Max Thrust Riot - Upgrades

[Keith Miles 2]

Posted by colin wray 2 on 30/11/2019 09:21:02:

Been flying my Riot all year Iuse 2200 lipo as suggested Had no trouble with rudder/elevator linkages or servos up to now everything has worked well The only problem has been the u/c mounting which has cracked possibly due to my landings All in all Ihave been impressed with the model

Had no trouble (up to now) or have no criticism or concern?

Oh, and I forgot to add that my pushrods, as well as being tight and misaligned, are also too long and will need to be shortened as others have apparently discovered.

I maintain that tight and poorly aligned control runs are, and always have been, a fundamentally bad idea for reasons previously stated. Although, possibly, a less likely cause of a “mysterious” crash of a single battery electric model in view of the larger current pulled by the motor and the advance warning that should be provided by the reducing motor power it is, nevertheless, not something to ever be complacent about, in my opinion. In cases such as this, where it could at least be improved, it again smacks of corner cutting to me and complacency on the part of manufacturers and/or designers.

Models never go out of control and/or crash for no reason and the old chestnut “interference” is probably hardly ever the cause (especially these days) but probably more often the result of model assembly or design flaws, poor maintenance or a component failure that, perhaps, could and should have been foreseen.

[Keith Miles 2]

Update!

Centring the rudder and elevator servos required moving Tx sub trim to just 4 on the rudder but 111 on the elevator!(Why not re-adjust the output arms, I hear you say? Read on!).

That done, my pushrods were also then too long (I must have another one of those one in a hundred models previously mentioned!).

No problem, thought I, I can now simply loosen the clamp screws on the “improved” servo output arm terminals (which seem to have replaced the z-bends of the original design), slide the pushrods out, snip off the required 10mm and put them back. No chance! Struggled for over an hour trying to loosen the screws. No joy. Then tried to get the servo output arms off their splines. No joy. Tried to raise the servos which are very tight in their slots. No joy. Had to resort to snipping off the necessary 10mm at the threaded end of the rods and then replacing both clevises with screw clamped type ones which, luckily, I’ve had lying around for centuries! So, I shan’t be needing the four spare screw- on ones supplied!

If a servo fails, it seems likely that I will need to replace the entire model! Maybe that’s the idea?

I then wanted to realign the elevator horn with the clevis by rotating it inwards but after removing the three horn screws, neither side of the horn assembly would come away from the elevator and fearful of wrecking the elevator, I gave up on that as well! Seems like both halves of the horn assembly might have been glued on!

The good news is that a Spektrum AR400 Rx sits nicely on Velcro in the front right hand corner of the servo bay, all of the control throws have been initially set up on three rates and a load test of the servos (which was a concern due to those “high friction” pushrods) seems to show that all is well current-wise, which is a relief!

I shall not be bothering with connecting the “gimmicky” tip lights or wasting a 6 channel Rx to do so! It ain’t a scale model and I don’t intend to fly it in the dark!

At the time of writing, I now just need to fit the prop, adaptor and spinner (for which there are no spares as was, apparently, the case previously) and set up the throttle.

On that point, the prop supplied seems to be a “cloned” APC and is 11 x 5.5 rather than the 12 x 6 apparently included previously.

Hmmm....didn’t somebody mention failure of the 40A ESC after about twelve months?

I will be interested to see, therefore, in due course, how much current is being pulled by my model and how it flies.

In that context, I shall be setting aside, for the time being, the two APC 13 x 6.5 props that were purchased at the same time on a recommendation that it would improve performance, which it no doubt would, but for how long I wonder?

P.S. At least replacing an ESC would seem to be a simple job!

 

Edited By Keith Miles 2 on 01/12/2019 13:24:26

Edited By Keith Miles 2 on 01/12/2019 13:27:25

[Shaun Walsh]

I haven't had any problems with the esc over the last 12 months flying and the stock motor draws 27 amps with an apc 12x6. Yes, changing the esc and the motor are both very easy.

[SCRCS]

Is it possible to use a watthour meter to check if a servo is drawing excess current because it is binding or is the current resolution too big on a watthour meter to register. Not sure what a typical servo current is but watthour meters seem to have a minimum resolution of 10 mA.

Edited By SCRCS on 01/12/2019 14:39:31

[Shaun Walsh]

Posted by SCRCS on 01/12/2019 14:39:05:

Is it possible to use a watthour meter to check if a servo is drawing excess current because it is binding or is the current resolution too big on a watthour meter to register. Not sure what a typical servo current is but watthour meters seem to have a minimum resolution of 10 mA.

Edited By SCRCS on 01/12/2019 14:39:31

You might be better off with a dedicated servo power analyser.

[Keith Miles 2]

For load checking I have, in the past, used a cobbled up lead and connector block and measured with a Fluke meter. The latter is a very expensive item used in my job as an electrician before I retired, so I don't recommend anyone buying one of those just for checking servos!

Recently I was given a a little square digital tester with LCD display that has JR/Spektrum IN/OUT sockets. seems to lack accuracy, though, and before checking the Riot, it was giving constant fluctuations "off load" of between 125 and 200mA! Maximum reading, connected between a NiMH battery and Rx was 400mA whilst moving the servos.

By comparison, my glo-powered Wot4 ARTF set up (measured with the Fluke) connected similarly, with all FIVE servos being operated together, would peak very briefly at about 300mA before settling at about 60mA "off-sticks".. In use, I was finding that I could comfortably get 7 or 8 15-minute flights from a 1000mah Rx pack with only 50% of the Rx battery charge being used. So, about 60mah per flight!

Whilst I believe, therefore, that the estimated servo current of just rudder and elevator on the Riot seems to be quite high by comparison, I would acknowledge that the servo current draw of any electric model, especially where only one battery is used, is probably pretty insignificant compared with the motor current! Hence, I have decided to bite my lip and just accept it and hope that the servos don't fail prematurely due to those less than free moving pushrods!

We seem to have gone off the topic of "upgrade"somewhat and I will accept some blame for that!

Or maybe "upgrade" could still be applied in a different context i.e. the correcting of a number of apparent manufacturing flaws without which I, for one, would already be giving this model a high score.

Looking forward to a test flight when the weather warms up a little!

 

Edited By Keith Miles 2 on 03/12/2019 00:31:23

Edited By Keith Miles 2 on 03/12/2019 00:34:12

Edited By Keith Miles 2 on 03/12/2019 00:35:41

[Chris Walby]

I just don't quite understand why all the modifications are needed.

We took my son's Mk1 out of its box (yes its build to a price, but that's what we wanted) and flew it close to 800 flights. We both passed our A tests and then moved on to different models.

It is what it is, a high wing trainer that is quite crash resistant and yes you could modify every component, but it will essentially be a Riot.

IMHO better repair it like for like (as the manufacturer intended) and devote your time and effort making your next model to move onto.

Parts failed due to poor manufacturing - none

Parts changed due to pilots error (mostly me) - Fuselage, 3 x motors, 4 x props, aileron servo, elevator servo, about 3 sets of U/C screws and a bit of trim on the rudder due to the wonky fuselage.

PS I could never understand why people made them 4S as the 3S2200 seemed perfectly okay to me as its messing about with props and watt meters for what gain - the ability to rip the wings off?

[Keith Miles 2]

Chris,

I totally agree with you about those who try, perhaps, to convert models into something other than the purpose for which they were designed! For example, those who suggest that a model of this type is underpowered because it won’t do a ballistic vertical climb immediately after take-off is just silly stuff (and, sadly, quite common) and not a valid criticism.

On the other hand, inherent flaws in a model cannot, and should not be ignored especially where most, if not all of the flaws could be corrected without increasing the price significantly, if at all.

A model is only good value for money if it is built at least reasonably well and flies likewise.

in my case, I would have been happy to pay a bit more for the following:

1. A top rudder hinge that was not off-centre.

2. Pushrods that are significantly less tight in the tubes to reduce the load on the servos.

3. Pushrods that are not too long, avoiding the need to shorten them.

4. Pushrod clamp screws at the “improved” servo connector that can actually be undone in order to achieve 3 or in order to remove a servo.

5. Removal of the need to scrap two supplied clevises and fit different ones due to 3 and 4.

6. Servo output arms that do not resist all efforts to pull them off the servo splines in order to reposition them OR

7. Servo output arms that are fitted in the correct centred position to begin with to avoid having to eventually make a massive adjustment to the Tx sub-trim.

8. An elevator control horn that aligns with the pushrod and clevis or is, at least, capable of being repositioned.

After 7 years in production one might have reasonably expected all past issues to have been resolved by now and without introducing any new ones!

Currently, in my view, the model still seems to fall somewhat short of the title of “Plug N’Play” and it is too easy for the experienced modeller to accept and then correct (or attempt to correct!) any faults. This may not be within the skills or experience of the many beginners within this model’s intended market, however, and in my opinion may start them off on the wrong foot in learning to determine what is acceptable or good practice in terms of model assembly and/or construction.

I will reserve my final judgement until I have flown it but it does sound, by comparison, that the flying experience has been largely positive.

Ignoring what will be a much shorter flight duration than an IC Wot4, if it flies anything near as well, as many are saying it does, then I might feel a little less frustrated!

[Capt Kremen]

Out flying in the glorious sunshine today, a fellow club mate was about to fly his 'Riot'.

Doing his pre-flight checks, (as we all conscientiously do ... don't we!!!) .... one of the original aileron clevis literally disintegrated in his fingers as he checked their security! This person is a relative newcomer, not from a modelling background. As others have said or alluded to, how many newcomers purchasing this model would literally fly it as is full of all the shortcomings in quality of items, construction, supplied servo, motor, esc etc.? then suffer a unexplained failure or worse whilst flying. Put it down to their inexperience when it is the quality of the product all along that is at fault.

Once ALL the issues with the components and construction are rectified, the 'Riot' is a great hack model, but as it comes out of the box ... ??????

[Shaun Walsh]

Strangely enough, mine was just fine "straight out of the box" apart from the battery box design. Was I just lucky?

[Colin Carpenter]

My original Riot is still flying on all original hardware ! A clubmate got a V2 spare fus and we had the pushrod problem but easily rectified ! Today the ESC failed completely on its second flight and wallop ! That was a Mk 1 ESC but it's only done less than 100 trips ! Because he's a learner and flies on a fixed throttle setting I wonder if it helps it fry  ! My throttle use is up and down like a yo yo flying aerobatics and no problems ??? Colin

 

Edited By Colin Carpenter on 03/12/2019 17:46:04

[Neil67]

Ditto Shaun's experience. Yes the battery box is an issue but with the right throws it can be fun to fly. Another menber of my club flies with a 4s - didn't change anything including century's advice to take out nose weight, no issues. I have gone down same road and if anything the c of g with the battery forward works better than the 3s. Yes I know there are not all the same - I use an overlander. Quite sensitive to c of g, mistakenly put the battery, 3s, back instead of forward one day and had an interesting tail heavy flight!

[Keith Miles 2]

Interesting discussion, this.

I estimate that an electric powered Wot4 ARTF could be made flight ready for between 200 - 230 quid plus battery plus you get to choose the quality of the gear that goes into it.

Admittedly you would need more tools and more time than should be necessary to put a Riot together and some adhesives.

All I can say, having owned 6 IC powered ARTF Wot4s (none having being lost to model or radio failures or faults) is that for the Riot to be a realistic rival in my book, I am expecting it to fly at least as well and for all of the components to last a reasonably decent length of time to justify the initial cost saving? Anything less could amount to a false economy, in my opinion, and would still make the Wot4 a better long term investment.

As for those looking for a basic trainer, I would suggest that there are already some better alternative options.

[Keith Miles 2]

I would, in fairness, correct what I said earlier in this thread and during a period of frustration!

I suggested that if one of my fuselage servos fails, I might need to replace the model. I have just realised that, in fact, I could just cut the pushrod at the servo connector to allow removal of the servo, and then replace the servo, servo output arm (presumably included), the pushrod connector (hopefully available as a spare or included) and the pushrod.

And of course, at worst, I would only have needed the fuselage assembly, anyway, and not the entire model!

Apologies for the tantrum!

[Keith Miles 2]

Posted by Colin Carpenter on 03/12/2019 17:45:13:

My original Riot is still flying on all original hardware ! A clubmate got a V2 spare fus and we had the pushrod problem but easily rectified ! Today the ESC failed completely on its second flight and wallop ! That was a Mk 1 ESC but it's only done less than 100 trips ! Because he's a learner and flies on a fixed throttle setting I wonder if it helps it fry ! My throttle use is up and down like a yo yo flying aerobatics and no problems ??? Colin

Edited By Colin Carpenter on 03/12/2019 17:46:04

Sounds like another poor quality ESC to me.

And it sounds like another example, possibly understandable, of a flyer reluctant to believe it!

One would expect the ESC to be capable of handling continuous full throttle especially in the air and provided that airflow has not been restricted in some way or too large a prop fitted.

I believe somebody quoted 27A on a 12x6 so the standard 40A ESC should be adequate.

As I have said before, I was puzzled as to why my recently purchased model came with an 11x5.5 prop.

Packing error or a quick and cheap fix for another inherent flaw?

I have yet to borrow my brother-in-.law’s clamp meter to check mine before I test fly it and I have also ordered an APC 12x6 for comparison.

[Denis Watkins]

Posted by Colin Carpenter on 03/12/2019 17:45:13:

Because he's a learner and flies on a fixed throttle setting I wonder if it helps it fry ! My throttle use is up and down like a yo yo flying aerobatics and no problems ??? Colin

 

You are right Colin

An ESC does the least amount of work at Full Throttle

As at this setting, the battery is almost connected directly to the motor

At say 50% throttle, the ESC is working hard maintaining the lower output from the supply, and getting hot

Tootling round at low throttle makes the ESC work hard and could account for frying

And is why it is best to go up some margin on ESC Amp rating

 

Edited By Denis Watkins on 04/12/2019 08:16:10

[Colin Carpenter]

Thanks for that Denis ! Amongst my group of fliers I’m the only one that seems to have no reliability problems. Club mate had his third crash yesterday after an earlier glitch. Flew straight and level into the bushes 😩Tx back to service agent twice and they can find nowt wrong. 🍋Rx in all planes going in ! I use them and have had no problems on oo’s of flights ! Dunno ! I’m aware that all foamies gear is basically rubbish but how do you explain some people always having trouble and others don’t ? Dunno ! In boating you could look inside a model and see who would have trouble but all foamies are pre installed ! Colin

[Keith Miles 2]

Denis And Colin,

First and foremost, let’s not blame the user in this case!

Quite simply, the gear should be fit for its purpose.

If Riot ESCs are regularly failing despite having the correct prop and motor fitted and no other modifications have been made to the model which might affect it, then the ESC is likely to be the problem.

One should remember, as well, that the Riot is also marketed as a trainer so, by definition, it should not need to be flown at high throttle just to save the ESC!

Also, if anything, at a given throttle setting, engines, motors and ESCs will run cooler in flight and use less energy due to the greater air movement and “unloading” of the prop. It is one reason that many full sized aircraft have variable pitch props using fine pitch for take-off and a courser pitch in the cruise. It is a form of gearing and is more fuel efficient at varying speeds and loads and kinder to the engine.

I suggest that you check the current of any electric model at low and high throttle settings and note the values. At most, there should only be a brief increase in current when going from low to high throttle before settling back and even then the ESC should be well able to cope with any such transients.

The only other things that I can think of that might cause a premature failure of an otherwise suitable and decent quality ESC in a non-modified set-up is a faulty motor, worn motor bearing, stiffness in the motor shaft or an inherent lack of sufficient airflow around the ESC.

An ESC rated at 40A in a sufficiently well designed model should be able to operate continuously at 40A let alone the 27A at full throttle being quoted elsewhere and a 25% allowance would seem to be a common margin applied when determining the required rating.

 

Edited By Keith Miles 2 on 04/12/2019 10:21:44

Edited By Keith Miles 2 on 04/12/2019 10:49:55

[Keith Miles 2]

Update!

Recently contacted Century with my observations and received a very prompt reply. Hats off to Mark Tilbury (co-designer) for politely responding to my observations and comments although he did not necessarily agree with all of them! I accept that some were a matter of opinion.

Since then, I have finally given my Riot a couple of test flights.

Decided to fit an APC 12x6 rather than the 11x5.5 now seemingly supplied with the later kits. Full throttle draw was 30A which seemed about right, based on the experience of other owners.

As I have said earlier, I was hoping for performance at least reasonably comparable to a similar sized and equivalently powered IC Wot4, especially given that the Riot is much lighter. Currently, however, the Riot falls well short of the former and I speak as an intermediate flyer with just an “A” certificate. A “hooligan” I most certainly ain’t!

I, too, would currently take the view that the model seems barely adequately powered, if not underpowered, or maybe it’s too light! With only a 10-12 mph headwind, it needs full throttle to maintain reasonable headway and, at that setting, will also “hover” with only about 30 degrees of “nose up”. Similarly, it “hovers” to a landing, in these conditions, with power required all the way down. Book figures for control throws are, indeed, VERY conservative. With twice the minimum suggested throws (full rate) the model is still relatively tame and it absolutely refuses to spin, despite my best efforts. Balance is fine. Trim is fine. Pitch control is fine but rudder needs considerably more throw, I reckon. Oddly, despite even throws, the model also seems to roll much more quickly to the right than the left.

I have also checked prop speed with a tacho and am getting 7600 rpm on the 12x6 which, instinctively, seems a bit low to me, even allowing for the relatively lighter weight of the Riot compared to my similar IC models (3.5lbs versus 5-6lbs) all of which turn 11x6 -13x6 props at around 9000-9500rpm and none of the latter models could be considered over powered, by any means. It ain’t my style!

I would entirely concede that the Riot represents excellent value for money for what you get but, maybe, amongst other “adjustments”, 4S is, indeed, the way to go with the Riot before it becomes worthy of its title?

Strange, isn’t it, how opinions and experience can differ so much?

[Peter Beeney]

Keith,

From some previous experience with a number of Riots, (Mk I) and some enthusiastic schoolboys I’d tend to agree with you that your model, as standard, may possibly be lacking in power somewhat.

I think that I’d be seriously inclined to start at the beginning and do an unloaded motor revolutions check; if I were using a fully charged 3S in good nick, I’d expect to see around 10,700rpm. I’d be looking for a 10% drop to around 9, 600, your 7,600 figure is very close to 30%. In my opinion the (only) 30 amps of current flow, at these revs that is, does not really tie in with this either so I’d guess a coat of further looking at is required.

If you consider 4S then you can get up to almost pylon racer style performance. I did a post on this a while back, I had to mod the ele and rudder servos and pushrods considerably to cope with the faster speed and therefore control surface loadings. I could probably dig it out if you wish…

Good luck.

PB

[Jeffrey Cottrell 2]

Peter

Did you find that earlier post?

Interested in your mods to rudder and elevator.

Cheers

Jeff

[Peter Beeney]

Jeff,

It actually came to light quite easily, I’d reposted in 2016 in Nigel Heather’s thread about the Ruckus. My thinking is that as it’s probably the same motor powering that model it may be of some interest.

Not really much detail as how I actually did this, though, I simply cut the holes at the back end by guesswork and fixed the servos in. Soldered the extension leads and made the appropriate fairly solid pushrods. Not too clear there either but I did use a BlueBird on the rudder as well. Playing safe! The rudder did get quite a lot of heavy stick, so to speak…

And by way of additional information I would also remove the metal weight in the nose as a first move; I faithfully follow the advice of the gentleman that coined the succinct little adage - ‘For success, add lightness’. All this tinkering moves the CoG back a bit further even, and probably gives the elevator a bit more authority, all good and useful stuff as far as I’m concerned.

Re, the theoretical speed figures I don’t know what the actual speed is but it’s certainly quick; relating to that, as I remember it weighed just over 3lb so at 33.3 amps of motive power that equates (I think..) to around 180 watts/lb, fully charged . It does show……

This is the post:

I have a ‘hack’ Riot which has flown on 4 cells for quite some time now. It’s certainly been through the wars, so to speak, but still keeps tramping on, actually it’s still rather lively; and it’s also been modified a bit to cope with the extra poke.

The motor is ok, but it is fairly basic, it has a plain oilite bronze bush bearing, they are not that easy to repair but I’ve vandalised mine more than once; and oddly enough, I can find every size of bush on the web except that one. Same with the rear end circlip, we have a very friendly motor accessory shop handy and they have every size of E clip bar the Riot motor! There is a compatible ‘Donkey’ motor from HK, exact same fit and very much cheaper; lower kV rating, though, 720 from memory. So a 9 x 7 might be ok here.

When I changed to 4 cells I straightaway found the rudder and particularly the elevator were very iffy, so I decided that the push rods were now not up to the job and I moved the servos to the rear end and used short stout metal push rods. Much better, but the elevator could still be a bit reluctant, especially at the end of a flat out power dive very close to the ground. Interesting times! Installing a Blue Bird 380 metal geared fixed it, now total confidence in any situation. The aileron servos have never blinked, though, despite having the max travel available. Like every thing else, they often have to work hard when I go flying, I sometimes tend to get a bit carried away in the heat of the moment…

I changed straight to a 9 x 7 ACP i/c prop, this was excellent until the motor started chattering loudly, on landing I found the bearing had knocked itself out and was mostly plastered around the motor on the inside of the fuz in the form of a black gunge. I replaced this with one from a motor with broken lugs, changed to a 9 x 6 ACP and it’s been fine ever since. I’m not too keen on the Century prop driver either, so I changed that too.

I tend not to generally consider watts and stuff too much, I just use a tacho and check how hot it’s running. Incidentally, if the motor starts stuttering cut the throttle immediately; the power system is being subjected to a full current flow and could quickly complain by rapidly overheating.
The motor is rated at 850 kV and 4 cells fully charged = 16.8V. 850 x 16.8 = 14280 rpm, which is about what I clocked for the no-load rpm. On the 9 x 6 it’s 12000 rpm, which gives a theoretical in the air speed of about 68 mph. The nominal voltage figure of 14.8 gives a speed of about 60 mph. The pack is a 2.2Ah Nano Tech, I fly for around 5 - 6 minutes if using a lot of loud pedal, but there’s always some ampere minutes left. I’d estimate a current flow of around 30 amps, perhaps, everything stays nicely cool even after a lively flight; but there is a good cooling air flow through; very important.

The next move might be upping the ante to some Hyperion higher voltage 4 cell packs. A little bit more get up and go and these have a reputation for being able to hold the voltage up under load, too.

Hope this useful for anyone who is looking to improve the performance a few shades!

Edit. Just for interest, I’ve just checked the current, and with a fully charged pack it’s 33.3 amps. So up to about 560 watts then.

Good luck..

PB

[Keith Miles 2]

Peter, many thanks for the reply. Your own observations chime with my own thoughts but I now have some good news which seems to confirm them!

Flew again today in zero wind. Still needed almost full throttle throughout for very sedate performance, especially for even basic aerobatics. It flies smoothly enough but in my view, in 3s guise (will come to that shortly) it would be better described as a relatively docile trainer rather than the “Riot” of a model that one might reasonably expect based on its description. Out of the box, and despite being significantly lighter, it is absolutely NOT, as some have suggested, and as I was therefore hoping, a rival to a similarly sized Wot4 ARTF on the smallest recommended IC engine (40). Nowhere near!

However......

As I was about to pack up for the day, one of my fellow club members found a 4s of similar dimensions in his collection, albeit lower capacity, and with the same Deans connector!

Initial bench test showed 37A at full throttle on the 12x6, so a power increase from the original 330w (90w/lb) to almost 550w (150w/lb)!!!

So, there was only one thing left to do, of course!

Let’s just say that NOW it flies like my previous Wot4s but without being “ballistic” as I might have expected and I can now, once I’ve sourced some suitable 4S batteries, get back to practising for my “B” Certificate!

It seems that there are suitable LiPos available that should drop into my already modified battery bay and I am also pleased to report that an after flight inspection did not detect any overheating of either the motor or the ESC.

I have subsequently put sets in the elevator and rudder pushrods to improve the joining angles, increased the full rate rudder throw to 35mm (so it should now be capable of spins and stall turns!) and also increased the full rate throws on elevator and ailerons by 50%.

I have yet, purely for interest, to tacho the prop but suspect that I will now also see something in the region of your suggested figures!

I might, in due course, try an 11x5.5 prop which, it seems, might be beneficial in reducing the ESC and motor loading without significantly affecting the performance.

We’re getting there!

 

P.S. Peter, just read your last post after my above one! I have taken note of your comments regarding servos and control surfaces! 

😊

Edited By Keith Miles 2 on 01/01/2020 22:03:00

[Peter Beeney]

Keith, thanks in turn to you for your answer, you certainly seemed have arrived at one solution!

I have to say though, I would still have some reservations here. It almost seems to me as though on 4S the model performs like a normal Riot on 3S; and as you mentioned practising the B routine I would consider the standard 3S Riot ‘as is’ to be very suitable for that; and, indeed, for eventually taking the test itself.

Certainly I agree the 11 x 5.5 will undoubtably reduce the current flow to at least some extend, and even possibly the performance may slightly increase because of the higher prop speed; and because of the reduced current required the duration will extend. Although whether any of this will be actually noticeable may be questionable too, although I’d always be up for some suck it and see.

Lots of different aspects to consider re. motors etc. but I think any discussions would soon take the thread way too far off topic. Perhaps a ‘anything goes’ type of thread would be more suitable sometime…

Many Happy Landings.

PB

[Keith Miles 2]

Peter,

As far as the performance issue is concerned I can only refer back to that 7600 rpm I was getting and the resulting (and not really surprising) very marginal power available for straight and level let alone for aerobatics!

The manual states “sensational flight performance” and “capable of a wide range of amazing aerobatic manoeuvres to thrill the experienced pilot”. Unless mine is not typical of others, I would certainly not describe it in those “sensational” terms but rather as, in standard guise, a gentle follow-on trainer probably best flown on light wind days!

Indeed, the initial control throws suggested would also seem, in the Riot case, to be aimed more at a complete beginner (although it doesn’t say that) rather than an experienced flyer of any level. In particular, a mere 12mm rudder deflection seemed well short of spin or stall turn territory and, indeed, it was! Fine for taxiing, though!

I also remain curious as to why, despite no changes apparently having ever been made to the motor or ESC since the model was first introduced, the supplied prop was relatively recently changed from 12x6 to 11x5.5. I did ask Century that question but was told simply that they found that it “flies better” on the latter. Hmmm...wonder why it took so many years to reach that conclusion if, indeed, that is the reason?

We have a Riot XL in the club (which funnily enough, a similarly disappointed original owner apparently sold to a fellow member very soon after its first few flights!) and several standard Riots so it might now (belatedly) be interesting to take a closer interest in those, for comparison with mine!

In the meantime, on with the 4S battery search and a bit more experimentation and tweaking!

Many thanks for the input!