Is IC best for larger models?

[Ron Gray]

1 hour ago, Nigel R said:

Rc life doesn't get better than a fast low pass on a twin with 2x 4 strokes.

Although the same with a Laser inline twin on board comes very close, twin inline twins would be awesome.

[Nigel R]

Twin twins, there's a project to aim for...

[Ron Gray]

Got to be a Mossie

[Nigel R]

Or hornet...

[Tim Hooper]

With me it's a matter of convenience and cost.

 

After several years of flying 10S electric models, I found the limiting factor was recharging at the field.  Either I invested in multiple battery packs (to be charged at home), or find a way of field charging using either a) a large leisure battery of b) a small generator.

 

Eventually, the penny dropped that it would be easier to take the engine out of the generator, and stick it in the front of the model!  So I turned to petrol for a while.

 

These days, the big electric models languish in the attic, whilst my self-imposed limit for electrics is a manageable 5S.

 

Oh, and the diesels........😉

 

Tim

[paul devereux]

15 hours ago, Learner said:

Please note I do also have 3s planes and have fun flying those too (just in case the 3s police are waiting to jump on me)

Lol! I agree, you have to be careful here!

Edited July 26, 2023 by paul devereux

[paul devereux]

15 hours ago, Ron Gray said:

I use both electric and IC with my largest leccy model being one with 110” wingspan running on 10s. 99% of F3A (2m wingspan) are electric (10s). So I would say that there is not definitive answer apart from EDF!

Regarding costs, I carried out an exercise based on my use of Laser engines and used the 155 as a yardstick (10s equivalent) and was surprised to find very little difference over a 5 year period.

I just looked up a 10s battery- several hundred pounds! Can that be right?

[aidan mcatamney]

I fly both and love both.  

[Paul De Tourtoulon]

9 hours ago, Ron Gray said:

Got to be a Mossie

Good luck with it, I built two and flew them, not any more, one sold off now hanging in its owner's garage, the other I donated to the local aero club also hanging from the ceiling,,,

[Ron Gray]

8 hours ago, paul devereux said:

I just looked up a 10s battery- several hundred pounds! Can that be right?

2 x 5s  5000mAh 70C approximately £100

[leccyflyer]

10 hours ago, Tim Hooper said:

With me it's a matter of convenience and cost.

 

After several years of flying 10S electric models, I found the limiting factor was recharging at the field.  Either I invested in multiple battery packs (to be charged at home), or find a way of field charging using either a) a large leisure battery of b) a small generator.

 

Eventually, the penny dropped that it would be easier to take the engine out of the generator, and stick it in the front of the model!  So I turned to petrol for a while.

 

These days, the big electric models languish in the attic, whilst my self-imposed limit for electrics is a manageable 5S.

 

Oh, and the diesels........😉

 

Tim

I think for models requiring 10 cells it becomes increasingly attractive to go to petrol power and accept the challenges offered by effectively silencing those power plants. All the claims about those models sounding more realistic are a bit off, since there is nothing realistic about the harsh bark of a petrol 2 stroke. My current limit is for 6s1p packs, but in practice some of those models which I'd used 6s1p packs in, have turned out to be very happy indeed flying on 5s1p 5200mah packs, with loads of power to spare.  5 cell batteries are massively under utilised, it looks like the market goes straight from 4 to 6 cells, in terms of number of sales.

 

For an  only occasionally flown larger model, accumulating a number of 5s1p packs then does make it a possibility of putting those in series to give 10s1p packs.  The same goes for 8 cell models, with more abundant 4s1p packs. I'm coming to the conclusion though that for those larger models petrol is the most viable power source. Haven't done it yet though.

[Nigel R]

19 minutes ago, leccyflyer said:

All the claims about those models sounding more realistic are a bit off, since there is nothing realistic about the harsh bark of a petrol 2 stroke.

 

I don't think anybody suggested a cheap and cheerful petrol 2 stroke sounded realistic.

 

Not even sure realistic was mentioned with regard to glow 4 strokes, better, yes, realistic, no, still nothing like a Merlin or DB600, or even a Lyco/Conti really. But better, yes.

[Paul De Tourtoulon]

It's a shame that no professional in the modelling world has looked more closely at the vibration problems of petrol engines from 20cc and upwards and a look at the noise that they make, a serious silencer system would make them more acceptable to model flyers and locals living near to the fields, and looking at the lead some of us put in the nose of our warbirds, weight won't be a problem.

 

I did fit a couple of stainless steel 26cc boat silencers to my Dle 20ra, it did look a mess but sounded like an old 10cc properly silenced from the 1960's.

[Graham Bowers]

9 hours ago, paul devereux said:

I just looked up a 10s battery- several hundred pounds! Can that be right?

If you read it on the internet, it must be true 😉

 

However it depends what question you ask.

 

It's commonplace to use two 5S LiPos connected in series to make a 10S !

[leccyflyer]

12 minutes ago, Nigel R said:

 

I don't think anybody suggested a cheap and cheerful petrol 2 stroke sounded realistic.

 

Not even sure realistic was mentioned with regard to glow 4 strokes, better, yes, realistic, no, still nothing like a Merlin or DB600, or even a Lyco/Conti really. But better, yes.

It's a frequently occurring theme that electric models are described as soulless and lacking the authentic noise of an IC engine. MY point is that those model engines aren't even remotely authentic - yes, even the four strokes are nothing like a full sized Merlin or Pratt and Whitney. The closest you can get to a realistic sound is a large sound system fitted to - yes and electric powered model.

[Chris Walby]

This is a highly charged debate that has no big end and we just have to hold differential views before motoring on to something more productive. Its just all torque and hot air that does not help lift the discussion due to some people just dragging us back down to the ground level. Can we just elevate ourselves and reach for the skies to promote the hobby rather than dive and roll about with no common porpoise. 

 

PS No answers here, just lost in the long grass doing my own thing.

[Frank Skilbeck]

39 minutes ago, Paul De Tourtoulon said:

It's a shame that no professional in the modelling world has looked more closely at the vibration problems of petrol engines from 20cc and upwards and a look at the noise that they make, a serious silencer system would make them more acceptable to model flyers and locals living near to the fields, and looking at the lead some of us put in the nose of our warbirds, weight won't be a problem.

 

I did fit a couple of stainless steel 26cc boat silencers to my Dle 20ra, it did look a mess but sounded like an old 10cc properly silenced from the 1960's.

My mates Moki radial is very smooth, doesn't sound too bad either 😁

[Ron Gray]

Laser 200 in-line twin sounding nice

 

 

[Martin Harris - Moderator]

Neither is better in every case but one or the other will suit individual circumstances. 
 

That 200 sounds superb Ron!

[Chris Walby]

16 minutes ago, Martin Harris - Moderator said:

Neither is better in every case but one or the other will suit individual circumstances. 
 

That 200 sounds superb Ron!

Dream on Martin, there is absolutely no chance of getting that under 82dB, but as the BBC would say "other clubs are available".

[Jon H]

2 hours ago, leccyflyer said:

The closest you can get to a realistic sound is a large sound system fitted to - yes and electric powered model.

 

Never seen/heard a sound system with the power required to make any impact when more than about 20 foot away. 

 

And again, i am not suggesting that my 360v gives my Sea Fury that centaurus sound, but its better than it sounding of nothing at all and certainly better than a petrol 2 stroke. Yes, even i would take electric over petrol 2 stroke. 

 

I have posted this before, and there is a solution. its just really expensive. We need to reduce the rpm of our props as we then loose that annoying whine. Scale that up and you get this beast. The flying is pants (40g pull ups not recommended for a Sea Fury) but the model sounds incredible. I just need to scale it down. sigh. 

 

 

[Cuban8]

Sounds very nice if somewhat poorly presented in terms of scale type flying. Still that horrible whine when throttled up.

 

Just can't get that lovely exhaust crackle and growl can we? https://www.youtube.com/watch?v=JzGmheYRb44

Edited July 27, 2023 by Cuban8

[Paul De Tourtoulon]

I agree the sound systems in a plane disappears at 50 metres, although the big Vario helicopters with their sound system are very convincing.

[David perry 1]

7 hours ago, Jon - Laser Engines said:

 

Never seen/heard a sound system with the power required to make any impact when more than about 20 foot away. 

 

And again, i am not suggesting that my 360v gives my Sea Fury that centaurus sound, but its better than it sounding of nothing at all and certainly better than a petrol 2 stroke. Yes, even i would take electric over petrol 2 stroke. 

 

I have posted this before, and there is a solution. its just really expensive. We need to reduce the rpm of our props as we then loose that annoying whine. Scale that up and you get this beast. The flying is pants (40g pull ups not recommended for a Sea Fury) but the model sounds incredible. I just need to scale it down. sigh. 

 

 

How is this done?  A gear box i understand, but what engine?  It does sound terrific

[Ron Gray]

Moki radial?