Review: iFlight Turbobee 120RS or 136RS (V2)

iFlight recently released two new micro models – the Turbobee 120RS V2 and 136RS V2. These are 2.5″ and 3″ micro quads that have been upgraded from the original Turbobee from a few months back.

Check out my other “toothpick” style micro quad reviews.

Where to Buy iFlight Turbobee V2?

120RS (2S Version):

136RS (4S Version):

You can choose different receivers, including Crossfire, Frsky XM+, Flysky A8S V2 and DSMX.

The accessories are the same in both kits, except the propellers.

  • RX antenna plastic tubes
  • A bag of screws of different length for mounting the props (not needed for the 120RS)
  • Two battery straps
  • Two sets of props: 120RS, HQ 65mm props; 136RS, HQ T3x2 props
  • Sticker and leaflet

Specifications

Both 120RS and 136RS use the exact same hardware, apart from the motors, props and frame.

  • SucceX Micro F4 Flight controller (16x16mm)
    • MPU6000 Gyro
    • 5V 3A BEC
    • Betaflight OSD
    • Flash memory for Blackbox
    • Firmware target IFRC/IFF411PRO (STM32F411)
  • 12A 4in1 BLHeli_S ESC (16x16mm)
  • VTX: 25mW/200mW Selectable Power with Tramp Protocol (VTX Control)
  • FPV Camera: Caddx Turbo EOS2  (2.1mm Lens 16:9 NTSC)

Here are the differences that set these two models apart.

120RS:

  • 120mm wheel base frame
  • BeeMotor 1103 4000KV Motor (for 4S) or 10000KV Motors (for 2S)
  • HQ 65mm Bi-blade Props
  • Weight without battery: 56g
iFlight Turbobee 120RS

iFlight Turbobee 120RS

136RS

  • 136mm wheel base frame
  • BeeMotor 1104 4000KV Motors (for 4S)
  • HQ T3x2 – 3″ Bi-blade Props
  • Weight without battery: 67g
iFlight Turbobee 136RS

iFlight Turbobee 136RS

A Closer Look at the iFlight Turbobee V2

Frames

The original iFlight Turbobee had a carbon fibre top plate which they replaced with a 3D printed TPU canopy in the new version. This is an obvious choice for weight saving and practicality. It’s also easy to remove the canopy and work on the electronics as there are only 3 screws.

Both Turbobee 120RS and 136RS V2 share the exact same canopy, both bottom plates are unibody, but the frame design is different.

iFlight Turbobee 120RS (left), 136RS (right) Size Comparison

iFlight Turbobee 120RS (left), 136RS (right) Size Comparison

The arms on the 120RS are very skinny, but thankfully they are 3mm thick so it should hold up well on a light weight craft like this. The 130RS’s frame, on the other hand, is also 3mm thick, but has much beefier design with all those arm braces and appears to be a lot more crash resistant and durable.

iFlight Turbobee 120RS (left), 136RS (right) Bottom Plate Comparison

iFlight Turbobee 120RS (left), 136RS (right) Bottom Plate Comparison

Antenna placement is very well thought out (for both VTX and RX antennas), they made good use of the 3D printed canopy. The RX antennas are well protected inside plastic tubes, and it looks slick.

However the tubes must have some negative effect on radio signal, as I am getting “signal low” warning only around 300-400 meters away. But still this should be more than adequate range for this kind of small drones.

And you should glue the VTX antenna to the canopy, as the antenna was pulled off from the VTX a couple of times in my testing and hit by the props.

iFlight Turbobee 120RS Antenna Mounts

FC/ESC/VTX Stack

Both Turbobee 120RS and 136RS have the same FC/ESC/VTX stack,

iFlight Turbobee 120RS (left), 136RS (right)

The flight controller stack is the Succex 16x16mm micro stack that consists of a 200mW VTX, F4 FC and 12A 4in1 ESC. I previously reviewed the original version of this stack, but the stacks in these quads are the latest V2.

V1 and V2 are actually quite similar except a few minor changes:

  • More powerful 5V BEC (from 2A to 3A)
  • Flash Memory for Blackbox logging – rarely seen on these micro quads!
  • Motor Connectors on 4in1 ESC

The connectors have “solid pins” which don’t impact performance as much as the “open pins” does. “Open pins” have higher resistance and results in worse voltage sag. I love connectors on these pre-built models, as they are easier to build and repair.

iFlight Turbobee 120RS 136RS FC Stack

This stack works as intended, however, the biggest downside is probably the tiny push pin connectors between the three boards.

Firstly, they are not great for isolating vibration and defeats the purpose of soft mounting.

Secondly, the boards can move a tiny bit due to the fact that they are mounted on rubber grommets. It puts a lot of stress on these small connectors during impact, and might break off in a hard crash.

Other 16x16mm FC stacks, such as the Mamba Nano stack, solves this problem by using silicone wires only.

The receiver is mounted under the canopy, which is a great touch.

FPV Setup

This quad has a top notch FPV setup: a proper nano camera with a 200mW VTX that has SmartAudio feature. IPEX/U.FL antenna connector, comes with a light weight dipole antenna.

The new EOS2 camera works slightly better than the previous versions tested, probably has a new firmware. Image is clear and handles lighting transition well. Also camera angle is adjustable and the lens is well protected by the TPU canopy.

Weirdly my 120RS came with a PAL camera while the 136RS came with NTSC. On the product page it says they should all be NTSC, maybe they were sent the wrong camera and didn’t notice. Not a big deal.

Motors

The 136RS uses BeeMotor 1104 4200KV.

The “bumper” at the end of the arm protects the motor in collisions. Here is a close up of the BeeMotor.

The 120RS uses 1103 10000KV which is rated for 2S.

Both motors have prop mounting holes. These motors are probably the least “notchy” motors I’ve tested so far (the resistance caused by the magnets when the motor is spun by hand), but it doesn’t seem to affect the quad’s performance in anyway.

Battery Mounting

The iFlight Turbobee comes with some high quality battery straps, they are the same length for both 2S and 4S models. But the strap seems to be slightly too long for 2S 450mah LiPo, and it’s too short for 4S 450mAh, a bit awkward really. I wish they could supply straps with the right length to accommodate different battery sizes.

There is a piece of anti-slip rubber pad on the bottom plate to prevent the bolts from digging into your batteries. Great touch.

Should I get 2S or 4S?

The 120RS offers two versions, 2S and 4S. The difference is in the motor KV:

  • 2S – 10000KV motors
  • 4S – 4000KV motors

I personally would choose the 2S version over the 4S for a couple of reasons.

Firstly, these small 2S batteries are cheaper and more widely available. We normally use “stick shape” batteries on these micro quads, and it’s harder to find them in 4S. Of course you can always use my hack to connect two 2S batteries in series to make a 4S.

Secondly, lower voltage tends to give less problems with voltage spikes, power noise and other technical issues on these micro quads.

I think 2S 450mAh is a good size. See my LiPo testing for some battery recommendations.

120RS or 136RS?

This is a tough call.

Overall the Turbobee 136RS and 120RS are both beautifully designed and built micro quads, but if I had to pick one, I would probably get the 136RS because it’s a more powerful model.

Buy the 120RS (2S Version):

Buy the 136RS (4S Version):

iFlight Turbobee 136RS (left) and 120RS (right)

Someone is going to tell me “you cannot compare apple and orange”. I know they are in different categories, one is 2.5″ (65mm) and the other is 3″, but the 120RS is just a tad too heavy for my liking. The larger 1104 motors and 3″ props are going to be better at managing that extra weight.

And the 136RS has a stronger frame design which should hold up to crashes better, and yet the weight difference is only around 10 grams between the two models.

The 120RS is NOT a slow quad by any means, but if we could shave a few grams off the canopy I think It would be much more nimble and fun to fly. If you prefer a “safer” quad to fly in smaller parks, maybe the 120RS is a better option.

The 130RS is an ultra-light 3″ running on 4S LiPo, it’s bigger, noisier (only slightly) and more powerful. The power to weight ratio is so high, it almost feels “floaty”. If you hit someone with it in the park, you are not going to get away with just an apology. But still it’s much friendlier than a 5″.

For the 130RS, the recommended battery is 4S 450mAh. I also tried 4S 520mAh and 650mAh, the quad handled them well. But lighter battery = more agile and responsive. Check out batteries here: https://amzn.to/2lUC3Pc

How to Setup for First Flight

The same steps apply to both models.

The flight controller is loaded with BF 4.0.2 (May 2019 release). It’s unnecessary to update firmware as this might erase the setting. Just set it up, go out and fly :)

It comes with a leaflet that shows you it’s got “reversed motor direction” and not much else.

There are two UART’s on the FC, UART2 is for serial RX like SBUS while UART1 is for Tramp protocol (VTX Control). No need to do anything here, all setup for you.

The first thing to do is to bind the receiver – to access the bind button you’d have to remove the canopy. If you are getting the XM+ version, see this tutorial how to bind Frsky RX.

It’s funny that iFlight actually asked me if I want R-XSR or XM+, and I said “R-XSR”. It turned out to be kind of pointless because there is no spare UART to run SmartPort telemetry anyway, and SmartPort isn’t connected. As a result it doesn’t have RSSI on CH16 either, which is inconvenient to setup. XM+ is a better option.

Adjust OSD screen.

Setup modes (switches) for arming and beeper.

Disable RX_LOST in ESC Beacon.

Change your rates.

PID and filter setting are not optimised out of the box and there is definitely room for improvement. I was getting quite a bit oscillations in the upper half throttle.

Performance

Stock tune is quite bad to be honest, I spent a few flight still not getting good result. Normally these pre-built quads are tuned in factory even it’s not perfect but at least flyable. But with the Turbobee requires a bit more patient.

2 thoughts on “Review: iFlight Turbobee 120RS or 136RS (V2)

  1. Jerrick

    Looking for my first drone thats for free style. Out of these four which one would you pick? geprc phantom, gtb229, larva x, or 136rs?

    Reply

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