This article aims to help you get into 2.5″ ultralight micro quads (aka Toothpicks). There are pre-built models and you can also build from scratch. I will explain how to choose the right components and setup, and give you some tips and accessories that might make life easier.
This article focuses on 2.5″ toothpicks, Introduction to 3″ Ultra-light Micro Quad (Toothpicks).
Table of Content
- What’s a Toothpick Micro Quad?
- Pre-built Toothpick Options
- Building Your Own Toothpick
- Lipo Battery
- Flight Controller
- Radio Receiver
- FPV Camera and VTX
- Useful Accessories
- Build Tips
What is a “Toothpick”?
Based on my understanding, a toothpick is a type of micro quad that runs 2.5″ propellers and weighs under 60g without battery. I also call them “ultra-light micro quad” if you dislike name “Toothpick”.
The “Toothpick” class was started by KababFPV, originally as a DIY conversion by taking tiny whoop components to a slightly larger carbon fibre frame (from 75mm to 105mm), and replacing with larger propellers (from 40mm quad-blade to 65mm bi-blade). You do lose the ducts protecting the props, but this simple conversion improves performance dramatically.
Toothpick setups have been evolving rapidly since, becoming more powerful and sophisticated. Manufacturers are now producing parts specifically for this class of micro drones, some even offer well designed pre-built kits.
The Future of FPV ?!
The ultra-light micro class is becoming my favourite type of quad to fly. I think they will get more popular in the future because:
- They are very tiny, but can be surprisingly fast and agile !
- Not as dangerous as a 5″ quad, some setups are as light as 60g including battery
- Legal to fly in many countries without license because they are under the 250g weight limit
- Crash impacts are lighter thanks to the light weight, hence more durable
- Very cheap to build since the components, batteries and accessories are way more affordable than those for 5″ racing drones
There are now 3″ ultra-light micro quad too, but I will focus on the 2.5″ ones in this article since that’s my personal favourite, they are safer and quieter to fly in parks.
If this is your first time getting into the Ultra-light micro class, getting an BNF model (pre-built) is a good idea. Not only it’s usually cheaper than building your own, you won’t have to worry about which parts to get.
The Process of Building Your Own
Beware of Compatibility
Because the Toothpicks started from DIY modifications, component compatibility has always been a major issue, for example FC/ESC stack won’t fit in some frames, and some motors have strange mounting pattern, etc.
Unfortunately I think this will continue to be a problem for a while, until this class becomes more main stream and standards are established. This is also why I recommend getting an RTF kit as your first.
If you still want to go over all the troubles to pick your own parts and build it yourself, make sure you do enough research before buying anything. Here I’ve gathered some of the most popular parts to give you an idea what are available on the market.
Picking “Cell Count”
First of all, decide on what LiPo cell count you want to run. The common cell counts are 1S, 2S and 3S. This article explains what LiPo cell count is. Battery cell count affects your choice of motors, ESC, and ultimately the AUW (All Up Weight including Battery) of your craft and flight performance. As a general guideline:
- 1S: Max AUW <40g
- 2S: Max AUW <80g
- 3S: Max AUW <90g
A 1S setup is going to be the lightest, essentially as light as a tiny whoop. It’s not the fastest, but definitely the quietest, and more suitable and safer to fly in public places. 3S is the a lot more powerful, but also the heaviest usually. A 2S setup is not too different from a 3S setup because most of the components are often similar, just different motor KV’s.
I’d recommend the 3S setup if you don’t know what to get, because it’s the most versatile and fun :) You can go fast or slow by adjusting the maximum throttle limit. You can also use 2S LiPo on a 3S setup, to make it fly slower without the need to setup throttle limit.
If you are all about safety then go with 1S, but beware that these might not handle the wind as well as the 2S/3S setups.
When picking motors, it’s good to meet the following requirements:
- Motor Shaft Diameter: 1.5mm (for mounting propeller)
- Mounting Pattern: M2 9x9mm (make sure the frame support it)
- (optional) it would be nice to have propeller mounting holes on the top of the motor bell, in case the propeller you want to use has a loose fit you can secure the prop with screws
- 1S: 0803/0804 11000-19000KV
- 2S: 1102/1103 8000-12000KV
- 3S: 1102/1103/1104 7000-9000KV
These guidelines is based on the assumption of running 65mm bi-blade props. If you plan to use other types of propellers you might have to adjust motor KV accordingly. I will explain more on that later.
Larger motors are also used in these tiny builds, like 1106, 1108, 12XX, 13XX or even 14XX motors. They will give you more torque to deal with higher pitch or larger propellers, but they are also heavier. There is nothing wrong with using larger motors as long as it works for you, however the essence of a toothpick is light weight. If you don’t care about the weight, then you are just building another micro quad, not really a toothpick :)
Here I will list some of the popular motor options. Let me know in the comment in case I miss any motors that you like.
1102, 1103, 1104
The lightest builds uses 1102 or 1103 motors, normally paired with 65mm bi-blade propellers.
- iFlight Xing Nano 1103: https://bit.ly/2kkq6SH
- AMAXinno 1103: https://amzn.to/31KZScm
- Happymodel EX1102: http://bit.ly/359IFLN
- Happymodel EX1103: http://bit.ly/2VegnuY
- BetaFPV 1103: http://bit.ly/2AIvIdW
- GEPRC 1103: http://bit.ly/2MeZoEW
- Flywoo 1103: http://bit.ly/2McV9ts
- Hyperlite 1103: http://bit.ly/2OowZyO
- Amax 1103: http://bit.ly/2AMSD81
- Mamba 1103: http://bit.ly/2o7jdGl
1105, 1106, 1108
For larger 3″ props, or 2.5″ triblade, larger motors are use.
- iFlight Xing Nano 1105: http://bit.ly/2o7jdGl
- BetaFPV 1105: http://bit.ly/336WxEN
- EMAX RS1106: http://bit.ly/2Vfq6Bn
- Returner R3 1106: https://amzn.to/35dj30O
- BeeMotor 1108: https://amzn.to/352dIsS
Our motors have 1.5mm shaft, so if you are choosing a “push in” style propeller, make sure they have 1.5mm holes too. You can drill the hole bigger if they come with smaller holes, but it can easily lead to “imbalance” as you can’t always get the hole enlarged around the centre.
These ultralight micro quads can be really picky about propellers. One prop might work fantastic on one model, but might be terrible on another. It’s best if you can get a few different props and see which works the best for you. If you don’t have the budget then just get what I recommend in the linked article below.
See my 65mm bi-blade propeller shootout.
To run these heavier props, it’s best to use slightly bigger motors for the higher torque, and the KV should be 2000-3000 lower than the ones you’d use for 65mm bi-blade props. For example, 1106 6000KV for 3S setup, or 8000KV on 2S setup.
For optimal performance, try to select a battery while keeping the AUW (all up weight) below certain levels. As general guidelines:
- 3S 300mAh – 450mAh (AUW < 90g)
- 2S 450mAh – 600mAh (AUW < 80g)
- 1S 450mAh – 600mAh (AUW <50g)
I tested a bunch of 2S and 3S LiPo batteries here, so you know which are good and bad.
A few things to keep in mind when picking a frame:
- Make sure it’s light weight but not too fragile – 10g is the average weight including canopy
- Camera support – AIO or nano size (14x14mm)?
- FC support – 16x16mm, 20x20mm or whoop FC?
- Motor mounting pattern – typically M2 9x9mm, but double check motor specs
There are a ton of custom made frames out there, and countless 3D printed canopy designs available on the internet.
To give you some ideas, here are some popular choices:
- Kabab toothpick frame: http://bit.ly/2MdTJPm – designed by kabab, note that it’s only a carbon fibre bottom plate, and doesn’t include the 3D printed canopy
- FullSpeed Toothpick: http://bit.ly/337fk2Y – really like this frame, affordable, robust and takes both 20x20mm and 16x16mm stacks – but not whoop FC
- Sailfly-X spare frame: http://bit.ly/2OnZpcq – probably the cheapest frame you can get, i like it because it takes nearly all the FC options on the market, 16x16mm, 20x20mm as well as whoop FC. However if you use 20x20mm you would have to mount it under the canopy and not on the carbon fibre frame, which might not be ideal in terms of durability and performance
- URUAV frame; http://bit.ly/31PJsj1
- RedDevil spare frame- http://bit.ly/2oZuvw3
- Velociraptor VCT-1: http://bit.ly/35dkvQO
- ZJWRC-110X: http://bit.ly/2Il372D
FC & ESC
When it comes to flight controllers (FC) and ESC for micro quads, there are two types: AIO board and FC/ESC Stack.
AIO (All In One) boards are basically the flight controllers for brushless tiny whoops. They are called AIO because the ESC is built into the same PCB as the FC, some even has built-in radio receiver. Although they are very low profile, the ESC usually has lower current rating due to the lack of space. And they tend to be wider in dimension.
FC/ESC stacks have separate boards for flight controller, ESC, and some even include a VTX (video transmitter). The two main form factors are 16x16mm and 20x20mm (mounting pattern).
The cool thing with a stack is that you can replace a faulty board instead of the whole thing, hence cheaper in the long run. However a stack can take more room so make sure your frame supports it. In my opinion, there is not much point to get 20x20mm when the more compact 16x16mm stack gets the job done just fine.
Here are some popular FC stack options:
- iFlight Success F4 Micro Stack (with VTX): https://bit.ly/2OTL7SA
- HGLRC FD413 Stack (with VTX): http://bit.ly/2miwSsL
- Mamba F4 Micro Stack (no VTX): https://bit.ly/2KABuEk
I have a round up of some popular AIO Boards, but these ones stand out particularly for the toothpicks:
- Mamba F411AIO: http://bit.ly/2Ve4Bkv
- BetaFPV F4 AIO: https://amzn.to/2Mazx3q
- GEPRC F4 AIO FC: http://bit.ly/33r3fXm
- Crazybee F4 Pro V3 (with RX): https://bit.ly/crazybee-f4-v3
- NameLessRC F4 AIO: http://bit.ly/2In5Zfi
- iFlight SucceX F4 Whoop FC (with VTX): http://bit.ly/2OtNIkx
If the FC doesn’t come with an integrated RX, then you’d have to get an external one and solder it to the FC. Pick one that is small and light weight, here are the options for Frsky users:
- XM and XM+: https://bit.ly/2nx0pe6 – recommend, small, cheap and full range
- R-XSR: https://bit.ly/2HZZkoy – maybe an overkill what micro quads, but these provides telemetry
I highly recommend updating your Frsky receivers to FPort, giving your control and telemetry in one wire.
FPV Camera and VTX
AIO cameras have VTX integrated, they are often used in micro quads and Tiny Whoops. However video quality and light handling (WDR) tend to be worse than standalone FPV cameras. And the VTX in AIO setup is often limited to 25mW which results in poor range.
However if you are looking for low weight, affordability and convenience, check out our AIO FPV Camera/VTX round up to see which we recommend.
I personally prefer a dedicated FPV camera and a separate VTX. Yes it’s going to be more expensive and slightly heavier, but this setup provides considerably better image quality, range and flying experience.
- Runcam Nano 2: https://bit.ly/2mrnYJn
- Runcam Racer Nano: https://bit.ly/2kxb1xa
- Caddx EOS2: https://amzn.to/2ViTC9t
- Foxeer Predator Nano: https://bit.ly/33aP2wI
- Caddx Kangaroo: https://bit.ly/2Vlybo1
- TBS Unify Pro32 Nano: https://bit.ly/2m9XMmT – Smallest, supports LiPo input, expensive but great quality
- Eachine Nano VTX: http://bit.ly/nano-vtx – Budget, 2nd smallest option
- Eachine VTX03S: http://bit.ly/2OqrAY3 – Cheap but takes up slightly more space
- Eachine VTX02: http://bit.ly/31NFt6p – Dirt cheap and reliable
Make sure to check if the FC’s 5V BEC supports the VTX (current rating). If not try to get a VTX that you can power directly off the battery.
These VTX all come with antennas, but if you need a replacement, or simply want an upgrade, these are some good options:
- Micro AXII: http://bit.ly/2IrRUNP – Circularly Polarized
- Lumenier Micro Dipole: http://bit.ly/2VnnscY – Linearly Polarized
HD Camera on Toothpick?
It’s possible to record 1080p footage from a toothpick. I’ve tested the 10-gram Runcam Split 3 Nano, when replacing the dedicated FPV camera, the added weight is only about 6-7g.
Here are some accessories you might find useful:
- XT30 Pigtail (20AWG 7cm): http://bit.ly/2ppnc19
- XT30 Parallel charging board for 1S, 2S and 3S LiPo: http://bit.ly/2ksvAux (… little trick about the connector)
- Two PH2.0 to XT30 adapter (male to female): http://bit.ly/2ouNyyk
Racewires (Motor Wire Extension)
Here are some tips and tricks you can apply to your toothpicks.
Throttle Cap Top End
For a 3S seutp, I normally put a throttle cap at 90% because it draws way more current than RPM increase, and it really impacts your efficiency and flight time. It also sometimes introduce oscillations due to props deflection when RPM gets too high.
Adding Low ESR Capacitor
Like our bigger 5″ quads, you can solder low ESR capacitor to the toothpicks. It helps to reduce noise in the power and protects electronics from voltage spikes. Simply solder the cap to the battery lead solder pads.
I think it’s only necessary on 3S builds. Make sure the capacitors are “low ESR” to be effective, common values are:
Battery Connector and Battery Wire Size
Use XT30 for 2S and higher voltage, instead of the little JST-PH2. The XT30 offers lower resistance that improves performance tremendously: more punch and power and longer flight time too.
Use 20AWG wires for battery lead. You can use even larger wires, but not necessary IMO.
Strap the battery lead to the frame with a zip tie for stress relief, to avoid pulling on the solder pads in crashes.
How to Keep Props on?
New props from brand names don’t usually come loose easily, but when they do, there are tricks to prevent it.
Apply a dab of E6000 glue, or super glue in the prop hole. E6000 takes a day to dry, but preferred as it’s easier to remove the props later.
Some people also use dental floss, and you don’t have to wait for the glue to cure. Cut an inch piece, put one end into the shaft hole of the prop, then push the prop onto the motor, the floss will be wedged between the shaft and prop. Finally, clip the excess floss.
How to Get Props Off?
When the props are stuck on the motor, I normally lift the prop off the motor with a pair of scissors.
I know these are small builds, vibrations are not as severe as 5″ quads, it’s still a good idea to add thread-lock (loctite) to the motor screws.
I also sometimes use 2-3 screws instead of 4 to save a little bit of weight, but only recommended if you use thread lock.
Avoid Motor Connectors
Whenever you can, avoid using connectors to connect motors to ESC. Direct solder the wires to the ESC solder pads. Yes, connectors are convenient but they can become the bottleneck for current going to the motor.
Rubber Band as Battery Strap
Use rubber band to replace battery strap, not only saving weight, it even works better sometimes.
Adding a Buzzer
I really think everyone should add a buzzer to their builds. It’s less than a gram and might save your quad one day.
Ways to Improve FPV Range?
- Use a circularly polarized antenna on the VTX (e.g. Micro AXII)
- Mount the VTX antenna 45 degree to the horizon, make sure nothing blocks the antenna (canopy / carbon fibre)
- Use a VTX with 200mW capability
- Jun 2019 – Article created
- Aug 2019 – Added a huge selection of components
- Oct 2019 – Updated product listing (I can hardly keep up with the rate of new products)-