Notices
RC Pattern Flying Discuss all topics pertaining to RC Pattern Flying in this forum.

Audax F3A - new project for 2013

Old 03-29-2013, 10:53 AM
  #1  
Alex Voicu
Thread Starter
 
Join Date: Aug 2006
Location: Trollhattan, Sweden
Posts: 512
Received 50 Likes on 26 Posts
Default Audax F3A - new project for 2013

While still working on the kit version of my [link=http://www.rcuniverse.com/forum/m_10970855/tm.htm]Radiance[/link] model, i started thinking about my next pattern design. I initially started with a modified, composite version of Radiance, but soon decided to try a completely different design, one that would use the advantages offered by Brenner’s contra drive, meet its specific requirements and still work well for conventional setups with a single propeller. I probably made over a hundred hand drawings and dozens of 3D models before settling on a design, but in the end i’m happy with the result.

The requirements of the contra drive and single propeller setup may seem quite different: while the contra favors the low drag fuselages, the single prop monoplane designs of today have more and more side area for better knife edge performance during rolling maneuvers. My solution was to create a clean, streamlined design with low form drag but with lots of side area, so I eliminated any sharp edges and completely integrated the canopy into the shape of the fuselage. Using my experience with Radiance, i tried to optimize the side area distribution along the fuselage, which will hopefully result in better handling in crosswinds. The vertical tail area is quite large to increase directional stability and has a flared rudder to eliminate yaw sensitivity.

The wing design features a high taper ratio for fast snap rolls and elliptical tips for improved efficiency of the wing. In my view the multiple rolls on the vertical uplines require a very delicate balance of the model; if the ailerons are almost full span, deflecting them for the vertical roll may influence the airflow over the stabs and therefore deviate the model from the perfect vertical line. That’s why I plan on using split ailerons; normally only the outboard ailerons will be used, but when switching to snap roll flight mode both inboard and outboard ailerons will work together.

The name of the new model is AUDAX ; for now the plan is to build a full composite model, but the light weight of the built-up balsa wings is quite tempting so I may design a wood version later. I will post here images of the progress so far.

I attached 2 images of the model in plain white so you can clearly see its shape and proportions.
Attached Thumbnails Click image for larger version

Name:	Jh14743.jpg
Views:	316
Size:	26.3 KB
ID:	1867930   Click image for larger version

Name:	Rn39534.jpg
Views:	301
Size:	28.2 KB
ID:	1867931  
Old 03-29-2013, 10:55 AM
  #2  
Alex Voicu
Thread Starter
 
Join Date: Aug 2006
Location: Trollhattan, Sweden
Posts: 512
Received 50 Likes on 26 Posts
Default RE: Audax F3A - new project for 2013

As usual, designing a color scheme that works with the shape of the model was the most difficult part for me; i tried creating a new color scheme from scratch but most of the times what seemed great on paper didn’t quite work when applied in 3D. In the end, i took my old Radiance color scheme, changed the colors, changed the lines here and there and with a lot of work, the results were quite pleasing.







Old 03-29-2013, 11:35 AM
  #3  
Lazer
My Feedback: (27)
 
Join Date: Sep 2002
Location: Georgetown, TX
Posts: 326
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Audax F3A - new project for 2013

BEAUTIFUL is all I can say. Keep us informed of your progress.
Old 03-29-2013, 12:25 PM
  #4  
Ryan Smith
Senior Member
My Feedback: (25)
 
Join Date: Mar 2002
Posts: 1,579
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Audax F3A - new project for 2013

Stunning work so far, Alex. I'm looking forward to seeing this airplane progress.
Old 03-29-2013, 12:31 PM
  #5  
danamania
Senior Member
 
Join Date: Oct 2011
Location: Stewartsville, NJ
Posts: 415
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Audax F3A - new project for 2013

I'm looking for the [[BUY NOW]] button!  No seriously, it looks like one sweet F13 machine and I'm just not there yet LOL. Cheers!
Old 03-29-2013, 02:43 PM
  #6  
bjr_93tz
 
Join Date: Dec 2006
Location: ToowoombaQLD, AUSTRALIA
Posts: 984
Likes: 0
Received 7 Likes on 6 Posts
Default RE: Audax F3A - new project for 2013

Living in Queensland, Australia our State motto is "Audax at Fidelis".

While hardly a scholar of Latin, I had to laugh during a program about ancient Rome where one persons profession was written as "OBSTETRIX". Not hard to figure that one out
Old 03-29-2013, 05:45 PM
  #7  
przytek
Member
 
Join Date: Apr 2011
Location: Stoke On Trent, UNITED KINGDOM
Posts: 32
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Audax F3A - new project for 2013

compilation of Caelestia ZNline, Gaudius JM and Sebart.
Nice work but nothing, sorry but nothing new.
Alex, i know you can do much more. Just keep your things. Not others.
Old 03-29-2013, 07:01 PM
  #8  
tschmidt
My Feedback: (1)
 
Join Date: Dec 2002
Location: Fort Scott, KS,
Posts: 376
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Audax F3A - new project for 2013

Nice work Alex! Really like your color scheme too!
Old 03-29-2013, 07:47 PM
  #9  
apereira
 
apereira's Avatar
 
Join Date: Jun 2002
Posts: 1,700
Received 1 Like on 1 Post
Default RE: Audax F3A - new project for 2013

Very interesting concept, your theory for the design makes sense, I hope the model will fly to your expectations. very nice lines and very pretty.

Alejandro
Old 03-29-2013, 09:23 PM
  #10  
highfly3D
 
Join Date: Aug 2005
Location: New York, NY
Posts: 719
Likes: 0
Received 3 Likes on 3 Posts
Default RE: Audax F3A - new project for 2013

I have no words.. the plane looks awesome..

What 3D software do you use?
Old 03-29-2013, 11:01 PM
  #11  
Alex Voicu
Thread Starter
 
Join Date: Aug 2006
Location: Trollhattan, Sweden
Posts: 512
Received 50 Likes on 26 Posts
Default RE: Audax F3A - new project for 2013

Thanks everyone for the kind comments, i'm glad you like it

I will soon add pictures of the building process.
The CAD software i used is Solidworks 2007.
Old 03-30-2013, 05:08 AM
  #12  
underdw
My Feedback: (2)
 
underdw's Avatar
 
Join Date: Nov 2004
Location: Erie CO
Posts: 370
Received 2 Likes on 2 Posts
Default RE: Audax F3A - new project for 2013

Beautiful!
Alex, I'm curious as to why you and other designers rarely put the wing on the thrust line? I don't know that that is better, but it seems to make sense to me.
Old 03-30-2013, 06:31 AM
  #13  
TimBle
Senior Member
 
Join Date: Apr 2010
Location: Cape Town, SOUTH AFRICA
Posts: 2,744
Likes: 0
Received 1 Like on 1 Post
Default RE: Audax F3A - new project for 2013

Will these be in glass composite and carbon composite versions? I really like your Radiance model but  I just don;t have the time to build that intensively
Old 03-30-2013, 11:21 AM
  #14  
sgsterling
Senior Member
My Feedback: (2)
 
Join Date: Feb 2005
Location: Richland, WA
Posts: 110
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Audax F3A - new project for 2013

Thanks for sharing I love the design.
Old 03-30-2013, 11:51 AM
  #15  
Alex Voicu
Thread Starter
 
Join Date: Aug 2006
Location: Trollhattan, Sweden
Posts: 512
Received 50 Likes on 26 Posts
Default RE: Audax F3A - new project for 2013


ORIGINAL: underdw

Beautiful!
Alex, I'm curious as to why you and other designers rarely put the wing on the thrust line? I don't know that that is better, but it seems to make sense to me.
I don't know what other designers think, but in my opinion the wing provides the lift but it's the stab that keeps the plane tracking straight. I placed the stab on the thrust line so it's in a more neutral position. The wing is placed a little lower to keep the stab in clean air, away from wing interference.

Timble, the plan is to have a full composite model. Carbon will be used only in the nose of the fuselage, the rest is glassfiber-airex sandwich.
Old 04-01-2013, 07:12 AM
  #16  
Alex Voicu
Thread Starter
 
Join Date: Aug 2006
Location: Trollhattan, Sweden
Posts: 512
Received 50 Likes on 26 Posts
Default RE: Audax F3A - new project for 2013

Work started in december with CNC programming and simulation of the milling process. The available CNC router was not large enough, so i had to split the fuselage in 2 parts.
Attached Thumbnails Click image for larger version

Name:	Ec87607.jpg
Views:	235
Size:	72.8 KB
ID:	1869052   Click image for larger version

Name:	Rm38246.jpg
Views:	255
Size:	726.2 KB
ID:	1869053   Click image for larger version

Name:	Ua70697.jpg
Views:	210
Size:	614.3 KB
ID:	1869054   Click image for larger version

Name:	Bu58913.jpg
Views:	193
Size:	475.2 KB
ID:	1869055   Click image for larger version

Name:	Se45962.jpg
Views:	205
Size:	395.0 KB
ID:	1869056   Click image for larger version

Name:	Xo88976.jpg
Views:	223
Size:	205.4 KB
ID:	1869057   Click image for larger version

Name:	Np19641.jpg
Views:	205
Size:	224.5 KB
ID:	1869058   Click image for larger version

Name:	Cb95189.jpg
Views:	200
Size:	132.7 KB
ID:	1869059  

Click image for larger version

Name:	Ih74056.jpg
Views:	214
Size:	240.9 KB
ID:	1869060  
Old 04-01-2013, 07:24 AM
  #17  
Alex Voicu
Thread Starter
 
Join Date: Aug 2006
Location: Trollhattan, Sweden
Posts: 512
Received 50 Likes on 26 Posts
Default RE: Audax F3A - new project for 2013

The CNC router had very limited travel on the Z axis and also the tools available were very short, so i decided to cut the fuselage and canopy together and separate them later. The fin was very thin and flexible at the tip, so i used a block of balsa to mill the fin tip separately.

Material was a block of polyurethanic foam made of a few 30mm sheets glued together.
Attached Thumbnails Click image for larger version

Name:	Tr50025.jpg
Views:	525
Size:	296.5 KB
ID:	1869061   Click image for larger version

Name:	Hc93965.jpg
Views:	408
Size:	304.5 KB
ID:	1869062   Click image for larger version

Name:	Ci98045.jpg
Views:	344
Size:	256.0 KB
ID:	1869063   Click image for larger version

Name:	Zs51141.jpg
Views:	419
Size:	287.8 KB
ID:	1869064   Click image for larger version

Name:	Qb37663.jpg
Views:	329
Size:	220.6 KB
ID:	1869065   Click image for larger version

Name:	Pg62612.jpg
Views:	310
Size:	204.1 KB
ID:	1869066   Click image for larger version

Name:	Ln10024.jpg
Views:	342
Size:	249.7 KB
ID:	1869067  
Old 04-01-2013, 07:25 AM
  #18  
Ryan Smith
Senior Member
My Feedback: (25)
 
Join Date: Mar 2002
Posts: 1,579
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Audax F3A - new project for 2013

Alex, when do you anticipate completion of the mold?
Old 04-01-2013, 07:30 AM
  #19  
Alex Voicu
Thread Starter
 
Join Date: Aug 2006
Location: Trollhattan, Sweden
Posts: 512
Received 50 Likes on 26 Posts
Default RE: Audax F3A - new project for 2013

Ryan, the fuselage mold is done, currently working on the canopy mold. I'll post here images with all the steps of the building process.
Old 04-01-2013, 07:39 AM
  #20  
apereira
 
apereira's Avatar
 
Join Date: Jun 2002
Posts: 1,700
Received 1 Like on 1 Post
Default RE: Audax F3A - new project for 2013

I really enjoy looking at all the pictures, very nice.
Old 04-01-2013, 10:59 AM
  #21  
Doug Cronkhite
My Feedback: (34)
 
Join Date: Dec 2001
Location: San Diego, CA
Posts: 3,821
Likes: 0
Received 11 Likes on 8 Posts
Default RE: Audax F3A - new project for 2013


ORIGINAL: przytek

compilation of Caelestia ZNline, Gaudius JM and Sebart.
Nice work but nothing, sorry but nothing new.
Alex, i know you can do much more. Just keep your things. Not others.
Some people just can't help but be negative. Why post a comment like this at all?

It's a beautiful airplane, Alex!
Old 04-01-2013, 12:09 PM
  #22  
flyncajun
 
Join Date: Dec 2006
Location: DENHAM SPRINGS , LA
Posts: 636
Likes: 0
Received 3 Likes on 3 Posts
Default RE: Audax F3A - new project for 2013

Right Doug,

Looks great to me, looks like a progression from his last design.
outstanding work!
There are a few new designers out there coming on strong with modern tools, and Good efforts,
Like Mark Hunt and Alex. I think thats Great and what this sport needs.
This keeps us all excited and even the old guys can learn from this

Bryan
Old 04-01-2013, 12:10 PM
  #23  
TimBle
Senior Member
 
Join Date: Apr 2010
Location: Cape Town, SOUTH AFRICA
Posts: 2,744
Likes: 0
Received 1 Like on 1 Post
Default RE: Audax F3A - new project for 2013


ORIGINAL: Alex Voicu


ORIGINAL: underdw

Beautiful!
Alex, I'm curious as to why you and other designers rarely put the wing on the thrust line? I don't know that that is better, but it seems to make sense to me.
I don't know what other designers think, but in my opinion the wing provides the lift but it's the stab that keeps the plane tracking straight. I placed the stab on the thrust line so it's in a more neutral position. The wing is placed a little lower to keep the stab in clean air, away from wing interference.

Timble, the plan is to have a full composite model. Carbon will be used only in the nose of the fuselage, the rest is glassfiber-airex sandwich.


Excellent, thanks Alex. I agree, stab on the thrust line minimises tracking issues. Also consider having the area of the ruder equal above and below the thrustline although this would need to be considered in conjunction with fuselage volume above and below the thrust line too.

Your targeted construction should see it coiming in at a reasonable price.


Old 04-01-2013, 12:43 PM
  #24  
Viper Driver
My Feedback: (1)
 
Viper Driver's Avatar
 
Join Date: Feb 2003
Location: Archer City, TX
Posts: 395
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Audax F3A - new project for 2013

Fantastic work Alex!

I am very interested to see how that wing planform performs. It looks like a winner to me.

Best of luck

Jeff
Old 04-04-2013, 08:50 AM
  #25  
Alex Voicu
Thread Starter
 
Join Date: Aug 2006
Location: Trollhattan, Sweden
Posts: 512
Received 50 Likes on 26 Posts
Default RE: Audax F3A - new project for 2013

Thanks a lot, reading all the nice comments is really encouraging.

The next step was to assemble the fuselage mold plug from the CNC machined parts. From this point on, i worked together with my friend Horia Florian; he has a lot of experience with composites and his work includes a full scale glider.

As mentioned before, the fin was a little flexible, so i added a plywood former at the back to solve the problem. The tip was cut off and later replaced with the balsa milled part.

We used an aluminium profile on the center line of the fuselage mold plug to make sure it stays straight and stiff. Since the fuselage and canopy were milled in 1 piece, i had to design a jig for separating the canopy. The jig was laser cut from MDF and after using some filler and sanding, the result was pretty good.

We also glassed the mold plug using 2 layers of 160g FG cloth.
Attached Thumbnails Click image for larger version

Name:	Jh16846.jpg
Views:	438
Size:	44.0 KB
ID:	1870130   Click image for larger version

Name:	Rm36292.jpg
Views:	449
Size:	105.9 KB
ID:	1870131   Click image for larger version

Name:	Va72705.jpg
Views:	501
Size:	81.7 KB
ID:	1870132   Click image for larger version

Name:	Zt54107.jpg
Views:	549
Size:	186.9 KB
ID:	1870133   Click image for larger version

Name:	Lw20640.jpg
Views:	504
Size:	176.8 KB
ID:	1870134   Click image for larger version

Name:	Kb45324.jpg
Views:	550
Size:	188.0 KB
ID:	1870135   Click image for larger version

Name:	Tv40128.jpg
Views:	460
Size:	193.2 KB
ID:	1870136   Click image for larger version

Name:	Ca92828.jpg
Views:	463
Size:	185.8 KB
ID:	1870137  

Click image for larger version

Name:	Fd62923.jpg
Views:	672
Size:	181.5 KB
ID:	1870138   Click image for larger version

Name:	Co71915.jpg
Views:	511
Size:	121.5 KB
ID:	1870139  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.