SMALL - espritmodel.com SMALL - Telemetry SMALL - Radio
Reply
Thread Tools
Old Mar 27, 2010, 11:18 AM
in persuit of low wing loading
Gordon Johnson's Avatar
Boston, Mass
Joined May 2001
6,431 Posts
Discussion
Aileron Vapor

Here's my conversion of a Vapor to have ailerons. At our last indoor my daughter's brand new Vapor had a mishap with a Sukhoi and had its tail covering stripped off. So, I ordered her a new one and attacked this one. My older son has been wanting to fly my Airbender so I thought I'd convert this Vapor and let him fly it.

My estimate is that the NET increase in weight over a standard Vapor will be about 2g. But, that comes after putting this Vapor on a diet and saving 1.5g or so in weight. I recovered the tail with lighter clear film and painted on some blue and a fake skeleton to sorta mimic the wing. I'll be using a Sukhoi brick and servo rather than solder a servo to the Vapor brick.

[edit] I made my own tail, which increased the weight gain (plus a few other things) to 3g over the stock. I've added the picture with my tail below, along with the version with the stock tail recovered and painted.

When I'm done with this conversion I'll post the plan for the wing and related bits for those who may want to do this themselves.

Gordon
Gordon Johnson is offline Find More Posts by Gordon Johnson
Last edited by Gordon Johnson; May 09, 2010 at 09:30 AM. Reason: added pic of version with new tail
Reply With Quote
Sign up now
to remove ads between posts
Old Mar 27, 2010, 11:18 AM
in persuit of low wing loading
Gordon Johnson's Avatar
Boston, Mass
Joined May 2001
6,431 Posts
The first thing to do is cut off the old wing. But, we want the molded plastic wing saddles. I cut off the wing right where the CF rod goes into the plastic wing saddles. Corresponding slots are cut in the foam wing. The wing saddles get glue applied and are inserted in the slots in the wing when glueing the wing on.

I also cut off the lower plastic part from the Vapor center wing rib to save weight and because it will interfere with the foam that will hold the servo and bellcrank.

The wing is very similar to my Airbender wing. Its span is the same as the Vapor wing so with a bit of modifications to the foam carrying box it will fit into the original Parkzone box for transport. Foam is cut from either 3mm Gediplac or Depron and covered with 2 um film from Dave Lewis (homefly.com). The film from Dave has the advantage of weighing 1/3 that of the covering that's used on the Vapor. The wing with outer two ribs (but not the center rib that holds the servo) weighs almost exactly the same as the Vapor wing that was cut off and removed.
Gordon Johnson is offline Find More Posts by Gordon Johnson
Last edited by Gordon Johnson; Mar 27, 2010 at 10:18 PM.
Reply With Quote
Old Mar 27, 2010, 11:19 AM
in persuit of low wing loading
Gordon Johnson's Avatar
Boston, Mass
Joined May 2001
6,431 Posts
I cut a center wing rib from 3mm Gediplac. This will hold the servo and also the bellcrank. Similar to my Airbender, the bellcrank is made from 1/64 ply and uses a BSD molded plastic wheel hub and keeper and short length of piano wire for it all to pivot on. Three stacked squares of 1/32 ply serve to hold the piano wire and anchor it into the foam center rib.

The center rib has UHU Por applied and is glued on the right hand side of the plastic Vapor rib, underneath the plastic lip.

The Foam center rib and wing saddles get UHU applied and the foam wing is glued in place. Note the wing saddles inserted in the slots on the wing.
Gordon Johnson is offline Find More Posts by Gordon Johnson
Last edited by Gordon Johnson; Mar 27, 2010 at 11:34 AM.
Reply With Quote
Old Mar 27, 2010, 11:19 AM
in persuit of low wing loading
Gordon Johnson's Avatar
Boston, Mass
Joined May 2001
6,431 Posts
I glued in a small rectangle of 3mm foam just behind the forward wing pylon. The purpose of this is to give the CF wing struts something to anchor into. I cut shallow grooves in the sides that will be glued to the fuselage rod and the forward wing pylon. Then, pressing the piece on these rods spreads this groove slightly and makes a channel for the glue and will result in a very strong joint.

Wing struts are poked through the foam and cut to length. Foam safe CA is applied to each end and each strut is installed. Care needs to be taken to get this right so the wing is not warped. I used 0.8mm CF tube for the front struts and 0.5mm CF tubes for the aft struts. CF rod came from homefly.com.

Landing gear is my replacement Vapor landing gear design. To save a bit of weight I used 0.5mm CF tubes with piano wire axles rather than the entire strut from piano wire. Added weight over the standard gear is about 0.13g.
Gordon Johnson is offline Find More Posts by Gordon Johnson
Last edited by Gordon Johnson; Mar 27, 2010 at 11:44 AM.
Reply With Quote
Old Mar 27, 2010, 11:20 AM
in persuit of low wing loading
Gordon Johnson's Avatar
Boston, Mass
Joined May 2001
6,431 Posts
reserved for future content
Gordon Johnson is offline Find More Posts by Gordon Johnson
Last edited by Gordon Johnson; Mar 27, 2010 at 11:42 AM.
Reply With Quote
Old Mar 27, 2010, 11:20 AM
in persuit of low wing loading
Gordon Johnson's Avatar
Boston, Mass
Joined May 2001
6,431 Posts
reserved ...
Gordon Johnson is offline Find More Posts by Gordon Johnson
Last edited by Gordon Johnson; Mar 27, 2010 at 11:42 AM.
Reply With Quote
Old Mar 27, 2010, 02:00 PM
Registered User
I R Irv's Avatar
United States, IL, Washington
Joined Nov 2008
1,955 Posts
Gordon couldn't you make a wing strut mount like your landing gear mount that way you could still slide your wing forward and backward possibly two of them one in front one in back.
I can't wait too see this one fly wish I lived buy you. TODD
I R Irv is offline Find More Posts by I R Irv
Reply With Quote
Old Mar 27, 2010, 02:04 PM
in persuit of low wing loading
Gordon Johnson's Avatar
Boston, Mass
Joined May 2001
6,431 Posts
Todd,

I thought about that. First, the landing gear ply mount is heavier than the piece of foam I went with. Two of those types of mounts are twice as heavy. And, with one in the back and one in the front you give up the triangle configuration. The wing will twist because the two wing struts and the wing and fuselage form a parallelogram rather than a triangle. To get any reasonable stiffness and no twist would require larger diameter CF rods. With a triangle configuration I can use the minimal diameter CF rod and save weight. The triangle method I used here is the same as what I used on my Airbender. The only difference is instead of the fuselage being made of foam where I leave a spot to pass the CF rods through I glued that piece of foam in. Also, my landing gear mount doesn't slide forward and back. It's fixed. I don't have any need to slide the wing on this forward and back.

Gordon
Gordon Johnson is offline Find More Posts by Gordon Johnson
Last edited by Gordon Johnson; Mar 27, 2010 at 02:12 PM.
Reply With Quote
Old Mar 27, 2010, 02:12 PM
I don't want to "Switch Now"
pmackenzie's Avatar
Toronto (Don Mills), Canada
Joined Dec 2002
16,926 Posts
Cool project
Is that 2 mil or 0.2 mil?
I thought the Vapor was covered in 1/2 mil = .0005" mylar.
2 mil would be .002" - pretty thick.

Thanks,

Pat MacKenzie
pmackenzie is online now Find More Posts by pmackenzie
Reply With Quote
Old Mar 27, 2010, 02:15 PM
in persuit of low wing loading
Gordon Johnson's Avatar
Boston, Mass
Joined May 2001
6,431 Posts
Oops, you are right. It's 2 um film, which is 0.08 mil. I have corrected that post.
Gordon Johnson is offline Find More Posts by Gordon Johnson
Last edited by Gordon Johnson; Mar 27, 2010 at 10:15 PM.
Reply With Quote
Old Mar 27, 2010, 02:24 PM
Registered User
I R Irv's Avatar
United States, IL, Washington
Joined Nov 2008
1,955 Posts
Ok totally understand know to bad that little piece of foam can't slide on the frame. You really take this hobby to were most just dream of, it wouldn't be were it is without you.
TODD
I R Irv is offline Find More Posts by I R Irv
Reply With Quote
Old Mar 27, 2010, 02:34 PM
I don't want to "Switch Now"
pmackenzie's Avatar
Toronto (Don Mills), Canada
Joined Dec 2002
16,926 Posts
Quote:
Originally Posted by Gordon Johnson View Post
Oops, you are right. It's 2 um film, which is 0.08 mil.
That is very thin
pmackenzie is online now Find More Posts by pmackenzie
Reply With Quote
Old Mar 27, 2010, 02:41 PM
Registered User
PeteSchug's Avatar
Elmhurst, NY (Queens in NYC)
Joined Apr 2004
7,061 Posts
Very interesting project. I am looking forward to hearing how it flies.

Pete
PeteSchug is offline Find More Posts by PeteSchug
Reply With Quote
Old Mar 27, 2010, 10:07 PM
in persuit of low wing loading
Gordon Johnson's Avatar
Boston, Mass
Joined May 2001
6,431 Posts
Quote:
Originally Posted by I R Irv View Post
Gordon couldn't you make a wing strut mount like your landing gear mount that way you could still slide your wing forward and backward possibly two of them one in front one in back.
I can't wait too see this one fly wish I lived buy you. TODD
To give you a sense of the tradeoffs, the laminated ply piece for the landing gear weighs 0.15g. So, two of those for wing strut mounts would weight 0.30g. The piece of foam I used instead weighed 0.01g.

But, the big reason is still triangle versus rectangle. The triangle method results in a wing which is not only stiffened for up and down rigidity, but it doesn't twist either. Try it. Its surprisingly stiff and twist resistant. And, it allows the use of pretty thin and light CF rods. Also, the light ply method does't allow CF rods to come in at an angle, they have to be perpendicular to the fuselage stick (at least the way I do them).

That said, on my Der Jager bipe I had it so the landing gear mount also had two sockets pointing up, and I ran a pair of CF wing struts down into those sockets. However, on that plane the outer wing struts take care of preventing twisting, and I didn't have a second pair of struts angled aft. See this picture. http://www.rcgroups.com/forums/attac...mentid=2463236

I've never needed to slide a wing on a vapor forward and backward. I achieve CG changes by moving the battery.

Anyway try this wing bracing method and see how it performs. you might be surprised.

Gordon
Gordon Johnson is offline Find More Posts by Gordon Johnson
Last edited by Gordon Johnson; Mar 27, 2010 at 10:19 PM.
Reply With Quote
Old Mar 27, 2010, 11:28 PM
del
Registered User
del's Avatar
north of Chicago
Joined Feb 2003
1,827 Posts
Good work, as always, Gordon!
I can't wait to hear your flight test reports.

As you might have guessed, I've been working on something similar (stick and tissue, of course..). The first couple of times I tried to fly it were, err, bad news.. But, third time's a charm this Monday at the gym..

Keep that laser cutter cookin'....

--del
del is offline Find More Posts by del
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Sold AR6400 with aileron servo Stall'n_N_Haulin Aircraft - Electric - Micro & Indoor Airplanes (FS/W) 1 Feb 26, 2010 11:22 AM
Discussion 2 servos for aileron Plane Hazza Radios 4 Feb 26, 2010 05:45 AM
Question how to swap rudder and aileron on vapor brick? indoor_fr Scratchbuilt Indoor and Micro Models 3 Oct 28, 2009 06:49 PM
Discussion Vapor 5th channel on vapor tx? LexusIS300 Scratchbuilt Indoor and Micro Models 1 Oct 14, 2009 03:26 AM
Sold 2x Vapor DSM2 transmitters, 1x Vapor LiPo charger philski Aircraft - Electric - Micro & Indoor Airplanes (FS/W) 6 Jul 30, 2009 06:50 AM