Chris True

My Feedback: (14)

I've been working on an electric conversion of a very old, original, JMP Starfire kit for about two months now. First up was some custom inlet ducting to allow the battery to be mounted in the center V.

Equipment used: DS-94 fan, Nue 1521-1.5Y motor, Castle Creations 110HV ESC, 4 Hitec 5125 thin wing digitals on ailerons and flaps, 2 digital 5245's on elevator and one on rudder, and a sub-micro analog on the airvalve + HS-225 on the nose steering. Battery is a Tanic 9S1P 5,000 mah pack. Classic B&D plastic framed retracts + BVM 5/32" wire struts and axles with Hanger 9 2.5" plastic wheels on the mains. The nose got a cheap Eurokit trailing link sprund strut and a 2.25" Skylite wheel. All up weight at this point with a bit of paint repair, markings and clearcoat still to go is 11 pounds 14 ounces. The fan generates 10 pounds of thrust @ about 2,800 watts. I've got a different wind motor that works on 12S, that will be something to try in the future

So, today was test flight day. Take apeak, nothing fancy. I just spent about 3 minutes or so trimming the three flap positions and feeling out the low speed handling. That plus the couple of full throttle runs to test thrust used 2.4 AH.

Video at:
http://www.rcgroups.com/forums/showa...mentid=1031904

GoeKeli

My Feedback: (18)

That is awesome Chris! I've been following your build thread, thanks for the video too. Congratulations on a great flying jet!

Joe

Chris True

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Thanks

A couple stills from the airfield today. Still needs some work on the paint obviously[:@]

EASYTIGER

My Feedback: (119)

Nice work, as always. Faster than the Viper, you think?

I like the hatch in primer. It looks like a 68 Charger I had in high school with the hood from a 69 on it. Nobody will steal it!

Nice work on the intake ducting, I know how much work that represents.

GoeKeli

My Feedback: (18)

Chris, what do you think a 8 minute flight will take from the battery? 5Amps? There is a guy out here that flys the heck out of this plane with an old 14lbs wren turbine. It looks to be a very good flyer and is on my list. How was the build? Are you going to add some rub on nomenclature or another color then clear? 12S? Oh man!!!

Joe

Chris True

My Feedback: (14)

Faster? Not YET . It's the same power system at the momentso I expect when I open it up (which I haven't done yet) it'll be similar. The inlets are bigger though so maybe not you know? 12S ought to make it sing, I flew that once in the Viper and it was signifacntly better but I couldn't get it to balance with the 4th pack installed. That's one of the reasons for the altered inlets That cockpit frame / canopy by the way are modern parts off the Yellow Aircraft kit. My old JMP kit was missing the canopy, originally it was fixed in place with glue. I bought the parts from Yellow and made them fit - there is some bondo and a ply frame involved in that.

Paint, don't ask! I had a disaster with some masking film and not quite fully cured paint. Wound up with adhesive on all the white areas and some spots that lifted. It'll all get fixed...




Joe - 8 minutes is a little ambitious. This is a 5-6 minute power system unless you want to fly around like an old timer. This flight didn't use much because it was a test flight and I was concentrating on trimming and then flying slow which is what's needed for that 1 mandatory test flight manuever - LANDING!

I have some markings on the way from Ralf Schneider, it'll be similar to one of those Swiss Hawks with a red circle / white cross on the fin, white cross on the wing tips, #'2 of the fuse side etc.

EASYTIGER

My Feedback: (119)

You should definitely do Swiss Naval colors. The Swiss Navy is undefeated.
As a sidebar, I made my own bungee and successfully flew my Hunter a bunch of times, finally smooshed the nose hitting a field table on landing, after I had to go around three times, each time slower than the next as the battery wound down, becuase some nimrod parked his car right on the approach path to watch, and was too thick to move...

What kind of range do you get out of the base-loaded white Deans mini antenna? Good enough for larger aircraft?

Chris True

My Feedback: (14)

How large? If you are concerned about it use the non-baseloaded whip, I've been putting them on all my .91 size jets. They get the antenna away from all the high power electrics and does wonders for range checking. For a plane smaller than that I"d have no resrvations about the Deans mini whip.

EASYTIGER

My Feedback: (119)

I have some of the larger whips arriving, I just wanted to test fly something tomorrow, but I think the shorty has reduced range from a full sized one, I have only had it in smaller models, this one is a big model, I should not risk it, I think...

Chris True

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Paint repair on the agenda today, might need one more coat on the hatch once it's set up for a day or two.

EASYTIGER

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When are you going to do something scale with a similar setup? Sport Hawk aside, got anything in mind?

Chris True

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I'm not that much of a scale enthusiast but who knows. I've got an A-4 in the attic and a very old, missing the stab linkage, Yellow F-4 kit.

The A-4 is maybe shy on inlet area a little and probably needs inlet different ducts. The F-4 is so old the landing gear was in the wrong spot and needed to be moved forward an inch and a half or so - I got most of the way through that enjoyable task before I set it asside last year. At the time, twin 90mm fans was the way to go, nowadays maybe the single big fan?

No burning desire to do either at the moment Maybe BV will release a new version of the Sabre or T-33 / F-80...

rjbob

My Feedback: (8)

Your report re your Starfire is timely. I, too, have a Starfire in which I'm considering EDF propulsion. BVM's system is reported to produce 12 pounds of thrust. Do you think the BVM EDF is a viable alternative for the Starfire?

BTW...I really enjoyed your video and congratulate you for the obvious success of your efforts.

Chris True

My Feedback: (14)

Thanks!

The only thing you'd need to check would be the physical dimensions of the packs - if they will slip in along the stock inlet duct into the space formerly occupied by the fuel tanks you are home free. Might need to thin out the hatch lip in that area a bit to make insertion / removal a little easier...

Chris True

My Feedback: (14)

On second thought, you might want the packs behind the fan for balance reasons. I'm thinking they might even fit better back there although you may have you elevator servo's in the way? Pretty sure it can be made to work

The reason I say further back for the packs is mine came out nose heavy! Without the heavy tuned pipe in the rear of the fuselage I needed to install my Rx pack back by the LE of the stab! I think if the packs were alongside the thrust tube behind the wing former and the Rx pack up in the nose it would all work out.

rjbob

My Feedback: (8)

Any battery cooling issues?

Chris True

My Feedback: (14)

Every little bit helps but realistically, there is only so much difference you can make when the pack is drained in 5 minutes I've added little scoops made from plastic spoons and a hole or two further back in a low pressure area to try and encurage airflow on some planes, others I haven't bothered with. I can't say there's really a huge difference but maybe some.