OK heli guys, so the next step for my MD500E 700 size is putting on a set of 5...
OK heli guys, so the next step for my MD500E 700 size is putting on a set of 5 blades and head. So I've got the Roban head and now looking at the blades.
The only 2 brands that I'm looking at are the Spin Blades that are Asymmetrical and a good price. The other is the Witte blades that are full symmetrical and more expensive. So we all know the difference between the two blades and both have pro's and con's.
The problem that I have is the gearing on my T-rex700N of 8.2:1. In Scale heli's it's all about LOW headspeed, say around 1300-1400rpm give or take. I was flying the X45H in Gov mode at 1900rpm ( with flybar ) and found the headspeed was always going up and down so I changed it to throttle curve and haven't had that problem anymore.
So the heli will be around 8-9Kg with the 5 blades on and full of fuel. So my question is, has anyone used 5 blades on an X45H yet? if so what blades? Will the motor overheat if I lower my throttle curve to get a lower headspeed? The black blades are Witte at 680mm long and 160g each blade the others are the Spin blades at 700mm at 125g each blade. Thanks for any help, Happy flying.
8 Comments
I also fly a T-Rex 700 with a gear ratio of 8.2:1:4.54 and the Spin Blades, which are asymmetrical. The Roban head rotates in a range of 1300-1400. I fitted the Wren 44i which is also very comfortable at rpm output – 12,000rpm.
At this head speed, the Spin Blads work very well. So for the price I can highly recommend it.
Hi Uwe, Thanks for the info. Your setup is very cool and exactly what I want to achieve. I think the Wren has more power over the Xicoy that's why I'm thinking more the Spin blades. If flying in the wind, does your heli want to bob up and down as the blades catch the wind due to the Asymmetrical lift from the blades? I understand that symmetrical blades will do the same to a point but in fast forward flight the spin blades are ok? I'm also thinking of getting Spin blades to cut them down to 680mm for me and have square tip. Do you have a photo of your throttle curve if available and your pitch setting low, mid, high? Cheers.
You can watch the flight behavior in this video. But there is still a slight nod that results from the poorly adjusted blade tracking.
https://youtu.be/yUYrWubJ9OE
Great answer from Uwe! I would also be aware of the ambient temperature when you fly. What is the altitude where you fly ?
Hi Michael, for me it's about 6 meters above sea level
No worries about density altitude then!
My throttle and pitch curve are absolutely linear. I assume that the upper pitch is around 8°. You have to try the maximum values step by step
Thanks Uwe for your help.