HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old May 30, 2011, 11:38 AM
It's a Great Day to Fly
LenBFP's Avatar
Melbourne Beach, Florida
Joined Jan 2002
3,863 Posts
Discussion
Electric AD from Dumas Rubber kit

The AD is among my favorites for some reason. It is not particularly good looking as far as planes go, but it is a monster in the single engine lifting category.

My father was a Naval Aviator and test pilot. When he was going through test pilot training at Patuxent River Maryland, he was flying an AD, the number on the nose was 013. It was his thirteenth touch and go and it was 13:00 hours on Friday the 13th. I think there were a few other 13s in the mix too that slip my memory after all these years. Anyway, he forgot to put down the landing gear. To this day he is not superstitious, and I am not either, but I tend to pay closer attention when events play out like that.

The Dumas kit is pretty nice, but I am going to forgo the bombs and stuff, save them for another model. The only modification (other than cutting in flying surfaces) was to put a 1/32" laminate on both sides of the fin and made the rudder 1/8" instead of 1/16" thick. The stringers are also basswood instead of balsa. I hate crushing the sticks with my fat fingers, especially after the covering is on. There is also a 1/32" vertical web between top and bottom stringers on the wing, out to the first rib after the aileron starts, to strengthen it a bit.

All up weight with the motor and esc was 99 grams before the laminations. Target weight will be around 6 ounces. I am planning on retracts, but they will be non-scale and fold in like a Mustang instead of rotating back like a P-40. If anyone knows of light rotating retracts suitable for a light model like this please let me know. I am not beyond building some myself, but would rather start from a proven design.

len
LenBFP is offline Find More Posts by LenBFP
Last edited by LenBFP; May 30, 2011 at 06:15 PM.
Reply With Quote
Sign up now
to remove ads between posts
Old May 30, 2011, 12:41 PM
Registered User
Joined May 2009
557 Posts
This is one I've looked at several times, but never did pick one up. Fuse looks big enough for micro servos and receiver. What do you have in mind for it?

I know what you mean, not a particularly graceful looking airplane but still, there is something about it that holds your attention, especially in flight.

David
cd_webb is offline Find More Posts by cd_webb
Reply With Quote
Old May 30, 2011, 02:29 PM
It's a Great Day to Fly
LenBFP's Avatar
Melbourne Beach, Florida
Joined Jan 2002
3,863 Posts
It is a bunch of stuff from HobbyKing The 24 gram motor, a 10 amp esc, Blue Arrow 5.7 gram metal gear digital servos, a 2.4GHz dsm2 compatable receiver and nano tech 460 mah battery. The prop is a gws 8040x3. Full throttle is 7.4 amps, but I'm betting it cruizes on less than half.
LenBFP is offline Find More Posts by LenBFP
Last edited by LenBFP; May 30, 2011 at 02:42 PM.
Reply With Quote
Old May 30, 2011, 03:48 PM
Registered User
Joined May 2009
557 Posts
How much room to spare will there be with the aileron servos? The wing must be thicker that I'd have guessed.

You're doing a really nice job of it. You don't mind being a guinea pig for me, do you?

David
cd_webb is offline Find More Posts by cd_webb
Reply With Quote
Old May 30, 2011, 06:07 PM
It's a Great Day to Fly
LenBFP's Avatar
Melbourne Beach, Florida
Joined Jan 2002
3,863 Posts
These servos will just make it. I'll post pictures when they're installed.

Thanks. No problem David.

len
LenBFP is offline Find More Posts by LenBFP
Last edited by LenBFP; May 30, 2011 at 06:13 PM.
Reply With Quote
Old May 30, 2011, 07:31 PM
It's a Great Day to Fly
LenBFP's Avatar
Melbourne Beach, Florida
Joined Jan 2002
3,863 Posts
Wing servo barely makes it. Two basswood 3/32" rails, 1/16" balsa platform. Thinnest doublesided foam.

len
LenBFP is offline Find More Posts by LenBFP
Reply With Quote
Old May 30, 2011, 08:50 PM
Registered User
Granby, CT, USA
Joined Jan 2001
939 Posts
Retracts

Zeke's sells a rotating retract upgrade for the Mountain Models Hellcat (30" w/s). Or at least did when I bought mine a year or two ago. But they look to build up light and being of wooden structure, look like they might be persuaded to fit the SPAD. At least the materials are compatible.
PeterH is offline Find More Posts by PeterH
Reply With Quote
Old May 30, 2011, 11:13 PM
Suspended Account
United States, PA, Grove City
Joined Jan 2011
751 Posts
Quote:
Originally Posted by cd_webb View Post
How much room to spare will there be with the aileron servos? The wing must be thicker that I'd have guessed.

You're doing a really nice job of it. You don't mind being a guinea pig for me, do you?

David
Yeah I'm watching it too for that reason. The LHS now has both of these Dumas Skyraider kits. They've been a thought.

Bill
Onna Vakkation is offline Find More Posts by Onna Vakkation
Reply With Quote
Old Jun 01, 2011, 08:07 PM
It's a Great Day to Fly
LenBFP's Avatar
Melbourne Beach, Florida
Joined Jan 2002
3,863 Posts
Landing gear cut in

The landing gear has been cut into the wing.

Still thinking about how to strengthen the wing where it has been weakened and at the gear mount point.

The actuating rods will have to sneek under the wheels. All very tight but doable.

These retracts fit into the moldings for the Formosa which typically came in at nearly a pound, this plane I expect to be less than half my lightest Formosa which came in at 12 ounces so they may be strong enough.

len
LenBFP is offline Find More Posts by LenBFP
Reply With Quote
Old Jun 04, 2011, 04:44 PM
It's a Great Day to Fly
LenBFP's Avatar
Melbourne Beach, Florida
Joined Jan 2002
3,863 Posts
Retracts are certainly fiddley things, but these are working and locking down. Had to extend the travel a bit. I guess it should go on a watt meter to measure the current draw with and without the gear servo hooked up. It doesn't make any noise, no hum or anything. These little 3114 Futaba servos have a lot of torque for their size. I used some stainless wire in some kind of jacket I bought from a hand launch glider place. I will try to dig it up if anyone is interested. It wasn't cheap however, something like $20 for two pieces, one bigger one for the elevator and a slightly smaller one for the rudder. I bought it thinking it would be good for ailerons in some of the little ones that I couldn't get servos into the wing and I couldn't just use torque rods. The actuation is very solid and positive. Maybe I can clear out some of the pictures on my camera and do a little video.
LenBFP is offline Find More Posts by LenBFP
Last edited by LenBFP; Jun 04, 2011 at 04:49 PM.
Reply With Quote
Old Jun 04, 2011, 10:09 PM
The "pro" in procrastination
Steve85's Avatar
Canada, ON, Kingston
Joined Mar 2004
2,655 Posts
Quote:
Originally Posted by LenBFP View Post
The landing gear has been cut into the wing.

Still thinking about how to strengthen the wing where it has been weakened and at the gear mount point.

len
Len,

You could try laminating a 1/64" ply doubler to the ribs over the retract bodies.

Retracts (and bones) look nice.

Steve
Steve85 is offline Find More Posts by Steve85
Reply With Quote
Old Oct 11, 2011, 03:57 PM
It's a Great Day to Fly
LenBFP's Avatar
Melbourne Beach, Florida
Joined Jan 2002
3,863 Posts
Dug out the AD. I was thinking about covering it, but decided to do a little balsa filling first. Figure that at least the cowel should be done, not sure how much more; maybe up past the cockpit.
LenBFP is offline Find More Posts by LenBFP
Reply With Quote
Old Oct 12, 2011, 04:09 PM
Registerd Beaver
Smokin' Beaver's Avatar
Australia, WA, Warwick
Joined Jul 2003
3,557 Posts
Subscribed
Smokin' Beaver is offline Find More Posts by Smokin' Beaver
Reply With Quote
Old Oct 13, 2011, 05:19 PM
It's a Great Day to Fly
LenBFP's Avatar
Melbourne Beach, Florida
Joined Jan 2002
3,863 Posts
Nose sanding

This may take awhile, did a little filling and sanding on the nose. This brings out the imperfections. ouch.

len
LenBFP is offline Find More Posts by LenBFP
Reply With Quote
Old Oct 14, 2011, 07:44 AM
Registered User
United States, NJ, Frenchtown
Joined Mar 2003
9,056 Posts
Thank you Len.

At 73, your build with wood is appreciated very much.

Rich
cyclops2 is offline Find More Posts by cyclops2
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Yippee! New kit from House of Balsa, Electric Commander Dennis Sumner Parkflyers 142 Jul 16, 2013 04:34 PM
25 set of Plans from .40 to rubber power planes. unclegeorge Non R/C Items (FS/W) 2 May 27, 2011 12:41 PM
Discussion Skatepark video from Droidworx AD-6 hexa Matt Gunn Multirotor Talk 7 Mar 24, 2011 09:06 PM
Question H-1 Racer rubber to electric conversion cad2blender Parkflyers 1 Mar 21, 2011 08:09 PM
Discussion Dumas Fielser Storch-Rubber to Electric Conversion DanF Scale Kit/Scratch Built 9 Nov 17, 2006 09:59 AM