Maxa 4 Ultimate F3J
Product Code: MAXA-4
Description
Maxa 4 Ultimate F3J
The Maxa 4 is Vladimir's Models latest and best ever F3J thermal soarer. It features an advanced design by Joe Wurts, the legendary Word Championship winner of all glider classes, and professional aerodynamicist. Joe spent many months optimising the Maxa for the F3J thermal soaring class, but the large size, light weight, high aspect ratio, and well cambered airfoils also makes it ideal for sport flying.
The large size and extreme light weight have been made possible by a new spread carbon fabric perfected by Vladimir Gavrilko and made by specially designed machines in his impressive fabrication facility. The wing is a monocoque structure with a skin of a double layer of spread carbon strengthened with a F3J strength spar made with a multi-ply 45º balsa and carbon shear web between substantial IMS 65 carbon spar caps. We are mostly stocking the "Light" (which used to be called the Hard Spread carbon) version. The even stronger slightly heavier "Windy" (double Hard Spread carbon) version is available to order if not in stock.
In mid 2012 the tailplane (called horizontal stabiliser or elevator in some countries) size was increased by about 10%. The latest 2013 models include a 13 cm longer tailboom to further increase stability and controllability.
Cut away drawing of the Maxa "Light" wing construction.

Cut away drawing of the Maxa spar, showing the IMS 65 carbon spar caps, amd the +/- 45º balsa/carbon/balsa ply spar web.

The fuselage is a well engineered Kevlar and carbon pod, with a diagonally wound spread carbon boom, and fin mounted cruciform tail. The model is totally complete, and almost no assembly is required. The tail pushrods are ready installed, and all the hardware is supplied for the wing servo installation. The model comes with a ballast tube and a wiring harness. The benefits of the Maxa include:
This combination of state of the art aerodynamics, low weight, and a good size makes the Maxa 4 the best model for competitive F3J soaring, bar none. See this RCGroups Maxa discussion and the Vladimir's Models Maxa 4 page for a lot more info.
The large size and extreme light weight have been made possible by a new spread carbon fabric perfected by Vladimir Gavrilko and made by specially designed machines in his impressive fabrication facility. The wing is a monocoque structure with a skin of a double layer of spread carbon strengthened with a F3J strength spar made with a multi-ply 45º balsa and carbon shear web between substantial IMS 65 carbon spar caps. We are mostly stocking the "Light" (which used to be called the Hard Spread carbon) version. The even stronger slightly heavier "Windy" (double Hard Spread carbon) version is available to order if not in stock.
In mid 2012 the tailplane (called horizontal stabiliser or elevator in some countries) size was increased by about 10%. The latest 2013 models include a 13 cm longer tailboom to further increase stability and controllability.
Cut away drawing of the Maxa "Light" wing construction.

Cut away drawing of the Maxa spar, showing the IMS 65 carbon spar caps, amd the +/- 45º balsa/carbon/balsa ply spar web.

The fuselage is a well engineered Kevlar and carbon pod, with a diagonally wound spread carbon boom, and fin mounted cruciform tail. The model is totally complete, and almost no assembly is required. The tail pushrods are ready installed, and all the hardware is supplied for the wing servo installation. The model comes with a ballast tube and a wiring harness. The benefits of the Maxa include:
- The Maxa’s aerodynamic qualities have been modelled to a new level of accuracy and by Joe Wurts. In the process Joe designed a new family of airfoils and optimised the shape of the model to get the best from the new spread carbon composites being developed by Vladimir. The result is a very low sink rate that ensures the longest duration in no-thermal conditions, while also maintaining gentle handling that inspires confidence from the first flight.
- The Maxa’s low wing loading and inertia makes it very respond to tiny air disturbances, allowing small bubbles to be detected and worked from low down, allowing short F3J tows and high scores.
- The Maxa 4’s large span allows it to be seen further away than smaller models, allowing a larger volume of air to be searched, and thermals worked for longer. This is especially important for the 15 minute flyoff task.
- The excellent lift/drag ratio, especially at higher speeds, gives good penetration, and thus the ability for the glider to return from distant thermals with little altitude loss.
- The long nose moment means little weight is required to balance the model, keeping the wing loading low, and the launch acceleration high.
- As the ballast system allows the model’s weight can be tuned to the conditions, allowing the Maxa to shine in even the strongest wind.
This combination of state of the art aerodynamics, low weight, and a good size makes the Maxa 4 the best model for competitive F3J soaring, bar none. See this RCGroups Maxa discussion and the Vladimir's Models Maxa 4 page for a lot more info.
| Maxa 4 Specifications | ||
| Wing span | 3.9 m | 155 in |
| Wing area | 82.2 dm2 | 1273 sq in |
| Length (2013 version) | 186 cm | 73.2 in |
| Flying weight from | 1750 g | 61.7 oz |
| Wing loading | 21.3 g/dm | 7.0 oz/sq ft |
| Aspect ratio | 18.8 | |
| Wing airfoil | rt01/td19sag/j00/j01/j02/j03 | |
| Dihedral (EDA) | 6.0º | |
| Centre of Gravity | 95-112 mm from wing leading edge | |
| Controls | Rudder, elevator, ailerons, flaps | |
| Maxa 4 Typical Weights | ||
| Pod | 170 g | 6.0 oz |
| Boom & Fin | 106 g | 3.7 oz |
| Wing c/s | 606 g | 21.4 oz |
| Wing tips | 423 g | 14.9 oz |
| Tailplane | 34 g | 1.2 oz |
| Accessories | 100 g | 3.5 oz |
| Total structure | 1439 g | 50.8 oz |
| Wiring & bits | 21 g | 0.7 oz |
| Pushrods | 0 g | 0.0 oz |
| Receiver | 20 g | 0.7 oz |
| Tail servos | 40 g | 1.4 oz |
| Wing servos | 90 g | 3.2 oz |
| Switch | 20 g | 0.7 oz |
| Battery | 120 g | 4.2 oz |
| Flying weight | 1750 g | 61.7 oz |
| Recommended Servos | |
| Elevator & rudder | MKS DS6125H, MKS DS6125e, Hyperion DS13-TMB |
| Aileron | MKS DS6100, MKS DS6125 Mini, KST DS115, KST DS135MG |
| Flap | MKS DS6125 Mini, KST DS125MG, KST DS135MG, Hyperion DS095-FMD, DS13-TMB |

