My next trick ...Graupner Neptun - RC Groups
Thread Tools
Mar 30, 2009, 07:47 PM
Cheif Bottlewasher
more coffee's Avatar
Build Log

My next trick ...Graupner Neptun

Picked this up in the fall ...Not a bad little kit . Builds fast clean and crisp parts ..the ply wood is fantastic..But what's up with that rudder?

Any way here she is soon to be renamed .....Not sure..
Sign up now
to remove ads between posts
Mar 31, 2009, 09:44 AM
Registered User
Keyzersooze's Avatar
Rudder, what rudder?

Mar 31, 2009, 11:08 AM
Registered User
Yeah!! Show me the rudder!!!
Mar 31, 2009, 12:14 PM
no wings any more, just dust!
Ghost 2501's Avatar
you have to make the rudder, and it comes out crap, however all isn't lost, Robbe do a rudder spare, designed for use as the rudder for the dusseldorf, or the front fins to the seawolf, part number 1481

you will need to chop the shaft, however it will go down the grupner tube. I used it as a direct replacement for the one on Gemini
Mar 31, 2009, 02:27 PM
Cheif Bottlewasher
more coffee's Avatar
Yes ..Thats exactly what i thought that the foot of snow is blown out of the driveway ..I can fabricate a new one

Im intending to make it out of 2 piece's of 1.5mm brass sheet ,3mm after its done will give it some meat. Same with the tiller arm I'll make it out of brass and solider a collar to it with a set screw... the rudder shaft will in turn be solidered to the rudder..

I'll try and get picture's of the remake up tonight ..
Mar 31, 2009, 03:23 PM
no wings any more, just dust!
Ghost 2501's Avatar
the rudder on Nord Icelandia has a brass shaft and brass blade, the shaft has a 1/2" deep notch cut into it about 1mm wide, this slides OVER the rudder blade. Two holes are drilled through it and a brass plug had been driven through it.

sorry I can't send you pic of nord icelandia's rudder, its now buried under plasticard as I have made it bigger.

After replacing the rudder on Gemini, when I came to build Miranda and Celestia, the Graupner rudders NEVER got built, instead the Robbe part was purchased.

Come on Graupner, you can do MUCH better.
Mar 31, 2009, 06:08 PM
Cheif Bottlewasher
more coffee's Avatar
Thanks Ghost ,,but due to the current economic situation this will be DIY

It took about an hour and a bit ..but I made it..
2x 1.5mm brass plate and the original shaft ,Silver solder ,and a little brazing fuel .....Install the tube in the hull and cut to length ...I think it looks all right ..
Because its rather heavy (I think so ) I will drill a hole through the top of the shaft to put in a catch wire should the set screw back off on the tiller arm
Mar 31, 2009, 07:00 PM
no wings any more, just dust!
Ghost 2501's Avatar
looks good.
Mar 31, 2009, 07:02 PM
no wings any more, just dust!
Ghost 2501's Avatar
oh i noticed you have a 280, thats small! i run mine with a 385 on 7.2v in one and a vision 400 in the other. both pull less than 1 amp
Mar 31, 2009, 07:40 PM
Cheif Bottlewasher
more coffee's Avatar
Can wise is the 385 about the same size ?...Dont really want to have to change the drive line and what not ..
Mar 31, 2009, 07:59 PM
no wings any more, just dust!
Ghost 2501's Avatar
specs for graupner speed400:

Nominal voltage 6 V
Operating voltage range 2,4 ... 7,2 V
No-load rpm 18000 min–1
No-load current drain 0,7 A
Current drain at max. efficiency 4 A
Current drain when stalled 25 A
Max. efficiency without gearbox 70 %
Length of case, excl. shaft 37,8 mm
Diameter 27,7 mm
Free shaft length 13,8 mm
Shaft diameter 2,3 mm
Weight 73 g

using a 380 you will need to cut the revs down as your boat will want to plane, the 385 on the other hand will be quite happy to poodle along at 75% power and be very economical. I run both of mine direct drive <==Miranda's build log.
Apr 02, 2009, 06:58 PM
Cheif Bottlewasher
more coffee's Avatar
Installed the rudder and linkage today..
Also i got to tinker with some brass for a formast..What do you people think
Apr 03, 2009, 08:07 PM
Cheif Bottlewasher
more coffee's Avatar
I dropped the Idea of a fore mast..for now....Decks glued in and Domestic test tank trials were successful....I"m thinking that the motor isnt a 280 like i thought ..A 6 volt 1000mah NIMH wedge pack shoved her around the tub well..and pooped the pack in about 20 wasnt fully charged...and i think it may be over rated

The 6 volt gel cell wont fit down through the hatches ....I thinking I'll get a couple more 7.2 volt 3800mah NIMH flat packs to run her on..any taker's

I cant get my hands on lead ,go to a tire shop and they look at you strange and politely ask a guy to leave.. ..In a pinch sand bag's?..anything thats free at this point ..
On to paint ..again not sure about the scheme ..but something will come to me sure
Apr 04, 2009, 04:17 PM
no wings any more, just dust!
Ghost 2501's Avatar
try a hardware store for lead flashing on a roll
Apr 04, 2009, 04:19 PM
no wings any more, just dust!
Ghost 2501's Avatar
foremast a bit large. 3" is about the right height,

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
My next project....the RAKE Tres Wright Parkflyers 12 May 20, 2002 11:55 AM
picking my next plane bluemax Sport Planes 1 Mar 23, 2002 07:09 PM
What should be my next plane ratman Electric Plane Talk 2 Feb 27, 2002 07:45 PM
My next Plane??? mism42 Parkflyers 13 Dec 02, 2001 08:14 AM
Looking for my next plane.... mbutrico Sport Planes 11 Nov 26, 2001 02:40 PM