BELGIUM - Protech
Protech Zoom 400 (2004)
Electric helicopters had been developing at a pace but their main drawback was in the motor battery combinations. Whilst powerful motors were available they required large batteries to get any decent flight time thus requiring relatively large models. Small helicopters tended to be fixed pitch in order to be light and whilst some had been successful, Aisonic of the eighties to name but one; it required the use of plastic and lighter batteries before they became popular. However in the early 2000's a new technology was beginning to make a breakthrough; Li-on batteries (lithium-ion). These batteries provided a much higher capacity for a given weight and thus the potential of a smaller helicopter could be released. Here was the opening for a full function collective pitch helicopter powered by a Megax '400' size 'can' motor capable of aerobatics in standard form.
The design originated from Taiwan (Gaui) and incorporated a full bell-Hiller head which in essence was a smaller version of the larger 'glow' engine type and thus the control was very good. Introduced in 2004, Protech provided the 'electronics' package which included a 'rate' type gyro of high quality and thus although the helicopter was small and tail control powerful, with the correct amount of 'Revo' mixing it well emulated a 'heading hold' type especially in calm conditions. There was, as always with a new model, a few problems; the skids were small, tall and not very wide thereby allowing the helicopter to tip over quite easily if not landed level and stationary. The tail drive also proved troublesome and catching it in grass would strip the teeth off the gears plus the main mast being made of aluminium, though light, bent at any slight bump.
These problems were dealt with by introducing a 'training' set of skids that were low and wide, the main mast changed to hollow steel and bevel gears fitted to the tail drive which proved much stronger. After market upgrades could also be had to change to a belt driven tail and also to fit 'metal' upgrades to the swashplate linkages to remove a lot of the 'slop' of the original plastic levers.
The helicopter was well received and tests of the day commented upon how well it performed especially outside though it was noted that the head speed was only adequate resulting in limited 3D capability. Following on from this was the 'brushless' motor upgrade along with CF blades that allowed the head speed to be wound up and now it really did perform very well.
Note that Protech were not the only ones to market the 'Zoom' and so it became available all over the world in exactly the same format or with only slight differences but known under a number of names such as Zoom 400 / Shogun 400 / Zap 400 / Microstar 400 / Dolphin 400 / 3D-X400 and possibly others.
After nearly a twenty year break, the Zoom 400 was my first collective helicopter and the one that allowed me up to attain competent hovering. However, this was not without 'mishap' as you can see I had to 'learn' in a very enclosed space and the reason it took me quite a few main shafts, blades and spindles; those chair legs were very 'unforgiving'. My first Zoom had over 250 flights and was still reasonably original; well, about 60% anyway. Still running a 'can' motor though compared to later machines its performance is barely satisfactory with cyclic control desperately slow. What is interesting is that there was a time when I though it was bordering on too responsive?????
Two more active Zoom 400's which have various levels of upgrades including metal swashplate's, rear tail servo's and both have brushless motors. Heads run at a much higher speed and so response is increased though as yet I have not tried any loops and rolls with these.
Protech Zoom 400 Pro
The Zoom 400 was extremely popular and with aftermarket supply could be modified with just about any upgrade possible. Because of this Protech themselves brought out their 'ultimate version' which incorporated all the upgrades that could make a difference.
Protech Zoom 425
Whilst the Zoom 400 pro was an excellent machine it proved to be a little on the 'small' side for serious outdoor work. The shogun had been released which although based on the zoom mechanics was a little larger thus allowing the used of bigger batteries; it was also 10% heavier and more stable when flown in the open. Align was also having success with their T-rex 450 and so Protech took the opportunity of revising the zoom to this 'larger' format and along with ECCPM control resulted in the Zoom 425. Though running 315 blades construction was still kept quite light at less then 700 grams with a 1800 MAh battery or it was also possible to just gat a 2100 MAh squeezed in.
Protech Zoom 450 EP
The Zoom 425 was then extended into their 450 format but again, like the 425, it was large for its size and more along the lines of other manufacturers 480's. This model was also higher in specification than the 425 with good flight performance.
Bought Nov 08 as an E-bay purchase and had only been used a couple of times but the owner could not get it to hover properly and so gave up. When checked out one of the Eccpm servo's was found to be defective with intermittent and jerky control which would appear to have been the reason for the owners problems. Must have also taken a knock because as well as a replacement servo it required a few new parts, spindle shaft etc. Tested and very controllable in hovering and circuits but tail tends to kick out in quick turns.
In Jul 09 I had carried out more testing resulting in a much better set up with the tail quite controllable (stiff linkage was the original problem).
Protech Zoom 450 IC
The Zoom 450 package developed for the SX-12 Glow engine.
T0500 - Zoom 400 / T0500PS - Zoom 400 electronic pack / T0510 - Zoom 400 Pro / T0520 Zoom 425 CCPM
T0502 - Zoom 450 CCPM plus T0502-350&400 - Electronic pack and T0502-500 - Power set
T0503 - Zoom 450 IC
Copies of tail upgrade instruction from here:
Whilst the Zoom 400 was quite a groundbreaking model it was expensive which was fine initially however, price wise, the Align T-rex was significantly cheaper for their 'base' model and also regarding spares. Thus the later versions were not as much of a commercial success and finally production ceased when Protech stopped trading in 2011.