Junco 75

By The Van on Jan 09, 2019

39  670  14

Project Junco

It’s an open source printable brushless whoop frame – currently available in 65mm & 75mm, designed around standard whoop-sized brushless components.

Goods & Info here - Project Junco

Little bit of extra background - I wasn't initially planning on making any micro frames this year. I knew that after starting to ship the Raven in October, there wouldn't be enough time to design, prototype, & produce a finished frame by winter.. so I decided it'd be fun to design something to be printed & make it open source. Even so, getting it to this point took about a month longer than I'd planned for. Now that most of the legwork is done, I'm excited catch up on some other designs!

This is currently my 75mm Junco build. The powertrain isn't exactly up-to-date with today's trends - but I do really enjoy the convenience of 1S. I will eventually be changing the motors out for probably an 0803, and then the Beta F4 2S AIO.

Even with these little motors though, it's a fun indoor flier and much more efficient than the same setup in a 65mm frame :)

Looking at the bottom you can see how I've hooked up the rubber bands - this is nice as (on each end) one band goes around the battery and one band stays down as padding. Keeps it from introducing vibes vs just wrapping it across the middle.

TBS and Rakonheli both make props (31mm & 40mm) with through-holes that can be mounted upside-down.


Part List


Project Junco
See Site

Flight Controller

F4 1S Brushless Flight Controller (Frsky RX+OSD) (3 builds)


0603 1S Brushless Motors (5 builds)


TBS Micro Brushless Props 4Blade 40mm (Black) (1mm Hub)

FPV Camera

Caddx Firefly - Micro FPV Camera w/ VTX (7 builds)
Show stores (4)


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StickyRice   3 days ago  

what it the battery was top mounted oOooOooO. Cool buid dude!!

StickyRice   3 days ago 

like the camera is infront and theres a battery slot you can put that attaches to 2 of the fc mounting holes
that would be lit!!

The Van   3 days ago 

There's an idea! I'm sure it wouldn't take much, maybe we'll see a variant like that in the future :)

StickyRice   2 days ago 

i just like top mount because i crash hard and the battery is ussually the one that gets dented huhu

cptandy   6 days ago  

Will you sell prints of the frame directly off your site I would like one please to build with. What a beautiful frame! WELL DONE

The Van   5 days ago 

Eventually, yes. But as it's still pretty early in development I'm going to wait until it's further along before I start selling it. Even though it's pretty clear that it's a project, there's a quality standard to reasonably expect when you pay for something & the Junco just isn't there yet! Also, my printers stay pretty busy between Raven production & new developments.

So, what I've done for now is made a printing service channel in our Discord server. We've got about 40 members and counting, so feel free to drop in and request a print. Otherwise you could take the model and upload to a printing service like shapeways & they'll be on Thingiverse soon as well, which has its own options for printing services :)

QU|(K_F0X   7 days ago  

I edited the design to work with 16x16mm stacks and the old racerstar 1103 motors, is there any place to upload the version on your website?

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ghostface   7 days ago 

Why not also upload it on thingiverse and add a remix?

The Van   7 days ago 

Eventually I'll post the main files up there, but for now I've decided to host them myself. Others are free to upload iterations wherever though

ghostface   7 days ago 

fair enough :)

Taylormadearmy   7 days ago  

Lovely build!
What did you print it in?

The Van   7 days ago 

Thank you! This one's in PLA - and cracks accordingly.. but the color is just too good! My best results so far, as far as durability, have been with PolyMax PLA. That stuff is really good on impacts, resists cracking, & prints pretty easy. I've still yet to get a good PETG print (never quite dialed that stuff in) and will be testing some other interesting filaments in the coming weeks & months :)

jazzyboy   7 days ago  

Love your project :)

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