Our friends over at Total Rotor recently offered us the opportunity to check out two of their new racing miniquad frames: the Katak Stretch SE and the Katak Stretch TRP edition. Having not had the opportunity to try out the new “stretched-X” frame design that has been very popular lately, we were more than excited to try this frame out.
Knowing that both versions of the Katak cost $55 and $75, I wasn’t expecting too much when I received my kits, but the Katak caught me by surprise. All of the parts came inside of a ziplock bag which was compartmentalized for easy inventory. Upon extracting the parts, I was also pleased to see that all of the carbon fiber parts have the edges filleted so there are no sharp corners whatsoever. The carbon fiber on both frames looked impeccable. I can tell there hasn’t been much skimping on the materials for this quadcopter.
The Katak Stretch SE comes with four identical arms that each have the word “Katak” milled into the carbon fiber on the same side. I like that all the arms are identical – but it kind of bothers me that only two diagonal arms will have the word “Katak” on them on each side of the quadcopter. It’s not a huge deal, but it might bother those who are meticulous.
Katak Stretch SE vs Katak Stretch TRP
Total Rotor sent us two frame kits – presumably to compare with each other. One big difference between the Katak Stretch SE and the Katak Stretch TRP edition is lightening cavities milled into the arms. This is the first frame I’ve owned with such a feature and I was pretty impressed – these cavities are professionally milled and filed so that there are no rough edges whatsoever.
The other differences between the two frames are:
- The Katak Stretch SE has a GoPro Session-style HD camera mount built into the frame, while the Katak Stretch TRP has a conventional flat top.
- The Katak Stretch TRP has the “TRP” logo milled into the carbon fiber in several places.
- The Katak Stretch SE has an independent carbon fiber cross member which can be used to guide antennas and hold an SMA connector, while this is built into the top frame of the Katak Stretch TRP. I prefer the latter.
- The Katak Stretch TRP has one less aluminum cross-member, saving a little bit of weight.
Overall, I like the flexibility of the equipment placement options afforded by the Katak Stretch SE, but much prefer the looks that come with the Katak Stretch TRP. The Katak Stretch SE has a big hump that makes it look a little dopey – I get why the designers named it after the Malay word for “frog”. The Katak Stretch TRP, on the other hand, looks fast – I really like the improvement.
I assembled both frames without any extra parts and weighed them. Here is how they compared:
20g is nothing to sneeze at. If you are going for a high-performance racer, the TRP version is a no brainer.
Both versions of the Katak Stretch come with a single sheet of paper which includes a packing list and an exploded parts view which you can use to aid assembly. I found the frame’s assembly process pretty self explanatory.
In this article, I’ll build up the Katak Stretch TRP. Pictured below are the major steps.
I started by aligning the arms into the two bottom frame carbon fiber sheets. I inserted the four screws on the corners of the frame to align the arms. Note that these screws also hold the vertical plates on so you should not put the nuts on yet.
Next I added the vertical frame plates. By holding the frame upside down, I was able to fit the locknuts into place in the corners of the frames then screw the assembly together. Each of the four locknuts are the only things holding the frame arms on. This is a good thing – the arms can each be easily replaced by removing a single screw. Once assembled, the four arms are extremely rigid as they press against one another like puzzle pieces.
I was mildly annoyed by the fact that the nuts will spin inside of their cavities in the vertical plates. This means you’ll need a wrench or a pair of pliers to hold the nuts in place while you screw them down. I much prefer the approach taken by Shendrones in their Krieger, where the carbon fiber plate captures the nuts and you don’t need a second tool for screwing them down.
The other step taken here was the addition of the four bolts through the bottom plates into nylon standoffs which will eventually hold the flight controller stack.
These eight bolts are pretty much all that holds the majority of the frame together. The only remaining parts to be added are some aluminum struts and a small carbon fiber top plate which adds rigidity to the vertical plates. Let’s get through component placement and installation first, though.
For this build, I’ll be using the following components:
- Airbot Asgard F4 combination FC/PDB/OSD/4-in-1 ESC
- EMax RS2205-S 2600kV motors
- Runcam Swift FPV camera
- LaForge video transmitter
The Asgard greatly simplifies wiring requirements because – well – everything is built into the flight controller. I’ll be doing a separate review on this flight controller in the future. The layout of the flight controller is a bit frustrating, though. There was not really any good ways to route the motor wires in to the front of the Katak frame, so I opted to mount the flight controller sideways with the motor pads facing out of the side of the frame. To do this, the battery cables exit the frame through a hole in the bottom plate. The pre-filed edges of the carbon fiber really help here – I shouldn’t have to worry about the wire sheathing wearing out and shorting to the carbon fiber.
Next up, I installed the motors. When installing motor wires using all-in-one ESCs, make sure the wires cannot stretch up and get sucked into the prop disc.
Only 3 wiring harnesses need to be made for the Asgard flight controller – those are attachment points for the RX, VTX and FPV camera. Pictured above is the completed harness and the parts ready to be installed.
Here, the FPV camera is installed. The Katak Stretch frame seems to be designed around the Runcam Swift-style camera which has two screw holes on each side. You should also be able to use HS1177-style cameras, but they won’t be mounted as securely.
The FPV camera adjustability on the Katak Stretch is stellar. You can point the camera everywhere from level with the frame to straight up, if that’s your thing.
With all the components installed, all that is left is to adhere the VTX and RC receiver to the frame. I used double sided tape to do this. The RC receiver fits behind the flight controller on the bottom plate. The VTX can be adhered to the top plate and the SMA connector pokes out of a hole pre-drilled into that plate.
The build is finished by screwing in the aluminum cross members and performing the other finishing tasks. This included tidying up some of the wiring, securing the RC antennas, and adding the battery strap.
Here is the weight of my Katak Stretch TRP with everything included except the battery. Not too shabby.
As I’ve often said, quadcopter frames have very little effect on flight performance. Instead of choosing a frame for flight performance, then, you should primarily look at:
- Look / Style
From what I can tell thus far, the Katak Stretch frame is a stand-out in these categories. The cost is competitive or cheaper than most other frames on the market, but comes pre-filed, which improves looks and should also positively affect durability. I love the looks of my new Katak Stretch TRP, though I’m not as much a fan of the Katak Stretch SE. As I continue to fly the frame, I will evaluate overall durability, although I am sure I will have no problems.
I have two complaints about the frame. First, the FPV camera pokes out of the frame quite a bit when mounted. This is an alarming change from my Armattan Chameleon, which has the camera fully encased in an aluminum body. Time will tell whether or not this is a real concern, but it probably won’t be as long as the camera lens is not angled above 45 degrees or so. Second, I was not pleased with any of the available options for mounting the RC receiver antennas. I ended up routing them along the rear arms with the elements poking out just beyond the motors.
Overall, it takes a lot to get me excited about a frame. I’m still regularly flying my Bolt 210 from 2015 and only recently (sort of) replaced it with the Armattan Chameleon. Having built the Katak Stretch TRP, I would have no problem turning around and buying it with my own money for my next build. It’s an aesthetically well-designed, high quality frame at a great place.
Thanks again to our friends at Total Rotor for giving us a chance to check out this frame – we’re really glad they did. The build quality of this frame is staggering when compared to the price. If you’re interested in the Katak Stretch series, check them out at the Total Rotor store using the links below:
Additionally, the team at TR are offering 10% off to our readers – use promo code “propwashed10” at checkout to get 10% off through November!
Katak Stretch SE Kit Giveaway
Hey – you’ve gotten this far through the article! Interested in a Katak Stretch frame? How about one for free? I really like my Katak Stretch TRP, but Total Rotor sent me a Katak Stretch SE to compare it against. I’m giving that frame away this month in our monthly newsletter. If you want an opportunity to receive this for free, make sure to sign up using the form at the bottom of the page, or in the right sidebar on our homepage.
Our monthly newsletter gives you the rundown on our top articles, videos, and guides from the previous month. Our next edition will have exclusive details to our Katak Stretch SE giveaway, so definitely be on the lookout for it.