HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old May 02, 2006, 08:40 PM
Registered User
alexcmag's Avatar
Sao Paulo, Brasil
Joined Aug 2004
600 Posts
Video
1:20 scale (3.1m wingspan) Martin Mars

This is my all foam MartinMars, movie taken this weekend on a farm.

Original thread in http://www.rcgroups.com/forums/showthread.php?t=400557
alexcmag is offline Find More Posts by alexcmag
Reply With Quote
Sign up now
to remove ads between posts
Old May 02, 2006, 09:16 PM
Yep I got another one.
mohillbilly's Avatar
Springfield, Mo.
Joined Jan 2005
2,529 Posts
Very nice
mohillbilly is offline Find More Posts by mohillbilly
Reply With Quote
Old May 02, 2006, 09:25 PM
foamhead
Joined Aug 2005
231 Posts
What a horse!!!! What's the weight?
Tentacle is offline Find More Posts by Tentacle
Reply With Quote
Old May 03, 2006, 07:22 AM
Lori, hey, you're home early
CarreraGTSCS's Avatar
United States, NJ, Trenton
Joined Jan 2004
9,130 Posts
Nice! Impressive flyer. More info please.
Mike
CarreraGTSCS is offline Find More Posts by CarreraGTSCS
RCG Plus Member
Latest blog entry: Split elevator set up JR 9303
Reply With Quote
Old May 03, 2006, 01:33 PM
Registered User
alexcmag's Avatar
Sao Paulo, Brasil
Joined Aug 2004
600 Posts
It is not heavy (2.4Kg / 5.35lb), in fact it is lighter then most glow trainers.

- Scale: 1:20
- Wingspan: 3.1m (120 in)
- length: 1.79m (70.5 in)
- Weight: 2400g (85.7 oz)
- Motors: 4*GWS EPS400C-DS with GWS 10x6 props
- Battery pack: 9.6V 1900mAh Kan (8s2P NiMh)
- Wing area: 100dm2 (10.76 sq ft)
- Wing load: 24g/dm2 (7.96 oz/sq ft)
- Wingspan of stab+elevator: 1.05m (41 in)

The tail alone is a mid-size parkflyer... Stab looks like a GWS Zero wing!!!

Some pictures...
alexcmag is offline Find More Posts by alexcmag
Reply With Quote
Old May 03, 2006, 02:36 PM
iumop ap!sdn w,I
G.P.'s Avatar
Joined May 2005
6,537 Posts
Very nice! Even sounds good.

Do you have any landing footage? Or even some ROW (rotate off water) footage?

Thanks,
Greg
G.P. is offline Find More Posts by G.P.
Reply With Quote
Old May 03, 2006, 05:50 PM
Registered User
alexcmag's Avatar
Sao Paulo, Brasil
Joined Aug 2004
600 Posts
Unfortunately, no...

In fact landings are not so beaultifull...

In the first flight one cell of my 10S2P Kan 950mAh failed, making it fly underpowered. When the failed cell short-circuited due to overheating it made a chain-reaction of cells melting the plastic insulation and shorting too. Result was a sudden voltage fall, I noted the lack of power and get it back with low power, but when I would flare for landing left motors quit (separate ESCs, separate cutoff levels for a few millivolts) and it made a tight turn and landed out of sight.

Second flight was with LiPo, good flight, good landing but only recorded in VHS.

Third flight was with Lipo too, but battery connector melted while flying, making the giant to make a long spiral until land softly on glass.

Connector was replaced and fourth flight was made. After 5 minutes of flight left ESC burn out while flying far away (300m horizontally over the farm's swimming pool). I noted a tendency for turns and got it back with differential throttle all right (giving me 50% power on right motors) and rudder almost all right, Nice landing but with no video.

After landing I noted a small hole on the foam bottom, the MOSfet of melted ESC overheated and fall from PCB, making a hole on foam... It was amazing, but it is not so difficult to fly with only a pair of motors running.

Due to these problems with battery/connector/ESC (40A, 480W is a lot of power), and the not so large lake, I did't tried ROW.
alexcmag is offline Find More Posts by alexcmag
Reply With Quote
Old May 04, 2006, 07:50 AM
Registered User
Airboatflyingshp's Avatar
B'ham UK
Joined Oct 2005
2,990 Posts
Sounds like you need a heat sink and or some ventilation, ALL that foam is too much insulation for a warm climate, that or you'l have to move somewhere a bit cooler like Antartica

Alex you or Eric Payen have to have a go at doing a Saro Princess foamy one day .

PS If this is too much of a distraction from your thread I will happily edit it down Clive.
Airboatflyingshp is offline Find More Posts by Airboatflyingshp
Last edited by Airboatflyingshp; May 04, 2006 at 08:09 AM.
Reply With Quote
Old May 04, 2006, 05:47 PM
Registered User
alexcmag's Avatar
Sao Paulo, Brasil
Joined Aug 2004
600 Posts
Actually sounds like I need better ESCs, battery and connectors... And a bigger car...

Nice seaplane, but I need to buy a truck first
alexcmag is offline Find More Posts by alexcmag
Reply With Quote
Old Jun 04, 2006, 09:21 PM
Registered User
rockbus's Avatar
Carlsbad, CA
Joined Sep 2004
4,726 Posts
Fantastic plane. Thanks for Sharing. Got any more Video?
rockbus is offline Find More Posts by rockbus
RCG Plus Member
Old Jun 04, 2006, 11:17 PM
Registered User
alexcmag's Avatar
Sao Paulo, Brasil
Joined Aug 2004
600 Posts
Quote:
Originally Posted by rockbus
Fantastic plane. Thanks for Sharing. Got any more Video?
Thaks,

Unfortunatelly, don't have a better video. Several friends recorded the same flight from near places, this is not so usefull.

The better part, when I replaced the battery pack by a 3S3P LiPo, was not recorded on video.

With 3S it made loops, hummerheads, tight turns, very funny, byt there was nobody with a camera.
alexcmag is offline Find More Posts by alexcmag
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
A-7 Corsair II 1/20 scale lphan Pusher Prop Jet Models 386 Feb 02, 2009 06:12 PM
For Sale Mini Mauler 1/20 Scale RC Monster Truck smaerd58 Cars - Cars and Parts (FS/W) 1 Jul 21, 2006 12:33 AM
Tupolev ANT-20 - 126" wingspan at 1/20 scale Martin Hunter Scale Kit/Scratch Built 766 Apr 29, 2006 07:21 PM
Sold Flying Styro 1/20 scale Corsair NIB Lammergier Aircraft - Electric - Airplanes (FS/W) 1 Sep 02, 2005 02:08 PM