What are the new Gemfan 5152’s and are they any good?
When Sage designed and released the Racekraft 5051 Tri-Blades a couple of months ago they revolutionised prop design in the miniquad world. Back in the day there were very clumsy and fragile prop designs. The typical trade-off was flexible GemFan 5045s which chucked blades every second flight or the more expensive HQ props which though stronger were very brittle and often cost more than a dollar a prop. Then Mr Steel began to fly tri-blade props which increased their popularity and DAL then came out with an indestructible prop series which helped cut of the cost of flying significantly.
However, all of these props were very similar in their basic design and most of their heritage came from fixed wing props. The RaceKraft 5051s and the work of Sage were arguable the first props to be specifically engineered for miniquad use.
Name: Gemfan 5152 (Yes actually 5.1″)
Noise profile: Low
Are they similar to the RaceKraft?
There is no doubt that the GemFans and the Racekraft are incredibly similar, one would be a fool to suggest that Gemfan hadn’t at least been inspired by the work of Sage. However, there are one or two key differences. Firstly, the scoop of the prop tapers off slightly less sharply then the RaceKraft probably in an attempt to increase their talk. Secondly and most importantly the winglets on the GemFans point downwards, while the Racekraft ones point slightly upwards. This makes sense when you think about it as the quad will be moving forward through the air and downward facing winglets should reduce the noise profile of the prop.
GemFan have stated that they will try and patent the downward facing winglets and “Go after anyone who attempts to use a similar design” however, considering Sage already tested them out on the FuriousFPV quad blades a couple of months ago and certainly had a similar design and idea it seems a little ridiculous for GemFan to try and patent the idea.
Design and Performance
As the Gemfans don’t taper off too quickly it is likely to have really good low down thrust generation giving you good control and good management of flying characteristics. It does have the improved vortex and is it downward facing so it’s going to be pretty efficient meaning it is also going to be pretty quiet. From the design and aeronautics of the prop it is likely that the sweet spot of the prop will be between 40-60% throttle meaning less linear power delivery and a much less brutal punch than the Racekrafts. The prop does weigh 5g meaning that it will be a bit too heavy for super lights.
Though we don’t have one in house at the moment, reports say that it could be one of the best props designed so far. It is not only good Racing but also Acro due to is unique mix of efficiency in the top end yet power in the low end thanks to that massive scoop. The control at low throttle lends its self to advanced maneuvers, however the trade off for this is a massive amp pull in some situations.
The Prop is made of Poly-Carbonate meaning that it is very stiff like the Racekraft prop. This tough material makes it very durable however, there are suggests of some warping at very high RPMs due to a lack of rigidity in the structural design. However, in saying this the science of miniquad aeronautics is still in it’s infancy so these fears of flexibility could have little to know impact on performance. We will simply have to wait for more reports before coming to a final conclusion.
All in all, if initial reports are correct then this is a spectacular prop. GemFan have managed to build on the work of Sage at Racekraft brilliantly and have definitely released not only a great prop but possibly another game changer. We are will be looking to release a full review very soon.