Bluehawk - RC Groups
Thread Tools
This thread is privately moderated by Conehead, who may elect to delete unwanted replies.
Jun 01, 2009, 05:57 PM
Flutter-Bys are fun
Conehead's Avatar


We had a flying field on private property and about 3 maybe 4 years ago we had one of our lawn tractors stolen. Somehow they got into our shed and got the one tractor out and so we were down one lawn tractor. Then we lost our field. The fellow who owned the property got an offer he couldn't refuse and so we have to still find a place to fly. We fly at two full scale airports presently. Empire Michigan (KY87) and Thompsonville Michigan (K7Y2). Both have some full scale traffic, but where we are, there is very little traffic. We do have a radio that we listen in for incoming full scale planes, we land our RC planes and then everything is fine. I donated an old John Deere lawn tractor that I had. I rebuilt the mower deck when I got it and since it was not running great, I said, here, you will need to see what is wrong with this tractor, there was very little wrong with it, but one fellow took it apart, went over it, replaced a number of parts and fixed the mower deck and now the tractor looks as good as new. We use this tractor at the Thompsonville Airport to cut part of the grass runway we fly off of. At one of the meetings last year, the fellows of the club decided that I should have Fred's plane. Fred was done with it and he didn't want it any more. Why, only Fred knows.

This Bluehawk was built by Fred Stafford, he got the kit from another fellow in the club, I don't know if he was given the kit or they traded something for it. Fred built this plane as a test bed for his new electric motors and to see if he had enough power for some of his older planes. Fred has a number of old timers that he built and he wanted to make sure the motor he chose would be enough to pull the planes up and then he could thermal them some. These old planes were gas powered and Fred used to fly them with just rudder and elevator. Fred has also built a couple of Puddlemasters and one of those Puddlemasters was a scaled up version and so he wanted to make sure the electric motor he got would pull that plane up off the water.

After Fred found out that his combination worked very well, in fact what he chose was way too fast for this plane, but about right for all his other planes and he planned to build some planes in the future that would use this combination.

This is a Sig profile Ultimate and was to be powered by a .46 engine. We all know that not all .46s are the same, so when it comes to electrics, one electric motor will be different from another one. I sure wish that all the manufacturers would get together and decide on a standard of specs for all electric motors. That way you could look at one motor, then choose with ease the motor that you want to put in your plane. Would make it much easier.
Fred used this combo.

AXI 4120 motor with a 12-6 or 12-8 prop
70 amp opto Jeti Advanced speed control
Ultimate BEC since the esc didn't have an internal BEC.
Also a 3700 mah Powerquest battery from Hobby Lobby.
This plane would go straight up.

So I was conversing with another fellow on RC Groups. He helped me pick out a motor that would work or general numbers that would work. So many thanks to Flieslikeabeagle. John put the numbers in and of what the planes wing area, weight, wing cord and came up with the recommended motor from his electric motor calculator.

The Bluehawk is a biplane,
42 inch wingspan
798 sq. in.
4 1/2 lbs aprox wt.
9 3/4 in wing cord each wing including ailerons.

So at Toledo this year I went to the vendor booth, got a motor. I bought a Scorpion S-II 3026-710 kv motor, I then got a Scorpion 70 amp esc with a BEC since I will be running 4 cell lipo.
I plan to run either a 3200 mah 25 C discharge rate, the other one will be a 3700 mah 35C discharge rate, capable of 2 C recharge.

I will post the assembly on the Glow to Electric conversions thread, and here in my blog.

I have some soldering to do, fit the motor mount to the firewall, the AXI motor that was on it has a different size motor mount than the Scorpion.
Here are some pictures of the plane before adding the electronics.
I will put an AR7000 receiver in this plane which I also got off of RC Groups.

I am pretty slow as to how to do all this stuff. I can solder fine, then comes the where to put what. Also the esc comes with a way to program it with their ir card. So after all that is done, battery purchased connections made, I will be ready to fly it. I hope to have it done by the end of the month, before the 4 th of July. I will fly it off the hard runway at our one flying site.
Thanks for looking.
Orrin Eldred
Honor, MI.
Sign up now
to remove ads between posts

Thread Tools