Electric vs. nitro running costs

workaccount

Hi,
I'm looking into the feasibility of getting a T-rex 600 electric.

I'm trying to weight everything up and have been surprised to just find the following.

Assuming you are getting 10mins (usually only 7 or 8mins anyway isn't it?) out of a 5000 mah 22.2v battery with a battery life of about 100 cycles that's a total flying time of 16 hours. The battery costs 300 euro.


Now to Nitro...again assuming 10mins per tank (about 150cc of fuel for example - can't find the exact right size now on the t-rex 600). That's 6 fills to a liter and 30 fills with a gallon for a total of 5 hours driving. A gallon costs 30 euro.

So for three gallons of fuel you get 15 hours and 1 battery you get 16 hrs.

The battery costs 300 euro and the fuel costs 90 euro.

Then adding in the cost of the engine at 50 euro each gallon it's much higher. (150 euros to replace engine after 3 gallons) so the nitro costs 240 vs. 300 for electric.

How long would the motor last in the electric though? How much would one be for the t-rex 600 aswell?

Cheers.

T-Maxx

Good to see someone using the noodle, but:

1. You can't be serious - €300 for a battery?
2. 100 charges only? (Don't know LiPo/LiFe/LiOn but seems wrong.)
3. An engine replacement after only 3 gallons? Maybe a rebuild, yes, if you can't tune.
4. Your maths don't check out, ie should be €300 vs €240.

BTW, a brushless motor should last indefinitely.

loopingfred

Interresting view !

But, having flown both IC and electric, I can guarantee that the Electric is cheaper on the long run. But much more expensive to buy at a start...

A brushless motor life expectancy is in theory unlimited (not like the good old brushed motors).
Your electronics, Heli and so on will last a bit longer too because of the less vibration (virtualy none) coming from the electric motor.
You can do more than 100 cycles with a battery pack these days, and that's talking about Lipos, not the new generation of batteries wish will even last longer.
More important to me.. Less hassle ! Just plug and fly ! Unplug and put all back to your car ! You spend time flying, not tuning the engine...:D

Changing from IC to electric is in my opinion a much bigger picture than the cost of the fuel in short or long run.

My 2 cents

Fred

workaccount

T-Maxx wrote: »

Good to see someone using the noodle, but:

1. You can't be serious - €300 for a battery?
2. 100 charges only? (Don't know LiPo/LiFe/LiOn but seems wrong.)
3. An engine replacement after only 3 gallons? Maybe a rebuild, yes, if you can't tune.
4. Your maths don't check out, ie should be €300 vs €240.

BTW, a brushless motor should last indefinitely.

1) Yeah about 300 for a 22.2v one. There expensive.
2) I've think that's the lifespan of these lipos - Open to correction.
3) I was lead the believe the lifespan of a nitro engine was about 40 hours.

How do my maths not check out even factoring out cost of engine?

coolwings

Electric should not be compared with 2-stroke.
Partially because it always starts!
Also it has a linear torque curve.

But electric can be compared with 4-stroke engines. Which are nicer than 2-stroke, more reliable, have a linear torque, and also have lower fuel consumption.

But 4-strokes also cost more than 2-strokes.
So in an appropriate comparison where the performance and reliability are similar, EP vs 4-str, electric is not dear.

DennisZ

FlightPower EVO 25 5000 6S (22.2v) 25/50C (125A/250A) High Discharge Lithium Battery
http://www.brchobbies.co.uk/?page=shop&action=additem&item=858

~200 GBP (including delivery) ... ~260euro

T-Maxx

workaccount wrote: »

1)How do my maths not check out even factoring out cost of engine?

Because €90 + €150 = €240 ≠ €420

But anyway, like loopingfred said already, in the longrun electric will be cheaper.

(Remember also that for nitro you still need quite a few things to get started, ie glowplug igniter, fuel pump, starter motor, etc.)

workaccount

T-Maxx wrote: »

Because €90 + €150 = €240 ≠ €420

But anyway, like loopingfred said already, in the longrun electric will be cheaper.

(Remember also that for nitro you still need quite a few things to get started, ie glowplug igniter, fuel pump, starter motor, etc.)

Back to school mate

90 + 90 + 90 + 150 = 420

The Doktor

totally agree with fred on this one...
Electric is just nicer! It always works (well mostly), no tuning, and soooooo much cleaner! Im never gonna bother with nitro anything again!

Also think some of your information is a bit dodgy (see previous posts on cycles/engine replacement etc)
you might also want to do a bit more research on the price of batteries as illustrated by Dennis ( http://www.budget-rc.co.uk/RC_Mega_Store/6s-5000mah-25c-125a-p-15.html?zenid=c4fe6ef0f29d928ec73c0c324704a927)


But one thing you have missed in your calculations of running costs is bits that you break!! (though electric or nitro wont make a difference to breaking things)

coolwings

The Doktor wrote: »

.... one thing you have missed in your calculations of running costs is bits that you break!! (though electric or nitro wont make a difference to breaking things)

That is a very vaid point.
I do not see this mentioned, but in a high speed impact, a glowfuel engine is physicaly stronger than an electric motor, due to containing more metal.

So although I am 100% sure that top quality electric is a superior method based on cost, power, reliability, vibration wear and tear removed from model and cleanliness of model .... I am also sure in a crash a dirty big 1/4" crankshaft will be more repairable later!

This leads to the question as to whether you crash more often with one over the other ........

Depends on how many actually tune their nitro engine right.
My feeling is that about 20% will never, ever master it, no matter how many times you explain and show them. Even tune it for them and they still fiddle, and next week it's going like a pig again, and they claim not to have touched it!

T-Maxx

workaccount wrote: »

Back to school mate

90 + 90 + 90 + 150 = 420

I suggest you read through your first post again!:cool:

coolwings

I know the title of this thread is "Electric vs. nitro running costs "

but this is losing sight of what matters. If you focus only on price, and particularlythe lowest price, you will almost always buy a model you don't enjoy using. Then you will want to move on and up, damning the power source you already have, even though there might be nothing wrong with it, due to yours being too difficult to start/maintain/use ... too low tech.

The real question should be...Which method of model propulsion do you prefer?

Nitro 2-str, nitro 4-str, electric inrunner, electric outrunner, gasoline, Electric ducted fan, kerosene turbine ... they have different costs, performances, expertise needs, and they all work.

You have to appreciate that surfing, windsurfing, yachting, skydiving, skiing, gliding, bobsleigh, slope soaring all achieve amazing speed with no engine at all. Performance is all around us, even though you might not have learned how to use it. eg I have made model dragster cars powered by a bow (like as in bow and arrow) mounted on top.

So: ...Which method of model propulsion do you prefer?
That's the right model for you. Now. The next time, you might prefer to try another type. But we all learn more and grow.

workaccount

T-Maxx wrote: »

I suggest you read through your first post again!:cool:

Please point out the mistake in my first post then.

FuzzyWuzzyWazza

I think what T-MAXX is refering to is that fact that 3 gallons of fuel for the 15 hours is €90, not €270.

workaccount

T-Maxx wrote: »

Because €90 + €150 = €240 ≠ €420

But anyway, like loopingfred said already, in the longrun electric will be cheaper.

(Remember also that for nitro you still need quite a few things to get started, ie glowplug igniter, fuel pump, starter motor, etc.)

FuzzyWuzzyWazza wrote: »

I think what T-MAXX is refering to is that fact that 3 gallons of fuel for the 15 hours is €90, not €270.

Ah I see my mistake now. D'oh!

Rectified.

derry

DennisZ wrote: »

FlightPower EVO 25 5000 6S (22.2v) 25/50C (125A/250A) High Discharge Lithium Battery
http://www.brchobbies.co.uk/?page=shop&action=additem&item=858

~200 GBP (including delivery) ... ~260euro

Yeah except the unknown factors
fork lift or post man whatever squashed the pack
Then you return in post for replacement hassle and other factors like 60 40 euro postage and its back up to 300 euros easy

Credit card charges 6 weeks later for this funny charge under exchange or similar hidden charges some times have seen items like that exceed the 300 euros again from those charges


The item is faulty and as above for claiming replacements



Lipo depending on makes can vary from 50 cycles to 300 cycles

Most cheap made lipos are ~50 cycles and good makes like Kokam that I use cost the double last often ~300 cycles


When the engine in a heli stops and the heli falls and breaks parts the electric wins hands down in costs

When you reach 30% nitro you are hit buy the huge extra fuel consumption compared to 5% glow

But you cant do 3D on 5% nitro and often only 30% will hack it but sometimes 20% if the oil is the ester types

I use Bectra 20% nitro fuel from dublin shop
www.greenhobbymodel.com
and it can keep up with lots of 25% type nitro fuels with less good lubricating oil types as it uses a more slippy oil so it means less power is lost

The reason high nitro is increased is roughly like this

you need double the fuel volume to use methanol fuel to do the same as gasoline fuel but methanol has 20% more power than gasoline and this is due to half the fuel in methanol is oxygen in the molicule and the rest is hydro carbons
Petrol has on its molicule only carbon hydrogen and takes all it oxygen i from the air

you need 9 times the fuel volume to use nitromethane fuel to do the same as gasoline fuel but nitromethane has 100% more power than gasoline and this is due to half the fuel in nitromethane is oxygen iand 30% is nitrogen and only 20% of the rest of the molicule is hydro carbons
Petrol has on its molicule only carbon hydrogen and takes all it oxygen from the air


If you figure in the ratio double for 40% the fuel for methanol and 9 times for 30% for the nitro and oil is held at about ~20 % it becomes clear that 30% nitro fuel types will be about two maybe three time the fuel consumpion use per minute compared to 5% nitro


As nitro methane is about 100 times the price as compared to petrol (but you are getting double the power ) it makes the price per gallon a lot more and works about this way

cheapecst fuel will be petrol
next cheapest will be methanol about 4 times more costly than petrol in runing costs
next not so cheapest will be 30% nitro about 20 times more costly than petrol to use in running costs or about 5 times more expensive than methanol

so a heli that is trainer non acro on 55 nitro will be probably marginaly cheaper than eletric heli with cheapo packs

when doing basic acro the high nitro fuel will be a considerably nore expensive than electric

However at top top end 3 d acro the GLOW will be the lightest most powerful solution and will win the competitions so to compete it will be needed to except the higher costs

Thats with the present tecknoligy

Within two years or three years electric will bury glow and then glow will dissapear graduly from the face of the planet as a nice activity praticed by stone age types that love smoking fumes

Lots of nitro heli guys who start with a nice 5% nitro fuel for basic hover and then ramp up to 30% nitro end up in the poor house and still haven't figured out how this magic sleight of hand has bankrupted them

Then the other half still havent figured out that some places are selling a cheaper fuel per gallon a USA gallon which is 20% less than a UK gallon about 4 gallons UK = 5 gallons UK and think they have a great deal until I explain to them how they got stiffed compared to my Bectra fuel a UK gallon which is actulay cheaper and really does the job

If i want a higher nitro I buy the extra nitro and good EDL oil ( not crappy castor ) from www.greenhobbymodel.com and add it to the formula and change the fuel to what I need often 25% will work better than most other stuff on 30% nitro as most the other fuels have castor mixes and castor creates extra friction

In the present world starting out in heli it often will make more sense to start with electric and stay with electric

If your in glow its probaly better for most to stay there for now and next year change into electric

It will vary from modeler to modeler

A guy who lives in the sticks with no noise issues who wil just buzz about with mild acro can use low nitro fuel and electric and electric might be marginaly cheaper than glow types


glow engines life spans vary from 15 hours for cheapo crap to maybe 50 hours for top engines before the first piston lining is changed ( not cheap 30% the cost of motor ) and another 50 hours then will often require bearing and another liner so 50% the value of engine in parts

Most guys sell and engine at 50 hours use and striff the newbe idiots so they get the clapped out crap


A guy in the city edges with noise issues has to keep noise low with electric

A top 3D guy for now through to 2010 probably has to stay with nitro until 2011 when electric will be superior and then he will change over about 2009 to 2010





Derry

syl77

When the engine in a heli stops and the heli falls and breaks parts the electric wins hands down in costs

That’s why it’s good to know how to auto, saved me last month when I blew hole in the piston...

In relation to Fuel prices for nitro, Magnum Fuel are bringing out a new blend of fuel which be cheaper than it nitro equivalent. I tested it out the 30% heli equivalent there two weeks ago in the states and was surprised at how it compared to 30%, nearly on a par.

Having said that, electric will surpass nitro once the initial price for batteries come down. For helis, electric has better performance in the 600 range but has still a bit to go before it surpasses performance in the 700 range.
But I don’t see nitro fading away completely, you will always have die hard nitro fans..

derry

Is this new magnum fuel blend a fuel blend for the new E85 Ethanol fuel type engines that OS is bringing out

Or is this a lowwer nitro fuel that is forced on them from the USA suffering from low nitro stocks

Seems in Europe there is no low nitro issues to be found and bought a half gallon only a few days ago no problems ( but its ~double the price of the USA)

The latest info I have is the Japanse and europeans are using only 10% synthetic oil but ester based oils which USA doesnt generaly use as they often do PAQ based oil and it reguires 18% PAQ oil to match 10% ester oils

With the ester oils then lowwer 20% nitro will be similar to 30% nitro with PAQ oils from my info

Also USA tend to do nitro content from weight not volume
so 30% nitro in USA would only be ~25% buy volume in Europe

You might know something differnt on that

Derry

coolwings

Couple of things about that:

The ethanol fuel can power a glow fuel engine. But a glowplug will only carry a glow from ignition stroke until next ignition stroke with methanol based fuel. The glowplugs we use are developed to glow only in the presence of methanol, so they are usless with a fuel made from E85.
If a model is to run on E85, it must contain another way to make the glowplug glow ... an onboard battery connected permanently to the glowplug. Four-stroke engine users are familiar with these devices, except with w 4-stroke it comes on when the throtle is reduced to keep the fire going so to speak.
However with E85 based fuel the glow lead must be continuously lit up by the battery no matter what the throttle.
So E85 fuel works, it costs less than methanol fuel, but it has problems ... another 2 extra devices (the onboard glow unit & battery) in the model to go wrong, added complexity and cost, and added weight.
But this has all been figured out already - anyone who used straight methanol based glowfuel (no nitro) knows all about cheaper fuel which has no added complications. You just fit a hotter glowplug and use same way as the higher nitro stuff.

syl77

Is this new magnum fuel blend a fuel blend for the new E85 Ethanol fuel type engines that OS is bringing out

The exact ingredients for the new fuel has not been published, the fuel has not been released yet, still in testing stages so even I don't even know what is in it. Were trying out different 'blends' in the U.S gave our opinion on them.

Or is this a lowwer nitro fuel that is forced on them from the USA suffering from low nitro stocks

They are trying to bring out a lower nitro content fuel which will have the same (if not near) performance as it nitro equivalent. They will keep there main nitro fuel but will have the new fuel at a cheaper cost to customer.

The ethanol fuel can power a glow fuel engine. But a glowplug will only carry a glow from ignition stroke until next ignition stroke with methanol based fuel. The glowplugs we use are developed to glow only in the presence of methanol, so they are usless with a fuel made from E85.
If a model is to run on E85, it must contain another way to make the glowplug glow ... an onboard battery connected permanently to the glowplug. Four-stroke engine users are familiar with these devices, except with w 4-stroke it comes on when the throtle is reduced to keep the fire going so to speak.
However with E85 based fuel the glow lead must be continuously lit up by the battery no matter what the throttle.
So E85 fuel works, it costs less than methanol fuel, but it has problems ... another 2 extra devices (the onboard glow unit & battery) in the model to go wrong, added complexity and cost, and added weight.
But this has all been figured out already - anyone who used straight methanol based glowfuel (no nitro) knows all about cheaper fuel which has no added complications. You just fit a hotter glowplug and use same way as the higher nitro stuff.

Good info, When we tried out the new magnum fuel we were given new magnum plugs, I thought it was a marketing ploy and when asked what was different, was told the glow wire was thicker/stronger and surrounding wall was thinner to give more space around glow wire. These two differences were meant to give a better glow.
Having said that, I tried new fuel for a flight on my O.s 8 plug and it worked just fine.

fannywart

Hi all
I have been out of the model world for the last six years:eek:
Now looking to get started again.
I am wondering what the cost of fuel is these days.
Back when I flew a lot i got 5 to 15 % nitro. At the time the cheapest place I could find for fuel was the model shop in capel st, dublin.

What is the price of fuel now, for what nitro % and from where?
Thank you.