Finished UK Efoil build

[Gazman79]

My efoil

Firstly I would like to thank everyone for the great wealth of information found on this site, it gave me a good understanding of what route I would like to take my build.

Nothing ground breaking here but I wanted to document my build to add to all the information on Foil Zone.

Main parts

• Flipsky 65161 120kv with carbon/PLA printed motor mount (files from the forum

• Propeller, Flipsky 7.25 x 5 cut down to 140mm

• ESC, Castle Creations HV160 ice, Passively cooled in aluminium box within the main compartment but the base protrudes to the bottom underside of the board

• Battery, 6x hobbyking zippy 8000mah 6s lipo packs arranged to get 12s 24ah pack

• Hydrafoil, Gong kite foil Allvator Rise ALU (I use this for kite foiling as well)

• Home made board 1500mm x 600mm x 100mm
  Polystyrene, plywood stringers wrapped in 2 layers of 200g carbon fibre.

• Remote Control made from 3d printed case, arduino and Orange tx module.

• Fail safe. Reciever has built in failsafe so loss of signal from transmitter sends throttle to zero, also I have a reed switch and magnetic lanyard on the signal wire between the Reciever and ESC which means the ESC detects loss of signal and sends throttle to zero.

• Hatch, the main hatch is fastened down with multiple bolts and an EPDM flat rubber seal used for windows. The round hatch is a standard 200mm boat screw down, used for charging and switching on/off

• Small IP68 clear plastic box for reciever on the nose of the board including LCD battery voltage display and magnetic lanyard.

• Weight including batteries 24kg

• Cruise speed 20kmh @ 30amps and top speed so far 27kmh

[Gazman79]

More pictures

[Gazman79]

[Lake_flyer]

Great build
The quality looks really good.
Can I ask what you have spent on the build?

[Gazman79]

Hi

Thanks

I already had the ESC and batteries from another project but I’ll list them below anyway.

In UK pounds

ESC £250
Batteries £450
Motor £320
Board £200
Gong foil £330
Other/wires/connectors/bits £150

So around £1700

[Sam]

Very nice build, thank you for sharing it. If you didn’t already have the batteries, would you still go for LiPo or rather Li-Ion?

[Gazman79]

I would definitely go with Li-ion, mainly due to safety concerns with charging and storing Lipo’s.

In the future I plan to build a 2170 12s10p pack.

Thanks

[alex13571357]

What EPS have you used?
It seems hard to get anything in the UK in small quantities that isn’t very lightweight.

For the magnetic lanyard, do you have a switch in line on the ESC signal cable or do you have a contactor arrangement?

[Gazman79]

Hi

I was concerned about getting EPS that was too light weight but I ended up getting this from Wickes which is actually fine, plenty strong enough once wrapped in carbon and easy to sand.

https://www.wickes.co.uk/Kay-Metzeler-General-Purpose-Polystyrene-EPS70---2400mm-x-600mm-x-50mm/p/210802

For the magnetic lanyard the reed switch operates directly between reciever and ESC. No issues so far and I have fallen off many times. Most ESC’s will revert to zero throttle on loss of signal, I don’t get any over run either it just stops.

[Gazman79]

Hi

An update on the reed switch between reciever and ESC.

Although this is working I have encountered an issue where sometimes when the magnet is released or reconnected it introduces a big signal spike and trips the ESC which when needs a power cycle, I plan on using a single channel failsafe device which hopefully will be a buffer between the RX and ESC but after the reed switch. I’ll update once it arrives and test it out.

[pablo_foil]

Thanks! I didnt know this failsafe existed. Great way to eliminate the 1sec latency that the esc has before powering off the motor

[sat_be]

If you add more logic, you could as well use a hall sensor with a magnet and then use an arduino with servo library to forward the ppm signal to the vesc based on the hall sensor state. This adds complexity but it is more reliable than a reed switch that can get suck.

[Gazman79]

I know I didn’t know either A few hours on Google and I found it, I was initially trying to find a way to do it with Arduino but ready made module

[Gazman79]

Yes I like that idea using the hall sensor but I don’t know how to program Arduino only upload sketches and use other people’s code, I need to learn really.

[Gazman79]

Hi

Just an update on using the single channel failsafe module mentioned above.

I had a full session yesterday with no signal problems when the magnetic lanyard was pulled off and reconnected.

Gaz

[Wingaddict]

Very clean build! Any info on the inserts you used to fasten the hatch ? Are they screwed or glued? Any water ingress so far?

[Gazman79]

Hi, the round hatches are glued and screwed. I used stainless steel screws screwed into polyester resin plugs pre inserted into the board before skinning, it’s glued with a polyurethane adhesive sealant.

Keep sand away from the threads and sealing faces, it grinds away the plastic otherwise.

They have stayed dry so far.

[Wingaddict]

Thx for the prompt reply any threaded inserts in the polyester blocks ? Are they Made of stainless steel?

[Gazman79]

I used these threaded blind inserts for clamping down the main rectangular hatch. Expensive but all I could find.

Blind Self Tapping Inserts Stainless Steel Marine Grade 316: M2 To M20 (5 Pack)...

[Wingaddict]

Thx Gareth, did you use M5 or M4?