Mick Reeves Gangster 63 Lite

[Nigel R]

Makes the flying side of things far more rewarding than just pottering about, having a goal for any given flying skill on any given day. The trimming process, when done, the difference is to make a good airplane a great one. 

 

70FS or Laser 80 would be great in the larger Chilli Wind. Food for thought? As Peter says, you might find the Acrowot a touch disappointing now you are flying something that genuinely goes where you point it...

 

[Jonathan M]

I'm now happily talked out of building the Acrowot!

 

The Chilli Breeze will most likely be my next build, and my first from a plan (keen also to know when Mike Delacole's new lighter wing design will be ready).  The larger Wind would probably be the more sensible size, but I want a suitable model for my OX35AX, and also interested to see how I'd get on with pattern aeros with a smaller model.

Another future build could be from the original Loaded Dice plan?  Although the original is quite big at 66" and heavy at 8.25lbs with foam wings etc, maybe a 90% scale version and/or constructed slightly more lightly with a built-up wing (with/out retracts) etc would prove a good stable-mate to the Gangster with a similar-sized engine?

 

Out of interest, I ran the cubic wing loading numbers for the different options - lightest at top, heaviest bottom (conventional loading in brackets):

 

Gangster 63 Lite - 5.45 lbs - 7.7 (17 oz/ft2)

Loaded Dice 66" - 8.25 lbs - 8.9 (22 oz/ft2)

Chilli Wind 58" - 5.25 0lbs - 10.7 (21 oz/ft2)

Chilli Breeze 48" - 3.30 lbs - 10.8 (18 oz/ft2)

Tornado 62" - 6.25 lbs - 11.1 (23 oz/ft2)

Bullet 50" - 4.75 lbs - 12.9 (23 oz/ft2)

 

However one cuts it, the Bullet is the heaviest by far, followed by the Tornado!  The Breeze looks quite respectable despite its small size, and a very slightly smaller or just lighter Dice would be an interesting proposition...

 

 

Edited December 20, 2021 by Jonathan M

[Andy Stephenson]

Jonathan,

Someone was advertising a new unused OS32F on BMFA classifieds, it's a steal at £65, it would be perfect for the Chilli Breeze.

I had an Irvine 36 in mine with a home made pipe, it was a bit over powered.

[Nigel R]

By contrast I found the 36 was perfect for the breeze ?

 

Jonathan, most of the 60 sized aerobats can be finished at around 7lb if you are careful with wood selection and go with all built up construction. With a fixed U/C you can get under 7lb. My twin (avatar) has about the same amount of wood and metal as a 60 size piped classic aerobat, and is 6-3/4lb dry (fixed gear). WCL comes out around 10, in that case.

 

Next in my queue is this one:

 

Aussie Challenger

 

It is a slight respin on the Steve Burgess Challenger, which Sarik carry the plan for. Slightly smaller than the Dice; slightly older too. It was first flown at the changeover from the bullet/tornado style of model to the slower / lighter Wind style models.

 

A couple of other simple but effective designs on outerzone:

 

Gitano

Rocket

 

Rocket has been built by a few of the forum members, I think.

Edited December 20, 2021 by Nigel R

[Jonathan M]

Thanks Nigel, interesting plans to peruse and analyse - and look forward to seeing your Aussie Challenger build!  But here's a question:  aside from foam-cored wings giving faster build times and more robustness, how complicated would it be to design and build a lighter built-up wing structure?

 

As to the OX35AX being potentially over-powered for the Chilli Breeze (Andy, or not, Nigel) what would happen - in terms of model aerodynamics, P/W ratio, structural strength, etc - if I got the plans scaled up by say 10% from 48" to 52/53" but kept all material thicknesses etc the same?

 

 

Edited December 20, 2021 by Jonathan M

[Jonathan M]

In the meantime, after another half dozen flights today with the the Gangster, I'm slightly flummoxed by the fact that - now with proper wing incidence of 0.8° and the CG 15mm back (to 111mm) from where I originally started (96mm) - it no longer falls naturally into a spin with just full up elevator and rudder.  Unless I apply aileron to help instigate a proper immediate spin, the model just wallows and flops around in all sorts of chaotic ways, even with less than a quarter of a tank of fuel left, until I eventually stop embarrassing myself and restore normal flight.  Have I simply got too little elevator (+7/-8mm) for the job?  Or is this something to do with having progressively tuned the model from a negative wing incidence, nose-heavy starting point (where I had no problem entering the spin on just elevator and rudder) to where it is now?

 

Edited December 20, 2021 by Jonathan M

[Peter Jenkins]

Jon

 

Did you get the classic stall with the nose dropping with the original wing incidence?  

 

The elevator throws sound too small to me but it depends on how wide the elevator is.  I would expect something like 25 to 30 deg up elevator for a stall and then spin.  

 

It can sometimes require a smidge of aileron, usually in spin but, I'm told, sometimes out spin, to get the aircraft to spin.  Main thing is to get the aircraft to stall and for that you are looking for a nose down pitch. 

 

Try moving the CG forward till you get your earlier aircraft behaviour.  If that produces a spin with just elevator and rudder then leave the CG there.

 

Alternatively, you could set up a spin condition where you can mix some aileron (start at 5%) with full rudder.  Wait for the stall before applying rudder as the nose is dropping.  As both wings will be stalled, the small amount of aileron applied with full rudder will not cause a wing to exhibit a snap entry by flicking up!

 

Mixing aileron provides a repeatable amount of aileron and a fixed spin rate compared with manually pushing the aileron stick.

 

If you try spinning the model when inverted, remember that to spin left (as you look at the aircraft) you need to apply right rudder stick and, if you need aileron, left aileron.  Left aileron always rolls the aircraft left regardless of whether upright or inverted.

 

Good luck.

[Nigel R]

Built up wings are easy enough to design. There are a million examples of the breed already ?

 

I wouldn't think a 10pc stretch would need any structural change. Wood weight goes up by 121pc though. As does wing area. 

 

Aerodynamics shouldn't change. You might be able to get a very slightly lighter wing loading if careful. 

[Jonathan M]

Peter

 

Yes, the original setup produced an immediate classic nose-drop and spin.  I realise now that this specific problem has almost nothing to do with incidence or CG changes as such, as it also had 12mm of elevator travel each way.  I'd decreased this progressively (as I moved the CG aft) to a latest range of 6mm up and 7mm down, which is simply too little!  As I'm happy with the overall setup and don't want to move the CG again (was 96mm, now 111mm), the solution is to start increasing the elevator travel back in 1mm steps until I get a clearer nod and proper stall, with the model falling into a rudder-only spin as before.  If it won't, then I'll have to start fiddling with aileron-assistance.

 

 

Aha, the inverted spin... I'd best leave that for a little while! ?

 

Cheers

Jon

 

[Jonathan M]

11 minutes ago, Nigel R said:

I wouldn't think a 10pc stretch would need any structural change. Wood weight goes up by 121pc though. As does wing area. 

Aerodynamics shouldn't change. You might be able to get a very slightly lighter wing loading if careful. 

 

That makes sense:  the increase in wood weight would equal the increase in wing area, but the weight of all the other major parts (engine, fuel, servos, battery, etc) would stay the same.  As these are a big percentage of any AUW a lighter loading would certainly ensue, and my guess is that the OS35AX would then be just the right engine...?

 

 

21 hours ago, Andy Stephenson said:

Jonathan,

Someone was advertising a new unused OS32F on BMFA classifieds, it's a steal at £65, it would be perfect for the Chilli Breeze.

I had an Irvine 36 in mine with a home made pipe, it was a bit over powered.

 

Andy, that's now gone.  However I also have a NIB SC32 in my very modest collection, which was the original plan if I was to do a built up wing at 48".  The prototype flew with an  OS32 on such a wing but used the Irvine 36 with the heavier foam wing.

 

I actually have a set of foam wings at 48" good to go, but am wary of either being impatient (my reason for ordering the wings) or having too heavy a model.

[Nigel R]

If you have the 48" foam wings, I'd just go ahead and use them with the engine you have, don't second guess the outcome too much, the Chilli designs are sensibly put together. You could always fit a free flowing exhaust (weston minipipe?) to the sc32 if you feel it needs a bit of a bump in power. Many flyers do make a lot of making models 'as light as possible' but don't be afraid of a moderately loaded wing, wing loading is simply one parameter of an airframe, think about what some of the warbirds and jets are carrying, by comparison the Breeze is a flyweight. I don't think using the foam wing will add much overall weight to a Breeze. Basically, just go for it with what you have, is my take.

 

As for the Gangster spin/elevator, you can set up rates (or flight modes, or whatever) so that you have 'normal' maneuvers with less movement and 'spin/flick' with more?

[Peter Jenkins]

Jonathan

 

Nigel R has made the point I forgot to make.  You must use a rate for aerobatics and one for spinning.  I hear that people don't like using switches in flight.  Well, that would cut out use of retracts and flaps then.  Sorry, flying proper aerobatics requires you should make use of rates and expo to give you the right movement for the phase of flight you are in.

 

As you have already found, optimising elevator movement for aerobatics doesn't cut the mustard when it comes to spinning.  If you use one elevator rate that enables the aircraft to spin it will work against prrecision in all other aerobatic manoeuvres.

 

I use 3 rates:  aero; land; spin.  Actually, I can and do use 2 other rates, if needed, for slow and very slow rolls.

 

Bite the bullet and you will find that you can have the best of both worlds?

[Andy Stephenson]

Jonathan,

 

Much has been made of increasing the amount of elevator used to initiate a spin but more rudder is important too and always spin to the left as the engine torque and prop vortex helps in this direction.

[Jonathan M]

Gangster

 

Point well made guys.  Not averse to using rate switches (use them aplenty on my DLG for launch and flight phases) so after a bit of fiddling with moving the elevator clevis closer in and setting up a sprung two-way switch (top-left, same as my DLG launch one), this is what I've got to flight-test next:

 

Normal Rate 50%:  +6.5/-7.5mm (appx 10° each way) - recently proven for smooth flying with rearward CG etc.

'Stall' Rate 100%:  +12/-13mm (appx 30° ea way) - previously proven for prompt stalling, spinning and immediate recovery.

 

I'll leave setting up a switch for landings till later - my brain can only handle one variable at a time! ?

 

Andy, I had considered whether the rudder had a part to play?  Whether it's gearing resulted in any blow-back, but this wouldn't a factor at such very slow speeds.  And whether it's travel wasn't sufficient, but its got an easy 50mm each way (same as the MR instructions and the original Gangster) whereas it binds at 55mm, so ruled this out.  Thanks for the advice to alway spin left and for the reasons why... I do like to understand why! ?

 

 

Breeze

 

This really ought to be in a separate thread (I think I've already got one somewhere!) but you're completely right Nigel.  No point in me overthinking things or making more work for myself - just get cracking with the foam wings!

 

I think with the slightly heavier foam wings I'll stick the OS35AX in it.  I can always limit throttle to say 80-90% at first, but it would be good to have the reserve power.

 

 

Edited December 21, 2021 by Jonathan M

[RedBaron]

To get into a spin it is necessary to be flying slowly and then the aircraft must be subjected to some yaw component either by rudder or say an unexpected gust in the air. The yaw then effectively causes one wing to stop flying whilst the other wing valiantly tries to do its job. Yaw + one wing not flying = spin. The only value of up elevator is to slow the aircraft.

 

To get out of the spin:

Centre the ailerons and elevator (do not attempt to recover from the spin by ailerons else you may end up spinning in the opposite direction)

Reduce power 

Use the rudder to counteract the yaw and let the speed increase until both wings are flying properly

When the aircraft stops rotating with judicious use of elevator recover from the resultant dive. The dive may be very steep so care is needed in pulling out of it even when the ground is close.

Then enjoy the rest of your flight.

[Andy Stephenson]

The technique I use for spin recovery is at the beginning or or soon after the start of the last turn is to neutralise the rudder and ease off the elevator at the same time as applying complimentary aileron which turns the manoeuvre into a downwards roll, then it's much easier to come out in the right direction. Done subtly this way, it's enough to make it look expertly controlled.

[Nigel R]

Spins are funny things.

 

Careful application of opposite aileron can induce a flat spin. Sometimes this is what you intend. Some airframes will do it easily. Some, not at all. Essential to try it with a lot of height at first. It can take a little power, opposite rudder, and some height to fully recover. Or, a lot of height. Be prepared!

 

My Chilli Wind will do a perfect inverted flat spin; but right way up, not a bit of it. My Aeromaster will do one the right way up - but not inverted. Both will take a rather nerve wracking number of full turns to recover with neutral controls and no power. Numerous other models I have never succeeded in getting a flat spin.

 

A little right thrust ought to make things about symmetrical on spin entry.

 

  

1 hour ago, Jonathan M said:

leave setting up a switch for landings till later

 

I'd expect landing setting to be about where 'high rates' puts things anyway. If you have enough elevator to get into a spin you definitely have enough for a flare out.

 

Edited December 21, 2021 by Nigel R

[Peter Jenkins]

Sorry RedBaron have to disagree on your post above.  The problem with saying you should fly so slowly that application of rudder, or as put it a gust of air, causes the spin to start by stalling one wing is it  ignores the fundamental use of elevator to cause the wing to stall. 

 

The reality of spinning is that to spin you need first to stall the aircraft since you have no way of knowing how slowly the aircraft is flying.  When wind speed is greater than stalling speed the aircraft will have to appear either stationary or flying backwards relative to the ground.  So, for a proper spin entry, you aim to stall the wing and for that the essential control is the elevator.  Once the wing is stalled, application of rudder will cause a yaw and the inside wing will remain stalled while the outside wing is unstalled.  This causes a rolling motion into the spin while the rudder keeps the yaw going and the maintenance of full up elevator keeps the inside wing stalled.

 

For most model aircraft, and for all aerobatic aircraft, spin recovery is almost always achieved by just centreing the rudder and elevator.  You can use a dash of opposite rudder to stop the spin dead but it's just that a quick pulse.  I have yet to fly an aerobatic aircraft that needs more than that unlike for a full size where you apply full opposite rudder and progressively more down elevator till the spin stops.   Only use aileron once the wing has stalled and the aircraft is falling into the spin if aileron is needed at all.  Most aerobatic aircraft will spin with just elevator and rudder but a few will need a touch of aileron - not much.  Too much aileron will speed up the spin making recovery on the desired heading more difficult.  If you apply full rudder and aileron to enter a spin it usually results in a flick entry with the outside wing rapidly kicking up.  This is not recommended for spin entry.

 

Andy Stephenson - I would not recommend use of aileron to assist in spin recovery as you do not want to turn the spin recovery into a downward roll.  You are aiming for the spin rotation to stop, and then to allow the aircraft to accelerate vertically downwards to build up speed and then gentle application of up elevator to perform a 1/4 loop to level flight.  Avoid pulling back on the elevator immediately the spin has stopped as with insufficient air speed you could cause the wing to stall and spin again.  I can assure you that using aileron in recovery would not make the spin look expertly controlled which is why it isn't recommended and you would lose a lot of points in an aerobatic competition for doing that. 

 

As Jon is aiming to do his BMFA B with this aircraft, then spin recovery is as I have described above with the added requirement to exit the spin on the same heading as spin entry.  To do that, you need to know how long your aircraft will take to stop spinning.  My Wot 4 (the balsa and glow powered version) takes 3/4 turn from centralising controls to stop spinning.  So I made the recovery for a 3 turn spin at 2 1/4 turns.  With my 2 m aerobatic aircraft spin recovery is within 1/8 turn of centralising controls.  Alternatively, using a pulse of opposite rudder with elevator centralised will stop the 2 m spin immediately at the expense of causing the aircraft to look as if it's been kicked so I prefer to let the aircraft recover with centralised controls.

 

 

 

[Peter Jenkins]

Oh, one more point, I also would say spin in the direction in which the aircraft wants to go whether it's left or right.  Prop wash is just one of the factors as there may be a very slight twist or difference in surface trueness in the fuselage or wing leading to a predilection to spin in a particular direction.  The other factor that influences spin entry direction is bank.  It is difficult to be sure that the aircraft's wings are exactly level at spinning height.  Any bank, no matter how small, will cause the aircraft to turn.  We don't normally notice this as at normal speed the radius of turn is large but as the aircraft is slowed down to the stall, the turn becomes more obvious and the spin will usually be biased towards the lower wing.  If you were to stand underneath the aircraft path you would see the flight path following a slight banana shape. 

 

So, close observation at the point of stall and pushing the rudder in the direction in which the model starts to turn is the best route to follow.  Forcing a spin in your predetermined direction will be penalised if you go on to fly in competition.

[Andy Stephenson]

Peter I do fly in competitions but the UK Classic Aerobatic Association isn't so prescriptive that it specifies the direction of rotation of this manoeuvre. Neither for that matter is the fixed-wing B Test.

Edited December 21, 2021 by Andy Stephenson

[Andy Stephenson]

1 hour ago, Peter Jenkins said:

...

Andy Stephenson - I would not recommend use of aileron to assist in spin recovery as you do not want to turn the spin recovery into a downward roll. ...

But this is exactly what I do want to do. Given that most long coupled pattern-ships spin in a very nose-down attitude it really isn't very noticeable if I use this method of spin recovery

[Peter Jenkins]

Well Andy that's fine then and you can do whatever you like.  

 

It has not been my experience of pattern ships spinning in any more of a nose-down attitude than say a Wot 4.  They spin much more slowly than most short coupled aircraft.  I can assure you that as an Examiner I would not wish to see that type of spin recovery you are promoting.  Anyone wanting to go on to fly pattern aerobatics in a competition would have to unlearn this recovery as you would be docked points for using it.  You say it isn't very noticeable but I think it's easy to spot.  Also, the notes on the B 3 turn spin say that provided the recovery is no more than 10-15 degrees off line, the heading can be corrected on the downline.  That is use of ailerons to roll the aircraft after the spin has stopped first.

[Peter Jenkins]

4 hours ago, Andy Stephenson said:

Peter I do fly in competitions but the UK Classic Aerobatic Association isn't so prescriptive that it specifies the direction of rotation of this manoeuvre. Neither for that matter is the fixed-wing B Test.

Hi Andy

 

All I said was spin in the direction in which the aircraft want's to go.  I didn't say that you must spin in a particular direction.  You said spin left as it's easier to get the aircraft to spin.  Are we at cross purposes?  As far as I am aware, no aerobatic competition specifies direction of roll, or spin unless there is a requirement to reverse the roll or spin as part of the manoeuvre description e.g. half roll and half roll reversed.  In such cases, it's up to you which direction you choose to roll or spin but you must reverse direction to meet the manoeuvre description.

[Jonathan M]

8 hours ago, Jonathan M said:

...this is what I've got to flight-test next:

 

Normal Rate 50%:  +6.5/-7.5mm (appx 10° each way) - recently proven for smooth flying with rearward CG etc.

'Stall' Rate 100%:  +12/-13mm (appx 20° ea way [I'd typed 30° in my post above by mistake, now corrected]) - previously proven for prompt stalling, spinning and immediate recovery.

 

So this afternoon's flying (cold but sunny!) proved the following:

 

Normal elevator rate needed to be a tad higher than 50% so increased it to 55% (+7/-8mm, appx 11° each way) with expo reduced from 35% to 30% to make things less sudden towards full stick travel.

 

High 'Stall' rate worked at treat at 100% (20° deflection):  model slowed to idle, nodded and then rudder alone triggered an immediate spin whichever way I chose, with exit right on the money the instant the sticks were neutralised, and no ailerons needed at any time.  So I experimented with dialling the rate down to find the optimum amount:

• 80% (16°) produced the same wallowing rubbish as normal rates.
• 85% (17°) reliably produced a stall and spin but only to the right (the right wing has some wash-in toward the aileron corrected by a tad of right-aileron trim - which explains why only the left wing will stall at this borderline rate).
• 90% (18°) reliably produces a stall and spin either way - the sweet-spot!

Re landings, I'm finding that I can consistently flare out at the normal rate, so don't need to mess around (or risk a premature stall!) with the rate switch.

 

Afterwards I asked an experienced club-mate if he'd like a go.  He flew the B Test schedule beautifully, except his attempt at the spin (because I hadn't briefed him on the rate switch malarkey), and his stall-turn was just about okay (I hadn't mentioned the need for a modest blip of throttle to encourage the rudder over).  He thought the Gangster had plenty enough power on the 46 generally, but found that knife-edge (he does it all the time on his own models without mixes) gradually lost altitude:  maybe there's some blow-back on the rudder (which is heavily geared for travel not torque), or maybe this would just work better with the extra thrust from the 53 (which I'll be fitting next).

 

Looks like the weather's going to close in from tomorrow onwards... but I've had a complete ball trimming out the Gangster and huge thanks for all the advice and discussion!   Learnt loads!  ???

 

[Peter Jenkins]

Very well done Jon.  Your methodical approach both to trimming and test flying the Gangster is most impressive.