Showing posts with label bell. Show all posts
Showing posts with label bell. Show all posts
Wednesday, 18 March 2015
Tuesday, 23 December 2014
Canadair New Motors
...more speed!
I fitted the Canadair with three-blade props of 7x4.5 on the basis that dropping a size from the standard 8" twin-blade props is recommended. However, in this case, the originals are big paddle-props so a change to regular three-blade props of the same size would probably have been a better equivalency.
An issue with the bearings in one of the motors, which I was unable to remove for replacement, had me shopping for new motors and I came across the more powerful 250W version of the specified motor. Being the same size and weight, although with a lower quoted current draw, it seemed a natural choice, now that I had a better appreciation for the performance of the Canadair having flown it.
Also, given that the 7x4.5 props were undersized for the original motor, the higher kV rating, 1650 vs 1400, suits them very well, and the Canadair seems happy with the new combination and generates an impressive turn of speed at full throttle...
I fitted the Canadair with three-blade props of 7x4.5 on the basis that dropping a size from the standard 8" twin-blade props is recommended. However, in this case, the originals are big paddle-props so a change to regular three-blade props of the same size would probably have been a better equivalency.
An issue with the bearings in one of the motors, which I was unable to remove for replacement, had me shopping for new motors and I came across the more powerful 250W version of the specified motor. Being the same size and weight, although with a lower quoted current draw, it seemed a natural choice, now that I had a better appreciation for the performance of the Canadair having flown it.
Also, given that the 7x4.5 props were undersized for the original motor, the higher kV rating, 1650 vs 1400, suits them very well, and the Canadair seems happy with the new combination and generates an impressive turn of speed at full throttle...
Thursday, 18 September 2014
Performance Anxiety
...how big is your prop?
The only minor concern I have regarding the Canadair 415 is whether the props are sufficiently large; I traded in the 8x3.8 slow-fly props for three-bladed 7x4.5's following the methodology of dropping one size going from two blades to three. However, in this case, the original prop is a slow-fly paddle version, so I'm thinking that going for a regular eight-inch three-blade would have been a better equivalency.
Anyway, I might do a power test on a scale just to get a rough idea of how much thrust to expect; the 210W bell motors are rated at a max 880g thrust which, pushing the lightweight Canadair 415, would probably give it unlimited vertical performance...
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