Arrows Hobby Viper

When Arrows Hobby started to release their range of small electric ducted fan (edf) models, they quickly established a reputation for being very well made, flying equally as well, and generally offering a very good fun/£ return.

 

By the time I succumbed to what was by now quite a craze, there were three or four different models to choose from. However, I opted for what I believe was the first one they produced, the Viper Jet.

 

I suppose this is arguably a scale model in that there is a full size Viper jet of a similar shape. However, whereas the Hawk and T33 which followed in the range are dressed in semi-scale colour schemes, the little Viper has no such pretences so I've put it here in the sport aerobatic section - and of course I fly it as such.

 

As my collection of models inexorably grows (although this time I did manage to comply with my self-imposed 'one in, one out' rule by selling my HobbyKing Hawk), my collection of different size LiPo batteries tends to do likewise. The Viper is designed to fly on a 3s LiPo of 1300-1500mah capacity. Unfortunately this is a battery size I recently moved away from (although I do use a few in some of the slope soarers). However, a couple of the magazine reviews mentioned that a 2200mah battery fitted in easily enough and, although this made the model slightly nose-heavy, it still performed well. I have several other models using 2200mah batteries so this was the way I went with the Viper. The two pics below show the two battery options.

It would perhaps have been clearer if I'd taken both photos in the same orientation but the one on the right shows a 3s x 1300mah LiPo mounted well forward, to get the cg to the recommended position. The picture above left shows a 2200mah battery mounted fully back up against the elevator servo. You can see that I've had to fit a more rearward Velcro strap to secure this battery, The battery bay has also been lined with non-slip matting ( I prefer not to use stick-on Velcro on the batteries).

To enable the battery to be mounted this far back, the receiver was mounted up alongside the elevator pushrods.

This model is so well reviewed elsewhere that I don't intend to say much more about the assembly. Indeed in truth, there is very little to say! The tailplane and wing tips have to be glued in place and the wing is then attached with four small screws, That's about it.

The little Viper really is a joy to fly. I bought it to replace the HobbyKing Hawk and there is no doubt it out-performs the Hawk and also sounds a lot better. Duration on the 2200mah LiPo is also excellent. Whilst hand launches are also an awful lot easier than with the Hawk, it is still possible to get it wrong so, at the time of writing, I'm fitting the Eagle Tree Guardian stabiliser from the Hawk. This is a bigger operation than anticipated because the only real space for it is in the front of the model, which means that there are half a dozen wires to route past the battery to the servos, ESC and receiver in the aft section. All of a sudden that spacious battery bay is beginning to look a bit crowded. I'm a bit ocncerned that all of this might make the model too nose-heavy, but time will tell. I'll try to remember to report back here on the outcome of this experiment.