The Sloperacer glider motor

Small, powerful, efficient and great value! £163.
(Modified Leopard 2860/2730Kv and 5:1 Reisenauer Micro Edition gear box with high torque pinion).

Electric Glider Motor

We put together a motor especially for gliders. It’s a light but quite powerful (up to 1Kw+) geared inrunner motor based on 28mm diameter can; perfect shape for vast majority of moulded E gliders and especially suited for use in converting gliders to electric. Running at this level of power means ‘hotliner’ territory which may seem excessive for some but it also means faster climb rates, which in turn means shorter motor runs. This opens up the use of much smaller and lighter high C rating lipos, after all if climb outs are 5-8s or less you don’t need to be carrying big heavy lipos. We’ve been sport flying with 1800mah and even as low as 65C, 1300mah! Typically this means for a ‘3m electric’ weighing just 100-150g more than the pure glider version. Being glider boys, we now ballast electric gliders routinely, which may sound abhorrent to long standing electric fliers! Approaching from a glider perspective it makes sense as you get as light as possible and heavy with the versatility to change weight according to the conditions and type of flying.

The motor and gearbox weighs just over 200g and even propping to 1.3Kw is still within ‘specs’ of its optimum efficiency band. This could get a 3m Racer type electric weighing in around 2.4kg or less (which now becomes possible) and yet climb vertically, not surprising with nearly 250w per lb input (or over 500w per Kg). This is just perfect for converting a skinny F3F/B 3m and the upcoming E Schwing which was designed around this power plant. Also for a F3B electric/practise plane it’s enough grunt to easily haul up a fully ballasted 4kg+ plane effortlessly (approx 300w per Kg).

The thing to remember is that whilst small motors can be pushed well beyond their rated power limits, it doesn’t all turn into thrust. Quite simply for power and efficiency there is no substitute for size, bigger is better (bigger magnets, bigger rotors etc) and if you don’t have room for a 36mm can motor then a longer case motor is the answer. The important factor is the efficiency.

Electyric Glider Motor

In conjunction with Leopard Hobby using their 28mm diameter motors but extra long at 64mm, we had them made with shafts suitable to fit a 5:1 Micro Edition gear box from Reisenauer. (Off the shelf this motor comes with 4mm shaft which limits the gear reduction possible to 4:1, this is fine for around 700w and 3s applications but higher than this needs bigger reduction to be efficient). The motors are 4 pole designs, 12 slot rotors, hand wound with high quality double bearings and rated up to 1300w. The gearboxes are one of the best on the market and one we know has been regularly used in glider applications well over 1Kw. We use the high torque pinion (not the standard) and assemble and test the power train for perfect running; all ‘Loctite’d’ and greased and ready to go.

Electric Glider Motor

Here are the static readings using 4s (Leopard 2860/2730Kv 5:1 Reisenauer Micro Edition gear box on 4s TP 1800mah 65c and Castle Creations 100a Ice Lite.):

17x13 Aeronaut cam folder 107a, 1.3kw
16x13 Aeronaut cam folder 96a, 1.1kw

Staying within the efficiency band of the motor, different number of cells and prop combinations can be used. Here is a guide:


Prop sizes

Static Power

ECS required




Approx 800w


Big thermal soarer





Most 2-3m fast, moulded gliders


13-14’’ High pitch



Fast 2m Hotliner!

We are also doing a few with different Kv motors better suited for different cell counts, basically if you want to use for more power. For instance 6s set ups running at 2Kw + is possible with an upgraded gearbox (Reisenauer Micro Edition Plus) and lower Kv version of this motor. You’ll be running outside of manufacturer’s specifications but a high voltage route is far safer and more efficient to do this than high amps. But for most, the ‘4s’ version and all it’s permutations will cater for most electric gliders, we think!

We also sell RFM spinners, usual folding props for gliders and ECS’s to make a complete power train. Contact us here