RC India

Guys,
Finally the time has come to induct a new airplane to the operational fleet :)
As usual, after several months of collecting stuff, and planning, I think I am in a position to start the build now.

Airframe details :
MX2 - 28cc - 30CC
Wingspan 73"
Wingarea 1025 sq in (66sq dm)
Length 68"
http://redwingrc.com/planes/mx2.html
http://www.rcdhamaka.com/index.php?main_page=product_info&cPath=3_64&products_id=500&zenid=abtkjjkkuo9som737op5hdm4l7


Features:
Strong and light construction
Carbon fiber wingtube
Foam turtle deck, for super smooth finish
Fiberglass double truss control horns
Ringed Cowl for no external screws
Aerfoiled tail wings - scale and better flight
Prehinged Wings, partially hinged tail
Beautiuful painted fiberglass cowl and wheel pants
High quality Ultra-Cote covering
Full bodied true to scale appearance
Finished cockpit area, requires no work by you
Pre plumbed tank, ready for gas



Setup :
DLE - 30CC engine with rear carb
5x Hitec HS-7985MG Coreless Digital Servo 10.4kg/62g/0.16sec
1x Hitec 5485-HB Throttle Servo
Futaba 6008HS 8 Channel Receiver
Futaba 10CHP Tx
A123 2200mah 6.6V Twin Batteries as a RX Power Source
A123 2200mah 6.6V for ignition ( will use 2 Diodes in series to reduce voltage to 5V )
Miracle Servo arms - All round

This will be my first 30CC airplane. I picked this up because of its vibrant colors, good reviews, and because it was meant to be fit for a 30CC engine.

The build will be slow one, as I plan to take the time and get this airplane set up as true as possible.
More coming soon !
Stay tuned.
Gaurav

gaurav i have seen this flying , flies beautifully, pull pull on the rudder, and smoke system on it. sweet, my hand is itching to fly it.

Eager to get it up now too. Took me 5 months to collect the stuff and find time to start at this.
Hopefully the 30CC would be little easier to carry around than the 50CC Yak i fly, and hence provide some convenience.

BTW, doesnt this design look like a mix of Giles and Extra ? What say you ?
All these new models that are coming up these days - MX2, MXSR, Sbach, Raven etc , bear a strong resemblance to Extra is it not

Hi gauravag,

That looks pretty nice plane and setup!
From where did you buy these stuff like airframe, DEL-30 and rest like servos and batteries?

Extra is an iconic design. I see it every where; on TV, on logos, games, wallpapers..
You've got a very very beautiful plane :thumbsup:
I'm subscribing to this thread  :)

Refer # Rep 2

you are right, little change in the horn, rudder trailing edge, sweep back etc however these small changes the flight characteristics quite a lot, giles 300 of the lot i found the best. MX2 is good, bailing out of hover though can be tricky, start at sufficient height

The box arrived in a double box - usual for ARFs. I was apprehensive about damage, as there were some punch marks on the box, but much to my delight, everything inside was sound as ever.

The airplane is gorgeous - The trim color scheme of red, white and black is unbelievably good. Covering also seems to be of good quality and has better gloss than the 50CC i had earlier seen from the same manufacturers.

30CC airframe seemed to be small in size ! I have been flying 50CC solely for the last 6 months and this model seems to be quite small in size compared to the huge Yak . But it should be just right - Should be easier to transport and hopefully give out great performance.

I was also surprised at how little wood is used in the fuselage :) The good side is that the structure is very light - Downside would be its going to be very fragile, but thats how all 3D planes usually are !

Fuel tank is preinstalled in the fuselage, and the ailerons are pre-hinged and glued. Still, I will be taking out the tank and re-assembling it, as its a critical element and i would never take chances with it.

One thing that sometimes turns me down is how these Chinese manufacturers use glue . Thy seem to use some kind of hot glue on the wood, and usually there is more applied than is necessary and in some places nearly no glue. I know i am being finicky here, but cant help pointing out. Though i plan to strengthen the firewall section with strips of fiberglass, i may do the same to the undercarriage, where there seems to be a complete lack of glue.

Overall, first looks are very nice. Just as expected. Enough of drooling. Time to start work.
Here is the agenda :
1. Will iron the entire airframe. to seal the covering, trim and shrink out the wrinkles. Best to do now than later when everything is assembled.
2. Use clear nail-polish to seal the trims - There are some fine detailing done, which I am pretty sure will blow off or peel itself out later.
3. Strengthen the Firewall /Undercarriage; Fuel proof the firewall/box
4. Install the Stabilzer
5. Install the elevator / rudder
6. Install servos
7. Install engine
8. Install switches / electronics

With the #1 on now .
More coming soon.

Good choice there and looks gorgeous. Good idea to go through every single component on an ARF and every single joint.
Remember most of the times the model would have been built by some one on wages and not someone who loves building model airplanes.

Some pictures ..

Some more..


True. Hate to see excess glue, or the lack of it . Was earlier debating on giving the entire plane a light coat of clear spray paint, but decided against it. Would rather use clear nail polish on the fine trims to make sure they stay put.

One thing that I forgot to mention was the hardware package . It is pretty decent. The landing gear is aluminium, and I am debating if I should replace that with a CF one. Will decide later, as CG will determine the decision. - No use using a CF landing gear and adding nose weight :)

Shouldnt the CF one be lighter than Al one? And I guess a light coat of clear on entire airframe would ensure longetivity

Hmm. Really thinking of giving this a coat of clear now ! This is the only time I can do it ( when nothing is installed and right of the box. I know it will add weight, but I might save some by changing the gear/or maybe it wont be that much.

Any tips on doing this ? From what i know of, it needs to be :
1. Done on a clear / hot day
2. Tested on the covering first ( back side maybe
3. Cleaned/ and dry
4. Adequately thinned and a very light even coat

Actually I may do it after assembiling the stab / and after doing the hinging.
Will also add decals, so they go under the clear coat.
After that Will continue with the isntallation of servos.

This is going to make things interesting !

Gaurav,
What i do is i got myself a Wood Glue called the Titebond II (A gallon of it) (Available here http://orders.ebay.in/ws/eBayISAPI.dll?ImportHubViewItem&itemid=180646781906) it claims to be Waterproof wood glue which passes ANSI/HPVA Type I water resistance. Superior strength, sands easily, water clean-up. i lightly brush it in all the joints and on the servo tray and on the fire wall on wood too. for the insides i use a long brush. it is required for 3D, YAK 54 EP which i had, couldn't take the abuse, thinking it is small plane doesn't require Titebond was a mistake i made. i hope this info was of help

the second picture is an addiction, did you started building it  ;)

in fighter pilot parlance, if you see a bogey first and at a far off distance, it is said , GOOD SPOTTING, you qualify for that ;)

Nice. But this addiction is far greater than the one illustrated in pic 2. Build has started. I will be travelling this weekend so will continue on Monday.
Cheers

Anyone has any tips on clear coat paint on the airplane ? Any hints on the consistancy of paint, coat strength, flash time etc ?
This will be the first time i will be clear coating on a covered airplane.

Will of course test , test and retest with the covering and decals, and start from the underside sections !

Related thread : http://www.rcindia.org/tools-materials-and-building-techniques/monokote-peeling-issues/

Started off the build a little differently this time. By applying the decals first. Idea is to apply the decals first, then do a clear coat on everything, before moving to install the control surfaces, stab etc.

The covering was OK on the wings but wrinkled a lot on the fuse. This is usual for ARFs. I ironed off everything, and used the heat gun in a few places too. Overall happy, though some wrinkles on the fuse didnt go away.

I would note here that one has to be very careful in the use of heat gun. If the covering is not tacked well, it will shrink and edges would creep, and the wrinkles would never go away, in fact would become much worse. The proper way is to first iron the edges to ensure the covering is stuck well, and then shrink the middle portal with the heat gun.

Decals were cut out from the big sheet given, and after cleaning the surface with a local glass cleaner - Colin, I put them in place. The way I put the decals were - Spayed the base liberally with Colin, then peeled off the decal and 'floated' it in place. Used an old credit card to squeegee out the cleaner fluid underneath it. This ensured no trapped air bubbles, and also that I had adequate time to position the decals correctly.

The decals were of OK quality - Would have liked them to be more crisp, to match the high quality covering used.

Next, i bought some PU clear paint, hardner and thinner from a local paint store. Did a test on both the covering and the decals. Seems like the paint is causing no harm. Good news.

I plan to pray paint the bottom of the elevators first. If this goes well then will move to spraying the stab, wings, and fuse ! I just hope this all goes well.


Will post pictures and more progress soon.

Thinner AND hardener ?

I intend to spray paint the structure with clear coat using an airbrush. I have a very old spray machine that I will be using. The paint is mixed with hardner, and then thinned with a PU thinner before it is ready to be used.

PU (or for that matter epoxy paint)requires hardener so that paint can dry to required hardness, else it would remain as a sticky gooo!
Thinner is to get the paint to flow to required consistency, specially when you are spraying the paint would need to be thinned to suit the spray equipment used. 

Hi gauravag,
I think you missed my reply#3 ?

I got the Servos and engine from Rotor Singapore and airframe from RCD

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.

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.

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

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. 

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.

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

gaurav, post some pics

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.

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

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)

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.

dear gaurav is there any progress?  :)

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.  :)