pda75
Well-Known Member
- Joined
- Jun 2, 2007
- Messages
- 83
Hi
I am thinking about a large rigger. The hull will be home made, with the following set up
10S 2P 5000 mA cells
ESC : YGE 200
weight of the hull : 6 kg
Length : 1,20 m (eg 45")
The objective is to run 5 minutes at 130 km/h (eg 80 mph). My assumption is that I need 4000 W for this weight and this speed.
Given the price, I will not buy a motor for "a test" and I need to choose the right KV with limited risk of mistake. So I would like to get your advice on the best KV .
kv = 750 (lehner 3040/14). Speed would be 80 mph with an 1667 octura prop assuming 15% slipery and 3,4 V per cells
Kv = 808 (Lehner 3040/13). Speed would be 80 mph with an 1467 octura prop assuming 15% slipery and 3,4 V per cells
Kv = 875 (Lehner 3040/12). Speed would be 80 mph with an 1462 octura prop assuming 15% slipery and 3,4 V per cells
The only true data point I have comes from the nitro guys. They get 80 mph with 25 000 rpm and a 1667 octura with an equivalent hull.
off course, I can target more rpm and a smaller prop but I am not sure that it will lead to sufficient propeller traction and that slipery will not dramatically increase.
Thanks for your help.
cheers
Pierre
PS: a lehner 3060/9 has a 778 kv. It could be an option but it adds some more weight.
I am thinking about a large rigger. The hull will be home made, with the following set up
10S 2P 5000 mA cells
ESC : YGE 200
weight of the hull : 6 kg
Length : 1,20 m (eg 45")
The objective is to run 5 minutes at 130 km/h (eg 80 mph). My assumption is that I need 4000 W for this weight and this speed.
Given the price, I will not buy a motor for "a test" and I need to choose the right KV with limited risk of mistake. So I would like to get your advice on the best KV .
kv = 750 (lehner 3040/14). Speed would be 80 mph with an 1667 octura prop assuming 15% slipery and 3,4 V per cells
Kv = 808 (Lehner 3040/13). Speed would be 80 mph with an 1467 octura prop assuming 15% slipery and 3,4 V per cells
Kv = 875 (Lehner 3040/12). Speed would be 80 mph with an 1462 octura prop assuming 15% slipery and 3,4 V per cells
The only true data point I have comes from the nitro guys. They get 80 mph with 25 000 rpm and a 1667 octura with an equivalent hull.
off course, I can target more rpm and a smaller prop but I am not sure that it will lead to sufficient propeller traction and that slipery will not dramatically increase.
Thanks for your help.
cheers
Pierre
PS: a lehner 3060/9 has a 778 kv. It could be an option but it adds some more weight.