I was wondering if any one had any experience with a Nitro Bob Cat 50 Jet ?
Have been thinking about putting a 5" 130mm ducted fan with a Scorpion motor on it.
This fan will develop over 8 lbs. of thrust on 12S 5,000 ma li po pack.
I figure the plane will weigh about 10 lbs. complete with batteries
The wing span is 51" and has 666 Sq. in. @ 10 lbs. this a 34.6 oz Sq. Ft. wing loading.
This is not to bad for a jet. piper cubs & trainers are about 20-25 warbirds are about 25-35 jes are 35- 75. sometimes more in bigger planes.
To figure wing loading: 666 divided by 144 =4.625 Sq. Ft. 10lbs. X 16 Oz =160 divided by 4.625 = 34.59 oz. per sq. ft.
Any ideas or suggestions will be appreciated.


Thanks Don B

go here: rcdon.com

theres a lot of threads in RCU on th ebobcat 51

do a small search and youll get what u need

can you post some pics of the PWR system, hence: Fan,ESC & Batt, pls?

I will get some pics of the fan and esc
where can I look to see the threads of the bocat 51 ?

Don B

Which Scorpion are you using and which fan? If it is the hoaye 127mm and a motor of over 550 kv or so your amp draw is going to be outragous; I can tell you this from experience with an HK4035-630 on 12S2P 9800 mAh pack it drew over 150A! Even on 10s it was too high.
I think the 5" fan is a better fit for the 120 size bobcat/falcon and a 3.5" - 4" would be better on the 50.

The main thing I've learned about wing loading for models is that it is very sensitive to Reynolds #, the smaller the plane the lower the wing loading needs to be. Any thing under 1 sq.ft and a loading of over 15oz/ft2 is a monster move up to 2sq.ft and 20 or so is about the same. The scale is not linear but 34oz/ft2 sounds pretty serious for ~4.5 Sq.ft.

If your examples are refering to full scale I think it should be lbs/ft2 not oz.

[8D]in rcu
jus do a search and u'll find it

Mark d

thanks for the reply the more I check this out the more it looks like it will not work well.

[&o] Thanks Don B