77cm (Volker‘s sixth)

[V_S]

Ooops, i did it again.

Size and evolution:

Here are some keyfacts:
77cm long
39cm width
55mm thick
Weight board incl. hatch and EVA Pad: 1819g

Getting this small board started is only possible with the “quirlstart” method. BUT: Same as Pinky, 90A motorcurrent are enough.

Light weight edition:
1819g Board
1443g 430Wh battery
0098g Vesc 6.7 Pro & Bremote Nano RX & cooling & cables
2646g Custom Carbon Mast & 5085 Incl Propeller & screws
1488g RL foil with custom fuselage
7494g in total , RTF (ready to foil)

In real life, there ist enough space for my 1300Wh battery 12S3P of those: (+2688g) BUT good for 60-90min fun or 30km+ autonomie

Build this one KISS (keep it stupid simple) and quick and dirty.
It Starts as usual with the monocoque:

Templates and hotwireaction and glueing monocoque in place:

Closing monocoque with a lid

Final hotwireing and a bit sanding:

Final CFk, top 3 layers 245g, bottom 2layers. Some reinforcement with 1-2 extra layers at cruisial positions.

Riding:

Quirlstart

- YouTube

Second ride 77cm

I love the return to home function

[V_S]

Space for more content

[Kian]

Wow. That’s really small.

[ludwig_bre]

@Kian

That’s really small.

[Jezza]

This is awesome!

Which VESC is that?

[V_S]

Flipsky 6.7 PRO
20char

[Jezza]

The 70a version? I tried it and it overheated in 30sec
Maybe I need to revisit the heatsink

[V_S]

Yeah, it can handle 90A for 25sec before overheating. (Dock tested)
Time enough to get on plane.
With my watercooling it can handle 50A continuous (about 70 degree) and thats more than enough.

[Jezza]

Thats might explain it, I want to passively cool it and it lasted 13sec before overheating.

[V_S]

This ist my static Pool Test,
Pinky, 63161 100kV, Vesc 6.7 Limited 90A at 90%
No water flowing though cooling. Got Like 25sec
A usual start takes less than 5sec. Then water ist running anyway

A real Log can bei found here:

BREmote VESC Telemetry Log - Deutschland, Hessen | LogTRC

[willo]

Really tight design work. Got any internal pics? Love to see the layout. I’m totally digging the simple hatch.

[V_S]

There ia a public foto folder on my website

[ludwig_bre]

@V_S

my website

Don’t think you posted the link here yet: https://www.77cm.de/

[V_S]

20char as usual

[willo]

My brother in nerd. Fantastic.

[willo]

ok so a couple of items:
Your site is great, but some pages don’t flip language. I’m not sure if you set that up or if that’s just chrome being chrome. (in particular the propellers page)

Also it would be great if you had notes about the propeller performance.

Second I was looking for info on your heatsink/water cooling setup. Didn’t find it.

Also I didn’t see any compartment layout (batteries, controller, etc) I did see batteries but now how you fit all that stuff into that thin board! Please share!

Again, fantastic, keep it up

Keep it up, this is great work!

[V_S]

This is almost all. A Bremote Nano RX with GPS sitting between the batteries. In this case my 12S4P 21700 20Ah.
In the back is a flipsky 6,7Pro. Thats it.

For cooling i soldered a piece of copper sheet metal and two brasspipes together and glued it on the FETs.

The Website has no english version yet. So all you got is the chrome translate version.

[V_S]

@willo

I didn’t see any compartment layout (batteries, controller, etc)

I guess you‘ll find some more pics in my fotostream

[V_S]

@willo

Also it would be great if you had notes about the propeller performance.

I’ll add more details as soon i can.
Logging and research is now so much easyer, thanks to @ludwig_bre with his Bremote and @Kian with logtrc.com
Thanks so much guys

Example:
65161 with my 2blade. RL foil 75kg Total

BREmote VESC Telemetry Log - Deutschland, Hessen | LogTRC

[V_S]

5085 performs OK, but atm 65161 still performs better