Do we overpower our models these days?

[Robin Colbourne]

Looking at the engine recommendations on older designs, it seems incredible how small some of the recommended engines are.  Even more so when you think that pre-schneurle ported engines were considerably less powerful than more recent offerings plus the servos and receivers were that much heavier.
Some examples:

1. MFA Yamamoto - the box says for .19 to .35. Would a Yamamoto get off grass on a .19, or was it expected to be hand-launched? Similar sized models these days would have at least a .40 on them.
2. Flair Puppeteer -  Engine recommendations are .25 to 40 two stroke.  Has anyone flown one on a .25?
3. Mick Reeves Hurricane (80") The box says a .60
   
   Was it that they were being flown with higher nitromethane content, open exhausts or just a more sedate/marginal flight profile?

 

[Paul De Tourtoulon]

Yes some silly power plants in a Baron, my first one had an OS .25, then an OS .25 fsr, third OS.35fp fourth HP .21vt, now an OS .30 four stroke.

The 'over powered' OS .35FP one was to get it off of the water as it was built as a float plane, all fitted with std 1980's servos battery's and receptors.

Tugs are even worse today.

[Shaun Walsh]

Not just these days. In the mid '70s a friend of mine put a .60 two stroke in a Keil Kraft Outlaw. Its flight characteristics were, to say the least, interesting.

[Jon H]

yes we do, but its not always a bad thing. 

 

My 1/4 stampe called for a 60, but at 82 inch a 60 would be revving its rod off to get in the air. So fine, fit a 120...ok great it will fly nicely enough but again the engine is screaming. Mine has a 180 with a massive prop. I take off at just over half throttle and waft around at a scale speed just under half throttle. If i want to loop i can effortlessly pull round a loop using power instead of diving to excessive speed and throwing it round. The only problem comes when our heroic pilot forgets what the throttle stick is for and leaves the power high the entire time. 

 

We tend to build heavier models these days as we have more stuff to jam into them and modern finishes tend to be heavier as well. Much of the gear is lighter in itself, but we wedge more stuff into models than we used to. 

 

That said, most models are well over powered and flown like it as well. ARTF manufacturers do not help as they see a 70 inch gypsy moth and 70 inch pitts, then recommend the same engine for both as they are both 70 inch biplanes. Clearly, this isnt right as the pitts needs to have loads of power but the moth needs just enough to leave the ground. The old black horse 45cc chipmunk (85 inch but light, 14-16lbs) was flown very successfully on Laser 180s and i sold a bunch of them for it, but i even heard tails of laser 150 and even OS120 4 strokes doing the work just fine. 

 

You are right about the flair pup though. i think one was flown on a 25fp back in the day. My dad's had a 48 and then 52 4 stroke, which was ample, and i have flown them with laser 70's and found them unpleasant. Admittedly a better prop choice (16x5 or something) would have tamed the 70 powered example, but still, it was ott. 

 

Your point about trainers is spot on as well and most are over powered. A plain bearing 30 or 35 would easily fly a typical high wing '40' size trainer, and yet we jam 55's into them. The trouble is smaller engines are rare now and cost the same as their bigger brothers so you would always take the 55 over the 35 at the same price. 

[Wookman]

Absolutely modern models are over powered. Throttles are the answer. Back in the day when the biggest motor you see at the patch was a Webra 61 I did see one in an MR Hurricane. No flaps or retracts but it did fly well. The tooth pick on the front looked a bit odd though. 
The prototype PMP Kerfuffle flew well on a MDS 38. Mine had a Irvine 53 with an inch cut off the front of the fuselage sides. Good fun. 

[Jason Channing]

My Junior 60 has a os 52 running on 30% nitro and flys much better than a 25 size engine.

[john stones 1 - Moderator]

My answer would be No, different folk take/want different things from the hobby. always been that way, does someone (myself included) who states "It'll fly on 1/4 throttle" overpower ?

[Brian Cooper]

Overpowered? Possibly, but I would prefer to call it "adequately" powered.

 

Back in the 1960s, models had smaller engines but they were screaming at full power just to stay in the air. . And if anyone was daft enough to actually want to do a loop, the model had to dive first  to gain enough momentum to get the job drone. . Crazy. 

 

Nowadays we can fit larger, more powerful engines and manage the power delivery with judicious use of the throttle. .  For the right kind of model, this expands the flight envelope and is much more fun. 

 

At the end of the day, it's horses for courses. Some models fly brilliantly with more power. 

For example, a 3D model comes alive with a power to weight ratio of 2:1 or more. But that kind of power ratio would be ridiculous in a lightweight Junior 60. 

 

 Whatever we fly, it is always nice to have some power in reserve. 

 

 

[Paul De Tourtoulon]

20 minutes ago, Brian Cooper said:

Back in the 1960s, models had smaller engines but they were screaming at full power just to stay in the air.

That's also because, carburettors were difficult to get right, we didn't know how to regulate them, and they wouldn't idle for the same reasons.

And the price of the bigger motors.

Don't forget a lot of us started with 1/2 channel radios, free flight and control line, without carburettors and a lot of us with Cox engines, without throttles.

[John Stainforth]

Cox engines were pretty pathetic, even in 1959! We quickly moved on to relatively enormous power of 1 and 1.5 cc diesels!

[Martin Harris - Moderator]

I think an elderly OS40 FS with little or no obvious compression would be similar to a decent .25 two stroke - in which case, I can confirm that a Puppeteer should fly adequately on one for scale purposes but without the “sparkle” that seems to be the expectation these days. 

[kc]

It's very clear that people are building very heavy models these days and then overpowering them too.  There is no need.   A glance at what the electric fliers are doing - building very light models and using just small Lipos will show what could be normal for glow models too.    If you haven't already seen what Ivan Pettigrew  has done look at his website - others have built in a similar manner and produced great flying large models using quite small Lipos.

 

 

 

[Jon H]

4 hours ago, Jason Channing said:

My Junior 60 has a os 52 running on 30% nitro and flys much better than a 25 size engine.

 

it might fly faster, but faster is not better. 

 

1 hour ago, Martin Harris - Moderator said:

adequately on one for scale purposes but without the “sparkle” that seems to be the expectation these days.

 

yes there is an apparent desire for all models to fly the same and as fast as possible. Not sure why though. I will always favour a model with just enough power over one that has a massive excess. I have an 85 inch sport model i use for engine testing. Its like an old precedent fun fly just its 85 inch and about 22lbs. I have flown it on 120, 155, 180, 240, 300, 310, 360, 400 and 450 size engines and it flew perfectly fine on all of them. It was fully aerobatic, and the only real difference was the length of the takeoff roll and the maximum climb possible in a vertical climb. Speed was not impacted as much as you might think, and i found the model more enjoyable to fly when running engines a the smaller end of the range. My seagull challenger is also fairly low powered with an OS 40 4 stroke, but as long as i preserve my momentum i can wring its neck all day long. 

 

I do miss the days of flying an old trainer which only left the ground due to the curvature of the earth. You can learn a great deal more from an 'underpowered' model than an over powered one. 

[Jim Hearnden 1]

7 hours ago, Robin Colbourne said:

Looking at the engine recommendations on older designs, it seems incredible how small some of the recommended engines are.  Even more so when you think that pre-schneurle ported engines were considerably less powerful than more recent offerings plus the servos and receivers were that much heavier.
Some examples:

1. MFA Yamamoto - the box says for .19 to .35. Would a Yamamoto get off grass on a .19, or was it expected to be hand-launched? Similar sized models these days would have at least a .40 on them

 

My Yamamoto was my original trainer & started flying with a fairly knackered Merco 35. That engine had done various duty on a control liner & a airboat where it went swimming more than once. 

One of my favourite models was a Neiuport (not the Flair one) which flew with a heavily silenced OS40FSR with a 12 x 6 scimitar prop. A pig to get off the ground once in the air at half throttle it was fantastic & chugged around looking totally real.

[john stones 1 - Moderator]

Some of todays lecky models are massively powered, I also think as a group our models are lighter than the good old days, having plenty power doesn't always mean it's flown fast, quite common for it to be used for big aeros and vertical aeros, speed is way down my agenda, as I suspect it is for many.

[David Davis 2]

13 hours ago, Jason Channing said:

My Junior 60 has a os 52 running on 30% nitro and flys much better than a 25 size engine.

Interesting.

 

I have built a couple of Junior 60s and assisted a novice in the construction of a third. Mine were powered by a variety of engines including an Irvine 20 and an HP VT 25 as well as a couple of electric motors in the end. I intend to build another Junior 60 over the winter, to cover it in tissue over doculam and to power it by an OS 15, after all the original was a free flight model powered by a 2.5cc-3.5cc engine.

 

There is footage of a Junior 60 powered by an ED Racer here: https://www.youtube.com/watch?v=LXd-IiVED98&t=149s. As the Racer was a 2.5cc engine, I think that my OS 15 should power it.

[Richard Acland]

I remember going to Much Markle several years ago and there was a chap with a Puppeteer with a 120 four stroke fitted to it. He informed me that with that much power he could prop hang the model. My answer was... Why.

[Nigel Heather]

I learned on a Yamamoto, later I had a Puppeteer, both flew really well on an OS 35FP.

 

Cheers,

 

Nigel

[J D 8 - Moderator]

18 hours ago, Jon H said:

 

 

I do miss the days of flying an old trainer which only left the ground due to the curvature of the earth. You can learn a great deal more from an 'underpowered' model than an over powered one. 

   Very true. It was using a motor glider with just enough power to get airborne that got this self taught flyer going.

   DB Rooky major/DC Saber 1.5

[Martin Harris - Moderator]

Yes - my first (successful) trainer was a “Lumpers” recommended by experienced members of my club and built from a MAP plan.  It was 48” span, designed for rough flying in East Africa, built like the proverbial, covered with doped nylon and powered by a “mighty” Enya .15 glow. Although designed for single channel, I  built it with rudder/elevator proportional control using a 2 channel Sanwa set. 
 

I don’t recall ever taking off from the rather small and bumpy Croxley Moor patch but it taught me a great deal from its hand launches and compulsory dead stick landings.  The wings survived vertical dives into the greenery (although the bag of nylon rattled a lot more as I progressed) and the nose area wore more and more Devcon (what happened to that firm?) five minute epoxy after most sessions!

 

No buddy boxing in those days - Brian Cooper will probably recall the tussles over handing him the transmitter - usually just in time for the model to have impacted into the ground again!

[Jason Channing]

21 hours ago, Jon H said:

 

it might fly faster, but faster is not better. 

 

 

yes there is an apparent desire for all models to fly the same and as fast as possible. Not sure why though. I will always favour a model with just enough power over one that has a massive excess. I have an 85 inch sport model i use for engine testing. Its like an old precedent fun fly just its 85 inch and about 22lbs. I have flown it on 120, 155, 180, 240, 300, 310, 360, 400 and 450 size engines and it flew perfectly fine on all of them. It was fully aerobatic, and the only real difference was the length of the takeoff roll and the maximum climb possible in a vertical climb. Speed was not impacted as much as you might think, and i found the model more enjoyable to fly when running engines a the smaller end of the range. My seagull challenger is also fairly low powered with an OS 40 4 stroke, but as long as i preserve my momentum i can wring its neck all day long. 

 

I do miss the days of flying an old trainer which only left the ground due to the curvature of the earth. You can learn a great deal more from an 'underpowered' model than an over powered one. 

It doesn't fly any faster at all, just has power when you need it to go vertical from a standing start.

[john stones 1 - Moderator]

Not sure what the relevance of our early days is, my first one was a gifted Ripmax trainer, repaired and covered in Solartex then hand painted with enamel paint, twas heavy and powered by a tired Enya 19, Like many I learnt to nurse a model of the floor and learnt to correct a stall on take off.

Always suspicious of this type of thread myself, are we implying someone who likes a model that goes a bit is somehow a lesser pilot ?

Are we overpowering models these days ? Define overpowered model.

[Martin Harris - Moderator]

20 minutes ago, john stones 1 - Moderator said:

Not sure what the relevance of our early days is,

I suspect that relating our early experiences will be useful for people new to the hobby to understand where the question comes from…
 

In relation to the OP, when the Mick Reeves Hurricane was first marketed, you would have struggled to find many engines of larger than .60 (10cc) capacity available to the normal modeller.

[john stones 1 - Moderator]

Where and why the question comes, interests me Martin.
There is no doubt propulsion units have improved, and leckys have excelled in that regard.

[payneib]

If the wing bolts and main spar can take it, is anything really overpowered?