Freewing EDF Group

Krikey!

Someone told me that the Freewing 64mm edf models could be built in an hour. An hour is about my limit for concentration, so I thought I'd give it a go. I started to unwrap a MIG 15 last Wednesday. Its Wednesday today and I have just finished setting the control throws. The anticipated "One Hour" build has in fact taken me a little over seventeen hours to get the model built and ready to fly. I watched the Freewing MIG 15 video made by the amusing Petrincic brothers from Slovakia. They reckoned to use a 3s 2700mAh battery, the handbook says "3s 1600mAh". Unfortunately I have 3s 2200mAh batteries, which when installed as far back as possible, the CG is still at least 1/4" (six and a bit mm for those that want to stay under European domination) too far forward. Shall I just chuck it into the air with full up elevator and hope for the best?
Or should I wait for HK to deliver some 1600 batteries?

Hi Brian

17 hours is impressive, not sure how you managed that! I didn't record my build but know that I did it in an afternoon, so definately low single figures and that included installing a rudder snake outer.

Mine was nose heavy with a 2200, but flew fine just needed lots of down for inverted flight. Just add a bit of up trim for the first flight.

I have since installed a rudder servo in the fin (didn't use the pre installed snake in the end) which has got it back to where it should be, it is better, but like I said, is fine for circuit flying in the nose heavy position.

For test flight you will need lots of elevator deflection, but not much aileron

Thanks for the advice Jon. I should explain that my "one hour" concentration span isn't quite right. Its a case of wandering off track and "improving" things as I go. I noticed that the tailpipe duct was covered in moulded pimples, I removed the fan unit and sanded the surface smooth. At the intake end, the moulding was a bit "off", the vertical part was poorly moulded, I thought it would cause unwanted drag and turbulence. I removed it, sanded the intake area smooth, then replaced the foam item with a more or less "airfoil section" piece of balsa. Of course, all the sanding needed to be repainted, silver intake and extremely "sooty" looking tailpipe. All in all, quite an enjoyable build. I like the idea of fitting a rudder. Is it worth the effort? Tomorrow, I hope to maiden the MIG. Watch this space for another exciting episode.

I understand now how you managed to stretch it to 17 hours, didn't realise you were including 'mods'

Whether it's worth installing a rudder servo depends on how much you normally use your rudder in flight Brian. I tend to use mine a lot, plus I needed tail weight, so it seemed worth it for me. Here's a pic of my rudder install, in case you fancy doing it. If you remove the fan unit you can see a channel in the foam under it, it was reasonably easy to poke a wire from the fin to this point, then draw the cable through.

Brian, Glad to hear you have joined the fray.

How did you stretch it to an hour? This is me - connect the RX temporary to ESC to verify fan is going in right direction. Nope! So swap two leads round. (5 mins) Fit receiver and connect servo/throttle leads. (1 minute) Fit wing using screws about 10 minutes (as holes did not line up perfectly). Sip tea. (10 secs) Mix up some of my own 4 minute epoxy, dry fit tail end. Glue tail end bits. Sip tea for 5 minutes. Epoxy has gone off. Fit control horns (20mins). Switch on RC radio gear, check servos work, and right direction, adjust clevises for neutral control surfaces (15 mins). Create some rates/expo on X9D TX. 20 mins. Set up throttle range. Done! Take to field and master launch method - a bit longer.:lol:

A few days whilst fiddling and modding by some error I cannot fathom :whistle: I put a servo lead into the fan. Wait four days for replacement from NL. Now refitted I may add.

I used Nano Tech 2200 3 cells 35C. 200 gms weight. sits in middle of battery bay

Thanks for the pic of the rudder mod Jon. When I've got the first flight out of the way, if the MIG survives, I'll have a go at fitting a rudder servo.
Phil, thank you for such a comprehensive description of your workshop activities. Getting leads tangled in the fan is a nuisance. I did exactly the same with my Tony Nijhuis 42" Hawk. I ran it up to test the system, I'd forgotten to cinch the battery strap. Fortunately, the damage was a shredded balance lead with amazingly, no shorts or fire. Waited a long time for HK to produce a Dr Mad Thrust rotor, but in the meantime, I had the exciting task of regenerating the balance lead and plug. That's when I found that lead colours aren't common to all LiPo batteries. Thank goodness for a BangGood digital multimeter, a pencil and piece of paper, and starting from 0V on the black lead, adding leads in 3.7V increments. I think I aged a bit due to the anticipation of a big fat spark that would have put an end to all the effort. Fortunately the balance lead ended up OK, and after major surgery, the Hawk had its fan re-installed. Happy daze!

You may not be aware of this but a few weeks ago I ordered an upgrade EDF unit for my Sabre from MotionRC. When the package turned up just a day before the EDF Jet day, the box info was correct but the EDF inside was the standard version. Right! Back on to MotionRC and was surprised how quick they responded to my email with an apology. Said they would put it right. So, in the meantime I had to fit the standard version for the weekend in question.

Heard nothing else for ages until this afternoon, 18th July. The correct unit is now on it's way free of charge and P&P. Problem is the Sabre was destroyed weeks ago. Does this mean I have to buy another? :lol:....

You could always give it to me Phil. I have a pristine Sabre!
Simon O

You could go for one of the other Freewing 64mm jobbies- f18 perhaps or donate it to a worthy cause I'll second your comments on MotionRC customer support; they are very good.