Hi

I have been reading up on the forum for stuff that I would require to build models. I have a few questions based on the video's i have seen that need clarification.

1. For a plane to fly the wing needs to have a aerofoil shape, but a few of the models that I saw on the video's posted here seem to have flat wings and are flying, so am i missing something in the videos?  or can we fly models with flat wings?

2. Most of the models that i saw seemed to be pretty large, on an average 40 inches in size! My question is cant we make smaller models (wouldn't it be easier? smaller = cheaper?)

3. This is a stupid question but I am still going to ask.... What happens if the model goes out of range of the transmitter? Will i have to run behind it or is there some mechanism where by the power shuts off and the model glides/falls down?

1.  rc planes can fly with flat airfoil (kfm airfoils). keep in mind that there should be enough power to fly.

2.  small planes can also be made. no problem.

3.   May be possible , in this condition , power can not be shut off. it will fly till fuel or battery last on god grace.

Flat bottom airfoil and KFm airfoil (Kline Fogleman) are two entirely different things.

I beg to differ as far as point # 3 is concerned. Once radio contact is lost with an electric aeromodel, the speed controller will shut down and cause the engine/motor to seize, prop will stop rotating and the model would lose all power. Thereafter it (the descent back to terra firma) all depends on the glide characteristics of the model. I've never experienced this, so I could be wrong.

I am explaining as simple as i can.

1. Airfoil shape is not a must. It just increases the efficiency. and reduce drag or air friction. But angle of attack is necessary to fly the plane to generate lift.
2.
a)Controlling Large model is easier as of slow flier i. e. you get ample time to response in Tx operation and a general purpose reflex will make you a successful flyer.
b)Most of the general purpose electronics has a weight and for that you need a minimum lift area. Special microelectronics can make smaller indoor planes but spares make costlier than regular.
c) Smaller planes makes narrow solid angle to eye and you can see only upto a certain distance for controlling. Larger plane makes it easier. Again spectators can see larger planes more clearly.

3. When the model goes beyond range, the electronics stops work. Your servo, ESC BL Motors etc will stop. but engine will rotate if it's IC one. So, servos will be uncontrollable. Some of us experienced this due to undercharge of battery. Then just reduce throttle to zero and link again and just glide the model to ground.
Aditya told for glow engine and VC for electric one.
Also receiver performance/program is crucial here. Some receiver makes servo signal at last/zero positioned (as programmed inside microcontroller) and rest just stop generating signal. So, last position of servos are maintained.

Thanks

Thanks Kalyan,

Considering the cost factor, I will initially use electric setup.

I had one more question, do the transmitter and receiver come in pairs? or is there any transmitter that can be used with more than one receiver?

Edit: corrected typo errors

The Tx+Rx allways come in pair for new and I request you to follow.

1. Purchase Tx+Rx from Indian shop to avoid custom.

2. Purchase turnigy 9x or FSth9x as it have mix features with good low price. you may check RCBazaar.com for lowest price.

3. Initially start with 9gm servo (I prefer HXt900, but aeolian s0009 is a good replacement), also check the operating voltage range (Min 4.8V).

4. While purchasing ESC also check the BEC output current. preferred for 2A.

5. Purchase 2822 or 2812 motor with suitable prop set (Min 3 prop).

6 Purchase battery of 3S 1AH or like that not only for cost but also for less weight. requested to use turnigy brand LiPO for good life. You may use NiMH for Tx but purchase for low discharge NiMH. (You may purchase 3xAA 1600mAh cordless cell battery as it costs less, 70-90/- for 3 cell).

7. Read every readings, tutes etc not only from thjis site but from other sites too.

8. Purchase a joypad with analog setup or good Tx with simulator cable and try on simulator first to avoid crash. use FMS or aerofly professional delux for practice.

9. You may use keyboard as input to FMS that at least improve your reflex.

10. before flying, make a glide test.

Hope these basic points can help you making electric.

What is the normal desired range that the transmitter/receiver pair should have?

This is the first question anyone who visits the field and watch you fly ask , does it matter unless it is drastically less? Won't you loose visual sight of a decent size models orientation before you hit it's max radio range, just for the records, I have checked futaba 72 & 35 MHz , on the runway on ground, it is good 2 kms, 2.4 ghz futaba 7c is a shade more, spektrum is slightly less, turnigy is shade better in range. Hope that answers

Ps
Did u mean price range

Pardon me if I am wrong - I know things have changed over the years but isn't it good advice for a beginner to start with a high wing slow flying trainer with good glide characteristics (flat bottomed "Clark Y" aerofoil section) rather than a fast flying flat wing? I am not very familiar with the KFm sections (stepped?) and have never really seen them on models. Any of you using them?

I was under the impression that these are fairly short ranged and was more worried of a substantial investment in time and money just flying away!!