shobhit17

I have been flying control line models for a while now, and am OK with most aerobatic maneuvers in the intermediate class. I have been flying 40+ inches span models with a .19 Cu in diesel of Glow engine. Presently I have been using the Pacemaker or the Shoestring wherein the outer wings have been made about 2 cm shorter and about 30 gms of weight added to the outer wing tip. My line is generally about 50ft in length.
I have a few very basic questions.
1. What should my control throws be when using only the Elevator Controls (I generally have about 40 deg of throws on either side) and what should the throws of Flaps and Elevator be when using the combination of Flaps and Elevators. I generally prefer only Elevator due to the ease of construction and no other reason.
2. Is the combination of flaps with elevator better for doing sharp aeros like square loops, triangles etc. or what is the advantage of using the combination of flaps and elevators.
3. Till date have not been able to do an overhead figure of eight as the line tends to loose tension and the model comes in. Request suggestions so I can keep the line tension intact and do the maneuver with relative ease.

AJ Sun

Fourty is a lot of throw. You can lesson that by narrowing the lines at your handle. If your at three inches go to something less. Over head eights on a fifteen even a 19 basicly is usually the same a 4 2 4 break helps, but still you need more power. You need more power even with shorter lines. Try it in a down wind situation. I only have two Veco planes that have flaps. What size lines are you flying? AJ

shobhit17

Thanks a lot AJ Sun..... Well there are a lot of issues....
1. I have about 4 inches of distances between the lines which is way more than 3 inches... Will reduce the same to about 3 inches or a bit lesser.
2. Here in India we mostly brew our own fuel and I use Diesel 40%, Castor Oil 30% and Either 30% for my diesel engines and 80% Methanol and 20% Castor oil for my glow plug engines... Am actually unaware of the 4 2 4 break and couldn't find much on the google search. Can you please help me understand that. Nitro Methane being a controlled item is not easily available.
3. Will try them on downwind side this time and give you a feedback.
4. I generally use about 50 feet... Guess I need to shorten it a bit for higher tension and better control overhead.
5. I can reduce the elevator throws on my models by using a bigger spacing on the control horn at the elevator... Will reduce it to say 25 - 30 degrees. Hope that will help.

Will request on your assistance in my understanding of 4 2 4 break and how do you achieve it on regular engines..

Thanks a lot
Shobhit

AJ Sun

I've never run Diesel engines. A 4 2 4 break is usually a term we used with Fox Stunt 35 engine. Adjusted thru the needle valve assembly. When the plane is level it runs like a four cycle a little rich then when you raise the nose of the plane vertical it leans and runs like a two cycle, hence 4 2 4 break. Best accomplished using 10% Nitro 28% caster. Don't know what model engines your running. So From model engine to model engine your tank location and engine set up can compromise thus theory of 4 2 4 break. Don't really think a diesel can be set up for this. Hard to say with no diesel experience.

shobhit17

I am using Sharma Diesel Engine.... a very reliable and robust Indian engine and also the OS 25. I don't know how to set my OS to run the 4 2 4 break as I have no clue how to adjust the fuel while in flight. This is the engine I been using.... been using these since 1982 onwards... as thats a very popular small engine here in India.

Today I tried a 9x4 prop on the Sharma 3.2CC instead of the 9x6 I was using always.... The model flew slower but had good tension on the lines. I managed to do one overhead figure of 8.

That was the icing on the cake.

shobhit17

Now I need to know how to go about doing that 4 2 4 break on my Glow engines. If you can guide me that will be excellent.

shobhit17

This is the engine I am using.....

AJ Sun

Hit17, I have never tried that break on a OS max engine. I only run the Fox Stunt 35. So I would guess you would have to experiment. 4 rich 2 lean 4 rich that’s the combination you have to achieve. 4 rich plane is flat flying position 2 lean raise the plane to a vertical position nose straight up. Then return to 4 flat plain goes rich again. That the 4 2 4 break. To my recollection I’ve never seen an OS engine do that. I’ve been flying a long time, just have never recalled it. On any engine, but the Fox Stunt 35. AJ

shobhit17

Thanks a lot AJ Sun.... Well I have no clue where to get that Fox 35 in India.....
Thanks for all that information on something I never knew is possible..... But still How do you achieve this..

Thankyou very mush

shobhit17

I still need more info on only elevator or flaps and elevator combination on the control line stunt model.... Someone please let me know..

AJ Sun

Well my experience with flaps is very limited only have two aircraft that I fly with elevator flap combination. Your bell crank only has a limited ability that controls the flap elevator combination. If rigged properly your throw between the two controls should be about the same. A lot of that is controlled at your handle. If your using a hard point handle. A handle with cable lead outs usually cannot adjust that belcrank throw. That’s what is nice about a hard point handle also a bias and non bias handle can offer a wide variety of adjustments. That effect the throw of your Bel crank and control throw. Usually with a flap configuration you need less throw because the relative wind changes over the elevator creating more lift to the elevator so you need less of a throw with flaps. Line drag is also a point of interest. Less line and lighter line weight all fall into air craft control. Shorter lines increase circle speed and your prop and engine also effect the air crafts performance. Proper weights and wing counter weights of a well balanced aircraft will increase its performance. If your lines go limp in a wing over something is not right. And until that’s corrected you should never attempt any other manouver AJ

shobhit17

Thanks AJ......Yes I use a fixed handle and I can't do much changes the line spacing as you can do on lines used at your place. Anyway... thats a bit of a drawback. Anyhow....this time I am making with flaps and elevators and planning to have about 25 degrees of thrown on elevators... and the same on flaps.... lets see how it goes.... on my last model with a 9x4 prop and Sharma 3.2, I got my overhead 8 with ease...... the line tension is good and the model flies well.... (thats only the elevators in use).

Thanks.... guess with no Fox 35.... its a no no on the 4 2 4 break for me....

Thanks again.

AJ Sun

Okay Have a great time flying. If you look on EBay you can find several for sale but some only in the states not over seas