What you should consider before converting your rc airplane gas engine to an electric motor system. With the changes in rc electric motor technology it is possible to fly ANY size model using rc plane electric motors. The biggest leap in making this possible has been two fold. In fact you can expect to see an increase in the performance of a model airplane in several areas.
Your take-off is shorter, climb rate will increase and you can now fly in areas that have noise restrictions. The debate between the benefits of rc plane electric and gas motors are as controversial as those between pc and Mac users.
It will continue for as long as they are both in existence. How long will the battery allow me to fly? The days of overheating the batteries and fire hazards are almost non-existent. There are many add on features that you can now purchase that all but eliminate battery hazards. Such as temperature monitors and voltage indicators. Here are some questions to ask before you start buying any components. These questions will help determine what components to buy.
What is the radio control plane that you are wanting to convert? Is it a trainer, sport plane, 3D etc. This is important because you will need to determine the electric motor based on your models capabilities, and what you want it to do. Example : Hangar 9 Alpha with a. Now you need to determine what type of batteries you will need.
This is based mostly on your budget and time till land variable. In other words, how long do you want to fly for and still get performance. The most obvious choice is going to be a Lithium Polymer battery, this is the most advanced battery technology available for rc model airplanes. They are also the most expensive. Other older battery technologies are available, such as, lithium ion and nickel metal hydride. They can do the job, but at a weight cost and flying time consideration.
Dualsky adjustable motor mount stand offs - Electric propeller e. Once this is done, you can mount the electric motor.
You may require the adjustable motor mount stand offs in order to securely fasten this motor be sure to measure the length to ensure that you purchase the correct stand offs. The motor should be mounted either to the stand offs, or directly to the firewall using the cross mount supplied with the motor. In many instances you will be able to use the same mounting holes from the radial engine mount.
You can attach the speed controller to the fuselage using velcro. However, if your plane does not have this hatch, you will need to make the connection through the underside of the fuselage. If you are going to use a large battery, such as the Dualsky mAh LiPo we recommended, you may want to make a plate using 3mm plywood to secure the battery in place.
This prevents it from moving around during flight. You can then fasten the battery to the plate using Velcro and battery straps.
The battery should be located so that the correct centre of gravity CG can be obtained. Typically the LiPO battery will partially occupy the space where the fuel tank would have been located.
As soon as the battery is connected, your plane has been converted to electric power. Charge the pack and go fly! If you have any questions about this procedure, please ask us in the comments section below. More from: FAQs. Latest Posts. February November October September New to RC flying? Get my popular ebook today, to help you on your way! The subject of radio control propeller size selection can be a bit of a minefield, especially for the beginner to the hobby, but outlined below are some generally accepted guidelines and recommendations for choosing the right prop for your plane.
In the worst case scenario, the wrong prop can cause serious damage to components and this is especially true for electric powered rc airplanes.
The manufacturer of the plane might also give a recommended prop size, but it's more common for the recommendation to come with the engine or motor. If you can't get the info from an instruction manual, get online and ask in an internet forum - someone somewhere will know! You'd be forgiven for just thinking of your rc plane's prop as the thing at the front of the plane that spins round very fast, but understanding a bit about how propellers actually work is no bad thing.
Propellers for rc airplanes are nothing more than vertically mounted rotating wings. Thrust is generated in exactly the same way as lift is generated by the wing, and that's why props have a profile airfoil section.
The 'twist' in the propeller is there to create the essential Angle of Attack of each blade, just like a wing has an AoA.
The twist is greater towards the hub of the prop because of varying airspeeds along the length of the blades, and hence varying thrust generation.
The picture to the right approximately illustrates how the Angle of Attack varies along the blade length. This difference in thrust generation occurs because the tips of the prop blades move faster than inner portions of the blades, so the AoA has to change accordingly along the length of the blades; more thrust is generated at faster speeds, just like more lift is generated over a faster moving wing.
At slower speed i. The first number is the diameter of the imaginary disc 'arc' created by the spinning prop i. The second number is the pitch and this is the harder of the two to understand - but we'll give it a go The pitch measurement of a prop indicates how far, in inches, that propeller will move through the air per single revolution of the engine i.
How to Convert RC Airplane Gas Engines to Electric
However, the pitch measurement of your prop must only be taken as a guideline because real-life factors come in to play to influence this distance eg the material of the prop, its condition, efficiency, air density on the day etc. So, pitch measurement is really only a theoretical value, but it is good enough to help you choose the right size propeller for your airplane. One way to understand propeller pitch is to imagine the gauge of two different screw threads, coarse and fine, and picture both being screwed into a piece of wood at the same rotational speed.
The screw with the coarse thread will cut into the wood a lot faster than the fine threaded screw will. It's the same for propellers 'cutting' through the air hence the reason why propellers are sometimes called airscrews.
In the illustration below, the two arrow lines represent the path of each propeller tip. You can see that the higher pitch prop eg 10x8 takes only one and a half turns to cover the same distance that the lower pitch prop eg 10x4 takes 3 turns to. So, with both engines and props spinning at identical RPM, the higher pitch prop will travel further in the same amount of time - hence a faster flying plane.
So you can see that selecting a different propeller pitch size is going to significantly change your airplane's performance, with speed being the primary factor.
The diameter of the propeller 10" in the example above will also effect how the airplane flies, but also how the engine runs and, again, following your engine manufacturer's recommendations is the place to start.
Roughly speaking, diameter influences the amount of thrust generated but an ever-increasing and non-performance related issue these days, linked to prop diameter, is that of noise.
A faster turning propeller and props can easily turn in excess of 10, RPM generates a lot of noise as the tips cut through the air. In fact, when you hear an rc airplane flying it's more than likely the propeller that you're hearing more than the engine. A larger diameter prop reduces the engine's RPM at any given power setting, because there is more for the engine to turn over and hence more work to do. And slower turning props generate less noise - therefore, larger diameter props run quieter than smaller diameter props, all else being equal.
In this environmentally-sensitive world that we live, this is a serious consideration to take in to account when selecting a propeller, especially if your flying site is 'noise sensitive' eg close to houses etc. As already mentioned, following the propeller size recommendations made by your engine manufacturer should always be your first point of reference. But there are generally recognised prop size ranges for each engine size and these are the sizes to choose if you're unsure about propeller selection.
Although this chart is related to Top Flight's Power Point range of props, the size ranges suit all brands. It's no secret that matching a prop to an IC engine is fairly easy if you follow the general size recommendations outlined in the above chart, which have long been accepted in the hobby. Fitting an incorrect prop would mean the engine would still run, but your plane would perform poorly. EP prop selection is much more critical because different combinations of motors, ESCs and battery packs can generate huge differences in operating speeds and loads.
As with IC, electric motor manufacturers give a specific propeller size range for their motors but it's more critical that the range must be adhered to.New to RC flying? Get my popular ebook today, to help you on your way!
More of a 'rule of thumb' than a hard and fast rule, the Watts per pound rule is one that lets you determine the power output needed for your electric rc airplane, to give it the performance that you desire.
Here are some Watts per pound values that should put you in the right ballpark for your particular plane By working around those categories you should be able to decide how much power your rc airplane needs to perform well, but it has to be said that those values aren't set in stone. They are very good starting points though. Over-propping an electric rc airplane is one sure way to burn out the ESC because the motor is forced to work harder than it's designed for, and so it tries to draw more current than you calculated the ESC to handle.
Incidentally, a Watt is the correct unit to measure electrical power and Watts are calculated by multiplying the voltage V by current in amps, for which the proper symbol is 'I' but you'll also likely see it written as 'A'. If you're looking for the IC internal combustion equivalent, 1hp horsepower is equal to W.
The only sure-fire way to determine how much power your particular setup is producing is to use a Watt meter. This useful little tool actually essential if you do want to start experimenting with different EP setups connects between the flight pack and ESC, and will give you various readings throughout the power range.
Simply connect it up and power up your plane, and read off how many Watts are being produced. Above: an RC Watt meter is essential once you get in to doing your own electric power setups. It's worth noting that although the Watts per pound rule works on the actual flying weight of the airplane, the more realistic and accurate reference to a plane's performance in relation to its flying weight is called the wing loading.
The larger the wing area and lighter the plane, then the lower the wing loading will be and vice versa. A lower wing loading means slower take off capability and better flying performance in many ways. But for the purpose of calculating power requirements for your model, in terms of the Watts per pound rule, work with the actual weight of it and don't worry about wing area or loading. If you're a complete beginner to the hobby with your first RTF rc planethen you won't need to worry about Watts per pound or wing loadings just yet.
But as you get more in to the hobby, do take the time to understand and know how to use these important calculations. Electric rc airplanes. Electric rc.Choosing RC electric motors for your RC airplanes isn't quite as straight forward as ordering the recommended size glow engine. All the different brands, sizes, and specifications can make choosing a motor quite intimidating if you're new to the hobby.
Understanding the basic fundamentals outlined here is essential for choosing a suitable motor for your airplane. Like everything in life, the more experience you have tinkering with different setups, the more confident you will be when choosing RC electric motors for different types and sizes of RC airplanes I personally recommend going with an RTF for your first electric airplane as it gives you hands on experience with the various components of an electric power system.
You also need to be fairly familiar with lipo battery packs. When shopping for RC electric motors, it's important to understand what all those numbers and specs really mean. This is how many RPM's the motor turns for each volt applied.
For example, if you apply 12volts to a Kv motor, it will turn at just under 12 x RPM's.Flite Test - Choosing A Propeller - FLITE TIP
You'll have to ask someone smarter than me where the comes from, cause I don't have a clue! Just accept it for what it is. In a nut shell, this means the faster the motor spins for a given voltage Kvthe lower the output torque will be Kt. Outrunners brushless motors generally have a lower Kv, which in turn produces more torque at a slower speed for spinning those larger props.
The opposite is true with inrunners. This is the amount of current it takes to spin the RC electric motor with no prop. For example, if your motor is pulling 25Amps, and the Io is 2Amps, then you really only have 23Amps turning the prop. This is the internal resistance of the motor measured in Ohms. The higher the Rm, the less efficient the motor is. Simply multiply the current by the battery voltage to get power. The larger the propeller's diameter and pitch, the more current the RC electric motor will draw for a given RPM.
For example, the Kv motor will run at RPM's regardless of whether it has a 10x6 prop or a 11x5 prop. But, the 11x5 prop will cause the motor to draw more current.
Drawing too much current will destroy the motor. The manual for most ARF'S and kits these days make it really easy for you by recommending a specific motor. For marketing purposes, they will obviously recommend the specific brand of RC electric motors that they are affiliated with.
If you'd rather use a different brand all you have to do is find another motor with comparable power and KV rating. If you don't have this reference, or are working on a glow to electric conversion, then you'll need to estimate how much power you will need. You may want to lower this number for a high lift trainer type airplane. Nailing down which RC motor to use is only one piece of the puzzle. Equally important is choosing the correct size electronic speed control and battery.
ParkZone is known for their high quality ready to fly models.It is now summer and still there are two questions that crop up in my emails. Can you equate an electric motor to a glow equivalent? How do you go about converting a glow model to electric?
The answer to the first question is technically no, but manufacturers do and they are doing the motor a disservice by doing so. The answer to the second question is the main thrust of this article. Unlike a glow engine, a motor does not have a narrow operating range. When you buy an ordinary.
If you are lucky, it develops about one horsepower. The first thing we should be learning when flying e-powered models is that if we are swinging a glow size prop at typical glow rpm on our models we are doing something wrong.
Calling a motor a 46 and using it on a 40 glow size model may work well for a sport model that, because of the design, cannot swing a much larger prop. However, it would not be the best answer for a lumbering 40 glow trainer with lots of room for prop growth. That 46 motor can be run on three LiPo cells effectively with a large prop and fly a lightweight but large model and it can be run on LiPo cells on a fast moving sport model with a much smaller prop.
This is why we should not give the motor a glow equivalent designation. It makes things easier for the marketing manager, but not for the modeler. I have put together a step method for converting a glow aircraft to e-power. I would like to begin by making two statements. If the model in question is considered overweight as a glow model, do not even start the process.
It will not fly any better as an electric model. In addition, most ARF and RTF glow models cannot be lightened enough to make a difference, so dont start putting holes in everything especially balsa! All you may be successful in doing is making the model weaker. I will be using a Hobbico Avistar for the purpose of this article. Although the glow to electric conversion presented here is rather specific, the steps involved are applicable to any type model of any size from.
The size Avistar is one of the most popular trainers still sold today and I dont see that changing any time soon. In each of the 10 steps presented, I will describe the process and then how it relates to this particular model.
Next month, I will describe the physical process of converting the model from glow to electric. Ten steps for electric conversions:.
Understanding RC propeller size
How can I do this if I dont know what I am putting in it? A simple way to estimate the weight of the model is to consider that after you take out the glow motor, mount, fuel tank, throttle servo and pushrod, you will find very often that when you add in all the electric components if using LiPo bat-teries that the weight of the model will only be a few ounces more than the glow model with an empty tank!
Add the fuel weight and the glow model can actually be heavier! The estimated weight of the Avistar is 5 pounds, giving us our first data point. How do I choose a prop when I have not chosen a motor yet? As I mentioned earlier, we desire to swing as large a prop as possible to reap the benefits of electric flight. The only exception to this rule is if you plan on racing your model that would be the subject of a different article.
Before you remove the engine, measure distance from engine shaft to ground with model level and subtract experience. Experience is a number that is directly related to your skill level. A skilled pilot can subtract one inch or so. A less skilled pilot might subtract 1. If you fly off a very rough field, even a skilled pilot may choose a higher number to avoid prop breakage. The measured distance on the Avistar is 7.She wanted to achieve good band score so that she could apply for immigration in her intended country,Student Background Shubha Kapoor (imaginary name) is a homemaker from the capital city, New Delhi.
She had been on leave from work for a while with the desire to apply for immigration to Canada. This IELTS case study is about thisStudent Background This inspiring IELTS case study is about Anand Kishore (imaginary name), software engineer from Indore with the desire to apply for immigration to Canada, who wanted to meet the cut off score in order to get himself registeredStudent Background Pooja Shetty (imaginary name) was a student studying in her final year of graduation who wanted to pursue her dream of higher education studies outside India.
She wanted to score 7. He had a dream of immigrating to Australia with his family for which he needed to meet the minimum criterion. He had appeared in IELTS examStudent Background Balachandran (imaginary name, not disclosed for privacy) is an experienced mechanical engineer from Andhra Pradesh. He badly needed to boost up his IELTS score from 5. He desperately needed 7 BandIELTS test stands for- International English Language Testing System.
There are two versions of IELTS to choose from: IELTS Academic IELTS General Training EveryoneThere is no way you can assess your own Speaking task and Writing task. IELTS is a tough exam and worrying about your Writing task and Speaking task, feeling insecure or looking for a way to estimate your score before takingWhy do you need an IELTS Diagnostic Test.
IELTS is a reasonably challenging exam, knowing where you stand can do a world of difference to your preparation. This IELTS Diagnostic Test can help you in the following ways Give youCoherence and Cohesion in Writing and speaking task have the highest weight age in IELTS exam. While this is probably taken lightly by the candidates and that is where they score a low band. You have to avoid the repeatedEvery candidate feels that the IELTS Reading test is tough and they have a very short amount of time to answer a large number of questions on very complicated texts.
You need to master the reading skills to get aIt is often said that getting good band score in IELTS writing exam is difficult, especially in IELTS Writing Task 2. Let us check and analyse a task response to find out what are its strengths and weaknesses, and whether itStudents intending to score high in IELTS develop several myths about it. Many students are found having misconceptions of getting Band 7 and above in IELTS.
Let us find out what these myths are: 1.
The More you Write,IELTS is a unique exam in its own way where you are being rated from 0 to 9 Band scale and there is no pass or fail kind of concept here. One of our trainers has published her letter as an answer to one of the IELTS Writing task evaluation with a model answer September 16, 2017ufaber Here is one more question that appeared in the recent IELTS Writing task.
Convert Your Glow Airplane to Brushless
Nowadays we IELTS Writing task evaluation with a model answer August 24, 2017K. Prabha IELTS Writing task evaluation is done for the given question that appeared in the recent IELTS Exam.
Do the advantages outweigh IELTS Writing task evaluation article with model answer August 24, 2017K. Prabha IELTS Writing task evaluation is given for the following question, as appeared on the cue card is given below.
The advantages provided by English as a global language What is the format of IELTS test General Training. August 23, 2017ufaber IELTS test stands for- International English Language Testing System.