The Dutch build

[Thijs]

Hi all,

firstly I’d like to thank Pacific meister for setting up this community and secondly Silvio on which my set-up is based.

My build is not yet finished yet, just want to share and i’m open for suggestions
After my chinese friends weren’t able to send me a PLE40 replica after 2 months waiting, I descided to swich to a setup similar to Silvio:

Motor: AquaStar 4084 620KV : https://hobbyking.com/nl_nl/turnigy-aquastar-4084-620kv-water-cooled-brushless-motor.html → i will run this on 12c.

Gearbox: Reisenauer Motor Chief 6/1, incl flange 4-P-CHIEF-Flansch PEGGY : https://www.reisenauer.de/aid-251-MOTOR-CHIEF-6-1-br-mit-Alu-Konus-Stahl-M10-br-o-h-n-e-Assorter.html

Custom printed part:
https://www.dropbox.com/s/mo3xugu0aduj8fc/thijsbuilt.STL?dl=0

https://www.dropbox.com/s/cjyuylrk2ufw0a7/thijsbuilt%20v2.STL?dl=0
(v2 is with duct)

Propeller: 7.25x5 : https://www.banggood.com/nl/7-14X5-A-Boat-Propeller-Aluminum-Marine-Outboard-Motor-For-Yamaha-2_0HP-2HP-p-1267579.html?rmmds=myorder

Batteries: 2x6s Multistar 10000mAh (want to double the capacity as soon as everything works)

ESC: flier boat 320A : https://www.aliexpress.com/item/Flier-new-version-12S-320A-brushless-ESC-for-RC-boat/32750220880.html?spm=a2g0s.9042311.0.0.63024c4dDBFr6e
honestly I think this is overkill now I switched to the 4084 instead of the 56114 motor. Would it be a problem?

Foil: Chinese SUP foil:
https://www.aliexpress.com/item/top-quality-hydrofoil-carbon-foil-with-alumimum-mast/32857409005.html?spm=a2g0s.9042311.0.0.5f394c4dPT4J40

Board: I build my own, PIR foam+3 layers of glass epoxy

My plan is mount the aluminium mast mount by 4 screws in the mast, and fill it with superfix 009 to make it waterproof and to give it strength. I will glue the motor as well.

I also plan to put the superfix 009 between the motor and the motorflange to waterproof.

I estimated worst case 35kg of thrust in axial direction, and the same in radial(in case i hit something). I called Reisenauer to ask if a axial and radial bearing is needed. He almost started laughing; the reisenauer motor chief can handle forces up to 50kg in forward, backward and sideward directions
So the bearing I already installed is not really needed, guess I leave it in there anyway.

I made a groove in the red printed part, in which I placed a rubber ring. This will be comressed by 4 bolts. The ‘legs’ of the printed part are 1mm shorter to make sure the rubber ring is compressed well. In the printed part, I will place a double lip seal.: https://www.amazon.de/dp/B01GEACKUC/ref=pe_3044161_189395811_TE_SCE_3p_dp_1

I put 2 wooden beams underneath which i epoxyd in the foam.
On the bottom and topside I epoxied a plate of 20x30x5mm carbon to give strength to the bolts

Last week I tried the foil behind our boat, it was surprisingly easy! I have no surf experience but i managed to stand a few minutes. Take of speed should be ±14kmh (our boat speed is 12kmh, so I could only come out of the water when making a corner)

electronic box, still have to organize and waterproof the connections…

I see some people use a forklift relais, what would be the benefit from that from what I use?

I have one question:
I can programm my ESC. Do you have suggestions about my settings?
Im especially curious about the max power:
My motor is 10C and I have 12C. Now I read that this motor can handle 12C, especially as my motor is cooled very well. But would it be wise to cut the power a little bit(say to 85%?)

Thanks and I’ll keep you updated! b.r. from Utrecht

[Alexandre]

Nice built , set up in // 6s ? Ubec 26v ?

[Thijs]

Yes, I bought the wrong one, but might be able to connect the ubec to only 1 battery.

[Bucky]

Looks nice
Hope I can build one in Holland as well

[Linzio]

Eindelijk wat nederlandse bouwers! Mocht iemand er straks wat van de hand doen als ze klaar zijn hoor ik het graag. Ben zeer benieuwd en zelf bouwen gaat me helaas niet lukken. Zet em op guys!

[Thijs]

Today it was time to launch the vessel. First imipression was the immense power! In the video I used about 25% of the throttle.
Unfortunately shortly my motor shaft uncrewed itself from the gearing; I’ll cut a slotted hole in the gearing shaft and put a screw trough the motor shaft to prevent this.

Some other concerns:

• I had some water in the electric box; probably because my compartment in the board is to small and the wires are pressed against its side.
• My remote is very unpredictable; the signal seems to be bad. I’ll go for a simple skateboard remote and waterproof it.
  BR!

New video by Thijs Thijs

New video by Thijs Thijs

[Alexandre]

Well done , yes the shaft unscrewed , i had lost one after 1h , i glued the new one with the same glue as the pignon but i don’t recommend it , impossible to take apart after

You may have a bad signal because your box may be in the water … You don 't need much water over the box to loose signal

You need some Space in the box , the lipo will swell …

[Thijs]

Thanks Alexandre, i grinded a slot in the gear shaft and a m3 in the prop shaft.

[Alexandre]

Is it easy to drill ? , i want to drill in the flat part for the shaft and get the front to a even 14mm diameter to put a seal

[Benjo]

Is it correct that the motor and gearbox are directly exposed to the water? Is the motor (or the parts that are exposed) watertight? Will salt water damage the materials?

[Thijs]

Hi Alexandre, forget about drilling the reisenauer shaft. Its hardened(probably some kind if CrMo?) Steel. I cutted it with a angle grinder/cutter. Make sure to cover the hole!(I put some toilet paper in it so no dust comes into the gears)

I don’t understand your 14mm seal idea btw…

[Thijs]

Hi banjo, it is correct; the gear and the motor are directly exposed. I put sealant(kit or locktite) to watertight the holes. The shaft is sealed with a custom printed part. I epoxyd 2 oil lipseals in it and filled it with grease.
I’m running mostly in fresh water. I’m n not sure about the grade of aluminium, but I don’t think it will be an issue in salt water because you van dry everything afterwards.

[Benjo]

Ok, thank you! I like the idea, it will provide perfect cooling for the motor and gearbox.
Did you change the grease in the gearbox with high speed lubricant? Does it come with any grease at all?

[Thijs]

Yes, cooling is good this way!
Reisenauer strongly advised to use their grease instead of e.g. Makita grease. Just bought 5ml for 5eur from them, didn’t want to take the risk and there’s a lot of technology in greases.
The grease around my shaft and seals is just for keeping the water out, therefore I use cheap marine grease.

[Benjo]

@Thijs I have another question
You posted pictures of your ESC settings above, did you stay with the extra hard braking? It may be best for the gearbox to turn braking off or to extra soft, so that the gears can keep flowing on the grease and don’t forcefully hit metal. It should also draw less power.

[Thijs]

Hi Benjo, I wanted to enable hard braking because of safety. But it turned out that I cannot enable this option on my ESC.
I sticked to the other options, except that I reduced the motor timing to 3°

[Alexandre]

I wanted the put the seal around the gearbox shaft , not around the propeller shaft , to make it shorter

[Thijs]

Yesterdaymorning I was able to make my first flight; it was amazing and not so difficult! @pacificmeister , do you also have the impression that the wing angle could be slightly better? I’m curious about your opinion

New video by Thijs Thijs

Unfortunately my motor broke down in the afternoon already. Honestly I saw it was drawing already 5000+w with not even full throttle, but I was to tempted to go for it anyway.
Afterwards I realised I have programmed my ESC motor timing to 3° which was more of a wild guess. and this is probably wrong?

As my old AquaStar 4084 620KV was originally designed for 10s, so I want to switch to the following setup:

Typhoon HET 700-98-670 brushless, @jakebarnhill1 and @Mat , I saw you were talking about motor timing degrees. Do you have any idea what would be the safest timing for such a motor? I can also select PWM, any idea what this means and how many kHz?

Elektro Flug Motoren: E-Motor Typhoon Impeller 700-98 670KV

Custom 7 7/8 x 7.5 honda 5hp prop
https://www.aliexpress.com/snapshot/0.html?spm=a2g0s.9042647.0.0.53374c4dMoI980&orderId=94220174299377&productId=32691369808

But then lathed down to 136mm, the same as @PowerGlider in this topic:

For who try/have tried direct drive with outrunner

Based on the calculation below(rough estimation), 1.1hp(800w) would give me a speed of around 14kn (25kmh). Probably the real figure is worse, I dont see a value for slip etc.

Vicprop - Prop Calculator for planing hulls

Hope you have some thoughts on this approach

btw, I will switch back to a configuration where my motor is inside the tube. The motor was not strong build(thin aluminium and tiny screws), the body was not really able to transfer the power.

[jakebarnhill1]

I haven’t had experience with in runners yet, but you need lower timing for in runners from what I’ve read. I think your guess of 3 degrees wasn’t a bad guess. put it in water and give it lots of throttle, if it loses sync i.e. the motor stops or squeals to a halt, increase the timing until it doesn’t lose sync.

awesome work on the build!

[jakebarnhill1]

The PWM rate is the rate at which the Fet switching is done I think an ESC guru could chime in here I don’t fully understand it.

from what I understand however a higher PWM rate is good for low inductance motors (usually smaller motors) so they run smoothly, with a high PWM rate the esc will run a little warmer due to more switching losses. With my outrunners 8KHZ works fine, at the current moment I’m running 10KHZ I couldn’t notice a difference.

maybe @PowerGlider @nickw1881 @Flo could chime in here and explain how it works more!