Premium Frame at Non-Premium Price
When I first seen the news that Armattan was launching a race orientated frame I was initial skeptical on how competitive they could be with established market leaders out there. Was this going to be another premium frame with a premium price tag of £100?
The quick answer was NO! I will explain why in this write up on my thoughts and experiences.
Being my first Armattan frame I couldn’t wait to get into the packaging and see what it was like. It arrived in a neat little packet with parts all sealed in small packets. Quickly snapped a photo of it to show others, and then tore through it all like a kid on Christmas morning.
Lets cover the technical spec of the frame and also whats included in the kit. The Mongoose is a 5″ lightweight racer. Made from high quality carbon it is configured as a slightly stretched X, with the aim to provide slightly more response in roll authority than in pitch. Other key features highlighted are use of stainless steel hardware and machined aluminium standoffs with integrated camera mounting, suitable for micro sized cameras such as the Runcam Swift Micro or the Foxeer Micro (to name a few). It has been designed for a short stack and has mounting holes for both regular and mini flight controllers. Finally it offers both the ability to top mount or low mount your lipo.
So whats in the bag?:
- 2mm Top Plate
- 3mm Bottom Plate
- 4x 3mm Arms (for 5″ setup)
- 2x Machined Aluminium Standoffs with integrated camera mounting holes
- 2x Regular standoffs
- Screws + Hardware
- Battery Strap
- Foam/Neoprene Pads for Battery Mounting (top and bottom) and Landing Feet
My initial thoughts were that this frame is high quality and that for the £38 it cost that it was well worth it! The hardware is high quality, especially with the anodised / machined alu camera mounting, the carbon is of a high quality (nice and stiff comparable to that of my Astro X frame at more than double the price, good laminate consolidation, and an even fabric texture) and cut very nicely. In comparison to other frames I certainly felt that I was under-charged!
BUT Armattan have been very clever here with the pricing and design. The separate arms and slim design will cut material costs down. As most clone frames (non exist for this currently) are priced around the £20-30 mark, its a no brainer that given the option most of us would opt to buy the real deal for a little more. Not to mention that competing frames such as the Mode 2 Ghost and the Hyperlite Floss also in this range are similarly priced. It is also cheap enough that you wont worry too much about breaking it as it wont bust the bank to buy another.
Quick assembly of the frame and a weigh in shows that it weighs a mere 67 grams, this puts it in competition with the Hyperlite Floss (66g) and the Mode 2 Ghost (55g).
The frame holds together using 2x M3 stainless steel bolts per arm. One points downward and nuts up using the captive insert which seats in a counterbore on the bottom plate (more on these in the build part of this write up) and the other points upward nutted up on the standoff. This holds the arms to the bottom plate, and the top plate is held on by 4x M3 stainless shell screws into the standoff.
So the frame assembles very quickly, it doesn’t come with instructions but it’s easy to figure out with the help of some photos from Google. There are a few points to note though which I figured out during my build.
1. Press in the inserts into the lower plate – at first I thought torquing up the downward facing bolt would draw in the insert into the recess, but it doesn’t. I couldn’t get enough torque on the bolt, the insert went in squint, and i almost rounded the bolt head. The tolerances on the bore are very tight and even trying to tap then in with a hammer didn’t work. Finally i had to resort to using a g clamp to press them into the bore, its a bit fiddly and probably better using a vice, but it get the inserts in and seated.
2. Use the correct length bolts – the frame comes with quite a few different bolts of different lengths. Make sure you use the correct ones in the right locations. The longest stainless bolts are for securing the arm to the plate and into the standoff. The medium one is for securing the arm to the plate and into the insert. The shortest stainless ones are for the top plate. Finally the rounded head black ones are for motor mounting. And small M2 ones are for camera mounting (although I would recommend using shorter ones).
3. Camera choice and mounting – Firstly this frame is built to suit the Micro cameras out there, regular sized cameras do not fit in the gap provided. Secondly use shorter camera mounting bolts as the ones that were supplied were too long for the camera (in my case the Runcam Swift Micro). Just watch you don’t force them in and damage the camera. You can see the difference in length on in the photo. On the left is the one that comes with the frame, on the right is the one that comes with the camera.
Other than the points mentioned above the frame went together very quick! The camera mounts beautifully between the standoff mounts.
The layout of components is simple on this frame. For my build I will be using components from a donor quad as listed below:
- Matek F405 Flight Controller + OSD
- Matek PDB
- EMax RS2306 2400kV motors
- DYS 30A ESCs
- IMRC Tramp VTX
- RunCam Swift Micro
- TBS Triumph Antenna
Due to the short stack an ideal build would have a an AIO FC and PDB, possibly even an AIO ESC which would make the build very tidy and light weight, but as I already had my components I didnt go down that route and it shows that a ‘traditional’ build works fine.
The ESCs mounted on the arms perfectly, the DYS escs are slightly wider than the arms but only by about 5mm. The FC fits perfectly onto the bottom plate with no extra width. The bottom plate has a central cutout which allows nicely for a pigtail and XT60 to hang down for a under mounted battery.
The stack is tight, giving me just enough space to mount my PDB onto the bottom plate (stood off using nylon nuts) with Matek F405 in rubber standoffs and finally my RX and VTX are sat side by side held onto the FC using double sided foam tape. The top plate allows for a tiny clearance to the stack, but it’s perfect.
The frame top plate has a nice cutout for the camera tilt, which can be set to almost 90 deg without interfering. Also the rear of the top plate has a number of holes for zip ties to hold the VTX pigtail / antenna. The build is finished off nicely with the flat headed stainless steel bolts and the supplied foam-neoprene battery grip and foam feet (which I havent installed as I will be running a low mount battery).
The Weigh In
Being a lightweight racer you’re all probably wondering now how heavy the build ended up being? Bearing in mind that my components were not picked for their weight, and in fact the motors, separate ESCs / FC / PDB and a full sized TBS antenna can be rather weighty compared to some of the parts on the market now.
But still the full build without a battery weighs in at 319g! With a Tattu R-Line 1300mAh my AUW is a touch under 500g! That gives me a thrust to weight ratio of about 11. Incredible.
I am confident with the right components we could shave up to 100g from the weight, bringing it in about 400g AUW. But for me this is already more than light enough.
So its the moment of truth, the build has went together nicely, its lightweight, the frame is beautifully made and affordable. BUT does she fly well??
I loaded the Matek FC up with stock betaflight and took her out on a brisk wintery morning. Conditions were perfect! But as it was a ‘school day’ and I had 10 mins to spare before going to work I only managed to squeeze in 2 packs. But oh man! Those two packs were perfect as could be.
From the moment I took off the mongoose was locked in, the punchouts were incredible, and it turns on a penny. Not much more to say at this point apart from it’s ready to race!
And a quick DVR of the second lipo, gives you an idea how locked it was even on stock betaflight. Sorry for poor video quality.. antenna placement was bad on my goggles.
If you are thinking about buying this frame i’m afraid I can’t give you a valid reason not to! Here are my thoughts and experiences so far:
- Low / competitive cost for a quality frame. You get Armattan quality for the price of clone frames!
- High quality carbon with high quality cut
- Lightweight design
- Machined aluminium standoff / camera mount is beautiful
- Built to run top or low mount battery
- Replaceable arms
- Flight characteristics are spot on for my build on stock Betaflight
- Can only run micro cameras, would be nice to have the option of mini camera too
- The bottom place bolt inserts are footery to fully seat and needed to be pressed in using a g clamp, tolerances seem a little on the tight side
- The camera position means that running low angles you have the props and motors obstructing your view. Not much of a problem if you fly with any decent angle though.
- The compact stack may be a bit tight for builders with less experience, there is no room to spare if separate PDB / FC is used.
- Needs an angle mount for GoPro / HD camera (my next 3d print project)
I’m really picking at the smallest things to find the down points of this frame. From me its a 9/10 so far. I will reserve the 1 point till I see how robust this little frame is. But for now, i’d recommend this frame to anyone who is considering it.