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| My thanks to Fabien of e-copter for the supply of the blades for this review. e-Copter have engaged BlueBird to produce some carbon blades for the T-Rex. The result is a set of black carbon blades in 320mm. The blade tip being slightly angled, very similar in design and shape to the SAB 320mm blade. Shape : symmetrical Length : 320mm Width : 32mm Weight : 48g / set |
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| The blades are very nicely made and have a nice quality feel to them. The
blades are carbon fiber throughout in a polished carbon. Black isn't my
favourite colour of blade as it tends to just go invisible as a blade disc
in flight but very few blades are white for the T-Rex (SABs being the notable
exception). The blade root holes for the blade bolts contain a brass bushing very similar to the Align wooden and carbon blades and adequately reinforces this area for the higher headspeed that these blades will run. Lengthwise the blades are extremely stiff and feel identical to SABs in this regard. Chordwise they are also very stiff, this time more so than SAB blades. So, this is one stiff set of blades overall. |
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| First task was to balance the blades, which actually proved unnecessary, they were spot on. However Fabien of eCopter has advised that this is not always the case and sometimes a small amount of balance tape is required to get them perfect. | ||||||||||||||||||||||||||||||||||||||
| Of particular interest to me was the aerofoil of these blades which can
be seen above right. The blades move into the taper to the trailing edge
very quickly. When running fingers over the blades this gives the feel
of a very sharp and narrow trailing edge with most of the weight of the
blade up front in the leading edge. This should make for a nice balanced
blade in flight as the chordwise CofG should be nicely forward. Initial Flight Testing Having fitted the blades I went for an initial test hop to check tracking and generally set up the machine for these blades. They tracked fine and required no alterations at all. In the hover they felt nicely stable and in fact very similar to SAB blades. In many respects (certainly from a flight point of view) these blades are similar to SAB blades except for the very thin trailing edge, SABs are much thicker at the trailing edge and 2mm wider across the chord. I have flown these blades for almost two months and so the comparisons from now onwards will be with regard to how these fly when compared to SAB 320mm blades. Standard and Aerobatic Flight Testing In forward flight these blades are every bit as stable as the SAB blades and feel very smooth. Power is less than with SAB blades but this isn't necessarily a bad thing. Even though I run 4S I notice a slight bogging of the motor (450TH) running SAB 320mm blades, with these eCopter blades this does not happen. The trade off is slightly less speed in forward flight and slightly less power in vertical climbs but not anything so significant that you find yourself wishing for it. Basic circuits, transitions to hover and hovering itself are all nicely controlled and there is no tendency towards pitching up in forward flight. Also in the hover the blades provide a very stable disc which holds it's height without constant adjustment of the collective to maintain consistent altitude. Moving into basic aerobatics, loops, rolls and stall turns the blades feel more slippery through the air than SAB blades. This comes across as a smoother feel to loops and rolls, the softer collective response helping here. The smoothness of these blades in flight does come across quite strongly and they have a more forgiving nature to them than the SABs. In tight turns and at the pull out of loops the blades produce a 'cracking' noise through the air as they strain against the wind, again this is almost identical to the SABs and there is a crispness to the sound rather than the dull thudding synonymous of a bad blade as it flaps or flutters due to the blade bending and flexing. The blades have a similar roll rate to SABs and I couldn't really tell any difference with regard to this between the two blades. 3D Flight Moving into 3D flight and again the smooth flight charactristics of these blades comes through strongly. They feel slippery through the air and flips can be performed very gracefully with a nice progressive feel to the collective as the blades go though transition from positive to negative pitch. Tic tocs are reasonable although the SABs have a slight edge here in that they produce a little more power and give a little more crispness to the stops on the tic tocs. Inverted the blades feel no different and this is no suprise as the blades are fully symetrical. Although, inverted hovering is certainly smoother than hovering the traditional way but this is fairly normal on any machine. Conclusion Anyone who has read my review of the SABs will know that I like the SABs a great deal. They have nice charcteristics, decent power and in the right hands will even pull off an autorotation. On face value they seem like an unbeatable combination. I have a set of SAB 320mm blades but I have been flying the eCopter blades in preference. Why so? The SABs have more power and for some maneuvers this is an advantage (like tic tocs) but for general smoothness of flight and providing the ability for graceful flips and smooth collective control the eCopter blades are superb. I like to have a lot of power for 3D but equally I want my blades to be slightly forgiving and above all predictable as I go through large collective pitch changes. This is where the eCopter blades deliver and for anyone wanting a blade that provides a nice predictable and progressive power delivery these blades have a great deal to offer. There is very little difference in flight characteristics to the SAB blades apart from this smoother power delivery. This has made me pick this blade in preference to the SABs for my style of flying. As always blade choice is a very personal thing. Overall I find these blades to be of good quality. They are extremely stiff, both lengthwise and chordwise and of comparable performance to SABs. They therefore come recommended and are my blade of choice for the time being based on their suitability to my own flying style. As always with blades it is often necessary to try them to see if you like them but before doing so you want some guarantee of quality. This will not be an issue with these blades. eCopter are currently not selling this blade direct but they can be purchased through www.helihobby.com If you have these blades then please rate them using the T-Rex Tuning rating system .... |
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