Review: Twisted Hobbys RC Factory EPP F-22 Raptor Pusher Jet

 

A pilot on the prowl for new model who spends a moment or two clicking about the Twisted Hobbys web site might easily conclude that Twisted only sells aerobatic and 3D capable models … Edges, Extras, Yaks and the like. While it is true that Twisted Hobbys has established themselves as THE go-to shop for EPP profile 3D aerobats of all sizes, the Twisted Design Team has of late been spreading their wings by coming up with a few models that break their usual pattern. One such model is the RC Factory 29 inch EPP profile F-22 Raptor pusher jet. We saw a local pilot having the time of his life with this model during a recent outing and instantly decided that we had to get a closer look at this unique model. Twisted Hobbys immediately agreed to send a Raptor our way and included their recommended Power Combo in the package. This combo pack includes a Twisted Metal Works 2204-1420Kv bruslhess outrunner and pair of ICE nine gram sub micro servos, as well as a GWS 8×4 prop and Lightning Series 10 amp brushless speed controller. The folks at Twisted even included one of their small six channel DSM2 compatible Crack Series receivers in the box!

CONSTRUCTION

One look at the relatively low parts count in the box and it is obvious that this is going to be a quick building jet. Our total time to build this model came in at just under four hours. The Twisted Hobbys product page includes a link to a full color 13 page assembly PDF that is long on helpful photos and short on words.  Pilots assembling an EPP foam composition model have several choices as to which adhesive they would like to use. Twisted included a few tubes of Welders brand adhesive with our Raptor kit. This contact style adhesive is very effective at gluing EPP foam. Medium cyanoacrylate and accelerator can also be used, as can traditional two part epoxy. The word on the street is that FoamTac is an especially good choice that comes with the added bonus of being non-yellowing over time.

The main fuselage plate comes out of the box in several separate pieces. These are all glued edge to edge to construct the main, upper fuselage. These parts key into one another nicely thanks to interlocking tabs. A large flat building surface is imperative when assembling the main fuselage assembly. The EPP foam airframe is reinforced and made more rigid with the insertion of a long wood spar that runs across the center section and out towards the wingtips.

Twisted includes a few trees of wee fiberglass composition parts, used to make up the carbon fiber control rods. This model requires but one pair of servos. They are used to drive both the ailerons and the elevators, thus necessitating that the radio system used to fly the Raptor be capable of doing a Delta mix. The long, small diameter control rods are potentially susceptible to excessive flexing. To stabilize them and minimize the amount of flex, small fiberglass standoffs are provided. These establish a semi-controlled path from the servo control horns all the way aft to the elevator control horns. We used hot glue to cement the Twisted Hobbys nine gram ICE servos into the pockets cut into the wings. Quick link style connectors are used on the servo horns and the aileron control horns, while the control rods attach to the elevator control horns using small clevises. The quick link connectors make it easy to neutralize all of the control surfaces.

The servo leads and speed controller all end up mostly hidden from view, thanks to a bottom fuselage plate. This also creates the appearance of ducting, very appropriate considering this is a model of a jet. Pilots will have to lengthen the speed controller’s battery lead. Though the ESC gets mounted inside the pseudo-ducting, hitting the recommended center of gravity required that we place the battery as far forward as possible. We decided to upsize the LiPo from the recommended three cell 850mAh pack to a slightly bulkier three cell 1,000mAh pack. Achieving the recommended CG required that the battery be placed towards the forward edge of the long, slender nose section. This part of the airframe lacks any real substance and could be vulnerable in an impact to the nose. Locating the larger pack further back in a meatier section of the airframe seemed the logical thing to do.

A small fiberglass X mount is used to attach the Twisted Metal Works outrunner to the aft end of the F-22. We used CA and then strengthened the bond further by applying epoxy filets around the edges of the X mount. The GWS 8×4 prop attaches to the small outrunner using a conventional O-ring equipped prop saver style collet.

 

IN THE AIR

All flights with this model will start with a hand launch. We found it easy and natural to grip the F-22 in a pincher style over-hand grip somewhere near the CG. The power setting used for launch is not that critical but what is imperative is to remember to follow through when launching this pusher prop configuration model. Any failure to do so could cause the prop to contact your launching hand.

Once in the air, the Raptor is really easy to fly. Choke down the rates in your transmitter and it can be flown as tamely as a pilot prefers. With throws cranked up to maximum mechanical throw, the Raptor really comes to life however. Even at slower airspeeds, the net effect of having the ailerons and elevators deflect together is an absolute abundance of control authority.

The Raptor can perform a wide variety of aerobatics and excels at high alpha flight. Maneuvers that require a rudder are not however a part of this foamy jets repertoire. We got a kick out of leaving the throttle towards the high side and then grabbing full elevator; the F-22 will perform some of the tightest loops you have ever seen!

Flight durations using a three cell 1,000mAh LiPo are on the long side, throttle use dependent of course. We were several times able to squeeze 7-8 minutes worth of flight time out of the batteries we used by exercising a little self control on the gas and cruising around at more sedate speeds.

While hot dogging for the camera and answering the peanut galleries calls of “Lower!”, we accidentally stuffed the Raptor into the grass field we were flying from. This airframe is so lightweight however that there is very little mass involved. We simply brushed the wet grass off the nose of our jet and flipped it right back up into the air! Should a pilot manage to break any part of the airframe, the very nature of EPP foam causes it to fracture cleanly. This makes repairs easy and usually virtually invisible.

Pusher prop powered models are usually substantially noisier than models equipped with tractor configuration propped power system. This is in part because the air being pulled through the prop is “dirty”, having already been disrupted by its travel over the wings of the model. We did not however feel that the F-22 was as noisy as some of the other pusher prop models we have flown. Landing the model can be done with the throttle completely chopped. The Raptor can be floated in with the power off and handily plopped at ones feet. We even managed to catch ours out of the air a few times!

We have used as many words as possible to describe how fun it is to fly this unique model. But now we will stop yapping and let you, the readers, watch a video of this model doing its thing:

CONCLUSION

The Twisted Hobbys RC Factory F-22 Raptor is a no-stress, maximum fun model. The EPP kit can be built in one easy evening and assembles quite nicely thanks to interlocking foam components. If sourcing appropriate electronic components is not your cup of tea, grab the Twisted Hobbys Power combo. It includes a potent and powerful brushless power system and a couple of nine gram ICE  servos that drop right into the provided servo cutouts. We really like the bright red and black color scheme and it is laid down atop the EPP foam so as to be very visible in the air. Launches and landings are simple to perform and once in the air, the Raptor is a real hoot! Whether parading it around inverted in high alpha or racing across the sky in a continuous rifle rapid roll, this model is a performer. Pilots of all skill levels are sure to enjoy the versatility of the F-22.

SOURCES

Twisted Hobbys, twistedhobbys.com, (941) 623-9553