The old glider pilots used to say that the truly great models begin at 100 inches of wingspan… and with the CUMUL 100, you will quickly discover how right they were.
A high-performance thermal glider is a treasure for any Sunday flyer. There’s nothing quite like relaxed cruising on a warm summer day, circling in rising air under white clouds—or serene evening soaring when you can sit back and enjoy watching your model glide almost effortlessly across the sky. But the CUMUL 100 is capable of far more. Thanks to its full-house wing with ailerons and flaps, you can take full advantage of modern radio programming: enhanced penetration for finding lift, extra camber when you’re in the thermal, or the extremely effective butterfly/brake configuration for pinpoint landings… just to name a few possibilities.And for the competition-oriented pilot, the CUMUL 100 fully conforms to FAI F5J rules as well as many national “all-up-last-down” and endurance classes.
Proudly designed and manufactured in the Czech Republic.
A Premium Builder’s Kit — With Electric Option Included
The CUMUL 100 is an excellent project for modellers who want to build a genuinely high-performance thermal sailplane that can also be easily converted to electric power. The precision CNC-cut, interlocking construction makes the build smooth and satisfying—everything fits like a puzzle. The kit includes parts for both the pure glider and electric versions.Although the assembly is well thought-out and straightforward, the CUMUL 100 is recommended for builders with at least some previous experience.
The fuselage features a moulded fibreglass nose section with a removable canopy giving easy access to servo trays, receiver, and (for the electric version) the motor, ESC, and flight pack. A cutting jig is supplied to simplify the electric nose modification. The carbon tail boom and reinforced balsa/liteply pylon ensure a strong, lightweight tail assembly. An adjustable tow hook is included.
Three-Piece Performance Wing
The wing uses the proven AG 40–42 airfoil series and classic rib-and-spar construction with a balsa-sheeted D-box for stiffness. The I-beam main spar combines spruce caps with a balsa shear web for excellent strength-to-weight ratio.Wing outer panels and winglets attach via carbon joiners and aluminium alignment pins. Flaps and ailerons are independently driven by four short-link servos. The wing mounts securely to the fuselage with two plastic bolts.
Tail Assembly
The lightweight empennage is CNC-cut balsa with plywood reinforcements. The horizontal stabiliser is detachable for convenient transport, secured with two plastic bolts. Elevator and rudder are actuated via fuselage-mounted servos using piano-wire pushrods through the tail boom.
Covering & Electronics
Covering is best done with iron-on film: transparent KAVAN or ORACOVER® are ideal for sport use, while ORALIGHT® or similar lightweight options are preferred for competition builds.
- Radio: Minimum 7-channel system
- Servos for sport flying: 15–20 g metal-gear micros (≥ 2.5 kg·cm)
- Servos for competition: Aileron/Flap: KAVAN GO-1023MG | Elevator/Rudder: KAVAN GO-1020MG or GO-1021MG
For the electric version, a 300–450 W 28 mm brushless motor is ideal. Prototypes have flown excellently with KAVAN C2836-1120, a 10×6" folding prop with 32 mm spinner, KAVAN R-30SB Plus, and 3S 780–850 mAh LiPos (≥ 30C for sport, ≥ 40C for contest).
Kit Contents
- CNC-cut balsa and liteply/plywood parts
- Hardwood strips
- Fibreglass front fuselage
- Carbon tail boom
- Hardware & accessory set
- Sticker sheet
- Full-size building plans
- Instruction manual
Specifications :
|
| Wingspan | 2540 mm |
| Length | 1435 mm |
| Weight (from) | 750 g |
| Controls | Elevator, Rudder, Ailerons (2), Motor, Flaps (2) |
At Aerobertics
At Aerobertics, we appreciate models that combine refined engineering with pure flying pleasure—and the CUMUL 100 embodies exactly that philosophy. Whether you are searching for a rewarding build, a relaxing thermal cruiser, or a competitive F5J performer, the CUMUL 100 is ready to become your next favourite glider.
If you’d like, I can also create a shorter product listing version, a French version, or a more sales-focused Aerobertics introduction.
