RC India

Hello All,
I was never tried for a Nitro Engine and decide to keep distance from nitro / glow engine because of cleaning, oil and other implications, but nitro models always attract me.
I found a old OS .46 FX engine and creates my interest to start scratch building from engine , which needs complete overhauling and adjustments of this engine.
This will also give me a understanding of RC engine and may be helpful to others also.
some pics of engine..

I was expecting only Gum deposition and just wants to clean the engine, but both bearing was rusty and completed life.. :banghead: and heavy gum deposition inside of engine ..now i have no choice , i have to overhaul completely.

OS used SKF bearings , but I could not found the same in market on time , so  I have changed both the bearings from local market ( Made in JAPAN) at the price of Rs 275. We can change the same bearing in NTN also.

Also changed the glow plug and start the engine , its start , but after heating up, compression was too low and not able to restart again early, so decide to change the sleeve and piston also.

I order the sleeve and piston of ASP S64M from hobby king and replace.
http://www.hobbyking.com/hobbyking/store/__13113__ASP_S46M_Cylinder_Piston_Set.html

ASP piston has a small Piston pin hole at one side as compare to other, while the all pistons have same hole size of piston pin on each side.
We have to place a piston pin circlip in small hole and insert piston pin from big hole.
 

Sleeve Pics

You should change the entire set: Piston, Ring, Cylinder liner, Crank, Gudgeon Pin, Bearings and remember it is an ABC construction so will be tight initially.

If you use original OS parts, cost is nearly that of a new engine, but it will be as good as a new engine.

BTW, if you get original NTN bearings they are good

Thanks sanjay ji ,

I could not found the desired NTN Bearings and SKF has not introduced the bearings in after market. My one of friend is working in SKF only , but it will take the time , so just arranged the bearing from local market , will post the pics..

Original OS parts will cost more then a new engine( Piston / Sleeve – 35 Euro + Shipping ). Crankshaft and connecting rod was OK , so used the old.

Use full Tips
•   We can remove both bearing easily by heating the crankcase on our house gas stove. Both bearing came out easily with out any hammering.
•   In this engine , two of head bolts lost the grip of of Ellen key , so I used a Drill Bit of same dia of Head Bolt and cut the head of both ( pl see pics).. we     
             can remove any ellen bolts by using this method.
•   Repair the Brocken back plate ( pl see pics)
•   DON’T use any thing except METHANOL to clean the engine, otherwise rubber parts will get swell.
•   Match the notch at sleeve with dowel in head
•   Position the aero mark on piston head towards exhaust

Meanwhile, I also started the fuse construction ..here is the progress..
I am targeting maiden flight on Sunday..

Plans are available at Spadtothebone web site.

Used 3 mm coro for entire build.
Made a box of 6 x 2.5 inch from 3 mm ply and used 10 mm ply for firewall.
entire fuse , Rudder and elevator have double layer of coro.
used hot glue to fix rudder on fuse.

Spadet's coming along well  :thumbsup: :thumbsup:  Be careful of weight!

I personally don't trust hot glue, but many swear by it

Sorted out the wing issues?

Also, fit all control rods while the fuse is open, including throttle. Gets messy later :)

Great work Mjet, the vert stab looks that of a swanky bizjet ;)

Yesterday , Started the wing also , worked till late night  I got the round leading surface in second attempt after  instructions taken from you sanjay ji.
You are correct , the expected AUW may be around 2700 gms.
Thank Girish for encouraging words.

Great Mohan. Be careful, your build is becoming too heavy!

Sanjay Ji,

I have stopped the further building, because AUW may hit 3 Kg as i again recalculated the weight.

Till date progress - Wing has been Completed with servo and Fuse is almost complete accept forward cowl.

Pl advise , how can i reduce AUW in current Situation.

Mohan:

1. Fuse box: use 3 mm ply. Use minimum, ply is heavy! Only firewall is 6 mm. You need only 3/4 of fuse vertical ply formers
2. No need for doubling Corro
3. Make wing of 2 mm Cooro (but 3 or 4 mm Ailerons)

see my build http://spadworld.net/forum/viewtopic.php?t=14919&highlight=sanjayrai55
4. Buy a 1" hole saw and do "swiss cheesing" (make lightening holes)

You could also get some idea from my Deb:  http://spadworld.net/forum/viewtopic.php?t=14919&highlight=sanjayrai55

Wing completed - 3 MM coro
Wood Spur
Span - 64"
Chord - 10"
Used Fevibond only
Servo - Hitec HS-311
Total weight along with Servo - 825 Gm

Need suggestions – to reduce the weight , can I cut the white color portion at lower wing and upper wing.

That is a wrong link

The correct one is http://www.rcindia.org/self-designed-diy-and-college-projects/spad-debonair-(modified-from-plans)-built-flown-successfully/

Sorry!

Mohan, don't cut holes in the wing. I really don't understand why the wing is so heavy, can only be the wooden spars, for which ideally we should use light wood. I normally cut lightening holes in the spars.

But this weight is still OK if you can get the finished model < 2.5 Kg, a good weight

May be 3 mm coro ,wood spur - 60' ( 5 mm thick)  , 6 nos  1.5 " screws are responsible for heavy weight.. ( 2 mm coro is not available )

can we cut the holes/ strips  in wing and cover it by tape ( as in balsa models)?

It will make it structurally weak. Reduce all that ply in your fuse

Sorry for a long gap. here is the pics of complete Fuse.

Complete SPAD , ready for maiden flight.

It looks fantastic

Sent from my GT-S7562 using Tapatalk 2

Congrats For the maiden that you have done today.. Flies like a bird.. really gr8.. :thumbsup: :thumbsup: :thumbsup: :thumbsup:

Nice build  :thumbsup:

Thanks Sanjay Ji and Raj, Here is the video of Maiden Flight. Some more colors and front cowel will be added in Model after maiden flight.

Used Lever for Nose wheel movement.

Thanks Tanmay for Maiden the Trainer :hatsoff:.

Engine - OS .46 Fx ( Rebuild with ASP piston/ Sleeve)
Servo - HS 311
Prop - Master Air 11 x 7


http://www.youtube.com/watch?v=7--Qd61OL0k&feature=youtu.be

Mjet, many congratulations on the fine build and the maiden flight.

Thanaks Girish.

Model is some fast On 11 x 7 Propeller, we will experiment with 10 x 6 to get a slow trainer.

Senior air modelers feel that the engine is giving more power than new OS .46FX  ;D.

Model was crashed on yesterday, because  I have not locked the clevis of elevator/ rudder and flu the model with out checking  :banghead:.

Engine Mount , Nut/ Bolts , Fuel Tank, Nose wheel arm , Engine back plate and ply box  all I lost. Wing was brocken from middle ( 2 Inch from Center line with spur)

Pl suggest , how I can repair it.

I have starting building fuse and wing again.

 {:)} {:)} Way to go Mohan!

The true aeromodeller spirit  :salute:

Great build ;D
Glad to see you aren't giving up. Keep it up  :thumbsup:

yes sanjay sir.. this hobby is addiction . i have to build.. ;D

Great build, terrible crash, TERRIFIC spirit. Keep it up!

Parallel , I am working on 2-3 Projects  ( SU 37,P51 and Wing for model purchased from Sphere Hobbies) , cutting lot of Foams and wood , will post separate build for that.

Sanjay and VC sir,

Made entire fuse and half wing.. pl have a look..

Very nice Mohan.

Is it an optical illusion or does the fuse seem curved?

And, look out for the weight this time. Keep the whole weight less than 2.3~2.4 Kg with engine, servos, empty tank etc.

I hanged up fuse with a rope, so. this is mark of rope, I will correct  it. This time I will try to keep below 2.4 kg.

During crash, nose wheel holes of Engine Mount were broken :banghead:, need suggestions, can I convert this model as Tail dragger 8-).

I dont know how you have built but I had so many rogh landings with zero damage

Sent from my GT-S7562 using Tapatalk 2

Change the engine mount Mohan. If you make it a tail-dragger, CG problems etc. Use a glass-filled nylon mount. And don't crash so much !!!