P38 1/4 scale
12-10-2009, 10:16 AM
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RE: P38 1/4 scale
Some other former cut done. I am almost done with the first boom formers soon some pictures.
I made little statistics here they are :
I have 286pieces to cut.
I have just done 33 pieces yet
that's 12%, the way is long...
Istill have some work to do on wing keys in order to start to buildthe center section.
I made little statistics here they are :
I have 286pieces to cut.
I have just done 33 pieces yet
that's 12%, the way is long...
Istill have some work to do on wing keys in order to start to buildthe center section.
12-10-2009, 04:42 PM
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RE: P38 1/4 scale
Hi!
Lot's of plywood there!
Even if your plane is going to be large there is a lot of plywood that could be removed in the formers to make it a better flier.
Light weight is always better!
Lot's of plywood there!
Even if your plane is going to be large there is a lot of plywood that could be removed in the formers to make it a better flier.
Light weight is always better!
12-11-2009, 04:38 AM
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RE: P38 1/4 scale
ORIGINAL: jaka
Hi!
Lot's of plywood there!
Even if your plane is going to be large there is a lot of plywood that could be removed in the formers to make it a better flier.
Light weight is always better!
Hi!
Lot's of plywood there!
Even if your plane is going to be large there is a lot of plywood that could be removed in the formers to make it a better flier.
Light weight is always better!
12-12-2009, 05:52 PM
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RE: P38 1/4 scale
I have the weight of the formers, and it is just 17 oz which is very light I think. Could you imagine this little weight for almost 10 feet long? Of course it is just former, and the weight will come with the rest of construction but I am not afraid of it till now.
12-20-2009, 05:01 PM
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RE: P38 1/4 scale
I am working on a detail that I found fun to realise. It is the ladder.
So here is the prototype in order to have the good position of the axes.
The prototype confirm me that I need to make a sliding part on the arm.
Here is the photos.
The Triangle part is the same shape than the back of the gondola.
The other problem that I have is that the gondola will be in two parts the the mecanism will be attached to the bottom part of the gondola which may be tricky to mount and unmount... so more reflexion to come.
So here is the prototype in order to have the good position of the axes.
The prototype confirm me that I need to make a sliding part on the arm.
Here is the photos.
The Triangle part is the same shape than the back of the gondola.
The other problem that I have is that the gondola will be in two parts the the mecanism will be attached to the bottom part of the gondola which may be tricky to mount and unmount... so more reflexion to come.
12-20-2009, 05:10 PM
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RE: P38 1/4 scale
Hi BigP38Lightning I'm sure you will go well! ... a great way would be to use the system sendwich and a ladder driven by a metal arm connected to a servo
12-21-2009, 12:53 AM
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RE: P38 1/4 scale
ORIGINAL: at-6 texan
Hi BigP38Lightning I'm sure you will go well! ... a great way would be to use the system sendwich and a ladder driven by a metal arm connected to a servo
Hi BigP38Lightning I'm sure you will go well! ... a great way would be to use the system sendwich and a ladder driven by a metal arm connected to a servo
12-21-2009, 01:00 AM
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RE: P38 1/4 scale
ORIGINAL: ram3500-RCU
I was wondering, are you going to counter rotate your engines? And how do you make that giant canopy?
I was wondering, are you going to counter rotate your engines? And how do you make that giant canopy?
For the canopy, I made some biggest so I am not necessary confused about it. Here is a canopy that I made for a 1/3 scale Pilatus PC9.
This is the master of course, after this step, There is two other steps to do before having the canopy done:
- Negative in epoxy or equivalent
- Positive in resin that resist to high temperature.
The canopy will be made in boiled oil which give better results with transparency.
12-21-2009, 09:05 AM
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RE: P38 1/4 scale
Hi bigP-38Ligthning This is GOOD! look this link i'm sure which you'll be surprised http://www.laserengines.com/
12-21-2009, 07:45 PM
#40
RE: P38 1/4 scale
ORIGINAL: BigP38Lightning
I whish to counter rotate the engines, but the question is which engine, and I need to know a little bit more about the final weight. It will probably be between 100cc and 140cc. If I made it counter rotate I will also need right propellers and left propellers three blades that is harder to find.
For the canopy, I made some biggest so I am not necessary confused about it. Here is a canopy that I made for a 1/3 scale Pilatus PC9.
[img][/img]
This is the master of course, after this step, There is two other steps to do before having the canopy done:
- Negative in epoxy or equivalent
- Positive in resin that resist to high temperature.
The canopy will be made in boiled oil which give better results with transparency.
ORIGINAL: ram3500-RCU
I was wondering, are you going to counter rotate your engines? And how do you make that giant canopy?
I was wondering, are you going to counter rotate your engines? And how do you make that giant canopy?
For the canopy, I made some biggest so I am not necessary confused about it. Here is a canopy that I made for a 1/3 scale Pilatus PC9.
[img][/img]
This is the master of course, after this step, There is two other steps to do before having the canopy done:
- Negative in epoxy or equivalent
- Positive in resin that resist to high temperature.
The canopy will be made in boiled oil which give better results with transparency.
12-22-2009, 01:18 AM
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RE: P38 1/4 scale
It is almost the same process as the "common" process with transparent PVC that you warm up in an oven and put on the shape that you eventually vacuum under the shape.
You put the PVC on a frame, put the shape in the oil that you warm up, then you go down on the shape with the frame.
I will post some photos when I will be at this step.
You put the PVC on a frame, put the shape in the oil that you warm up, then you go down on the shape with the frame.
I will post some photos when I will be at this step.
12-23-2009, 03:06 AM
#42
RE: P38 1/4 scale
ORIGINAL: BigP38Lightning
It is almost the same process as the ''common'' process with transparent PVC that you warm up in an oven and put on the shape that you eventually vacuum under the shape.
You put the PVC on a frame, put the shape in the oil that you warm up, then you go down on the shape with the frame.
I will post some photos when I will be at this step.
It is almost the same process as the ''common'' process with transparent PVC that you warm up in an oven and put on the shape that you eventually vacuum under the shape.
You put the PVC on a frame, put the shape in the oil that you warm up, then you go down on the shape with the frame.
I will post some photos when I will be at this step.
12-23-2009, 07:44 PM
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RE: P38 1/4 scale
Some years ago 3W made a counter rotating ignition for me for one of their engines, they were also able to supply the props. Perhaps they can still do this.
Mike
Mike
04-25-2010, 01:45 PM
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RE: P38 1/4 scale
That's a long time now that I did not work on the P38, because the PC9 take all my free time.
Here are the wing keys.
I still have a lot to do on the PC9 so it will probably stay this step for a while.
Here are the wing keys.
I still have a lot to do on the PC9 so it will probably stay this step for a while.
04-25-2010, 10:45 PM
#46
RE: P38 1/4 scale
I am no expert on this, But I think the traditional rotating engine would be on the left side, from pilot position.. and the reverse rotating one would be on the right.
That way in a one engine situation the torque would help fight a spin...I think?
I believe I have heard of twins having outboard thrust to help eliminate the engine loss problem as well. Just some stuff I have overheard... don't let me be the last source you check !
That way in a one engine situation the torque would help fight a spin...I think?
I believe I have heard of twins having outboard thrust to help eliminate the engine loss problem as well. Just some stuff I have overheard... don't let me be the last source you check !
04-26-2010, 12:28 AM
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RE: P38 1/4 scale
Normally on a twin with counter rotating propellors the props rotate outward, ie, the downward moving blade is towards the wing tip. This is so torque will help to lift the dead side in an engine out situation. However, on the P-38 they rotate inward. Apparently the prototype started with outboard rotating engines but the airflow caused some sort of instability issue with the airplane and the rotation was changed. The inward rotating engines are the reason the full size P-38 had such a reputation as a killer in an engine out situation, especially low and slow. This is one area where I would definitely suggest deviating from scale on a P-38 model.
04-26-2010, 12:30 PM
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RE: P38 1/4 scale
ORIGINAL: SHANEC
The engines spin outward on the P-38. Left engine, ''left hand rotation'' Right engine. ''right hand rotation'' Here is a pic of a real P-38. Notice the pitch on the blades... Excuse the P-40 pic.
The engines spin outward on the P-38. Left engine, ''left hand rotation'' Right engine. ''right hand rotation'' Here is a pic of a real P-38. Notice the pitch on the blades... Excuse the P-40 pic.
Yes, reverse what I said in my previous post! Most twins with counter rotater have INWARD rotating engines to help lift the dead side in an engine out situation. The P-38 goes just the opposite of the norm.