Valkyrie Designs - Lockheed Electra Junior

[Jim Barry]

Oh and AlexM @AlexM, the Prop is TOUGH no doubt. It'll make you want to just do jets, but I do it now by lofting the base profile (like in this case a circle) to a basic NACA profile with a curved top and flat bottom) at about 90% of the props length. Then, if you are a fusion person then you control the shape of the prop (front view) with rails. These same rails also control the twist which means the rail is drawn in 3D space. Both rails and 3D sketches are advanced requiring a bit of practice but if you just fool around with those two skills and get comfortable, you can then move on to applying the learning to the prop work. Now the tip is a real bear too because its still a loft and just because it's small does not mean you can get away with just hacking it out. You have to "get small" and work all the geometry to fit the prop and get a rail etc.  Again, you will long for jets when learning this, but stick with it and you can then do anything except perhaps the props on a Super Hercules.  (Shudders) 

 

 

[Jim Barry]

5 minutes ago, Breaker said:

 

Utterly batsh*t useless idea. Make them threaded so they screw on and off! 🤪

 Fusion will do threads....but yeah, no. 

[Jim Barry]

 

[Jim Barry]

@AlexM

 

video of prop work

 

 

[Jim Barry]

More rivets. There are more than this in real life and they are smaller. I know this, but for effect I'm going with this approach. I think real size would just get lost in the paint and if you were utter the word sanding just above a whisper, they would vanish.  Let's see how it goes in testing. If I need to adjust size, as I said, it's easy. 

 

 

[AlexM]

7 hours ago, Jim Barry said:

Oh and AlexM @AlexM, the Prop is TOUGH no doubt. It'll make you want to just do jets, but I do it now by lofting the base profile (like in this case a circle) to a basic NACA profile with a curved top and flat bottom) at about 90% of the props length. Then, if you are a fusion person then you control the shape of the prop (front view) with rails. These same rails also control the twist which means the rail is drawn in 3D space. Both rails and 3D sketches are advanced requiring a bit of practice but if you just fool around with those two skills and get comfortable, you can then move on to applying the learning to the prop work. Now the tip is a real bear too because its still a loft and just because it's small does not mean you can get away with just hacking it out. You have to "get small" and work all the geometry to fit the prop and get a rail etc.  Again, you will long for jets when learning this, but stick with it and you can then do anything except perhaps the props on a Super Hercules.  (Shudders) 

 

 

 

Thanks a lot. The way you describe and show it on video makes it look feasible.

If it wasn't for that darn propeller twist that is stil twisting my mind 

Drawing those 3D-lines for the leading and trailing edges seems to be the tricky part. 

 

Cheers

Alex

 

Cheers

Alex

[Hubert Boillot]

8 hours ago, Jim Barry said:

Ok, I found by going to the mesh workspace and converting the solid bodies into meshes via the "Tessellate" function and selecting "high" I get much smoother rendering when I then export as an STL file. 

 

 

 

 

 

 

SO BEFORE: Blocky 

 

 

 

 

 

And After. Smooth        This does multiply the file size by 5.  Elegoo Satellite had no problem opening this. 

 

 

 

 

 

 

 

And to Hubert's concern about the engine fit. Yes, to get it  in there, I will print the front of the cowl separately. Something like this. if you want to show off the engines perhaps micro magnets like Jay W's Jug. Maybe I can design fitting features that are magnet ready ?? 

 

 

Great ! Maybe add three small location lugs, that will fall between the cylinders, and will avoid a delicate butt-joint gluing of the two cowling halves ?

This said, on the real aircraft, the cowlings were split in the way I have shown on my design for the Duck. The panel lines, which I suspect were close to the rivet lines, were the natural separation lines for the cowling panels …

 

Hubert

[Jim Barry]

5 hours ago, AlexM said:

 

Thanks a lot. The way you describe and show it on video makes it look feasible.

If it wasn't for that darn propeller twist that is stil twisting my mind 

Drawing those 3D-lines for the leading and trailing edges seems to be the tricky part. 

 

Cheers

Alex

 

Cheers

Alex

 

Yes, the twist is hard and I have yet to master it, but once the rail is built you can edit the points like sculpting. I think 4 rails (sides, top and bottom) might be best and a few more points than I have in my video. Find a prop  from a in a kit and keep by your side at the computer to keep your head in the 3D game. 

[Jim Barry]

4 hours ago, Hubert Boillot said:

Great ! Maybe add three small location lugs, that will fall between the cylinders, and will avoid a delicate butt-joint gluing of the two cowling halves ?

This said, on the real aircraft, the cowlings were split in the way I have shown on my design for the Duck. The panel lines, which I suspect were close to the rivet lines, were the natural separation lines for the cowling panels …

 

Hubert

 

 

Thank you. Perhaps I'll split it like you have on your Duck( e.g.  realistic), but with almost no detail on the back of my engines, it might just be a split to allow for the build to happen and not display. I'll think more about it.  BTW, If I have not said so, you've done some great work on the Duck. 

[RCPlym]

15 hours ago, Jim Barry said:

Ok, I found by going to the mesh workspace and converting the solid bodies into meshes via the "Tessellate" function and selecting "high" I get much smoother rendering when I then export as an STL file. 

 

 

 

 

 

 

SO BEFORE: Blocky 

 

 

 

 

 

And After. Smooth        This does multiply the file size by 5.  Elegoo Satellite had no problem opening this. 

 

 

 

 

 

 

 

And to Hubert's concern about the engine fit. Yes, to get it  in there, I will print the front of the cowl separately. Something like this. if you want to show off the engines perhaps micro magnets like Jay W's Jug. Maybe I can design fitting features that are magnet ready ?? 

 

 

 

Just goes to show what a zero can do! 

 

In your Tesselate box, you should see 'custom' which will allow you to put various settings that will produce best results for quality V file sizes.

Worth experimenting with. 👍👍👍 

Edited August 9 by RCPlym

[Hubert Boillot]

I designed my R-985 as a kit. If you want the back of the engine only, I can send it to you.

 

Hubert

Edited August 9 by Hubert Boillot

[Jim Barry]

Thanks for the offer Hubert

 

I think I can do the back. It's not as  crazy as I thought. It's a slippery slope here though. How does it attach to the plane exactly ?? It appear the picture below has some open holes that probably bolt into some frame of perhaps common design. 

 

 

 

4

[RCPlym]

They do indeed bolt into a circular frame 

[Hubert Boillot]

Exactly, the round holes at the end of the triangular shapes are threaded to receive the bolts going through the circular tubing frame …

The two black angled boxes are the scintilla magnetos, one (the right, IIRC) feeding the rear ignition ring (between the intake manifolds and the cylinders) with cales going to the rear spark plugs. The other magneto feeds the front ignition ring, with cables going to the front spark plugs.

The bottom black «  thing » on the picture is the carburetor. The R-985 typically had a Stromberg carburetor (the one on the pic does not seem to be a Stromberg).

 

HTH

 

Hubert

[RCPlym]

4 hours ago, Hubert Boillot said:

the one on the pic does not seem to be a Stromberg

 

It is a Bendix Stromberg NA9RB.