Goldwing 30CC MX2 - 73" Build thread

[gauravag]

Update : First coat of paint went OK. My plan is to give the airplane 2 coats of paint. The first one a very light misty one then after a day another wet coat will be added. This will make the base coat adhere well to the covering and the gloss would be long lasting.
Did the first coat today. Used approx 35 gms of paint+ hardner. I guess overall i would be adding approx 60-70 gms due to the paint. Hopefully that will not be a big problem.

[gauravag]

Question : Would the PU paint help in fuel proofing the Firewall section ? Have never used, so wanted to ask.
Typically I use Thinned epoxy, but if the PU clear can work, it will might be neater to use that.

[SunLikeStar]

I read a discussion about it here http://www.rcuniverse.com/forum/m_23722/tm.htm

[flyingboxcar]

Gaurav, dont know about petrol but PU is very good fuel proofer for glow fuel including high nitro content.  Why dont you test some bare wood ? Soak with PU, allow to cure and then let the piece soak in petrol for a day or so and then check. 

[gauravag]

Will be doing exactly that. If PU works, then I am going to use it for sure. Much easier to apply, will be more even, and probably be lighter, since when using epoxy we tend to use more than needed.

[gauravag]

BTW PU paint should be goot for petrol too - as its used on automobiles...

[rcpilotacro]

gaurav, post some pics

[gauravag]

Lots of progress here over the last  2 weeks.
1. Spray painted the entire airframe with clear PU. Since i am not that experienced with spray painting, the results were mixed.
Overall happy with the outcome. The decals were all sealed, though the paint was a little uneven.
It gives a wet, glossy look. Will definitely spray paint all airplanes now.

Next, on the wing, the Aileron Hinge gaps were sealed with clear Lamination roll. and the Fiberglass horns epoxied into the ailerons.
Servos Installed, though

I did not want to use the supplied Anodized aluminum horns, and rather use the Miracle 1" Servo horns.
Now the geometry is a little off in this case. See attached. I think a 3/4" horn would be best used here.
Suggestions needed on whether this geometry is OK or should I do something about it.

[flyingboxcar]

Gaurav,
Why could the horns not be moved more outboard so that the hole on the servo arm and horns were in line? In its present configuration while it would work, it would sure loose some mechanical advantges

[flatspin_king]

Nice build Guarav - had been eying this plane for a while. Guess you beat me to it! Please give us a full flight report.
Flyingboxcar -Actually that is supposed to be the correct geometry - since you want maximum mechanical advantage at stall torque and not for rotational torque. At the highest deflection the (stalled) servo will hold the control surface better because the linkage would be at the most advantageous angle with respect to the servo arm (thats the theory anyway, dont know if it really makes difference in practice)

[flyingboxcar]

FSK yes what you say could be right as it makes perfect sense due to angular movement of the servo horn instead of linear and the very high deflections demanded by the fliers for 3D.

[ravi223kar]

dear gaurav is there any progress? 

[vinay]

Hi Gaurav,

I have a few questions:
1) what diodes did you use to reduce the voltage to 5V? And is the technique reliable?
2)Was the torque from the servo enough for rudder?
3)Is it necessary to use 2 batteries? 1 for ignition and another for RX? Or can just a big one be used. If so will there be any interference to the RX from the ignition unit?
4)How long will the ignion battery last and how long will the RX battery will last per charge.
5)Can you pls give the link of a123 batts u used.
6)What servo extensions wires did you use? is 22 awg enough? or 20 awg a must?
7)Is the spray paint really necessary?
8)What oil did you to breakin the engine?
9)Which epoxy did u use for building? 30 mins?

Iam planning to build a 30CC gasser. So was wondering! Sorry for a huge list of question.

Thanks.