Back to Balsa Roots - Seeking out less covered designs - The Duranita

[Joker 53150]

Peter,
I think you've got more time than you think. You mentioned 16 days to finish, but here's what is on the original post regarding the contest:

- Registration for entries will open and the Build-Off will start on Jan 12th 2015.
- Registration will close on April 1st, 2015.
- Build-Off will close on June 1st, 2015.
- Build-Off adjudication will be completed and points accumulated will be posted by June 30th, 2015.

If I'm reading this right, you've got until June 1 to finish up and have proof-of-flight, but only a few weeks left to join in on the contest. But I've been wrong in the past...!

 

[PeterGregory]

AMPLAN Buildoff

Peter,
I think you've got more time than you think. You mentioned 16 days to finish, but here's what is on the original post regarding the contest:

- Registration for entries will open and the Build-Off will start on Jan 12th 2015.
- Registration will close on April 1st, 2015.
- Build-Off will close on June 1st, 2015.
- Build-Off adjudication will be completed and points accumulated will be posted by June 30th, 2015.

If I'm reading this right, you've got until June 1 to finish up and have proof-of-flight, but only a few weeks left to join in on the contest. But I've been wrong in the past...!

Hmm, I entered three RCG contests - the first one due up is the AMPLAN buildoff.
Your comment made me go review the three contests I entered, and it looks like the one you mentioned is the second that is listed below.

The contest the plane of this FT thread is entered in is the AMPLAN buildoff:
The rules are here:
http://www.rcgroups.com/forums/showpost.php?p=29139081&postcount=1

I entered a reduced scale, vintage design Miss America in the Balsa Builders Conversion Contest BBCC 6 here:
http://www.rcgroups.com/forums/showpost.php?p=30663682&postcount=1
(RCG Forum Aircraft General/Balsa Builders)
For that one, the build is July, Aug, Sept 2015

For the contest you referenced, I entered (Electric/Scale Kit-Scratch Built/Scale Build Off 4) a Guillows Stearman.
http://www.rcgroups.com/forums/showpost.php?p=29687352&postcount=1
The build period for that contest is Apr, June, July, and then up to 15 Aug.

So those are the there - I have some building to do(!)

Best,
Peter

 

[PeterGregory]

Necessary additions

Last eve I was able to lay up both sides' framework.

The two photos attached here show the original design and then the three added frame elements, above and beyond what was originally designed.

One thing that bothered me was that the "datum" to be used as the fuselage takes shape was in a void.
The lower wing bottom surface was the 0 degree line for the plane.
Yet, when you made the cutout for the wing, you lose that reference line to work from to establish the thrust line of the engine, the 0 degree incidence of the horizontal stab.
When you sit the fuselage up after framing, it would be sitting on a void - so I put in a temporary frame member to make sure things stay straight and level.

Original plan:


With 3 extra members. The temp member is there so the fuselage will sit square on the bench surface - all other angles are measured from this plane. Without the extra member, the fuselage would be sitting on a void cut out for the lower wing and I thought that was precarious.

 

[PeterGregory]

Fuselage and engine progress

Getting along on the fuselage and engine mounting.

The original design has a light ply firewall for the .049 diesel which was radial mounted.
I am using a heavier .09 which is beam mounted so have to add rails.
The ASP .09 has the rear exhaust and a cute round/cylindrical muffler I have to find space for.
Two addition bulkheads had to be added for the heavy beam mounts.

It took some time to fabricate the bulkheads as they contain different amounts of detailing to get them to fit just right, as designed.
Photo filenames also describe the step...


Beveling bottom edge of one of the bulkheads to match slope of the fuselage underside.



Lots of "3D" work on getting all the bulkheads to fit perfectly.
Ideally these ply bulkheads would be laser cut.



A general photo of bulkhead location.



Another general photo of bulkhead location.



Forward bulkhead and rear bulkhead.



Getting toward actually assembling the bulkheads in the fuse sides.



Trial fit of engine on rails and bulkhead.



Test fit of engine on rails in the major bulkhead that bears the weight and thrust of the engine.

 

[PeterGregory]

More Fuse

Here's a few shots of the fuse coming together this eve.

This shot is straight down showing alignment to one of the cutting mat's lines as the centerline reference point at the very end of the fuse that I am gluing.




Taking a quick look with the tailfeathers attached.
Looks Ok but I see something I am going to have to figure out - more on that later.
Probably have to add a rudder post down into the fuse for the control horn.



Bottom sheeted, bottom view.



Bottom sheeting, top view.



Sort of a view of further frames for the fuselage - somehow missed the more aft parts of the fuse in the shot - weird.
There is very little framing support for the sheeted fuse - was designed originally to be uber light.
How else could a little old .049 diesel haul around a 43 inch wingspan (original dimensions) biplane?



Cheers,
Peter

 

[tntrcnutz]

looking god so far
your like me ,,, I love to build , especially covering ' and with all of the arf and foamies it just seems that the craft is leaving aircraft keep us updated

 

[PeterGregory]

Well, it has been some time...

Been away to teach a college course, and that was like an additional full-time job, getting it together, presenting, grading, etc.

Here are a couple shots from when I was last on the bench - now it's time to get the project finished...
Photos' names explain what it is.

 

[PeterGregory]

Intermission on the Duranita.

It's summer and I am throwing that flag as all rules (and some discipline) are off while we can fly. Any building is gravy, in my mind!

I am starting a build thread on my Guillow's Stearman. As opposed to the Duranita, this plane is very popular and fairly well covered.

An expected interruption of that interruption will be a (simpler) build of an electric conversion of the free flight Miss America.
That one is due for a completion date for a build-off in a couple of months which is doable.

Therefore I will have three builds simultaneously, with two blown schedules.

 

[PeterGregory]

Side Trip to Run Some Diesel Engines I Acquired

Well, I thought I would throw in a part of my "Program" that has taken my attention lately. It is loosely related to the Duranita in that the original Duranita had just a .049 McCoy Dura Glow diesel engine for its big wings. I have thought about using the .09 version of that engine for some connectivity to the past but I prefer a version with a throttle to increase survivability of the plane thru its maiden and early flites. I am getting a group of my diesels up and running so I can get them into classic airplanes like the D.

Spellbinding diesel action: https://www.youtube.com/watch?v=mir_KxjxcUc

Sorry about the castor covered lens on my GoPro for the vid :black_eyed:

And, Back to building as soon as I can...

 

[gabrielete]

I really wish i could cut and glue the wood as cleanly as you guys do. It's amazing

 

[PeterGregory]

There's a fair number of redo's. : )
You have to treat it as a learning experience.

This plane originally had had a McCoy DuraGlow .049 Diesel in it.
I was able to get a similar engine, an OK Cub Diesel off eBay. It won't go in the plane but I might build a normal size version of the model and wanted to have the original suggested engine in it.

So, today I worked for 5 hours and could not get it to run - but I will. The total revolutions were about 3,000 over 300 minutes, so that is 10 rpms - not too impressive.
Not going to get off the ground with that.

Thankfully, the expertise on the internet is fantastic and someone will know either what I am doing wrong, or what is wrong with the engine. But you just have to "do stuff" and you get more crafty over time.

Big thing is the goal is to go fly the thing when you are done - so you economize on time.
Admittedly, I am a little stalled on this project. :black_eyed: