Electric PPG - ONE motor project -

Hello friends, Gianni from Italy, tired of the poor results using commercial BLDC motor exploiting my 42 years in the world of 5-axis machine tool for the aerospace and defense sector finally I design and build my brushless motor.The motor is designed also for liquid cooling for heavy use. My idea, and the results are proving me right, is to have only one model of motor that can be used on different projects and with uneven performance and power demands.
Please take a look on this video:

a.s.a.p. more details will be available .


hi gianni,

sounds interesting. I am curious to see how the weight-performance balance looks with liquid cooling. So far it has not been an advantage for eppg because you are heavier overall. but i will be happy you surprise us if you show us flight videos with weight and performance data. greetings to italy.

Awesome! I hope everything works out for you. I am a bit concerned about the weight but I think it should be manageable.

Hi, we are glider pilots but in my flying clubthere are trike and PPG pilots then my goal was design one motor suitable for each application with only one model !

For PPG application and light UL motor not need liquid coolant system , only for heavy application motor could be equipped with this system. Probably from middle of May we will allowed to travel then will be possible for me start tests on this prototype of motor ( I live in Lombardy region and from MArch 7 I’m locked in house… )

a.s.a.p. I will share my tests with video and detailed viseo .

Keep in touch


This is very interesting. Could you go into more detail about where you see the advantages vs. others, e.g. Rotex or Plettenberg?

There’s always room for another excellent motor on the market, esp. one with water cooling capability.


maybe a note: if you are interested in the engine as a series also for eg. Germany, Austria, Switzerland, it would make sense to keep the maximum load speed in the range below 2400 rpm (e-trike) 2200 rpm (e-ppg) with 14 S batteries. purely for noise reasons. there are also very good propellers for this speed range. all of this relates only to the countries listed. of course i know that in other countries it doesn’t matter if you make a lot of noise.

Hello, performance - efficiency - weight - noise and OPEN DIY technology are a must in this project. I already explain reason why I’m developing my own motor, what i didn’t say is that the last motor i tried was the M40 which on paper looked like a great product with very interesting performance, I bought this motor paying a lot but confident in performance (even if not equipped with HALL sensors), once the motor arrived in Italy I realized that both the performance and the construction (very poor and approximate assembly and design) are NOT comparable with what I have spent ed exactly :
1) M40 is advertised in the web as 36N42P , unfortunately the magnets are 30.
manufacturer never replay to my question
2) Magnets are badly glued see
photo A - A1
3) To balance the rotor was glued with resin , this is not acceptable and unprofessional
see photo B – B1
4) The main shaft is poorly and bad machined
see photo C
5) Low quality bearing and undersized for the declared power
6) Propeller locking with m4 screws

sorry … as new member i can upload only one pics … anyway pics are available on request

Impossible have comunication with manufacturer then I requested to refound money as a non-compliant product and after three months I got a non-total refund.

This is the reason I stop to use middle level market motor and start my project .




Photo A

Photo A1

Photo B

Photo B1

Photo C

it is good that you show details. maybe it now helps to make people understand that (currently) china cannot build aircraft motors. That is why, since 2006, professionals have only been using e-ppg and e-trike motor from German and Czech development and production. examples from e-ppg / e-trike

1 Like

Hello , as anticipated we are not professional builders but mine background and the technology I can access is high standard thanks to my previous job ( for my luck I have many many friends worldwide). Back to your question, I know well the manufacturers and the fantastic products you mentioned they are excellent indeed more… I have no ambition to overcome them but my product has an advantage that they cannot offer and exactly the fact of being an open source project DiY .
My idea when tests ( hope corona virus leave early ) will be finished and published (we will build a dedicated WEB page) is to freely distribute the project for which want build himself, sell the individual pieces ready to assemble or sell the complete engine…

We are not professional builders and profit does not interest us … but we are interested in divulging our experiences to everyone as we love electric flight

keep in touch my friend



Ugh, that sucks, but not completely surprising. I poked a teensy whole in MAD’s offering, Single MAD motor - #23 by kubark42, but your testing blows it wide open. So sorry about the wasted time and money.

I love your ambition in this project, and am looking forward to the results. Are you looking to create a self-launching PW5? Keeping weight down in an FES-style glider application is so much more important than in PPG, and so if the PW5 is your primary target I’m even more excited to see what the results will be.

P.S. One thing that makes LMT motors so good is that they use a press to compact the windings in order to cram more copper in. I don’t know if the claimed increase of packing factor of ~40% is true, but in any case it can only do good. I wonder how easily a DIY person could compact the coils? Maybe with vacuum instead of a hydraulic press?

You have the wrong specs for the mad m40 80kv

This says it should have 30 magnets

With the Lehner Torquestar, the copper fill level is actually slightly more than with industrial motors. compared to china rc motors, the difference is actually up to 40%! that is true. the advantage of the size can be kept somewhat smaller in diameter. the disadvantage of this is that the heat is difficult to get rid of. so i was trying to build an LMT -eppg with a water-cooled version. But it didn’t make any sense despite the high-end cooling system etc. for e-aircraft motors , the degree of filling is not the only decisive factor. in the picture you can see a system that is still one of the best in the world, even though the development is now 15 years old. the efficiency is over 90% when working with a well-adapted esc.

since enough air can pass through the coils, the cooling is very efficient. but also with other systems with a high degree of filling such as rotex, hacker, e-glider etc. that use the air centrifugal effect, the cooling works well because the copper constantly transports and distributes the heat.

1 Like

Hi Bob27 you right , unfortunately I was one of the or the first in Europe to buy M40 and specs was wrong this was strong points con convice PayPal to refound me…

Hello , do you have different view pics ? Thanks

Interesting to know. My instinct is that it’s better to avoid generating the heat than it is to try to remove it, but it sounds like you’ve got real-world experience and that beats hunches every time.

What do you see as the decisive factors in e-aircraft motors?

BTW, very nice looking motor. What is it?