The basic idea of the Micro Long Range (MicroLR) ist quite simple: Scale down a 7" long range quad until it is sub 250g AUW. While there are many sub 250 micros the clue here is the electronics layout with a 16x16 stack in the center plus 20x20 stack in the back
as well as the dead cat design and 4" inch props for maximum efficiency. This frame configuration allows you to easily fit an impressive amount of feature in your sub 250 setup:
- GPS for speed, location, return home etc.
- 4K video footage with no props in view
- And independent buzzer for easier post crash recovery even if the battery is ejected
- 3+ miles of range with and 800mW VTX
- 10+ minutes of flight time (11:20min of cruising on 850mah 3S)
- Max. Prop Size: 4 Inch
- Frame weight: 36g
- Front Stack: 16x16 only
- Rear Stack: 20x20 only
- Cam mounts: 19mm Micro
- Motor Mounts: 9-12mm 4-hole
- Standoffs: M2x25 and M2x20
This frame is intended to be used for pretty specific components and I have invested a lot of effort in testing so please make sure to read the following recommendations:
Motors: Flywoo 1404 3750kv or iFlight Xing 1404 3750kV. I tested a total of six different motor options and 1404 3750kV is my recommendation for the moment. Anything smaller like 1303 is not suitable to swing the pretty hefty T4x2.5 props properly. The frame does in theory fit much bigger motors with a 5mm shaft like 1408/1506/1606 etc. but I really recommend not going in that direction since the frame is not designed for those kinds of loads and rotating masses. Update 18.12.2019: BetaFPV just announced 1505 3600kV that could be a good match too. I'll test them as soon as I can get my hands on a set!
Batteries: With an 850mah 3S you will get up to 10+ minutes of cruising. You should also take a closer look at the GNB 1100mah 3S that is only 66g. I haven't t tested it yet but the specs are amazing. The smallest battery size you should go for is 650mah 3S (7:30 min of cruising). I don't recommend going up to 4S. 3S has PLENTY of power and 4S on today's 16x16 ESCs will just not be reliable enough for long range. Also, please just forget about 18650 Li-Ion cells and other shenanigans! I wasted a lot for time trying to make them work but ultimately failed to get better overall performance than on a LiPo.
Video Transmitter: The VTX should have 20x20 mounts and sit on the rear mount. The Rush Tank Mini 800mW is currently the best option. It's very user friendly when it comes to switching the channels through the buttons instead of using SmartAudio. Not having to use SmartAudio is a big plus here because it frees up one of the scarce UARTs on your 16x16 FC.
Receiver: Crossfire Nano RX is the way to go! You can comfortably zip tie the Immortal-T antenna to the front of the quad.
Camera: The Caddx Tarsier is the way to go if you want the best video quality (both FPV and HD). The Runcam Split 3 Nano is the best low cost and low weight option. Important: The RunCam Hybrid does not fit in the standard frame because it's stupid big. Please use the dedicated version of the top plate for the Hybrid that is included in the thing files. If you don't care about HD footage and want to have the best FPV quality go for a RunCam Micro Eagle with it's best in class image quality. You can also add a DVR with 20x20 mounts like the RunCam DVR
ESC/FC stack: I recommend getting the HGLRC 16x16 stack since it has two main advantages: First a cable connector instead of fragile pins and second two fully accessible UARTs (RX and TX). UPDATE: Flywoo now has a 16x16 with two fully accessible UARTs too. It's the Goku F411. Overall quality looks better to me than the HGLRC.
Props: HQ T4x2.5 are pretty much the only option for 4 Inch t-mount prop at the moment. They are really smooth and efficient.
FPV Antenna: I had the best results using a full sized Lumenier Axii but you can also go for the Nano version if you want to shave off a few extra grams
Buzzer: An independent buzzer is absolutely crucial on a micro long range build. Good luck finding such a small quad without it! My recommendation is the Full Speed Luck Box. Not the loudest at 90dB but incredibly light and small.
GPS: The GPS mount is designed for the BN-180 GPS
- Setup & Tuning: You can expect my recommended setup to run just fine on BF4.1 Stock PIDs. The Throttle is pretty touchy (cruises at 20-25% throttle) so upping the throttle mid is pretty helpful to have more precision / resolution on the lower end.
Custom motor mix for the MicroLongRange (thanks NorfFPV for sharing!):
mmix 0 1.000 -0.809 0.659 -1.000
mmix 1 1.000 -1.000 -0.659 1.000
mmix 2 1.000 0.809 0.659 1.000
mmix 3 1.000 1.000 -0.659 -1.000
CARBON PARTS SOURCES:
North America & Global: Send an email to Nick from CNC Madness. They have the files and will know what to do if you ask for a MicroLR. CNC Madness will charge you around $24 inclduding standoffs and screws.
Global:Armattan Productions... Good quality but kind of slow (3-4 weeks). Standoffs and hardware not included.
- Germany / Europe: AHLtec Please be aware that you will have to email them in German. Hit me up if you need some help ;-)
Disclaimer: I'm not directly affiliated to the the above third party CNC service providers. These are recommendations only and I cannot guarantee prices, quality and shipping times.
Youtube Video: https://youtu.be/2ewA5KHs02E