Propulsion System - Motors, Gears, etc


The TPPower 58 series is capable of being used without a gearbox. You just need to put the right size prop on it. However the cost of the motor is almost the same as a motor and gear combined. Virus has used one and it seems to work quite well.


Hello I am selling a new (never used or even wired for that matter) APS APS 70110 Outrunner brushless motor 100KV 3200W


MODEL: APS 70110
KV: 100
MAX VOLT: 10S (42V)
SIZE mm: 70 x 110 ( without shaft )
WEIGHT (g): 1.530
SHAFT: 10mm with thread and locking hole
Accessory pack: NO
Stainless steel WATERPROOF case

Looking for $80.00 USD


Hey guy! Does anyone needs SSS motors? I looked at this item and seller offer discount for large quantities. Let me know if anyone is interested on joining to buy a bulk. Thanks


Hello! What about car starters gearbox? I bought today one. $10. 62mm diameter. Gearbox from russian car vaz 2110. Roller bearings on each sattelite.


Looks really cheap to try. What’s the gearing ratio? Thanks for the idea @ArtemkaMAX! How do you think to attach it to the motor? What type of the motor do you have? Alien 56114?


Now I on direct drive 6374, but want to try geared version. I plan to buy 360kv motor. Gear ratio is 4.25:1. I read that this starter tests with up to 20nm torque. Nominal is 10. The good thing is that I can replace gearbox every day with this price:)


Where did you buy it from?


Local store… But you can ask gearbox in starter&generator repair service as spare parts. I found 55mm, but without bearings on sattelite.


Keep in mind that is the 56104, if you want more torque get the 56114 model :slight_smile:


Hi Pacificmeister,
I posted this link on a complete kit somewhere else and should have put the link in the comment to you as a hyper? link but I am not as computer savy as I once was. is the complete unit but they also sell just the motor, housing and ESC for $1700 something?

This is almost exactly what the “ideal” brushless motor is that we are looking for.

Apparently it even has the built in ESC?

Best regards


Hi Anti,
I found this pre engineered solution which feels like cheating but whey reinvent the wheel?


This subject deserves a dedicated thread IMHO, as the cordless gearboxes
From the Valeo spare part Catalogue for starters 2015, here is the name to ask/search for in different languages:

EN Reduction gear assembly / Reduction gears
FR Moto réducteur complet / Reducteur
ES Moto reductor completo / Reductor
PT Moto reductor completo / Reductor
IT Motoriduttore completo / Riduttore
NL Reductieinrichting compleet / Reductie tandwielen
DE Untersetzungegetriebe komplett / Untersetzungsgetriebe
PL Przekładnia redukcyjna kpl. / Przekładnia redukcyjna
TR Şanzıman sargı kollektör takımı / Şanzıman
RU Модуль стартера в сборе / Mолyь стартера
BR Moto reductor completo / Reductor

Other trail: 55€ 60USD with holder - very thin and discrete
Valeo Gear Reduction Assembly

Technical Information: New complete planetary gear reduction assembly complete with gear track (part # D6RA-GEAR) and epi-cycloidal gear wheels (part # D6RA-GEARWHEEL), and splined shaft for mounting starter drive gear assembly. For clock-wise rotation only.

Information about the D6RA Valeo Starters and their planetary gearboxes here:

Bosch starter planetary drive ref : 1006200178
25€ here :
48€ here:

p7 and 9 of this catalog, Yamaha, Kawasaki, Sea-Doo Jets seem to use planetary gear assemblies for their starters as well;


Interesting. It’s roughly three times the price of the currently most popular solution (SSS motor, Neugart reducer, SeaKing ESC). And I assume you would have to create a new housing to mount it onto a foil. So I wonder if you are really that much ahead at that point.


Hi Sunrise
I totally agree and only pointed it out to either confirm or deny our defautl collective design strategy which is 56 to 60 mm OD motors with planetary gear systems, versus the similar problem/solution of trolling electric motors which finally (FINALLY) seem to be embracing brushless and even have their own built in ESCs.
Waterwolf also seems to be embracing a larger diameter (about 80-100 mm OD) with a direct drive being the most likely solution based on hte diameter and shortness of their motor hub.
Basic physics is non negotiable so power densities can be realitically determined just by the physical size of the motor housing, then it becomes a process of eliminating small diameter in runner motors unless the guy designing the motor housing would make something that much larger than needed…possible but unlikely…
I figure two or three to one profit margin means a direct drive power train and system should cost about $400-800 max not including batteries but including a basic housing?

Knowing motors burn out without a gear system is very discouraging when the gear system is $400 and is extremely likely to burn out when we exceed the 5000 RPM input never mind if we get closer to 25 000 or 40 000 as an input?

I am in very strong agreement with another poster here that direct drive is really the only long term solution even if it means collectively agreeing on all agreeing on one motor and get someone like Alien Power Systems to custom wind and fabricate something ideally suited to our small community.

Best regarsd,
BTW thank you taking the time to point out that it is a possibly very fruitless endeavor to look at overpriced trolling motor solutions unless one considers them as guidelines only.


Thanks Peter. Well said and all good points. It’s possible the jury is still out on the default SSS56104 motor + Neugart PLE40 5:1 combo since it seems most of the problems I’m hearing about are either: 1) Damage due to water incursion, or 2) Use of a different reducer than Neugart (Parker, Chinese, etc). But my data is only anecdotal. I also wonder if comparing trolling motors to the needs of an efoil is apples-to-apples since most trolling motors are designed to move a 1,000+ kilo boat at a couple mph while an efoil motor needs to move maybe a 100 kilo package (including rider) at much faster speeds. The Torqueedo outboards might be an interesting comparison. Looks like they use an out-runner with planetary gears:

Two other issues I’ve seen raised elsewhere on this forum: The first is drag. The larger the OD the greater the drag. Not sure if that is critical for an in-runner. Usually comes up more with out-runner motors which can get pretty bulky. The other issue is run-time. The more efficient the drive package the more minutes we can spend riding and the less battery bulk we must carry aboard. I have to assume that alone surely is a vote for direct drive even if the PLE40s or some other gearbox proves durable over time. That said, the Torqeedo guys are really industry leaders now and they are still using a gearbox. So…who knows! :slight_smile:


trolling motors work different , they push 180 lbs at a very slow speed. i looked into this also and have moved away from it now. but if you try keep us posted i could be wrong.


Hi David and Hi Sunrise,

Thank you Sunrise for the positive feedback, much appreciated.

As much as I enjoy designing stuff but my biggest fear is wasting time reinventing the wheel…
this rather lame youtube video merits fast forwarding to get to the part where you see the size of the motor and prop

To me it shows a rather HUGE diamter motor and fairly modest propeller.

The board seems to behave beautifully under dynamic conditions as in I would buy one if I had $12 000 lying around.

Cheaper to just figure out what motor, propeller and electronics are needed leaving $9000 for machining?**

Leaving $1000 each for the motor, electronics, battery housing…


yeah i definitely agree but from what i have found trolling motors are configured to be a heavy slow oil tanker ship while efoils is more of a jetski speed boat configuration .

but again i could be wrong and would love to see your tests if you get one working with a trolling motor


Thanks for sharing. I have not seen this video before. Yes, the motor is huge by comparison! And I love the integrated heat sink! And yes I too am happy not to reinvent the wheel. In large measure that’s why I’m mostly following Pacificmeister’s build. I just now have all the parts in hand so we’ll see how that goes.


They running the torqeedo cruise prop and I would bet they also running a 5.5kw motor through the torqeedo cruise gearbox. They using 14S batteries to bring the ESC requirements down.