 blades propeller (I mounted short blades)

The 3 blades propeller

The pitch would be controlled by mini LA if motorized or just a handle in the cockpit if not.

Nice designs! The system I used on the Super Cub won't work because I'm trying to use a mini-turntable for part of the propeller hub. Since the mini-turntable has 28 teeth on it, I'm having to use a new style differential (28t also), instead of the old style differential. The overall principle is the same, but the new style differential just complicates things a bit. The mini-turntable should be much better for the propeller hub though.

Posted

It's gone very quiet here. Are you all building? I've not come up with anything as yet.

H

I have done some work in LDD and last week I received the parts sent by Lego. So I should be able to continue. However, I seem to be lacking some time lately. Hope to get some building done next weekend.

  • 2 weeks later...
Posted

Somewhere 2018 :tongue:

No fixed deadline. I must admit I haven't been able to continue my build, due to lack of time.

Posted

Somewhere 2018 :tongue:

No fixed deadline. I must admit I haven't been able to continue my build, due to lack of time.

Time is a-lacking here as well.. Looking forward to seeing your dual rotor/chinookified 9396 :thumbup: That is, if that's what you are still working on :classic:

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