Toronto Micro Marathoner

By Polymerization on May 19, 2021

27  1,552  16

Continuing on the trend of using 18650 batteries instead of lipos on micro drones, this frame takes it to a weird place as a partially inverted plus frame. It is designed to be a NanoLongRange style 1s quad but I chose instead to refer to it and the genre as a slightly more acurate but still slightly misleading Micro Marathoner. This is just the first build to test how well it flies (you could probably tell by the tape and wires), it still has a long way to go.

Link to Thingiverse for STL files:
Link to video on the design of the frame:

Link to flight footage:


Part List


Toronto Micro Marathoner by designingpoorly
See Site

Flight Controller

Happymodel Crazybee F3 Pro Flight Controller Mobula7 5A 1-2S Compatible DSM-X DSM-2 Receiver for 2S Brushless Tiny Bwhoop (2 builds)
See Site


JMT Mobula7 V2 Mobula 7 Spare Accessories Crazybee F3 Pro Flight Controller Frame Canopy Camera Buzzer


4 x RCINPOWER GTS V2 1202.5 11500KV Motor - Choose Color (13 builds)


HQ Prop Durable Prop T65MM (5CW+5CCW)-Poly Carbonate (30 builds)

FPV Camera

Eachine TX06 Split FPV Camera Transmitter Micro 700TVL 5.8Ghz 40CH 25mW 1.8g AIO VTX CAM for RC Drone Tiny Whoop Mobula7 (2 builds)

FPV Transmitter

Eachine TX06 Split FPV Camera Transmitter Micro 700TVL 5.8Ghz 40CH 25mW 1.8g AIO VTX CAM for RC Drone Tiny Whoop Mobula7 (2 builds)


JMT Mobula7 V2 Mobula 7 Spare Accessories Crazybee F3 Pro Flight Controller Frame Canopy Camera Buzzer


LG HG2 18650 3.6V 3000 mAh 20A Li-Ion Rechargeable Battery - 18650 Canada (2 builds)


Samsung 25R INR 18650 2500mAh 3.7V battery Canada - 18650 Canada

Power Distribution

3.5A DC DC 3V 3.3V 3.7V 4.2V 5V to 5V 6V 9V 12V Step up Boost Converter Voltage Regulate Power Supply Module Board


FlySky FS-i6 2.4G 6CH AFHDS RC Radion Transmitter With FS-iA6B Receiver for RC FPV Drone (15 builds)


Eachine VR006 VR-006 3 Inch 500*300 Display 5.8G 40CH Mini FPV Goggles Build in 3.7V 500mAh Battery

Misc Parts

10PCS New Ultra thin 5V Active Buzzer Alarm AC 9MM*4.2MM 9x4.2MM 0942 MINI Active Piezo Buzzers Fit For Arduino Diy Electro

Battery Charger

HTRC iMAX B6 AC RC Charger 80W B6AC 6A Balance Charger Digital LCD Screen Li ion LiFe Nimh Nicd PB Lipo Battery Discharger

Battery Charger

XTAR VC2 charger for 10440/16340/14500/14650/17670/18350/18490/18500/18650/18700/26650/ 22650/ 20700/21700 battery Charging

Soldering Iron

Soldering Iron EU US Plug 110V 220V 60W Thermostatic Electric Mini Solder Iron Station With 6pcs Soldering Tip Solder Wire Rosin


1Pcs Creative Circle 8 Grid Box Travel Pill Case Splitter Pill Organizer Box Cutter Tablet Container Pastillero Storage Box
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Kstone   Jun 30, 2021  

3D printing the 18650 holder will drop half its weight. Even then printing it as part of the integrated frame would reduce the weight even more. Furthermore, Nylon is far better than PLA for printed quads. More durable in a crash and can be infilled with CF fiber making it very stiff.

Polymerization   Jul 20, 2021 

Yeah, PLA isn't very durable at all for this type of build, especially since it is so heavy!

Kstone   Jul 20, 2021 

Here is an Ultra-Light 18650 holder i designed a few weeks back:
Using TPU, its 6 grams!

A few things that come to mind:

  • 3 to 3.5" Props would really extend the flight time but at the cost of some throttle response.
  • You've a few screws that are much longer than needed. This adds weight and makes the connection of parts suspect if the screws are not pushed completely thru. (Such as with the forward motor)
  • Due to the weight of the quad you could use Nylon screws to connect the motors to the frame. This should save an additional 2-3 grams.
  • Inverting all of the motors should allow for greater efficiency as the thrust doesn't have to contend with the frame being in the way. It's not like your going to tilt forward much if your just cruising around so prop-wash shouldn't be much of an issue.
  • Plus frames can run different sized props on the arms allowing you to have better throttle response where needed. Ideally, smaller 2.5" props front/back and larger 3-3.5" props left/right. This will allow for much better response overall.

Here is my latest build:

rocafel90   Jun 13, 2021  

Such an interesting and cool design!

jeffcd   May 21, 2021  

Well that's something unique!
Great creative design. Nice work!

lgustol   May 19, 2021  

Very interesting design.

Have you considered setting the motors at an angle to get better aerodynamics? Since it's 3D printed you're not bound by the 2D design of frames that use carbon fiber sheets, so you can go crazy with the shape to get more rigidity using less material, and try different ideas like this. You could add vertical support struts on the arms or something. You could even create some lift if you angle the motors like that, making the main body be slightly angled upward when the quad tilts forward. I think the new DJI FPV drone tried to do that a little bit.

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Polymerization   May 20, 2021 

wow that plane looks awesome, yeah I think a lot of work will have to be done to make function partially like a plane but could also offer an increase in range.

BaTTaN   May 20, 2021 

I came to multirotor after 20+ years of fixed wing and understand what you are talking about with having a lifting wing airfoil shaped design as Igustol mentioned you would have to be able to rotate the rotors in the direction of lift, as thrust in any other direction would prevent any lifting effects. Still this is a great 18650 nano build youve made here. I'd bet if you shared the stl there will be others trying it out. When I purchased some of single 18650 trays, I also purchased a few double trays and will be trying to mount them in a few foamy planes down the road but doubt any will be rotorbuilds worthy ;-(

Jayembee67   May 19, 2021  

Very nice! I am partial to Plus config machines, and this is a lovely little thing. Can you set your YT videos to public? We can't currently see them, and I would like to see this in flight!

Polymerization   May 19, 2021 

Thanks for letting me know haha, sorry about that. They should be public now!

Jayembee67   May 19, 2021 

And there they are! Looks like it's flying well, a bit of a tune notwithstanding, and plenty of time in the air! Nice work. Splendid design, and a great project, I like this very much.

So the Plus frame builds I have are rather twitchy in the roll axis, and they are 5" machines not teeny things like this, so this is likely just a characteristic of this geometry - it is visually very nifty though, and the machines do move in an interesting, somewhat sinuous manner.

BUDLoNG   May 19, 2021  

any guides or links to how you constructed the power system?

Polymerization   May 19, 2021 

More or less I used the same wiring and general idea of the original NanoLongRange for it but you can find more information on the video that I have on the page. I also recorded some footage on the construction and design of it which I will upload it in the coming weeks on my channel but if you have a specific question I can try to answer it!

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