Is it worth while to convert your nitro heli to electric yet.

I read a post on here by one member saying he would have paid $1000USD in fuel rather than <$500USD on batteries. (using 2 gallons a week).

Certainly gets you thinking. At what price would it be worthwhile converting your 30-50 nitro to electric.

Could you just take out the engine, clutch and fuel tank and replace it with a suitable motor mount, electric motor, battery and ESC. That would be simple to do.
Or would you require changing the main heli gear to get the correct RPM, or installing an extra couple of gears. Would a motor and suitable pinion using your existing main gears be OK to get the correct rotor speed. This would be the cheapest option if available. My Trex 450 seems to have a very small pinion with a large heli main gear.

I get 15 minute flights with my 30 nitro (Caliber 30). Batteries to even give you 10 minute flights may be $300-400USD at present. At what price per pack would it be worth converting. I normally do (3) 15 minute flights at a time, so I would want 3-4 Battery packs available at any one time. A Thunder Power 5000MaH, 22.2V 6S is around $300USD. What sort of flight time would you get in a Trex600 or 30 sized nitro conversion with one of these batteries.

Also how heavy would a nitro conversion be compared to a bought electric (such as the Trex 600). If you want an electric now, buy a Trex 600 as parts etc, are cheaper. But with the number of 30-50 nitros out there, will people consider converting them rather than buying a new electric.

I know some have converted a few. I saw a video of a 90 conversion. But I wouldnt think it cost effective to convert a 90 sized machine yet. Maybe a 30 though.

Ive just bought a new engine for my 30 nitro, so it got me thinking. Therefore I wont be converting just yet. But it may be the last nitro heli or heli engine I buy. I would like to buy a larger electric, or convert my 30 nitro in the future. But only if its more cost effective than running a nitro.

Anyone done the maths and converted a 30-50 nitro for cost sake yet.

As I mentioned before, Ive had one battery pack swell after only a few flights (more likely my fault), but recently one of my new packs with only 40 flights on it is loosing power, I have taken all precations with my new packs. They are not well known brands, but that would certainly pxxx you off if they were $300 packs.
I had water in my fuel bottle once, threw out 1/3 of a gallon of fuel ($5USD). No big deal. But ruin a battery pack somehow, or get bad pack at $300-$400 and it is a significant loss. Hell I just bought a brand new OS 37SZ-H engine for $150.

Some may factor in where they can fly. Eg: a one hour drive to the flying site as opposed to 10 minutes to a nearby field or park. Theres no doubt electric seem more acceptable in that respect, even though they may be just as dangerous.
I flew my small Trex450 in many public grass areas (not busy areas, but public areas none the less) and the few people that were nearby didnt blink an eye. If it had been a noisy nitro they may have considered it less desirable to be around.

There must be a level where electric is more cost effective. Are we there yet FOR THE 30-50 SIZED MACHINES. If not at what price per battery pack, price per ESC, flight time available / per cost of pack, would you guys consider it time to convert.

When I do convert Ill miss the smell of castor oil, but look forward to the cleaner running heli, and occasional tuning / /water in fuel / hole in tubing / messy oil, etc, problems of glow engines.

For scale flying, I think electric would be a good conversion, better sound and a better look with no smoke - and no oil to clean off.

But for sport / 3D I think you have to factor in crashing to your equation. One crash could totally wipe out your very expensive battery pack(s). The WORST crash I have ever seen on a nitro required a new crankcase for the engine - about US$30.

Apart from that, I would really miss the smoke and noise from my Raptor - brute, in-your-face power is what it's all about!!

It is really up to you. Batteries will probaley cost in the upwards 300-500 a piece. That will give you only one 10 minute flight. Then you got to sit and re-charge for 2 hours. Okay, so just get another battery right. Well it takes like 4 to have just 40 minutes of flying. 4 times 500= 2000 [X(]. Then addd your engine. At least 150. And don't forget that ESC, 200. WOW, we are really gettting up their. Oh, and maybe a BEC, 40 more dollars. AND SO ON AND SO ON...... Electric is cool but i really can't afford it. Doing the math, gas makes more sence. You can probabley get about 10 flights on a gallon which is about 10 minutes depending on the needle setting and how you fly. That is 150 minutes of flying per gallon. Now you can by 13.6 gallons for 300 dollars (the price of one battery). 13 gallons will give you 130 flights or 1,300 minutes of flying. Now add that extra battery you were going to get on their and you have 26 gallon, 260 flights, at 2,600 minutes. Most batteries that i have seen loose there charge between 50-100 flights. But with gas, you never have to wait to charge .

Generally speaking, a nitro helicopter is heavier than one built from the ground up for electric flight. The main reason being that nitro engines vibrate considerably more than an electric engine. Because of this, a nitro helicopter has to be built more robustly compared to an electric model to make sure the vibrations don't physically stress the helicopter in a negative way.

Case in point, my .50 size T-rex 600 is lighter than my e-converted Century Hawk Pro which is a .30.
Now, depending on what you're doing, I would not rule out conversion all together depending on what components you decide to go with.

The main benefit (and main headache) of doing nitro to electric conversions is that with electric, you have a huge choice in motors, and you can tailor your power to anywhere from mild scale like flight, to ballistic power that would put any nitro engine out there to shame.
The trick is trying to figure out what motor, gear and voltage combination will work for your conversion. Generally, a nitro engine revs higher than an electric motor simply by design (that's not to say you can't get an electric motor to rev as high as a nitro engine, but most motors in the size range you need for a helicopter conversion have lower rpm since they generate more torque this way). Because of that, gearing changes are usually necessary, but it's entirely dependent on the model in question.

Theres nothing that says you have to go out and spend $200 on a speed controller and $200 on a motor unless you're obsessed with having best of the best and top brand names. There is a lot of good chinese imports that are significantly cheaper than a lot of the more popular and very expensive brand names. Obviously, as with anything, you get what you pay for most of the time, and though imports may not be totally lacking in quality (indeed, some of it is quite good for its price), but if something goes wrong, you usually have no manufacturer to stand behind the product for warranty issues. So you do take some risks.

When I converted my Hawk Pro, I only spent $120 on the power system ($60 motor, $60 ESC). With the setup I used I was even able to use the default clutch bell as the main gear, I simply adapted it to fit on the motors shaft. RPM is not as high on the head as I would like, and a bigger main gear would solve that, but I can't find any that will fit with the hawk pro, which means I either need a hotter motor or more voltage. Obviously, there are more suitable motors for not much more than what I paid, I simply chose what was available to me at the time at the lowest possible price (this was a bit of an experiment on my part to prove it was possible). Works like a charm, see the video link at the end of my post.

The main cost for any electric setup is, of course, the batteries. You need roughly 6 cells to put a .30 size nitro conversion into the air (due to weight). I think the big mistake a lot of guys do is they go out and buy a single 6 cell pack. Here's the problem, if you crash, or if you damage the pack in any way, you're out a single $200 battery. I would personally suggest to buy 2 high capacity (e.g 4000+ mAh) 3 cell packs and connect them in series instead of one 6 cell pack. The benefit of this is that if you happen to damage one pack, you're only out 3 cells instead of a full 6 cell pack, your overall costs will be lower should you need to replace a battery.

The obvious disadvantage is that you need to charge 2 separate packs for a single flight. A bit more of a hassle, but if you've been in electric flight for awhile you'll realize it's unavoidable. By using smaller packs you also have the benefit of being able to use those same batteries in smaller models or planes that don't need 6 cells. The other thing is with electric, your average flight time will only be about 6 to 8 minutes on 4400 packs, shorter than you'd get on a nitro machine.

Not including other standard electronics (servos, gyro, etc.) it only cost me about $300 to convert my hawk pro to electric power. This isn't a powerhouse setup, but I didn't want that for the hawk anyways (it's certainly no 3D machine, that's what I got the t-rex 600 for ). But it does fly quite well on such a modest setup and would be great for a scale ship.


In the end, it comes down to what you want. I only converted a Hawk Pro as something to do, I knew it wouldn't be a powerhouse simply because of it's weight. If you want a good flying, good performing electric model, you're better off buying one designed specifically for electric flight. Easier to work with, less hassle to adapt motors, better power to weight ratios, etc.
If you just want to convert a nitro ship to electric for the hell of it (I love to tinker personally ), it can be done, and for not as much as most would have you believe, it just depends on how much performance you want and how much you're willing to shell out for it .

Below is a video of the very first flight after my conversion on my hawk pro. Keep in mind nothing at all had been trimmed at this point on the model (that's why the tail is all over the place). I was flying in -15 weather at the time (which is why I did not bother fixing the tail till it's nicer out, gyros don't like cold weather, no sense in trimming it in the cold and then having to re-trim it once warm weather got here). Anyways, enough excuses, here's the link:
http://www.truenorthernhobbies.com/m...lightfeb16.avi


To answer your final question, do I think it's cost effective to convert nitro to electric? No, not really. If you want stick banging 3D performance, electric, while considerably more powerful than a nitro helicopter, will cost you considerably more upfront. And at the rates that we deplete our lithium batteries, you're lucky if you see over 100 cycles, so I don't even think that the electric over the long run is cheaper than nitro argument really applies either.

archiebald

Good point. Ive seen some sound generators for RC, for sale. It would be better to have an electric scale heli with a speaker putting out full scale turbine or piston engine sound, rather than a smoky 2 stroke.

Also crashing a $300USD battery pack is a real consideration.

Cambo

I agree with you and others on the cost. Personally I still think its too expensive.

Im trying to work out the other members figures. I cant find the thread now but he said he pays $30 a USG for 30% nitro. He goes through 2 USG a week. and spends $1000 a during his flying season. (which works out at 16.5 weeks (4 Months)).
He spent under $500USD on batteries (im guessing only 2 packs then, as theyre about $300USD for a TP 5000Mah pack. So maybe $500 for 2x 4000Mah packs)

Working on your figures of 10 flights a USG, he would do approx 20 flights a week for 16 weeks (say 320 flights).
That would require his packs to last 160 cycles each.
Mine are certainly not lasting that. I think 50 to 100 cycles is more reasonable.
What about the top brand 22.2V 6S lipos, would thay last 150 cycles.

Also 20 flights a week would be 3 flights a day, so you would want 3 packs at least, (unless you wait 2-3 hours for the pack to cool, and be recharged).
Now 3 packs at $300USD each is $900USD and that may only give you 3x 8 minute flights, not 3x 10-15 minute flights.

Im not trying to imply he was wrong, just trying to work out his figures because I cant see how hes better off going E rather than nitro.

credence,

Thanks for the info.

Your info is great as you may be one of the few that not only has converted a 30 sized nitro heli to Electric, but you also have a Trex 600 to compare it to.

I have seen a Trex 600 in a shop and thought my nitro may have looked a bit sturdier. (just guessing though). Didnt think they may have built them that way to compensate for the vibration associated with operating single piston engines.

The fact that they are heavier than an original electric may actually put off many people converting their nitros to E unless the battery prices drop QUITE CONSIDERABLY, as even a Trex 600 only gives you 8 minute flight times with a $300USD battery.
Also Ive seen a Trex 600 for sale for around $500 - $600USD (Heli, ESC, Motor, BEC). So with the price of batteries so high You would be better off buying a Trex 600 than converting a 30 sized nitro.
Also Trex 600 parts are much cheaper than the nitro heli parts I believe.

Im surprised at the cost of batteries for these things. Also at the cost of ESC and motors. It may just be me, but Ive just bought an OS37SZ-H engine for around $150USD, which to me sounds a reasonable price for such an engine. But for some reason I just consider $200USD for a brushless ESC, or $150USD or for a brushless motor quite expensive. Why are they so expensive to produce, or are the prices inflated for some reason.
As you say you may be able to pick up an ESC and motor cheaper than those prices, but with a heli the size of a Trex 600, it would have to be reliable.

Thanks for the video link. Its certainly a bit noisier than my Trex 450.
So what sort of flight time do you get from your (30 Hawk conversion) and what capacity Lipos are you using. Are you using 2x 3S 4000MaH in series. I guess you would only get about 5 minute flight times.

Im happy with my decision to buy a new nitro engine rather than convert it to electric. But maybe in a year if prices fall it may be a different story.

Planeheli,
I have not done much since my initial maiden flight on my hawk because of the weather here. I've yet to even trim the bird out. Because it's not a 3D flyer, i'd actually suspect flight time to be closer to 8 minutes on the 4400 mAh packs, though i've yet to fully test it.

At any rate, it's grounded at the moment because I ripped the ESC out to stick it into a .40 size plane that we recently e-converted. Once the weather gets a bit better i'll be going back to the hawk and setting it up properly. Naturally, i'll videotape the whole thing .

At the moment, it's rainy and kinda cold, not ideal flying weather . I can't really do proper trimming in my garage as was shown in the video because it's too small of a space. If you'll notice in the video the helicopter was difficult to hold in a hover because of the constant rotor back draft from hovering in such a small space, not ideal for trimming the model!


As for the prices of the motors, I think much of it is severely overpriced, and I say this as a retailer of many asian imports so it's not like i'm just pulling figures outta my arse.

A good example would be the new Welgard motors we got in recently. Everything about these motors screams good quality design and quality control nearly comparable to AXI motors, yet they're a fraction of the cost of the AXI motors. Not everything that comes out of china is garbage (though much of it IS garbage, so you gotta be careful).
I make it my first priority when dealing with overseas manufacturers to make sure everything is of acceptable quality (and consistency, more importantly) among their product line. If something does not meet my own expectations in regards to it's relative price point, I discontinue carrying it, simple as that. I won't sell garbage to my customers.



Oh, and yes, the hawk pro is a noisy beeotch. Theres like 3 gears in the main drive assembly, plus the tail is gear (not belt) drive. All that gear lashing makes a good deal of noise. I kind of like it though, makes it sound mean..

credence

Let us know how the flight times and heli work out once you get it sorted.

Its 30-34C (85-95F) here all year. A bit hot to go out midday. If you let me know your address perhaps I could mail some warm weather in exchange for some cooler. LOL.

I like the idea of E Planes too. I have 2x 40 sized planes, one running an OS46AX and the other OS55AX. Again this is where the price point of electric conversions come in.
I paid about $105USD for the OS46 and $120USD for the OS55. Very reasonable prices for such engines I thought.

However batteries, ESC and Motor to get similar performance and flight times would be very expensive.

What plane have you converted and at what cost and performance.

Id be interested in hearing your results for it as well as your E heli conversion when the weather improves.

One advantage of owning your own Hobby Store.

I will look out for the Welgard motors you mentioned.

Cheers

Yeah, i'm definitely my own best customer . Best part about being a retailer is you get to see (and often play) with all the new stuff. Can't really say I hate selling hobby items!

I've converted 2 .40 sized planes to electric power, both with excellent results.

I'll actually give you a link for the first one I converted. It was a Great Planes F4U corsair. Real great flyer, pain in the ass to take off and land though. Don't think i'll be doing any more gull-winged planes for awhile!

http://www.truenorthernhobbies.com/f...topic.php?t=45

Actually, the motor and controller you see in this plane is the same one being used in my e-hawk. When I retired my corsair, I took the electronics out of it and used them for the hawk.

The second plane i've converted (just recently) is a Tower Hobbies MK2 .40 trainer. Pretty impressive model actually for such a low price. Using one of the Welgard motors, the plane gets airborne on only a single 3 cell, 4400 mAh pack. Plane is approx 5 or 6 lbs (got it rough it out since I don't have a fancy digital scale).
Obviously, because it's a trainer it doesn't need a ton of power to get off the ground, but nonetheless, I didn't think it'd fly on only 3 cells, certainly surprised me! This is where the 60A Dynam ESC (That was being used in my hawk pro) has gone right now.

It's a very smooth, gentle flyer, very relaxing .

If you wanted to convert a .40 trainer, you could probably use the packs you use for your t-rex (just connect them in parallel to up the flight time and amp capacity).

This way, the only cost is a motor and speed controller, which, if you go non-brand named, would cost you roughly what you'd pay for a nitro engine .



I will being doing a post on my hawk e-convert once I get it all setup. The post will be in the century forums here though, not in the main heli forums.

credence,

Thanks for the link.

Im surprised it worked out as well as it did. I really thought a 40 sized plane would be under powered and require more batteries.

You said it was overpowered with the batteries in series. I wonder how it would have flown with the batteries in parallel to give longer flight times.

You also mention that the trainer runs well on only one 3S pack. What sort of flight time do you get with that. Could you put 2X 3S packs in parallel to increase the flight times without throwing out the trim.

Perhaps E flight with 40 sized planes is closer than I thought. Of course my Trex 450 batteries are only 2200Mah 3S, but if flight times were reasonable with two in parallel.

Quote "Yeah, i'm definitely my own best customer ". Reminds me of a story I heard about a wealthy person buying a Jewelers shop in London. Turnover and Profits were high, but dropped off considerably for some reason after he bought it.
He may have finally realised that he was its largest customer before he bought it, spending several million pounds a year.

Will look out for the Eheli review.

Cheers

The corsair was flown on 22 volts and was seriously overpowered. But it wouldn't fly on only 3 cells as then it was way underpowered.

The "right" combination would probably have been 5 cells, but I don't have any 4400 mAh 2 cell packs, so 6 cells (3 x 2) was my only choice. Worked out well enough on the corsair, and you can clearly see in the video in the thread I linked you to above, the plane certainly had no trouble pulling it's weight around.

The trainer on the other hand is, if anything, underpowered on only 3 cells. Only reason I say this is because I have trouble taking off from the rough field I fly off of (same one as seen in the corsair video). The grass (especially now when everything is soggy after winter) provides a lot of resistance and the plane can't generate enough speed to get airborne when it's bouncing around. I'll be trying some larger props and bigger wheels to see if they help matters any.

If I take off from pavement the plane has no trouble getting airborne, and certainly, once it IS airborne, it has more than enough power to fly and climb at a pretty good rate, which is why I don't want to increase the voltage. The model flies nicely once airborne, just needs more power to take off from the (very poor) field I fly from.
4 cells would probably be perfect for the model all around, giving it plenty of power, but I haven't got any packs I can use to make up the 4 cells in voltage without dropping my pack capacity (my 4400 packs are all 3 cells, i've got 2200 2 cells, but they're only rated for 12C, and 2200 isn't very much for a large model like that). So i'll make do with the 3 cells.

Given current flight times and the fact the model, once airborne, will quite literally fly with almost no power, flights could probably be stretched to 15 minutes or more. Under full power, i'd guess around 8 to 10 minutes. Can't say for sure since it's a new model. Had to correct some CG issues after the maiden flight. It's all ready to go for it's next flight now, just need the weather to cooperate .

Obviously, what power will fly what plane varies very much on the design of the plane as well. The Tower Hobbies trainer happens to be very light and have a lot of wing area, so it doesn't take much to get it airborne (this is, actually, true of most trainers). But there's a lot of .40 sized models that are real pigs and require a lot of speed to get airborne, so it all depends. The corsair needed double the voltage to get airborne compared to the Tower Hobbies trainer, and they're nearly the same size (Corsair is heavier, though).

In my experience, it's much easier (and cheaper) to convert a plane to electric than a helicopter. Helicopters require quite a bit more power than a plane does to get airborne. With a plane, the model moving through the air and the wings airfoil does much of the lifting, so you can get away with quite a bit less power.
With a helicopter, ALL the power is being supplied by the motor and the comparatively small blades with their airfoil generating the lift. On top of this, the motor is always under near full power, so the entire electrical system is taxed more heavily.

This is why the same motor that made the corsair near ballistic in power is only adequate for the Hawk Pro on the same voltage. It's tricky stuff messing with electrics, a lot you need to take in and consider when deciding on what you need, but it can be fun, if a bit frustrating at times .

credence,

Thanks again for all the info.

Will look out for your heli conversion results.

I prefer the 40 sized glow planes. If I ever tried a 60 or larger would probably prefer that so best I dont.

I was thinking at todays battery, ESC, motor prices perhaps starting with .20/.25 sized Electric planes would be a better starting point at this time. Could use my Trex 450 batteries.
May have to look into it at some stage.

Cheers

Yep, it would be easy business to convert a .25 model, and power requirements would be quite low .

Models in the 40 to 55 inch wingspan make nice e-converts and don't cost much to do. They're great for grab and go flying too .

You mention the electric conversion doesn't spool up like the nitro powered version and they don't sell a big enough gear to speed it up. Did you know the spur gear on the jack shaft comes intwo sizes? The Falcon uses a bigger gear and would speed up your head speed. Or do you need to slow it down?

I reread your post.... yes the Falcon gear would increase your head speed. The gear is bigger to make up for the peak torque being at a lower rpm for a .46 engine as compared to a .32.

Evan, that's good info, i'll look into trying one.

The problem was that, to start with, the motor i'm using is a high torque (thus low kV) motor. It's really meant for plane use and not heli use.
The second problem is that Century uses a very strange pinion module and I can't find anything bigger (i.e 26 or 28T) that will match it. It never occurred to me to check for a bigger spur.

Thanks for the tip on the gear. I'm going to see about ordering one. As it is, the head speed is not terribly low, but I certainly would not mind it being a bit higher .

Evan, I re-read your post.

Are you referring to the small pinion gear that is in place under the main gear? I notice this comes in two sizes, 13T and 14T, not sure if that's what you were referring to.

I'm not sure if going up 1 tooth would be enough, it's certainly worth a shot though .