Chimera 5.1

Chimera 

A no BS race quad, blended together from 5 years of racing experience, national and international podiums and a boat load of podium wins to boot. Chimera is a simplistic race quad with an exceptionally locked in flight feel, clean lines and well thought out easy to maintain functionality. 

Chimera Technical Highlights

Weight // 64grams (including the standard steel hardware pack)

Props // 5.1 inch maximum

MTM // 205mm on the diagonal

Motor Planform // Hybrid – X

Stack Accommodation Planform // 30.5X30.5mm and 20X20mm

Stack Accommodation Vertical // 25mm

Camera Accommodation // 19mm width

Included in the Kit

Carbon

4 X 5mm carbon fibre arms

1 X 2mm carbon fibre top plate

1 X 2mm carbon fibre top chassis plate

1 X 2mm carbon fibre bottom chassis plate

2 X 2mm carbon fibre camera side plates

2 X 2mm carbon fibre camera washers

2 X 2mm carbon fibre chassis lock plates

Hardware

2 X 25mm aluminium standoff

2 X 15mm aluminium standoffs

9 X M3 stainless steel press nuts

9 X 12mm M3 counter-sunk bolts

4 X 30mm M3 counter-sunk bolts (optional for stack if needed)

5 X 10mm M3 button cap bolts

5 X 6mm M3 button cap bolts

Accessories

There are print files available for:

·         SMA Style Antennas

·         Lollipop Style antennas

All the print files are available for free download, HERE! 

Else search FridayFPV Chimera on Thingieverse.

Why Chimera?

One of the most controversial topics amongst race pilots, must be camera position. Hands down and without question, for ever pilot who loves a low-down props in view camera position there are equally as many pilots who don’t not like it, they down-right hate it. Chimera was the result of one of these kinds of conversations. I realised we didn’t have any low-down props in view racers on the store and for no real reason whatsoever. Yeti, does have that sort of camera placement, but I felt we could do better as a pure race frame. Yeti was kind of a cross over frame between racing and freestyle.

I thought back for a moment to Apex as that was purpose built for racing and pilots loved it, low down camera, only thing I didn’t like was the unibody main plate. Way too expensive and time consuming to replace. Ok, so the Apex concept with four arms? Slate arms were ridiculously strong, but it had front arms and back arms. We need identical arms for quick swop outs if something goes wrong. Taboo arms were all identical and as tough as nails, symmetrical and simple, I decided to go with that concept. Finally, Yeti, although not designed as a true race frame it became quite popular at race meets because of its locked-in flight characteristics and never say die attitude. Yeti is definitely a tough frame and the camera protection it offers is second to none, we’d keep that I decided.

We love our mythical names

Chimera in Greek mythology is one variation or another of a fire-breathing monster comprised of the forequarters of a lion, the hindquarters of a dragon with a goat’s head somewhere in between. We have taken the best aspects of Apex, Taboo and Yeti to create a brand-new race monster, Chimera seemed apt.

I take no credit for this artwork, it is taken from God of War III, with the utmost respect for the artist!

Early Chimera Concepts

With that as a basic outline, I started sketching out some new concepts. The flip top lid on Apex was revolutionary at the time, but the camera remained in place and you couldn’t access the front of the stack, so that needed to be fixed. I moved the hinge point of the camera side plates below the camera and fixed the top plate to the sides, that gives you the flip lid functionality to very quickly and easily reach your electronics, plus you get the camera out the way without disturbing the camera tilt or position.

            A simple arm

I went back into the CAD file archives from 2016 and pulled up the Taboo arm file, I like the symmetry of the arm and wanted to keep that. It definitely performs better than an arm which isn’t symmetrical. We slimmed it down and re-filleted everything to give it that sleek aggressive look which is still functional but less war-axe looking like the original Taboo arms. After that, we completely redesigned it again just to get everything straightened out the way I wanted it. The result is a clean and rigid arm weighing in at 6.9 grams.

            A not so simple top plate  

We also spent a fair amount of time on the top plate, it may seem trivial as its only a top plate but everything on it serves a purpose. The small tooth that sticks through the camera side plate is meant to deflect gates and prevent mid-air contacts from damaging the front of your electronics stack. The forward tooth and all the saw-tooth like edges along the sides of the top plate are also designed to jam up propeller strikes from other quads which could possibly damage the sides of the stack. These side protrusions also induce small scale turbulence which in turn reduces overall drag. This is a minute aerodynamic improvement which may not be felt by some but it showed enough of an improvement over a straight edge to warrant it been included. We used computational fluid dynamics (CFD) to confirm this. A crisp and clean movement which may be interpreted as a more precise feel will be felt in cornering and less buffeting will be felt in a straight line. Lastly the huge cut-out at the back of the top plate, again, this serves to distinct and unrelated purposes. From an aerodynamic perspective a decreased frontal area will reduce overall frontal area and hence drag, but removing conductive carbon fibre material in the area where you are likely to put your video antenna will also improve your video quality as you are no longer shielding your video antenna. The cut-outs in the centre of the plate reduce weight ever so slightly. Lastly, you’ll see a small slot at the rear of the plate, this is for a zip-tie, if all you want to do is run a simple whip antenna a zip-tie with some heat shrink tubing makes a perfect lightweight antenna stalk.

Everything serves a purpose!    

            The flip

The flip functionality of the top plate went through so many iterations I lost count and I was honestly ready to give up on it and just use standoffs. The rest of the frame worked so well and it was ridiculously simple to build and maintain, we just needed to fix the flip part! Finally, we got the movement of the camera and side plates just right, we locked in place both chassis plates with this mechanism and it was still simple, strong and clean.

            Chassis plates

The chassis plates were the last part of the puzzle, the biggest challenge we had with these was getting all the interlocking parts of the camera sides to work together. Once this was sorted out, we again carved out as much carbon at the back of the plates as we could. This has the same function as the large wedge shaped cut out seen on the top plate. Reduced frontal area for decreasing drag and it will help with minimising the shielding affects of your antenna due to conductive materials in the area.

The top chassis plate comes pre-installed with all its stainless-steel press nuts. The bottom chassis plate comes with access holes for your 20X20mm stack screws and also counter-sunk holes for the arm bolts, this keeps the bottom of the chassis plate super clean and prevents bolt heads from damaging batteries.     

            Hardware

Lastly, the frame uses no special hardware or fasteners, everything we use on this frame is commonly available. I really liked this feature as most pilots would probably have spare hardware lying around in their toolboxes if they lost something.

Final Thoughts 

If you have any comments, queries or suggestions about Chimera or any of our other products please email us directly at, mail@fridayfpv.com.

As always, be safe and happy flying!

Dave.