The Happymodel Mobula7 uses a F3 based flight controller and since Betaflight 3.4, these boards have not had full functionality of F4 and F7 boards due to smaller memory size for firmware storage. However in this article I will cover how to upgrade to the performance edition of Betaflight 4.04 kindly compiled by UAVTech (his in depth YouTube Channel is here). This special version adds the key performance functions at the cost of typically irrelevant features like servo control, acro trainer, camera control etc. In this article I will show you where to access this firmware and then I'll show you the filters that suit brushless whoops best as well as some good starting PIDs.
This is the seventh and likely final article in my series of HappyModel Mobula7 upgrades, many of which can be used for the Trashcan too. Also to come are:
Betaflight 4 Performance edition for F3 boards
This is the final version of Betaflight you can use and I strongly recommend you use this version rather than the one on the Betaflight configurator to get full performance functionality otherwise you will miss out on features like:
The Happymodel Mobula7 (reviewed here), Eachine Trashcan (reviewed here) and many other brushless whoops use generic 4 bladed 40mm props that are cheap and readily available but are they the best? Simply put, no. They are from a toy grade mould and we have accepted them because when these brushless whoops were first released there was simply nothing else available. Fast forward to the present day with the growth in popularity of these models there are a lot more options, some readily available internationally, some not so much. In this article I'll give you my experiences on what I found to be my favourite prop and the justification of why (what it is I look for in a propeller).
This is the sixth article in my series of HappyModel Mobula7 upgrades, many of which can be used for the Trashcan too. Also to come are:
What props are available?
If you're in North America probably the full list of what is below. I'm not in North America though so I was limited to what was locally available and what had low (or no) international shipping cost. Therefore this is not an exhaustive test, my approach was more on of pragmatism.
I'll compare all my findings back to a baseline result of the stock props for simplicity
Gemfan 1636 (4 blade)
I used these when I was running the v3/trashcan frame which I blogged about here. These were a direct improvement over the stock props in all aspects but were a little more amp-hungry. Grip and speed was improved and control felt better. Props are well balanced but heavier than stock. They are extremely durable especially when you consider the protection afforded by the ducts. You will achieve hover at very low throttle
These props are a good upgrade but not my personal favourite.
Note: These are more like 41mm than 40mm and frustratingly don't quite fit in the ducts of of the v3/trashcan frame - the ones you see above were painstakingly sanded down and even then still rubbed every now and then. I hear TBS props have the same issue
The Happymodel Sailfly X is my favourite quad I've reviewed so fat this year (review is here) but as with any product, there are shortcomings especially when is it built to a price. Like I did with the Mobula7 I'm starting a new series of articles on upgrading and customising the Sailfly-x.
Step 1: Software only
The most simple mod to do is ensure the onboard receiver is given an armchair ride from a software standpoint. This means changing D16 to D8 mode in betaflight and turning off telemetry which has been known to lock up the flight controller. This can be done as below.
Voltage sensing is critical in Betaflight not least of all because it is the best indicator of when to land in order to protect your batteries to make them last longer. I've always taken for granted that this reading is correct on every board from the factory but I can tell you it is not. On 2 recent quads I've set up it was well out (Happy model Sailfly-x and my 2019 freestyle build) to the point were it reported my 6s battery as being 24v instead of 22v.
First you'll need to connect your quad to betaflight and enter the "power and battery" tab. Next plug in your battery (please do it in this order). With you battery plugged in you'll see the voltage as shown by betaflight in the area highlighted below:
Next use the digital multimeter to test the battery voltage using the balance connector. Do this by touching the multimeter probes on the terminals at the extreme edges of the balance connector as below. Don't worry if on backwards, your multimeter will just report a negative voltage which is fine. It is important to do this whilst the battery is connected to the quad as the electronics (especially the VTX) will draw a small amount of current and thus cause the voltage to drop a little compared with having the battery disconnected.
Both the Happymodel Mobula7 (review) and Eachine Trashcan (review) both come with 4 x 1s batteries that are designed to be used in series 2 at a time with a fiddly ph2.0 series connector. This introduces a lot of resistance in the power circuit and resultant voltage drop under load which shows as battery sag. It is easy to upgrade to a true 2s JST connector as I've shown in this blog or a XT30 if you'd prefer. Although 2s 300mah batteries are not expensive it does feel wasteful just leaving the old batteries to die. This article covers how to convert these or any other 1s cell into a 2s battery and is scaleable up to 6s!
This is the fifth article in my series of HappyModel Mobula7 upgrades, many of which can be used for the Trashcan too. Also to come are:
A Word of Warning
Lipo batteries - even these tiny ones - have a lot of power. Anytime you modify you run the risk of rapid discharge (shorting) which generates heat and possible worse. Only do this mod if you are confident around electronics. Please wear eye protection at a minimum and work in a well lit space. Just go buy the 2s batteries if you are unsure at any point.
As well as having a well lit area and a good soldering iron, solder and flux (see my article on budget tools here) you'll nee the following items:
In order to solve the charging issue FullspeedRC (yes the same ones that launched the Leader series of micro quads) have released a simple board that allows the batteries to be balance charge using the existing USB port. It can be bought for around $10 at the following retailers:
Please note this is not a beginner install but if you can solder a FPV cam and vtx to a flight controller you can probably do this. I've put in a LOT of photos and steps in below to make it as straightforward as possible since Fullspeed's manual is accurate but overly short. As usual click any image below to embiggen.
Tools I recommend for this job:
I promise I'll keep this one short. We are forever taking antennae on and off our quads and goggles as we arrive and leave our flight locations. I'm guilty of being too eager to get in the sky and not tightening my antennae correctly thereby leaving a poor connection to the active element on both the quad and goggle ends. Using a spanner is not a fix I'd recommend as it is easy to over-torque and damage the antenna or mount.
The fix here is really easy and I got the tip from my favourite VAS antennas which all include a plastic knurled grip (now I know why). Using a knurled grip that sits over the hexagonal drive on an SMA-style connecter allows you to get a better grip and more torque on tightening whilst avoiding over torquing as above. To put this another way - using these grips allows you to get the right tightness every time - good for the best connection and it will also help them coming loose in flight.
I love the emax tinyhawk, even though it is 'only' 1s it is well suited as an indoor racer and they've recently started a spec class near me just for this. My full review of it is here. One one common furstration however is that the FPV camera can come loose in a crash and if you try to push it back in the wrong way you can easily snap the tabs on the frame that hold it in. I've prepared a simple step by step walkthrough heretht will allow you to fix it safely in less than 5 minutes (I timed it!).
The Emax Tinyhawk is a 1s brushless whoop-style quadcopter that has steadily grown on me since I first reviewed it here. It's certainly not the fastest but is probably the most well designed ducted quad available at present. It comes stock with very good 3-bladed emax props that perform well except that lack thrust when running in reverse meaning "turtle mode" does not work. I've installed and reviewed their new 4-bladed props where turtle mode works and how they perform in general.
Reversing the rotation of all of your propellers (known as 'props out') is something you commonly do on larger quads to eliminate debris bring flung into your FPV camera and to push obstacles like branches clear. Obviously these don't apply when the props are gaurded like in a Mobula 7 but there is also a hypothesis out there that it can improve flight characteristics such as note on KababFPV's video here. Some of the beta fpv guys also believe it helps with yaw washout but the evidence appears inconclusive. Typically to do this correctly you need to
This is the fourth article in my series of HappyModel Mobula7 upgrades, many of which can be used for the Trashcan too. Also to come are:
The crazybee F3 and F4 series of all in one boards that are the heart of the mobula7, m7hd, eachine trashcan, snapper7, ur65, uk/us65 and even beta75pro2 are an amazing piece of technology that incorporates a flight controller, 4xBL_HeliS ESCs and a receiver. Cramming all of this on one board does mean some compromises though and the biggest one for me is the poor receiver range. This brief article will show how to get a minor improvement with zero investment. Note: this mod is relevant for all the models listed above.
This is the third article in my series of HappyModel Mobula7 upgrades, many of which can be used for the Trashcan too. Also to come are:
In order to run 2s, the Mobula 7 comes standard with 2 x PH2.0 connectors that allow you to run 2 x 1s batteries in series. When running in series the strength of the connection is determined by the weakest link in that circuit. The strength of connection determines the maximum current that can pass and the voltage drop that results. Although it works this system has a very low current overhead from a design perspective - 2 x budget PH2.0 connectors with the dreaded 'folded' pin and very lightweight 26AWG wire. All this adds up to a lot of voltage drop when even reasonable current is pulled - something all will be familiar with on the mobula where you see voltage drop to scary levels (6v and below) during punches even when you have a full battery. Although it recovers almost immediately it does mean you don't get access to the battery's full voltage potential.
This is the second article in my series of HappyModel Mobula7 upgrades, many of which can be used for the Trashcan too. Also to come are:
Introduction and why I like the Mobula7 better.
It's been a few months since I reviewed the HappyModel Mobula 7 (here) and have more recently reviewed the Eachine Trashcan here. Since reviewing the Trashcan I've been flying the Mobula 7 more and find I actually prefer it. Why? Even thought the image quality is better I can't get used to the narrow vertical field of view on the traschan's EOS2 16:9 camera and I find the 0803 motors on the trashcan draw too much power on without delivering a whole lot more speed. The Mobula7's major downside is the frame which breaks easily even though the v2 frame is an improvement and e6000 glue (as tested here) is great for repairs.
For this reason I've written an article for newcomers on how to upgrade to the V3 (trashcan) frame which completely addresses the strength issues.
This is the first article in my series of HappyModel Mobula7 upgrades, many of which can be used for the Trashcan too. Also to come are:
Instead of just writing about it, please see the steps below with captions. Click on the picture to embiggen
Recently I've reviewed the Eachine Trashcan and in many ways it is superior to the Mobula7 as I found in my review here. One omission from the trashcan though compared to the Mobula7 is the lack of a physical beeper. On the upside though is that the trashcan (like most other brushless quads) uses Dshot as the ESC protocol meaning you can use the motors as a beeper. This is in fact immediately available on the Trashcan with some simple software changes which I will outline below.
I did a thing. After reviewing the new FullSpeed TinyLeader 2s-3s brushless whoop (review here) I learnt to fly around the heavier weight which has come about because of it's larger motors and better FPV system. I still think that 1103 motors like on the TinyLeader and Beta75x are better suited to a lightweight 2" propeller like my ultralight build here rather than the 40mm props (1.6") as we see so commonly on the brushless whoops now. I decided to put my money where my mouth is so to speak and prove it rather than just hypothesing.
To those of you that choose to upgrade the vtx in your hawk 5, like I did with the AKK infinite VTX/DVR (in this walkthrough here) I've updated my recommendation for the powersupply. Previsouly I relied on the flight controller's 5v BEC circuit that also powers the receiver and of course the board itself. I've now updated this recommendation to use the VBAT (or VCC) power supply instead assuming of course your VTX can take up to 24V as most modern full-sized VTXs can, including the AKK infinite I installed. This is because the BEC struggles at higher output making the video feed noisy. Over the longer term this is likely to irreversible damage the BEC rendering the flight controller pretty well useless but not before having random failures as a result of the compromised BEC. Picture below is using the power supply from the original VTX - the flight controller's 5V BEC:
There is no doubt that the mobula7 as reviewed here is an excellent quadcopter that has redefined what ducted micros can achieve at a fair price but the key flaw in this model (and other ducted quads) is lack of durability in the frame. Frames for the Mobula are not expensive at $4 here but waiting on a frame to be delivered represents downtime.
Welder's glue is often recommended but is not available everywhere and shipping can be precarious on this. I tried the E6000 glue from banggood on a whim and am really please to report it works perfectly, is inexpensive and being available from Banggood, is available worldwide. It comes 15ml, 50ml and 110ml tubes for $3, $4 and $7 repsectively at time of writing. 15ml is plenty for the small amount we need for repairs. It also has a very fine metal nozzle which is just perfect for the fine work we do on repairs. The cap has an integrated pin that sits inside the nozzle for storage so never blocks.
The Taranis X-lite brings a whole new level of portability to FPV transmitters thanks to its compact design and I found this to be one of the most surprisingly useful features of this controller in my review.
The x-lite comes with a very nice lightweight zipcase as you can see in the picture below which allows you to stow some spare parts too. For quick FPV missions though I find all I need is the controller though but the gimbal protectors that come with the controller are just too loose to stay put if I put the controller in my bag without the case. Hence I've been on www.3dhubs.com/he lookout for some gimbal protectors that not only hold more snugly but also protect the screen. There are a number of designs already avilable on thingiverse if you have a 3d printer or access to 3dhubs but what if you just want to buy a cheap solution that does this for you?
The Emax Hawk 5 is arguably the best bind and fly quadcopter going as I found in my initial review but can also be greatly improved with a few budget modifications as I wrote about in my blog on bang for buck improvements. I do however see a number of people complain about the stock Emax Hawk 5 vtx however mine has been functioning well. That being said, you cannot adjust setting in betaflight OSD via smart audio or tramp telemetry which is a let down on a 2018 quad. In the interest of sharing I've removed the stock VTX and replaced with one of the larger VTXs currently available (the AKK Infinite VTX/DVR) to prove it can be done.
The VTX I chose is the AKK Infinity DVR VTX. This is very similar to the HGLRC VTX/DVR that was reviewed here. As the name suggests this is a smart audio VTX in 30.5mm VTX with a built in DVR. I chose those for 2 reasons: First it's big. If I can fit this in you can fit anything! Secondly I like the DVR for recording breakup-free footage. For me I like the nimbleness of the Hawk 5 and don't want to weigh it down with a HD Cam. Other key features of the VTX/DVR:
Just quickly I used the following tools and parts in the instructions below:
Please note all the pictures below relate to the install of the AKK Infinite but install should be identical or at least nearly the same for others. I had to remove the buzzer and relocate the receiver for this VTX but depending on the size of the VTX you install you may need to do only one or neither. Follow picture left to right then down. All pictures will enlarge if you click on them.
Hopefully you've seen my announcement here about the 'performance edition' of the betaflight target for Onmnbis F3 flight controllers as used in the Leader 120 and pretty much every other micro quad that runs an F3 board with OSD (including the Emax Babyhawk R and MANY others). This differs from the stock version offered bia the betaflight configurator in that it includes the fatastic new features that made betaflight 3.5.0 really shine - iterm relax and rc smoothing in particular plus the return of LED control. These were openly available for betaflight 3.4.0 but not for 3.5.0 until sbstnp kindly re-compiled for the community and shared on RCGroups.
Further to this I've installed on my recently revised Leader 120 and confirm that it does indeed allow these important features that were otherwise unavailable - see below.
How to install
I'm going to assume that if you are reading this you kinda know how to update betaflight firmware on your quad so will take a few liberties. Firstly, download and unzip the file below to your desktop. Please note this version is only suitable for FRSKY receivers - leave a comment if you want me to link FLYSKY or spectrum too.
Next, go to the firmware update page in betaflight configurator (preferably configurator 10.4 on) Choose "Load Firmware [local]" and choose the unzipped hex file from the first step. If things grind to a halt here run the Impulse RC Driver Fixer to allow your computer to access your FC DFU
That's kind of it, you're done. Now you can enable all of the options that made 3.4 a real improvement for larger quads plus the improved dynamic filter from 3.5.0 which is more sympathetic to micros and the new feedforward system that allows you to better control the 'feel' of the quad without having to mess with PIDs so much. I'd strongly recommend reading the tuning guide for betaflight 3.4 and the tuning guide for betaflight 3.5 since there are many new features that improve flight performance. Just a quick note you can run Gyro/PID loops at 8k/4k with all new features on at 48% CPU and 4k/4k at <20% CPU as below
A quick announcement - user sbstnp from the RCGroups Betaflight Thread has kindly recompiled the betaflight Omnibus F3 target to allow the good stuff - RC smooting, absolute control, Iterm relax and even LED Strip. For those of you familar with the 3.4.0 'performance' version this is much the same but for 3.5
If you are not familiar this file will allow you to run all of the great new features of betaflight 3.5.0 that make it more suitable for micros (esp new dynamic filter and feedforward) and the massive improvements from 3.4.0 as above. I strongly recommend this for your leader 120 or any other micro brushless as all tend to run the OMNIBUS (F3) target. Will follow up with install guide in a few days. Full credit goes to sbstnp for this recompile.
Hex file can be found here:
For my list of recommended hardware changes please see my blog: My leader120 is a year old! What I've changed in that time
Note: I've now completed my full review of the X-lite which can be found here
The Taranis X-Lite is out and it's great. I have mine and it feels great in the hand, a lot of though has gone into the detail. This is not a review, I'll get to my experiences there soon enough but I want to cover an alternative for the one downside - the uncommon size of battery required to run it.
Battery sourcing issues
I live in New Zealand and if you think you are having trouble sourcing 18500 batteries where you live then you should try it here. In fairness one of the local quad shops sells the genuine panasonic cells but at $USD25 including delivery it's more than I want to spend. Also being impatient I did some lazy research. The "18" part of the "18500" refers to the 18mm battery diameter (some where between a traditional AA cell and a C cell) whereas the 500 refers to a 50mm length - identical to an AA or C cell. Just for a laugh I tried a NIMH AA cell in either side and you know what? It powered up. Since the AA cells are the right length, there was enogh tension in the springs to make sure they stayed connected and didn't jiggle around. The AA's however are not a viable option since they only provide 2.4 - 3.0v in series. One of the rechargeable lithium battery technologies is clearly needed here in order supply the necessary 6.0 - 8.4v the controller requires.
You can use a 14500 battery
Based on the above the more common 14500 cell is viable (an AA sized battery with Lithium technology) and these are much more common than the 18500 albeit with a little less capacity. See below for how they fit in the X-Lite:
Get a pair of batteries for less than USD$8
If you live in Australia or New Zealand the cheapest place you can get a pair of these is actually Bunnings Warehouse - see below for the picture but there are the Solar Magic 3.2V 600mAh 14500 Lithium Batteries 2pk and are only $11.98 in NZ (here) or $9.98 in Aus (here). They are based on LiFePO4 Chemisty meaning they put out 3.2V per cell which is fine for the X-lite. Below is a picture of the battery pack and also a picture of it successfully powering the X-lite:
Considerations for LiFePO4 batteries
Since the chemisty of these batteries is slightly different to Li-Ion or Li-Po that we are more familiar with, I changed the voltage range from 6.0 - 7.0v with the warning coming on at 6.0v. Charging these at 3.5V will get you to 95% capacity and 3.65v will get you to 100% capacity. Do not charge higher than this!!! I'd recommend charging to 3.5V only for safety. There is a good article here on what to expect with voltages and charging on this type of battery but in short it looks like it is well suited to this application.
Continuing with the NZ/Aus theme you can pick up a battery box for only $1.50 from Jaycar here or alternatively you can find one at Banggood here. than can be easily adapted to a balance charger for you to safely charge the batteries on you Lipo charger (don't forget the voltages above). Below is a picture of the battery box and how to adapt for balance leads.
It's early days yet but it's working well in the controller. Not sure about the heritage of these batteries so next time I charge I'll see how much capacity they take. For $10 for 2 batteries I didn't need to wait for though it is a good option.
Gearbest were kind enough to provide me this Taranis X-Lite to review so I'd encourage you to purchase from them if you are considering one. It only took 3 days to arrive to me in NZ so not bad with ragard to delivery speed. It is available here in either black or red.
Update! I've just finished writing an extremely detailed walkthrough about how to upgrade the VTX - full blog here
The Hawk 5 ready to fly 5" quadcopter has been out for several months now and has been a real hit for Emax - so much so that it is only widely available from a stock perspective now. I have one which I've reviewed (here) and can quite easily say it is the most well-balanced and complete bind and fly quadcopter I've come across. Gearbest and Banggood currently have this is on special for $209 and $229 respectively (check out my discount page here)
My real life work means I'm always looking to improve on systems and it's no different for my quad obsession. So I've made a list of my favourite 'improvements' or probably more accurately personalisations as these are more about changing the feel of the quad to suit my taste rather than the basic operation. I'll also cover off the things I haven't touched because I've not yet thought of a better alternative.
6 inch arms
The 6 inch arms are available as a direct uprgrade from Emax rather than a third party offering. All four can be had for less than $20 so it's fair to say Emax is looking to expand their ecosystem rather than profit of these in particular. They are very easy to fit since the frame uses captive nuts and arm retention hardware is independent to the stack mounting hardware. This means you can change the arms without pulling anything apart. Arms are sold in pairs and are presently in stock at Banggood for $8.99 per pair.
The new arms will push the motors out by 15mm in each direction and the good news is EMax allowed for enough slack in the motor wires so they they don't need to be extended - making the whole process VERY simple. To start I flew with 5" props on the new 6" arms and was suprised to find how much more stable it was in regular flight. I've found examples where several pilots prefer 5" props on a 6" quad for a more stable HD platform (e.g. Gapit) or for improvements to a racing rig (Serge from Piroflip noted that his son Dolma FPV runs a 6" frame with 5" props. KababFPV who works with Piroflip has suggested this is likely due to the lesser amound of turbelent air to each prop given the additional spacing. One potential down size is the additional width but in reality this is only an extra 9mm wide on either side. Theory aside I really liked the feel of stability.
The next obvious advantage this gives is the ability to physically use a 6" prop. In most circumstances you'd need to revisit your motor choice (stator size and/or kV) but in this circumstance the seemingly low kV that Emax chose (2300kV) and and reasonable stator size (2206) means that it can swing a 6" prop on 4s with no issue. I chose to use the Gemfan 6042 bi-blade but have heard good things about the 6" LR Avan prop too. Since the quad is light and the 6" adds so much prop area, they have more than enough grip - much more than a 5" tri blade... feels like they stop on a dime. There are a number of good 3 blade 6" props available now from Dalprop and HQ but I feel the extra weight these add is unnecessary because it will take away from the response of the 'just big enough' 2206 motor. In the air hover is achieved on a much lower throttle as is everything else. Most flying is done at low to mid and the sense of control is strong. Full throttle draws a LOT of current: 135A on 6042 vs about 90A on the HQ 5x4.8x3. High throttle is less about more thrust and more about current draw suggesting the motor has probably hit its limit. This would be a great candidate for scaled throttle reduction in betaflight 3.4.0 onwards as per my setup guide. That being said the thrust is immense for such a light quad and actual battery life was somewhat similar to 5" props but so much more variable - it will be way more efficient than 5" at light throttle but way more inefficient at heavy throttle. For the cost of the arms and props and ease of install I'd definitely recommend giving it a try. The video below shows my first flight on 6" props, please turn the sound down. punch outs at 0:23 and 0:40.
Changing the props
I love the idea that Emax created the 5" Avan Flow around the Emax LS2206 motor on the Hawk 5 but I just don't like the feel. Don't get me wrong, I love the idea that the weight is kept close to the hub and that it is durable and well balanced but just don't like the way it delivers power. To me the HQ props feel much more familiar and I've found the 5x4.8x3 V1s with it's relatively steep pitch is a good match for the LS2206 2300kV stock on the Hawk 5. The other thing I prefer over the V1s design is efficieny. Top speed 'feels' similar but maximum current draw is only 90A on the HQ 5x4.8x3 but 110A on the Avan Flow using my best batteries. Plenty more props for me to try including the HQ 5.1x5x3 but at this stage I'm really pleased with the 5x4.8x3
I find the video transimission surprisingly good on the Hawk 5 but the antenna solution is a let down. Dipoles are fine for flying alone but the Hawk 5 one is not secure. I did the cable tie/heatshrink trick to secure but still lost it after and upside down landing anyway. I wasn't bothered though, because my race club doesn't allow dipoles as a vtx antenna because of the increased likelihood of bleed over to other channels. Emax were good enough to include a UFL to SMA cable and 2 x excellent Emax Pagoda LHCP antenna but recommend a rubbish way of mounting them with cable ties that is just not secure and risks the antenna getting caught in spinning props. The best solution in my opinion is a 3d printed one. I don't own a 3d printer but a service like 3d hubs means I can download an appropriate file from Thingiverse and have it printed and delivered to me - it was only about $5 for 2 printed mounts. Here is the design I recommend since it elegantly incporated and SMA VTX antenna mount and receiver antenna mount using forever tubes. I had a 3d printed mount from an old floss 2 frame and found the standoff spacing is identical (31mm) so have just used this for now. Here is the link for that design. It's a tidy solution that keeps the antenna safely away from the props and allows a good and for a racing quad that is commonly tilted forward fairly heavily.
What I haven't changed:
Motors. Many (including myself) questioned the choice of 2206 2300kV motors when Emax had the 2207 mid-high kV variants available. I no longer question the stator size or kV as I think both are an excellent match for this quad - the 2206 is plenty for a lightweight build and the 2300kV offers great efficiency and flexibilty as per 6" props whilst still being suprisingly powerful. The only change I would make is going to lower kV IF I decided to run 6s which this stack is apparently capable of - Conrad Miller (Furadi) is an EMax team pilot and has run 6s on a magnum stack with a 1700kV motor. If I did go for a low kV motor the standout option for price/performance in my opinion is a Brother Hobby Returner R3 2207 1700kV which is only $15 under the HobbyCool Logo. I've used these on my 6s race build (blog here) and they are super nice.
VTX. The included VTX is limited to 200mW and has no smart audio. Many users have reported poor performance or reliability problems although I have found signal and reliability to be just fine. If it were to die I'd probably install the AKK infinity VTX DVR combo or HGLRC AIO VTX DVR (reviewed here). The stock Hawk 5 is too light to carry an HD cam so an onboard DVR would be a satifactory backup. Given the current VTX shares a stack layer with the XM+ receiver this would need rewiring and I can't bring myself to do this on a receiver that is currently working well for me.
Camera. The Foxeer Micro Arrow Pro as on the Hawk 5 is hands down my favourite budget camera. It gives consistent performance regardless of sunny or overcast day unlike many of the new CMOS cameras. An exception to this is the Micro Eagle which is the best camera (IMO) period. It's not cheap though so I can't justify replacing the Arrow pro but this is the only camera I'd uprade to.
All of the mods I've included here change the feel of the quad except for the VTX antenna mount which is a MUST HAVE in my opinion. I do like the longer arms with the HQ props and this is what I've settled on but this is a feel thing more than anything else and was not expensive so, why not?! I'll only replace the cam and VTX if mine break down. If I break motors I'll replace like for like unless I change the whole fleet to 6s which is presently unlikely.
Please feel free to browse the rest of my site, I now have almost 100 reviews and tips/tricks blogs as well as a regularly updated specials and discounts page.
Update: This is relevant for all versions of betaflight 3.4.0 and up.
One of the new "minor features" in betaflight that I'm very excited about is throttle limit. Previously throttle limit could only be done through your transmitter software and is a pig to set up and even if you could set up it is difficult to flick between option.
For the first time this can be set up in Betaflight with the release of 3.4.0. I'll cover only one type of throttle limit here that will most commonly be used and how to assign varying limits and rates to a transmitter switch. I've put this tutorial together because the throttle limit feature must be accessed through the command line interface (CLI) rather than the graphical user interface (GUI)
Firstly if you have played with rate profiles in betaflight before, this is what your the throttle limits are tied to. You can cycle through these with the betaflight OSD when disarmed or if you assign to switches you can change mid flight.
Why would I want to limit throttle?:
There are a few reasons that are all based around the fact that lmiting throttle will limit current drawn and so limit max RPM and thrust.
It's important to note that your flight controller still has full access to 100% of your throttle meaning that there will be overhead to speed up motors to perform maneouvres and corrections rather than slowing down saturated motors.
How do I do it?
First, choose the rate profile you'd like to limit throttle on, up to 6 are available in betaflight now but I only use 3 since I map to a 3 way switch on my transmitter. In the example below I have my 'race rates' on profile 1 and 2 which are identical and use profile 2 for limiting throttle. FYI profile 3 is my freestyle rates. Make sure you press 'save'.
Next go into the CLI mode. type or copy and paste as below:
set throttle_limit_type = scale
set throttle_limit_percent = 85
In this example the throttle _limit_type is scale where it creates a linnear throttle curve up to the throttle_limit_percent value. In this case the throttle will linnearly increase to 85% at max throttle on your transmitter.
If you wish to turn throttle limiting off again, use:
set throttle_limit_type = off
Lastly there is a second throttle limit type "clip" which simply makes the throttle stick have no impact over a set percentage. I think it will only be exceptional case where someone might use this, particularly playing practical jokes on your mates when you have access to their quad.
To confirm that your throttle limit settings have stuck you can see in you CLI "diff" as below:
As per the example I used, my rate profile 2 (shown here as rate profile 1 since betaflight uses n-1 naming) has throttle limiting as scale limited to 85% maximum.
Setting it to a switch
The real usefulness comes in when you set to a switch so I've taken a screen grab to best illustrate - click to embidden. In this same example
Flick the 3 way aux switch will have rate profile 1 in the 'up' positiion, 2 in the 'mid' position and 3 in the 'low' position. I use this across ALL of my brushless quads: 2", 2.5", 3", 4", 5", 6". Now that betaflight has 6 profiles you can get creative and map to a potentiometer or whatever else smokes your tyres.
In practice this works well for me on quads with older motors that either vibrate or prop/motor combinations that don't practically put out any more thrust after a certain amount of throttle, rather they just draw more current. I do really like the new filtering of the newly released 3.4.0 but for me throttle limiting is one of the most underated features in this release which I expect to see in all subsequent releases too.
The original betaflight throttle limit pull request can be found here:
I've now had my FullSpeed RC Leader 120 for 1 year and have completed a bench review and flight review. After hundreds packs and many replacement props I thought it would be good to look back at what I've changed to keep this up to date and fun because at it's core, the Leader 120 is still an excellent quad and sits in a class of it's own as a ready to fly 2.5 inch quadcopter.
The core of the quadcopter remains the same - original ESC, original flight controller, original 1104 7500kv motors. The bearings on the motors are a little noisy now but no detriment to flight. especially with the modern filtering available on beta and butterflight.
My original review quad was kindly provided by Gearbest but is also available now from Full Speed RC's own website. Full Speed is a little more expensive but offers an excellent customisation service. Speaking of Full Speed the proprieters are pilots and test their products a lot before release - it's no accident they have good products. The Leader 120 is available at Gearbest here and FullSpeed RC here. It sells for anywhere between $100 and $130 depending on sales, discounts.
So what have I changed in the last year?
The Leader 120 ships with a VM2751 CMOS AIO cam and while ok for a whoop I don't think it does the Leader 120 justice given the speeds you can move at. I cannot emphasise enough how much an improvement the FPV system makes. Choose any camera you like, mine happens to have an HGLRC elf as that is what I had available at the time. Now there are many options, my personaly favourite is the Arrow Micro Pro - a 4:3 CCD cam which has an excellend image and can often be had for $20. For the VTX I personally use the Fullspeed FSD-TX200. This has proven to be an excellent long term reliable vtx that mounts easily to the back of the camera. There is no smart audio but then again you can get it for only $11. If smart audio is a must for you I'd recommend FullSpeed's new FSD-TX600 or the AKK FX3 ultimate.
I've made a full article on the install here but with one recent change that has made this much more robust (see picture below).
You may have a receiver already but if not I'd recommend the Fullspeed model. They are less than $10 each and are available in DSM or FRSKY. More importantly they weigh less than 1g so help preserve the lightweight aspect of the Leader. Another thing I really like about the Fullspeed nano v2 receiver compared to the FRSKY XM is the fact that RSSI (control link strength) is enabled on aux 5 by default for immediate use in betaflight OSD. Frsky XM and XM+ receivers need to be flashed for this functionality. The Fullspeed FRSKY Nano V2 is available from Fullspeed RC, Banggood or Gearbest.
This is a personal choice. The stock 2.8" Kingkong 2840 props are fine but power hungry due to weight and pitch on 2s and almost unusable on 3s. Probably the best alround props is the Gemfan 2540 (@Bangood, @Gearbest) which offers the benefit of grip as in the stock props but at a much better efficiency with marginally more noise as reviewed here. Another option is the Gemfan 3025 twin blade (@Bangood) trimmed down as detailed here. These offer better efficieny again with but with less top speed. I got 9 minutes of flight when using a new 950mah 2s on these props... full review here.
Now running betaflight 3.4.0 which is release candidate at time of writing. Best features for me? Improved filters and much wider PID tuning window. I especially like the throttle limit options that are tied to rates as I think all I get between 90-100% throttle on 3s is noise with more current draw and very little increase in power. I believe my leader originally came with 3.1.7 Low pass and dynamic filtering has improved dramatically since then.
1 year on the Leader120 is surprisingly relevant with a few minor mods. Don't forget that Fullspeed have made minor tweaks throughout the life of this quad - 20a esc upgraded to 28a, FC upgraded with better board layout, UART access and improved BEC. No one has really got a comparable lightweight 2.5" ready to fly that compares - the shift to 1105, 1106, 1107 and even 1108 motors on 2.5" have changed flight characteristics and durability for the worse. Even the Skystars Bolt 120 which looked like Heir to the throne with 4s capbility felt like a porker to fly.
Enjoy this quad if you have it and upgrade at you leisure or not at all. Plenty of options on this community favourite.
Parts mentioned here: