Redpinelabs board #2

There are a lot of options bout there now. One of the nicer variants I have seen is the customised sphinx 55 from open builds

I run sherline mills for my smaller parts, but am now looking at building my own bigger variants that I can cut much faster on.

Looks good, actually it looks very similar to the ESC/electronic box of the elevate efoil upgrade kit that is available since 3 months from at approx. 199€ in aluminium anodized!.. They made it adoptable for trampa, maytech and flipsky VESC. I use it with flipsky and it works perfect. Never got above 50° temperature even if powering 3,5Kw.


Yes I was partially inspired by that and it looks awesome! Before I was designing something that would be inset in the board and I saw yours and thought I’d try something similar. Probably would have saved me money and time to just get that, but I wanted a good project to try and cut aluminum on my cnc.



Main hatch didn’t leak using the @michion method of a silicone pour.

Did have some leaking in the ESC up through the mast. Luckily ESC is fine and my conformal coat worked. Took it all apart and cleaned with 99% IPA and put another layer of conformal on there. MG Chemicals 422B/422C is great stuff!

Here is the short video cruising around

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Looking great! How/where do you think the water was leaking up through the mast?
Was it one of your o-rings or the siliconed wires?
Also, how did you decide how high to mount the motor on the mast above the fuselage?

It was through the siliconed wires. I ended up drilling and tapping a Schrader valve to the esc box so I can pressure test it. When I hooked up the air compressor and tested it at low pressure, I could hear air coming out the motor mount area.

Going to test it out some more today.

Got it tested at like 20 psi! Should be able to use a bike pump and test in the field or top it off with a little positive pressure.

For the mount point I probably have it a little high. Just eyeballed it at the time and I didn’t know what prop I was going to use. Could always cut it down a bit on the bottom. Usually riding the foil that high is already starting to get tippy so don’t tend to do that always.

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Got out today for another full session, butBrr with our recent snow the water was cold on the hands! Need to bring some gloves next time.

Need to improve the reception by bringing out the antenna some more. Currently with the ~90L board a lot of it is under the water when I’m starting out and have to be careful to get the board planeing before I move the remote out front and try and stand.



Got some EVA on the board. Much less slipping around.

Still having problems with reception while starting, going to extend the antenna up the box some more more amazon arrives on Sun. As soon as move my weigh around trying to stand up it cuts out unless I do it just right…

Also got stopped by the Colorado Parks police. They weren’t sure this was legal, but talked to them on the phone later after checking with the boss, it was OK if I register it as a boat for $60 - Annoyingly it is good from Jan to Dec, so not sure how many more days I can get before water gets hard. Found my gloves and they worked pretty well for the 40F water temp and 40F air temp.


Sounds like a great day. Sorry to hear the authorities didn’t like seeing you have too much fun.
“Will the state allow you to register it without an HIN and a huge, legal hassle?” is the next question.

They said it could register as a homebuilt, but got to go into the local park office to do that. I’ll probably go in for that today just because the weather is looking so nice and wasn’t to ride a few more times.

I got a efoil registered as a boat now… Also they told me boating ends dec 1st in CO… ugh
I did get out the last few days despite the cold. 40F air temp but had a great session.

Did got a sandbar going fairly slow but no damage!


Got some riding in on the last day boating was allowed on byod lake. Found another small lake that I might be able to still go on with some warmer weather coming up though!

I like the VESC with current control, but the annoying part is when the duty cycle is maxed out so the current can’t go any higher so the top part of the throttle doesn’t do anything (except on take off). Messes me with when I want a little extra power and nothing is there, or release the throttle a bit and it doesn’t slow down (because it is still asking for too much throttle). Want to jump to 14s so I have that top end wiggle room. Tried duty cycle control, but it doesn’t seem to act that great, maybe there is some settings to help fix that.

Looked back at my stats a bit for max speed with my different wings. (on 12s with FR prop)
21.6 mph with the slingshot space skate (65mm)
19.5-20mph with slingshot infinity 84

Hopefully get out on the liquid force happy foil this weekend - that was the fastest on my old board (with arc200 esc) with some speeds > 22mph.

Next spring bump up the battery to 14-16s and see how that does.

Working on 14s8p p42a pack!

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Welcome to the club, it’s the best balanced choice before the M50 prices become competitive!
Have one with same conf in a Max 004 case since this summer with >50 cycles.
They work well and only dip ca 3v@100A draw.
Dont expect it to be a range monster thought at 32AH…

You need to raise the pitch of the propeller then