Xaircraft x650 v4 (GemFan Carbon Fiber Props 13×6.5)

Click here to view my gallery!

After doing a lot of reading and asking question on RCG forums I was informed that the best setup for the aircraft and AP recording I wanted is 13×6.5 props with 3506 T-Motors and 3S lipo. Initially I started with Thin Composite APC Props andI liked how much power it had but it felt really heavy. Without adjusting the gains the quad flying a bit rough in light wind. After I increased the gains a bit the videos recorded with my camera was a lot smoother.

Then I picked up a set of GemFan Carbon Fiber 13×6.5 props. Since I never used CF props before, I really do not know what to expect. The first thing I did was balance them.

Xaircraft x650 v4 - GemFan Carbon Fiber Props 13x6.5

 

From afar the CF props looks pretty nice and it is very light. In fact it is more than half the weight of the APC props.

Xaircraft x650 v4 - GemFan Carbon Fiber Props 13x6.5

 

This is the APC prop weighing in at 34 grams.

Xaircraft x650 v4 - GemFan Carbon Fiber Props 13x6.5

 

Here you can see that the GemFan Carbon Fiber prop only weighs 14 grams.

Xaircraft x650 v4 - GemFan Carbon Fiber Props 13x6.5

 

Take a closer look at the hubs and you can see it is poorly made.

Xaircraft x650 v4 - GemFan Carbon Fiber Props 13x6.5

 

Especially on the back side, it does not even look flat. I hope the hole is centered so I can balance the props correctly. These are pictures of brand new props, don’t they look used.

Xaircraft x650 v4 - GemFan Carbon Fiber Props 13x6.5

 

Take a look at the edge of the prop, it is cracked and chipped.

Xaircraft x650 v4 - GemFan Carbon Fiber Props 13x6.5

Here is one example of surface imperfections.

Xaircraft x650 v4 - GemFan Carbon Fiber Props 13x6.5

 

The design of the 2 props after very similar.

Xaircraft x650 v4 - GemFan Carbon Fiber Props 13x6.5

 

The hub on the APC is 11mm thick, where as the GemFan CF is only 7mm.

Xaircraft x650 v4 - GemFan Carbon Fiber Props 13x6.5

 

The first CF prop balanced perfectly but hubs were out of balanced for all the props.

Xaircraft x650 v4 - GemFan Carbon Fiber Props 13x6.5

 

Then the next 3 was not balanced at all. I use some scotch tape to balance the props first then velcro and hot glue to balance the hub.

Xaircraft x650 v4 - GemFan Carbon Fiber Props 13x6.5

Xaircraft x650 v4 - GemFan Carbon Fiber Props 13x6.5

Xaircraft x650 v4 - GemFan Carbon Fiber Props 13x6.5

Final thoughts about the GemFan Carbon Fiber 13×6.5 Props… The overall construction is pretty low quality with rough cracked edges, uneven hubs, and some surface imperfections with cracks. Moving past the quality issues I like how these props are so light and quiet. They are so quiet that it almost felt like it had less power and responsiveness than the APC. It seems like I needed to move the throttle past the midpoint more often  with the CF props. I am only flying by sight so the sound or lack of it can deceive my perception.

So far the props are holding up pretty well (only 4 flights), but I need to keep an close eye on the few surface imperfections where it might lead to prop failure.

UPDATE (March 2013):

Since changing to a different frame and mounting the ImmersionRC EZOSD I was able to get some more data.

My setup:

Frame: Tarot FY680 – Hexa
Motor: T-Motor 3506 650KV
Lipo: Turnigy 4s 5000mah 35C Lipo
Video: Xaircraft gimbal with GoPro Hero 2

 

GemFan Carbon Fiber 13×6.5 Props

AMP Draw: ~25a

Flight time: 10:30 minutes

Power Consumed: 4000mah

 

APC 13×6.5 Electric Props

AMP Draw ~20

Flight time: 14 minutes

Power Consumed: 4000mah

 

From the data listed above you can see that I am getting better flight time and less amp draw with the APC props. However, I am having a hard time getting the APC props to balance. As a result the videos are coming out with a lot of jelloing and the GemFan CF props has little to none. Until I get the APC properly balanced it is still a tossup between which prop I like better.

Leave a Reply

Your email address will not be published. Required fields are marked *