Ripmax Mini Bolero

David Ashby enjoyed his big Bolero, right up to the moment he ran out of talent, but finds consolation in this new compact version

A laser-cut balsa/ply ARTF model, this mini version of the freestyle and 3D aerobat spans 950mm, flies from smaller fields and is compact enough to be easily stored and moved about in one piece. Designed and developed in-house by Alan Wood and Nigel I’Anson at Ripmax, Bolero and this new mini version were clearly influenced by the Bossanova, an ARTF that gained popularity some 17 years ago.

Like its big brother, Mini B’ is designed to fly freestyle and 3D aerobatics, the large control surfaces, shorter coupling and thicker symmetrical wing being obvious pointers. Saving weight without compromising strength has been the aim, yet while that means dispensing with side force generators (and looking better for it), I think they’ve achieved their goal. Unlike some of the distinctly light and fragile bespoke 3D machines I’ve seen, with care this one is strong enough to serve as an aerobatic hack or club Sunday flyer. I think it’s attractive too.

Kit Out
You’ll need to find some servos and a power system. Ripmax suggest a 2217-size 1100kV outrunner, or one of their Quantum II 400 1100kV units, swinging a 10” x 5” prop with power from a 3S 1300-1800mAh LiPo fed via a 30A ESC.

sept20bolero3

Quantum II 400 outrunner recommended by Ripmax.

This is a model for good 9g digital micro servos with a minimum 2kg torque, perhaps something a fraction larger such as the 11g New Power XLD-09HMBs recommended.

sept20bolero4

I just happened to have the servos suggested so in they went. The long canopy hatch means everything is to hand.

Build
Assembly should be straightforward, especially for anyone whose put an ARTF model together, the full colour manual guiding the process step-by-step. In summary, it’s really no more than a case of hinging up the control surfaces, dropping in the servos, adding wheels, bolting on a motor and fitting the cowl.

sept20bolero5

The hardware is fine - fit and forget.

sept20bolero7

The battery bay. Anything in the 1300 - 2200mAh 3S range will fit, although I prefer the smaller, lighter packs.

I used the 11g New Power units suggested by Ripmax but found all servo recesses a shade too small to accept them, so a little trimming was required.

sept20bolero9

Servo holes need a bit of trimming to fit the recommended New Power units.

The wings are retained with a plastic bolt fed through the fuselage and retained by a captive nut in the wing root. The nut in my starboard wing was misaligned. It’s impossible to get to, so removal of some material from both the wing and fuselage to create the necessary clearance was necessary.

That 37mm dia. colour matched spinner looks nice but adds a chunk of vibration and noise when the prop moves. The backplate is the culprit and I’ve since replaced it with a carbon effect 38mm metal backplate number from the Irvine (Ripmax) range.

sept20bolero8

Colour matched it may be but my spinner backplate was poorly balanced. I’ve since replaced it.

A thin wire tail skid is supplied, although the fixing method suggested (CA adhesion) won’t retain it for long. I’d suggest clamping it with two offset servo screws instead.

sept20bolero6

Using cyano and, in my case, a little tape to secure the tail skid isn’t enough. I’ve since used a couple of offset screws.

Systems Check
Swinging a 10” x 5” prop, my wattmeter revealed 170W and 17A peak. An 11” x 5.5” records 190W and a 12” x 6” prop 210W and 19A. That’s around 100W/lb for the bigger props. I’ve stuck with the 12” x 6” as although the power increase is modest, the larger prop’s braking effect is a quality I prefer.

Flying
ROG’s are fine from short grass but if your field is bumpy or the grass is long then be reassured that a full power hand launch is easy and safe thanks to the model’s benign nature and wide speed range. If you’re new to agile aerobats like this then it’s important to realise that it’ll take a few flights to get comfortable, while taking the time to tweak and trim to suit your flying style.

sept20bolero12

Full power hand launches are safe and easy when the grass gets a bit too long.

Pilots who prefer a more 3D-influenced flying style will simply max out the deflections, dial in the exponential and fly with the battery back as far as it’ll safely go. Those who fly with a more traditional aerobatic remit in mind will do the opposite and flyers who like a bit of both… something in-between.

Even the low rate deflections deliver a snappy response in roll and inverted flight needs a smidgeon of forward stick pressure when the C of G sits at the forward end of the suggested range. That won’t be the case when the C of G is further back and the model feels neutral, but I tend to prefer the former; it’s nice to feel needed by the model when it’s the wrong way up.

The elevator has a powerful effect, so the expo suggested (50% across elevator and ailerons) is essential as a way of taming the response. The same goes for rudder. Knife-edge flight is straightforward with a modest amount of coupling evident. Spins are easily entered and finished.

sept20bolero14

A contrasting scheme helps during aeros.

Stalls are benign; you certainly won’t find a rapid response, wing drop or flick, just a mushy nod at best. That means landing should be uneventful and I’ve found that the nose can be raised without fear to let the wing blunt the speed where required. Harriers do exhibit a little wing rock, just a tad, but transitioning to a vertical prop-hang is straightforward enough.

Freestyler
Prop-hanging does expose the system’s power limitations. The model isn’t under-powered but dedicated 3D pilots will certainly want more than there is. It’ll hang about easily enough and fly away slowly upwards from the vertical, but no less than full throttle is required to achieve that, and the result is far from punchy.

sept20bolero15

There’s power for a prop hang and enough to pull away vertically too!

So, 3D or Freestyler? Which is it?

It’s the latter, although that’s not to criticise the model. It’s a nice little aerobat, a perfect back-of-the car machine that any intermediate or experienced pilot will enjoy. Flying duration will depend on your flying style and power system set-up, especially the battery size you prefer. I’ve settled on 3S 1400mAh and 1800mAh packs as a 3S 2200mAh battery just seems a shade too heavy for my taste. Accordingly, the 1400mAh packs provide for a good five minutes of stick banging.

sept20bolero16

It’s a pleasant freestyle aerobat, but one that’s better in calmer conditions.

I loved the big Bolero, right up to the point where I ran out of talent, and they’re impossible to find these days, so it’s great to have this new version. It’s light, so not a model that flies on windy days, but in calmer conditions you’ll have fun. If you’re looking to move up from a park-fly aerobat - a WOT4 foam-e or similar - to something that offers greater precision and a wider aerobatic repertoire then Mini Bolero should be on your short list.

DATAFILE
Name: Mini Bolero
Model type: ARTF 3D/Freestyle sportster
Manufactured by: Ripmax
UK distributor: Ripmax
www.ripmax.com
RRP: £189.99
Wingspan: 950mm (37.5”)
Fuselage length: 950mm (37.5”)
All-up weight: 870g (30oz) with 3S 1800mAh LiPo
Wing area: Approx. 340 sq.in.
Wing loading: 12oz./sq.ft.
Suggested power: Quantum II 400, 1100kV outrunner,
10” x 5” prop, 30A ESC,
1300-1800mAh 3S LiPo
Suggested servos: New Power XLD-09HMB (11g) or
Quartz P-QZ102 (12.6g)
Functions (servos): Ailerons (2), rudder (1), elevator (1),
throttle (via ESC)

X