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Guide: Nitro vs. Electric
My take on the “Which is Best: Nitro or Electric?” argument…
As forum users, we all like to have a good argument now and again, and I’m sure that we’ll all agree that one of the most common ones is “boobs or bum?”. Wait, wrong forum… No, this is the classic “nitro or electric” discussion/argument/flame war/bunny fight.
So which is better? Which should you pick? Which will you prefer? I cannot answer those questions; only you can as an individual.
This guide is not definitive and is purely based on my opinion and experience in 6 years of heli flying. I am no professional, nor am I an engine or charger guru. I’m just an average heli pilot that wishes to take on this question from my own perspective.
I will split this guide into various sections, hopefully outlining various pros and cons of both nitro and electric power. I will not delve into anything in great detail, as this is not intended to be a complete start to finish model setup article. I will also not be comparing brands against each other and will not be totting up costs etc. down to the exact penny. My aim is for this to be a rough guide to help you make a decision that is right for YOU. My comparisons will be based on a typical 90/700 machine like a TRex 700E/N for example.
So, before I start, I hope that this guide will be helpful, especially for beginners who are looking to enter this amazing hobby and community, but are overwhelmed by all the choice!
Setup
Choosing nitro or electric should not affect the general build all that much. Both will use the same tools, you will set your model up more or less the same from the transmitter regardless of the power plant. The differences mainly lie in the setup of the power plant itself. One question to ask yourself; are you mechanically minded, or are you an electronic whiz? There are elements of each in both options (FBL controller as a prime example), but perhaps you prefer working with engine needles and carburettors than with motor timing and pulse widths? Both have their learning curves, but this is exactly what RCHA is there for.
With Nitro, the biggest concern (for me) is getting the engine alignment and throttle linkage geometry correct. This is not very difficult, but will take a bit of practice to get right. A few blasts of the starter before tightening up all of the mounting bolts usually sets it right. On electrics, it is usually a case of following the instructions to match motor settings. This can be more technical, but once set, you’re good to go most of the time. After this, it is a case of programming curves in your radio etc., and setting up the governor on the FBL unit or ESC, but that is beyond the scope of this guide.
So that’s covered, onto tuning the model…
Tuning
Now, tuning is similar to Setup in that the majority of the differences lie with the power plant itself. It is the process of tweaking the electronic and physical parameters of the model to get it to fly correctly and to your liking. The word tuning is applicable to the model as whole, but for most, they initially think of engine tuning.
Nitro engine tuning can be a dark art and relies on experience and a ‘knack’ as much a technical understanding of the engine itself. It is vital to get the best performance and longevity out your engine; too rich and you’ll have little power and use more fuel than necessary; too lean and you’re going to kill off your shiny new engine more sooner than later.
Nitro engines also require ‘breaking in’, as do LiPo batteries for electric models. In my experience, nitro engine tuning only takes slightly longer than it does to consider a 700 size LiPo “broken in”. I personally think that the following link is a great and concise guide to get your motor pretty much tuned: The Dark Art of Engine Tuning :: Skyline Models
Breaking in a LiPo is simply the process of ‘going easy’ on the packs at first. Some do it in a very strict fashion using car headlight bulbs, or custom charge/discharge charger cycles, whilst others think of it as a myth and do none of any sort. Personally, I do not reduce my flight time, I just stick to light sport flying for about 5 flights, making sure they’re kept cool and in at storage charge between sessions.
Tuning of a nitro engine, unlike the settings of an ESC, is not ‘set and forget’. State of tune changes depending on local climate and temperature (due to resultant air density), and is rarely drastic, but it is something that you should be aware of.
Next up, performance and power…
Performance / Power
Probably the second most discussed aspect between the two power systems, delivered power is definitely different between the two. This is where many arguments are formed, as it is difficult for most average amateur pilots (and most certainly myself) to statistically compare the two. Most agree that electric has more power overall. The heli will move around and change direction more swiftly, has more energy and therefore will not ‘bog’ as quickly. For those new to the hobby, ‘bogging’ is where you place a large power demand on the power system. With RC helicopters, it is usually a large collective input that results in a lot of pitch on the blades – too much and you’re going to sap all the power out of the motor reducing the speed of the rotor disc. My personal experience tends to agree with this. For raw power, electric wins. There are times when I fly my Rush 700, that I forget just how insanely powerful it is and scare myself. This obviously depends on hardware and battery packs used etc., but this seems to be the general consensus. I find that doing Tictocs etc. on a nitro much easier. I have no logical explanation for this – as said, I have no proof or statistics to say one is better than the other, it’s all down to feel for me. Perhaps I’m better with typical nitro throttle curves than I am with electric. This is why I said right at the start that the majority of this falls to personal feel and preference.
How else can we judge power? Well, for example, in winter, nitro tends to gain power, whilst the opposite can be said for electric. The air is colder, therefore denser, making for a leaner mixture (richen accordingly). LiPos do not perform at their best in the cold, and (especially if charging at the field in the cold) they should only be charged to 4.1v per cell, instead of the standard 4.2v to prevent an overcharging effect when they warm up. This will lower power (small but measurable) and flight duration, but will be better for the batteries in the long run.
Flight duration, could that be the biggest argument causing element?
Flight Times
Now, comparing like for like, 3D vs. 3D etc., there is no arguing against it: Nitro wins hands down. Let’s take a TRex 700E vs. 700N as an example. Yes, there are detailed differences between weights etc., but for arguments sake, they’re the same model. There are wild claims that nitro gets 12+ minutes and electric gets 3 ½ minutes if you’re lucky. As said, comparing style and setup like for like, this is simply exaggerated. In my experience, with a 700E machine on a 5000mAh 12S setup, I’d see 5 ½ minutes on average. On nitro however, I’ll see 9 minutes. Now, of course, there are many other factors in play (well yes, of course there are…). Weight, flying style, head speed etc. will all affect duration: drop your head speed to 900RPM (from 1800RPM) on a 6S setup, and you’ll pretty much double your flight time. The point is to take the typical scenario and compare the two. And, nitro wins…
Why is this a concern? Well for some, it isn’t, so pick what you like. For most however, it’s all about the stick time which is vital for newcomers in particular. It’s no good just getting confidence to get the model up into a controlled hover and then having to land because your 5 ½ minutes are up. Electric is favoured in competitions of late, and my take on this is that you simply don’t need duration. You want every ounce of raw power for your 4 minute slot (I’ve never entered one so I’m assuming it’s about that?) so for 3D competitions I can see why many prefer electric. There are still plenty nitros in competitions however, which I, amongst others, am glad to see!
But how much is all of this time and power going to cost?
Costs
Either way, this is an expensive hobby. We enjoy it, so that’s all that matters, right? To sum up to costs involved getting either to run, I’ve split it down to two sub topics: initial setup costs and running costs. To be clear: I am not stating that building a nitro will cost the exact same as building an electric will as it is entirely up to which motor, ESC, muffler etc. you purchase. The point of this is look to look past the model itself and to work out what each power system option as a whole could cost you.
Initial Setup Cost
This is how much you are going to have to spend getting into the hobby. To keep things fair, let’s eliminate things that are irrelevant to the discussion, like radio gear and hand tools etc. and assume everything is purchase new from a store. Electric or nitro, the hand tools are going be the same more or less.
With either, you’re going to need some sort of charger. With nitro, a small 4 cell LiPo charger will do, as realistically you’re only going to be charge 2S flight packs and 3S/4S starter batteries. This should only set you back up to £50 or so. Then you need starting equipment. Whether it be a Dynatron or an Align super starter (for another debate!) is up to you, but you’d be looking at about £100+ with a suitable LiPo. And there are things like glow stick, pump and other bits and bobs which will set you back another £40 or so. So rounding up, you’ll be looking at £200 or so.
Now, getting going with electric is a field all on its own. As some will recall, I recently asked a rather difficult and very subjective question about LiPos on RCHA. Like everything, it’s hard to say what a LiPo will cost as it depends entirely on which brand and capacity you go for. For the purpose of this guide, I simply want to give the newcomer a rough estimate of what setting up with electric may cost.
So, you have a few options… Do you just get one flight pack (2x 6S for a 700E), fly then go home to recharge? No, realistically this is not likely at all. You have two main choices if you’re leaning towards electric flight: stock up on several packs, or buy a generator or large capacity Lead Acid leisure battery. The obvious answer is to buy more packs, then charge them all up prior to your flying session. I know Lee ‘Made2Fade’ Egan likes to watch the latest episode of Coronation Street while he charges his packs…
Let’s look at the cost of packs. Again I do not want to compare packs as this is not the purpose of this guide, so I’m going to assume that the average cost of a 6S pack is £60 (going off current prices), meaning that per (typical 12S setup that most fly) flight pack, you’re going to need to spend £120. So for four flights, before having to return home to charge, you’re already at £480 on LiPos alone. But now, you have all of these batteries, are you going to charge them all one by one at 1C (8 hours!). Well, yes, of course you can. No one is saying you have to buy a seriously expensive charger – a standard 6S charger would suffice. From my experience however, this is a horrible and slow way to do it, and like many others, I eventually went to parallel charging. For this, I love my Revolectrix PowerLab8. But they are expensive... To get a PL8, parallel charge board and PSU (or a competitor’s alternative), you’re looking at approximately £350, depending on the stuff you buy. You can see how this is all starting to mount up…
Now to go further, if you’ve decided purely on electric flying, you can go down the field charging route and buy less packs – say two pairs (£240 in our example). The leisure battery is the cheaper option, but really you’re only going to get one or two cycles out of it before the voltage drops to low. A 120Ah 12v Pb battery would cost around £100. Many, including myself, went for a suitcase generator. These cost anything from £150 to £800 depending on what you want. Anything more is likely overkill.
Here, nitro wins in initial cost, but to be fair, there are so many choices it’s hard to compare one fairly against the other. I did warn you that this is very subjective!
So, you’ve bought all your gear, how much is it going to cost over time to keep at it?
Running Costs
This is where Nitro loses the battle for the obvious reason that you’re burning up fuel and will have to replenish it. There is less choice of nitro fuel on the market and cost is (albeit, very slowly) creeping up. A well popular brand of 20% five litre fuel is around £23. From my personal experience, and judging by what others get, a 90 size nitro (typical 90 engine) will bag you around 8-10 flights out of a five litre bottle of fuel. Your mileage will vary depending on flying style, tuning, temperature etc., but for the sake of this discussion, we should assume that on average you’re looking at around that number. You could get an exact value by dividing five litres by the capacity of the fuel tank, but then how many of us fill to the brim, and drain the tank dry every flight? For the sake of your engine, none of you I hope! A simple bit of maths tells us that a typical 90 nitro flight is going to cost you around £2.30 - £2.90. Again this is based on using what I’ve deemed to be the most popular and what I use, which is 20%. 30% is around the £30 mark, costing you £3 - £3.75 per flight. It starts mounting up!
What about electric then? Well aside from the things that apply to every model (oils, lubes etc.) there are no real direct costs. I’m not even going to bother talking about electricity bill to charge the packs as, compared to the cost of a nitro flight, it’s negligible. The only real indirect running cost comes from the fact that LiPos do not yield infinite cycles. You don’t just buy packs and recharge them for ever – eventually they will expire, or get to the point where they’re no good for 3D flight. As said earlier, it’s hard to put an average on this as there are so many factors at play… Have you followed the ‘20% rule’ (LiPo batteries should not be discharged by more than 80% of their full capacity)? Have you kept them at storage charge when not in use (charge them back up to 50-60%)? Do you fly gently, slow sport flying with low current draw, or do you prefer every amp possible for extreme 3D? All of these will affect how long a LiPo lasts overall; some brands more than others. So as a very rough guide, we can say that LiPos will need to be replaced for most, after around 150 – 200 cycles or so. Again, after doing a little bit of simple maths, (just dividing the average cost of the LiPos by the estimated amount of cycles/flights) we can approximate that an average electric 700E flight to cost around £0.70 - quite a bit cheaper than nitro!
Other thoughts
There are a couple of other concerns that you should be made aware of. How fussy is your flying club on noise levels? I know one club that I have been a member of have strictly prohibited flying of any 90 size nitro due to the noise. In my personal opinion, there is little difference at all between a 90 nitro and a 50 nitro, but as a whole, nitro tends to be quite a bit noisier than electric, for obvious reasons. If this is a concern, and you’re not bothered about other issues, electric is something you could consider. This would also apply to the use of a generator. I’m aware of clubs that strictly ban ANY IC engine running in the pits.
Nitro can also be messy. Exhaust gasses contain oils and other chemicals that, whilst arguably good for the bearings etc., require cleaning up after each flying session. It’s not a big concern and takes 5 minutes with a baby wipe etc., but it’s something to consider.
Another thing that you could think about is what is popular at your club? This is should not be the deciding factor, but it is always handy to have friends flying similar equipment that you can rely on for help and advice. Nothing more annoying than realising you’ve left your nitro starter at home, and everyone else is electric only for example…
Conclusion
Assuming I haven’t bored you to death, I hope you’ll agree that deciding which is purely a matter of taste. Regardless of what you pick, this is not a cheap hobby, but it is as expensive as you want it to be. If you want to pick only one type, pick which is best for YOU and what is most enjoyable, not what the current fashion is. There are pros and cons to both, and there is no fact stating one is better than the other. Many, including myself, have chosen to go both routes so that they have an option whatever mood or situation dictates. There are days when I simply cannot be bothered with charging my packs, even with a fairly decent charging setup, so I just take my Raptor G4 and a couple of bottles of fuel. Easy back to back flying with no charging interruptions.
References and Thanks
I used the following guides to compare against my experience to make sure there was some validity to my statements.
Running a nitro 90 – discoferret, RCHA
http://www.rcheliaddict.co.uk/main-d...itro-90-a.html
Average LiPo Cost and Cycles – Planehazza, RCHA
http://www.rcheliaddict.co.uk/main-d...st-cycles.html
LiPo Break-in – Arwel, RCHA
http://www.rcheliaddict.co.uk/optipo...-breaking.html
The Dark Art of Engine Tuning – Skyline Models
The Dark Art of Engine Tuning :: Skyline Models
Radio Control Helicopter Association - A great site with a helpful and knowledgeable community. I’d still be crashing my first fixed pitch model into walls if it wasn’t for this site!
Your Friendly Rc Helicopter Community
Thanks to Made2Fade for proofing and editing, and to Stuart et al for keeping the site going every day. Images courtesy of Made2Fade and Allenkey, as well as ones from my own collection.
Glossary
“6S / 12S” – 6 or 12 Cells wired in series. 12S is the typical configuration for 700E class
Cycle – in the context of a battery, a Cycle is a complet process of a discharge followed by charging back up again
ESC – Electronic Speed Controller
FBL – FlyBarLess.
Governor – The unit that governs or controls the head speed at a set RPM
IC – Internal Combustion
LiPo – Lithiumn Polymer Battery
Parallel Charging – The concept of wiring 2 or more batteries to a charge in parallel to charge simultaneously.
PSU – Power Supply Unit– convert 240v AC (mains) into 12 or 24v DC (typically)
Rich / Lean Mixture - Rich means there is too much fuel in the fuel/air mixture, which has a lowering effect on fuel economy and performance. Too Lean is too little fuel resulting in an engine that runs too hot at the risk of causing damage.
Tuning – The process of tweaking to ones liking and get to get optimal performance.
PDF Version with images:
N v E Guide.pdf
As forum users, we all like to have a good argument now and again, and I’m sure that we’ll all agree that one of the most common ones is “boobs or bum?”. Wait, wrong forum… No, this is the classic “nitro or electric” discussion/argument/flame war/bunny fight.
So which is better? Which should you pick? Which will you prefer? I cannot answer those questions; only you can as an individual.
This guide is not definitive and is purely based on my opinion and experience in 6 years of heli flying. I am no professional, nor am I an engine or charger guru. I’m just an average heli pilot that wishes to take on this question from my own perspective.
I will split this guide into various sections, hopefully outlining various pros and cons of both nitro and electric power. I will not delve into anything in great detail, as this is not intended to be a complete start to finish model setup article. I will also not be comparing brands against each other and will not be totting up costs etc. down to the exact penny. My aim is for this to be a rough guide to help you make a decision that is right for YOU. My comparisons will be based on a typical 90/700 machine like a TRex 700E/N for example.
So, before I start, I hope that this guide will be helpful, especially for beginners who are looking to enter this amazing hobby and community, but are overwhelmed by all the choice!
Setup
Choosing nitro or electric should not affect the general build all that much. Both will use the same tools, you will set your model up more or less the same from the transmitter regardless of the power plant. The differences mainly lie in the setup of the power plant itself. One question to ask yourself; are you mechanically minded, or are you an electronic whiz? There are elements of each in both options (FBL controller as a prime example), but perhaps you prefer working with engine needles and carburettors than with motor timing and pulse widths? Both have their learning curves, but this is exactly what RCHA is there for.
With Nitro, the biggest concern (for me) is getting the engine alignment and throttle linkage geometry correct. This is not very difficult, but will take a bit of practice to get right. A few blasts of the starter before tightening up all of the mounting bolts usually sets it right. On electrics, it is usually a case of following the instructions to match motor settings. This can be more technical, but once set, you’re good to go most of the time. After this, it is a case of programming curves in your radio etc., and setting up the governor on the FBL unit or ESC, but that is beyond the scope of this guide.
So that’s covered, onto tuning the model…
Tuning
Now, tuning is similar to Setup in that the majority of the differences lie with the power plant itself. It is the process of tweaking the electronic and physical parameters of the model to get it to fly correctly and to your liking. The word tuning is applicable to the model as whole, but for most, they initially think of engine tuning.
Nitro engine tuning can be a dark art and relies on experience and a ‘knack’ as much a technical understanding of the engine itself. It is vital to get the best performance and longevity out your engine; too rich and you’ll have little power and use more fuel than necessary; too lean and you’re going to kill off your shiny new engine more sooner than later.
Nitro engines also require ‘breaking in’, as do LiPo batteries for electric models. In my experience, nitro engine tuning only takes slightly longer than it does to consider a 700 size LiPo “broken in”. I personally think that the following link is a great and concise guide to get your motor pretty much tuned: The Dark Art of Engine Tuning :: Skyline Models
Breaking in a LiPo is simply the process of ‘going easy’ on the packs at first. Some do it in a very strict fashion using car headlight bulbs, or custom charge/discharge charger cycles, whilst others think of it as a myth and do none of any sort. Personally, I do not reduce my flight time, I just stick to light sport flying for about 5 flights, making sure they’re kept cool and in at storage charge between sessions.
Tuning of a nitro engine, unlike the settings of an ESC, is not ‘set and forget’. State of tune changes depending on local climate and temperature (due to resultant air density), and is rarely drastic, but it is something that you should be aware of.
Next up, performance and power…
Performance / Power
Probably the second most discussed aspect between the two power systems, delivered power is definitely different between the two. This is where many arguments are formed, as it is difficult for most average amateur pilots (and most certainly myself) to statistically compare the two. Most agree that electric has more power overall. The heli will move around and change direction more swiftly, has more energy and therefore will not ‘bog’ as quickly. For those new to the hobby, ‘bogging’ is where you place a large power demand on the power system. With RC helicopters, it is usually a large collective input that results in a lot of pitch on the blades – too much and you’re going to sap all the power out of the motor reducing the speed of the rotor disc. My personal experience tends to agree with this. For raw power, electric wins. There are times when I fly my Rush 700, that I forget just how insanely powerful it is and scare myself. This obviously depends on hardware and battery packs used etc., but this seems to be the general consensus. I find that doing Tictocs etc. on a nitro much easier. I have no logical explanation for this – as said, I have no proof or statistics to say one is better than the other, it’s all down to feel for me. Perhaps I’m better with typical nitro throttle curves than I am with electric. This is why I said right at the start that the majority of this falls to personal feel and preference.
How else can we judge power? Well, for example, in winter, nitro tends to gain power, whilst the opposite can be said for electric. The air is colder, therefore denser, making for a leaner mixture (richen accordingly). LiPos do not perform at their best in the cold, and (especially if charging at the field in the cold) they should only be charged to 4.1v per cell, instead of the standard 4.2v to prevent an overcharging effect when they warm up. This will lower power (small but measurable) and flight duration, but will be better for the batteries in the long run.
Flight duration, could that be the biggest argument causing element?
Flight Times
Now, comparing like for like, 3D vs. 3D etc., there is no arguing against it: Nitro wins hands down. Let’s take a TRex 700E vs. 700N as an example. Yes, there are detailed differences between weights etc., but for arguments sake, they’re the same model. There are wild claims that nitro gets 12+ minutes and electric gets 3 ½ minutes if you’re lucky. As said, comparing style and setup like for like, this is simply exaggerated. In my experience, with a 700E machine on a 5000mAh 12S setup, I’d see 5 ½ minutes on average. On nitro however, I’ll see 9 minutes. Now, of course, there are many other factors in play (well yes, of course there are…). Weight, flying style, head speed etc. will all affect duration: drop your head speed to 900RPM (from 1800RPM) on a 6S setup, and you’ll pretty much double your flight time. The point is to take the typical scenario and compare the two. And, nitro wins…
Why is this a concern? Well for some, it isn’t, so pick what you like. For most however, it’s all about the stick time which is vital for newcomers in particular. It’s no good just getting confidence to get the model up into a controlled hover and then having to land because your 5 ½ minutes are up. Electric is favoured in competitions of late, and my take on this is that you simply don’t need duration. You want every ounce of raw power for your 4 minute slot (I’ve never entered one so I’m assuming it’s about that?) so for 3D competitions I can see why many prefer electric. There are still plenty nitros in competitions however, which I, amongst others, am glad to see!
But how much is all of this time and power going to cost?
Costs
Either way, this is an expensive hobby. We enjoy it, so that’s all that matters, right? To sum up to costs involved getting either to run, I’ve split it down to two sub topics: initial setup costs and running costs. To be clear: I am not stating that building a nitro will cost the exact same as building an electric will as it is entirely up to which motor, ESC, muffler etc. you purchase. The point of this is look to look past the model itself and to work out what each power system option as a whole could cost you.
Initial Setup Cost
This is how much you are going to have to spend getting into the hobby. To keep things fair, let’s eliminate things that are irrelevant to the discussion, like radio gear and hand tools etc. and assume everything is purchase new from a store. Electric or nitro, the hand tools are going be the same more or less.
With either, you’re going to need some sort of charger. With nitro, a small 4 cell LiPo charger will do, as realistically you’re only going to be charge 2S flight packs and 3S/4S starter batteries. This should only set you back up to £50 or so. Then you need starting equipment. Whether it be a Dynatron or an Align super starter (for another debate!) is up to you, but you’d be looking at about £100+ with a suitable LiPo. And there are things like glow stick, pump and other bits and bobs which will set you back another £40 or so. So rounding up, you’ll be looking at £200 or so.
Now, getting going with electric is a field all on its own. As some will recall, I recently asked a rather difficult and very subjective question about LiPos on RCHA. Like everything, it’s hard to say what a LiPo will cost as it depends entirely on which brand and capacity you go for. For the purpose of this guide, I simply want to give the newcomer a rough estimate of what setting up with electric may cost.
So, you have a few options… Do you just get one flight pack (2x 6S for a 700E), fly then go home to recharge? No, realistically this is not likely at all. You have two main choices if you’re leaning towards electric flight: stock up on several packs, or buy a generator or large capacity Lead Acid leisure battery. The obvious answer is to buy more packs, then charge them all up prior to your flying session. I know Lee ‘Made2Fade’ Egan likes to watch the latest episode of Coronation Street while he charges his packs…
Let’s look at the cost of packs. Again I do not want to compare packs as this is not the purpose of this guide, so I’m going to assume that the average cost of a 6S pack is £60 (going off current prices), meaning that per (typical 12S setup that most fly) flight pack, you’re going to need to spend £120. So for four flights, before having to return home to charge, you’re already at £480 on LiPos alone. But now, you have all of these batteries, are you going to charge them all one by one at 1C (8 hours!). Well, yes, of course you can. No one is saying you have to buy a seriously expensive charger – a standard 6S charger would suffice. From my experience however, this is a horrible and slow way to do it, and like many others, I eventually went to parallel charging. For this, I love my Revolectrix PowerLab8. But they are expensive... To get a PL8, parallel charge board and PSU (or a competitor’s alternative), you’re looking at approximately £350, depending on the stuff you buy. You can see how this is all starting to mount up…
Now to go further, if you’ve decided purely on electric flying, you can go down the field charging route and buy less packs – say two pairs (£240 in our example). The leisure battery is the cheaper option, but really you’re only going to get one or two cycles out of it before the voltage drops to low. A 120Ah 12v Pb battery would cost around £100. Many, including myself, went for a suitcase generator. These cost anything from £150 to £800 depending on what you want. Anything more is likely overkill.
Here, nitro wins in initial cost, but to be fair, there are so many choices it’s hard to compare one fairly against the other. I did warn you that this is very subjective!
So, you’ve bought all your gear, how much is it going to cost over time to keep at it?
Running Costs
This is where Nitro loses the battle for the obvious reason that you’re burning up fuel and will have to replenish it. There is less choice of nitro fuel on the market and cost is (albeit, very slowly) creeping up. A well popular brand of 20% five litre fuel is around £23. From my personal experience, and judging by what others get, a 90 size nitro (typical 90 engine) will bag you around 8-10 flights out of a five litre bottle of fuel. Your mileage will vary depending on flying style, tuning, temperature etc., but for the sake of this discussion, we should assume that on average you’re looking at around that number. You could get an exact value by dividing five litres by the capacity of the fuel tank, but then how many of us fill to the brim, and drain the tank dry every flight? For the sake of your engine, none of you I hope! A simple bit of maths tells us that a typical 90 nitro flight is going to cost you around £2.30 - £2.90. Again this is based on using what I’ve deemed to be the most popular and what I use, which is 20%. 30% is around the £30 mark, costing you £3 - £3.75 per flight. It starts mounting up!
What about electric then? Well aside from the things that apply to every model (oils, lubes etc.) there are no real direct costs. I’m not even going to bother talking about electricity bill to charge the packs as, compared to the cost of a nitro flight, it’s negligible. The only real indirect running cost comes from the fact that LiPos do not yield infinite cycles. You don’t just buy packs and recharge them for ever – eventually they will expire, or get to the point where they’re no good for 3D flight. As said earlier, it’s hard to put an average on this as there are so many factors at play… Have you followed the ‘20% rule’ (LiPo batteries should not be discharged by more than 80% of their full capacity)? Have you kept them at storage charge when not in use (charge them back up to 50-60%)? Do you fly gently, slow sport flying with low current draw, or do you prefer every amp possible for extreme 3D? All of these will affect how long a LiPo lasts overall; some brands more than others. So as a very rough guide, we can say that LiPos will need to be replaced for most, after around 150 – 200 cycles or so. Again, after doing a little bit of simple maths, (just dividing the average cost of the LiPos by the estimated amount of cycles/flights) we can approximate that an average electric 700E flight to cost around £0.70 - quite a bit cheaper than nitro!
Other thoughts
There are a couple of other concerns that you should be made aware of. How fussy is your flying club on noise levels? I know one club that I have been a member of have strictly prohibited flying of any 90 size nitro due to the noise. In my personal opinion, there is little difference at all between a 90 nitro and a 50 nitro, but as a whole, nitro tends to be quite a bit noisier than electric, for obvious reasons. If this is a concern, and you’re not bothered about other issues, electric is something you could consider. This would also apply to the use of a generator. I’m aware of clubs that strictly ban ANY IC engine running in the pits.
Nitro can also be messy. Exhaust gasses contain oils and other chemicals that, whilst arguably good for the bearings etc., require cleaning up after each flying session. It’s not a big concern and takes 5 minutes with a baby wipe etc., but it’s something to consider.
Another thing that you could think about is what is popular at your club? This is should not be the deciding factor, but it is always handy to have friends flying similar equipment that you can rely on for help and advice. Nothing more annoying than realising you’ve left your nitro starter at home, and everyone else is electric only for example…
Conclusion
Assuming I haven’t bored you to death, I hope you’ll agree that deciding which is purely a matter of taste. Regardless of what you pick, this is not a cheap hobby, but it is as expensive as you want it to be. If you want to pick only one type, pick which is best for YOU and what is most enjoyable, not what the current fashion is. There are pros and cons to both, and there is no fact stating one is better than the other. Many, including myself, have chosen to go both routes so that they have an option whatever mood or situation dictates. There are days when I simply cannot be bothered with charging my packs, even with a fairly decent charging setup, so I just take my Raptor G4 and a couple of bottles of fuel. Easy back to back flying with no charging interruptions.
References and Thanks
I used the following guides to compare against my experience to make sure there was some validity to my statements.
Running a nitro 90 – discoferret, RCHA
http://www.rcheliaddict.co.uk/main-d...itro-90-a.html
Average LiPo Cost and Cycles – Planehazza, RCHA
http://www.rcheliaddict.co.uk/main-d...st-cycles.html
LiPo Break-in – Arwel, RCHA
http://www.rcheliaddict.co.uk/optipo...-breaking.html
The Dark Art of Engine Tuning – Skyline Models
The Dark Art of Engine Tuning :: Skyline Models
Radio Control Helicopter Association - A great site with a helpful and knowledgeable community. I’d still be crashing my first fixed pitch model into walls if it wasn’t for this site!
Your Friendly Rc Helicopter Community
Thanks to Made2Fade for proofing and editing, and to Stuart et al for keeping the site going every day. Images courtesy of Made2Fade and Allenkey, as well as ones from my own collection.
Glossary
“6S / 12S” – 6 or 12 Cells wired in series. 12S is the typical configuration for 700E class
Cycle – in the context of a battery, a Cycle is a complet process of a discharge followed by charging back up again
ESC – Electronic Speed Controller
FBL – FlyBarLess.
Governor – The unit that governs or controls the head speed at a set RPM
IC – Internal Combustion
LiPo – Lithiumn Polymer Battery
Parallel Charging – The concept of wiring 2 or more batteries to a charge in parallel to charge simultaneously.
PSU – Power Supply Unit– convert 240v AC (mains) into 12 or 24v DC (typically)
Rich / Lean Mixture - Rich means there is too much fuel in the fuel/air mixture, which has a lowering effect on fuel economy and performance. Too Lean is too little fuel resulting in an engine that runs too hot at the risk of causing damage.
Tuning – The process of tweaking to ones liking and get to get optimal performance.
PDF Version with images:
N v E Guide.pdf
V-Bar x2
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