TGoodwin

Hey Uncle Joe. Thanks.

I should be there Weds-Sat.

Ted

john agnew

Ted

I don't see any reason why the Wren 44 should not fly your lovely little F16 If you can keep the dry weight under 10 / 11 lbs you will still have a thrust ratio of at least 2:3 which will fly a jet model comfortably.I am putting together an AMD Hawk which I anticipate will be in that range.

Look forward to more information.

John

TGoodwin

Hi John.

I have calculated the weight increase with fuel and a stronger design to be a total of .75-1 lb. The current EDF version ready to fly weighs in at 6.75 lbs. One of the early prototypes weighed in at over 8lbs and did fly with only 65% of the power of my current setup. It was seriously under powered. Most of the flight was at a high AOA and just bordering on stall. It was still very stable and easy to control. Notice from the picture that the wing plan-form may be different giving the L39 a greater span but the total wing areas are close. Also the design of the full scale F-16's lifting body allowed the total wing area to be 40% smaller that it would have needed to be with an L39 type fuse to carry the same loads. The 40% may not relate directly due to reynolds number but the fuse does provide a substantial amount of lift.

Thanks Ted

Yann

Is this F16 available as a kit yet ?

TGoodwin

Hi Yann,

The kit waiting list for the electric version is now open and the first kits should ship some time around June. I am working on the 7 lb turbine version but it is not yet ready.

Check this website for updates. www.CrosswindComposites.com

Thanks Ted

P. Richards

My Feedback: (3)

Yann as far as I know it is ready for a kit release a few kit manufacturers are lined up for a production run. Parts have been set up through a laser cutter and moulds are prepared and ready. The moulded wings are not yet completed. But foam cores are ready to go.
Dixie Jet Rally is next and then I will see if Ted needs my help in getting the orders filled.[8D]


P. Richards aka Swat Team

Yann

Ted,

What kind of retracts will you be using for the turbine version ?
Will they rotate 90° as they retract ?

Yann

PhilLin

How to keep same left & right sides.....

To add to Pat's & Ted's explanation, I use the mirror command in my CAD after drawing half of a former. Then you will have perfectly matched left & right sides, depending on how you keep the shape thru the sanding process. Good luck with your scratch build!

Cheers,

Phil

TGoodwin

Ahh the gear. The gear is actually one of the weakest links in this design. Rite now I am using SpringAir 602's which do not rotate. This is a problem on the nose as it limits the size of the nose wheel. The mains are not really a problem. The other problem with the Springair 602's on the nose is as the weight increases to 7.5 lbs and up the wire nose gear strut is no longer strong enough so unless you grease the landings on a hard smooth surface every time then the wire nose strut bends. The only solution that I can see is to add scale gear. As far as I am aware their are none of the correct size being manufactured. So the only solution that I can see is to have a custom scale gear set machined. I think this will also really set this plane apart and be a great final touch to this project.

TGoodwin

Thanks Phil. Yep that is exactly what I do also.

Ted

Yann

Ted,

I know the nose gear is a critical part.
I wanted to know if you had a solution.
I already found suitable legs (oleos) for both nose and main.
I also found suitable rotating retracts for main, but not for the nose.
Steering AND rotating does not seem to exist at this scale...

Yann

TGoodwin

Small oleo's? Where?

Thanks Ted

Yann

Sorry I can't upload anything else but jpeg, and I have pdf files...

TGoodwin

You can send pdf file to my email.

CWComposites (at) cox.net

Sorry I dont want to post a working link here due to SPAM.

Thanks Ted

Yann

Sent you an Email Ted.

Yann

TGoodwin

Cool. Got it. Thanks Yann

Ted

Yann

Let me know what you think of it !!!

P. Richards

My Feedback: (3)

Another award at the Dixie Jet Rally and a new speed milestone for the F16, well Ted decided to try another fan and motor combination. The result 10 m.p.h. faster bringing it to 145m.p.h. in level flight. A thermal shutdown forced an early landing and a tour of the surrounding landscape. But thank goodness it's repairable. Thanks to all the guys at Dixie for such a great event...

P. Richards aka Swat Team

TGoodwin

I think that should read "in the fastest high speed low pass".

Thanks Ted

TGoodwin

My new propulsion unit is in for this plane. Will be redesigning the internals, changing the layup schedule and creating conformal fuel tanks. Here are some pictures of two of the current electric propulsion units with the Wren 44 for size comparison. The weight of the Wren is the same as the EDF unit, motor and electronic speed control on the left.

Ted

TGoodwin

The redesign of this electric 90 mm jet to a MW44 powered turbine version will require new tooling to be created due to engine placement requirements and some time in redesign to handle the increased speeds and flight loads. If there is enough interest in the small jets I will go ahead with the kevlar composite fuel tanks and other such details. If not I will probably not waiste my time and just install two kidney tanks on the CG.

The tanks, fuel, ecu, pump, etc. will weigh about the same as the flight batteries used to power the EDF model now. The Wren unit weighs the same as one of the EDF units, motor and ESC. Any weight increase will come from structural improvements. I expect the RTF weight to increase from 6.5 lbs to around 7.5 lbs with this conversion. Some of that increase will come from the addition of flaps and rudder.

I have a question. What is the benefit of a bypass? I notice some turbines use them but some do not.

Thanks Ted

Shok

My Feedback: (28)

it will be hard to use a bypass on an engine that needs a wand to start.
With that engine I really don't think you will benefit very much if at all.

I have alot of experence now with the 44 and its a wonderful engine. It pushes 12lbs planes around with ease.

TGoodwin

Hi Ronnie,

I see your point about the wand start but what is to be gained with the bypass versus without? Why do some installations have them and some not?

Thanks Ted

john agnew

Ted

The weight of the Wren 44 installation complete with pump battery is about 1lb 8oz. It flies my AMD Hawk very nicely at a weight of 10lbs 4oz. dry.

John

TGoodwin

[link=http://www.crosswindcomposites.com/videos/Viper_music.wmv]33mb wmv video[/link]

Most of the internal redesign for Wren 44 is now complete. Will be making a new set of molds to add a turbine access hatch on the top and eliminate the motor access on the bottom for the EDF unit.

Here are some pictures of the EDF units and the Wren 44 side by side.

Ted