Propulsion System - Motors, Gears, etc


#222

Indeed adding blades reduces cavitation, but the efficiency is going down a lot! So it depends on what you want :slight_smile:


#223

I think, there is little misunderstanding, they added blades to add thrust at slow rpm, eliminating the need to go high rpm and cause cavitation. High tip speed is usually responsible for cavitation, not sure, blade count will have much impact on that.


#224

Having problems getting a Neugart ple 40 5:1 reduction drive. Has anyone got a supplier?
I tried ebay and been let down twice. I have tried HMK in the uk just awaiting on a quote from them?
Any suggestion be greatly appreciated.


#225

Have we identified an RPM range for optimal performance?


#226

Hello, I’m trying to design a propulsion system too. Liftfoil makes a great electric foil that perform very well. But I can’t see how they put a planetary gear in their system ! It seems like there is just enough space for the motor and some seals.

Also, knowing that their board is max 5 foot 6 (167 cm) by using the proportion (on a picture), I can tell that the aluminum tube is 120-125 mm long and a diameter of around 70mm
Do you guys have an idea is they use a gearbox it in their system ?


#227

No gearbox, more likely direct drive with a custom designed low kv inrunner motor. Lots of discussion here about what a motor like this needs to look like and I am sure we will soon see someone designing and selling the perfect motor to us builders. Maybe someone from Lift wants to chime in here and give us some details on their specs :smile:


#228

what do you think of this motor ?

they have some other powerful DC motors


#229

@morgansteven1970 I had the same problem. I ended up ordering directly from Neugart in Germany. The waiting time is around 3 months for delivery .


#230

Are you sure? I think there is plenty og room to add a gearbox there? Our shortest unit is about the same size with gearbox (and it can be even shorter).


#231

Pretty sure yes. Just my gut feeling. I guess we will find out soon. Cool that your pod is that short, I assume that is because your motor is shorter than my SSS?


#232

i ordered from france neugart gearbox, i get a 8 week 2018 delivery … used to buy on amazon (prime) this is crazy for me too, but that’s the deal, they can can do (in .fr) a 2-3 weeks delivery but double the price …lol? i have seen someone here abe to get it in one week, please, let me know … thinking about a 100kv from china will be faster … anyway, some room for improvement before gearbox


#233

If they use a custom gearbox(that can handle axial forces) which is likely, they might have the propeller directly attached to output shaft. So they can loose the coupler. Might also have a shorter motor as well. Noticed that in their commercial they say they have smooth acceleration curves (which I believe is to make the gearbox last). But we will see, would be nice if it’s a direct drive, so much easier.

Yep we use a shorter motor, and we cut the output shaft and motor shaft, and have a really short adaptor between.


#234

Haha might be all the diy builders (and commercial builders) that are ordering all the gearboxes.


#235

Hey Hiorth ! So how long is your motor+gearbox (from the back of the motor to the end of the gearbox shaft) ? also how much thrust do you have ?


#236

170mm. So assuming a specialized gearbox with the propeller directly attached to the output shaft, there should not be “impossible” to get everything inside, but it will be a tight squeeze. We have not measured the thrust, but its more than enough to foil on Kite/SUP foils.

Cheers


#237

Which Motor is it? Doesn’t look like the sss :smiley:


#238

It look like a TP Power


#239

Its a TP power motor :slight_smile:


#240

hi guys i was thinking tonight while driving home, has anyone thought about cutting the mast maybe 100mm from the bottom and bolting the propulsion tube between the two sections of the mast,
that way the motor could be inside the tube around the mast area, making the tube more compact overall


#241

I just been quoted £352 from HMK in UK.
How much was it from Neugart in Germany?