Eurofighter FPV build

[ez hawk]

Cant wait for first flight:]

[Zeeflyboy]

Managed to get some work on "Zeecatapult" done, and it's now almost in a beta state! As I say, I'll give many more details and pictures when I'm finished because I want to do some good testing and work out all the kinks first... but here's a little video I put together. Still need to just put in the launch pin, and come up with a foot pedal or similar for releasing it. I'll also have the front legs adjustable for more or less height as the situation requires.


You can see in the video how the catapult separates and fits together for easy transportation, then you just assemble! Takes about 3-5 mins to put together so far.


I'm pretty chuffed with how well it seems to be working so far - now you just need to picture the eurofighter on there... the big plate of ply you see at the beginning will mount to the top of the sled, and it has a small ring on a nylon strap that hooks under the eurofighter's tow hook. Then when the sled hits the buffers and stops, the ring goes forwards and falls off the hook and the euro carries on... upwards in theory lol.









and a video of it in action:

Catapult testing

Let me know your thoughts!

[Zeeflyboy]

and just a few more pics












I was at this point praying my retaining strap and pin would hold while I took the pics lol.

[SouthPawPaul]

I think I'm having a crisis!  :o

Damn that looks good.

[Zeeflyboy]

haha, cheers.

So who wants to start a sweepstake on whether the launcher works? lol...

[FPVSteve]

Only one way to find out :)

Stick a cat on it...

[electricmick]

Have you got another plane of a similar weight to test it before the Eurofighter?

[Zeeflyboy]

nah, I've been more into heli's the last couple of years.

The only planes I have left are a 50" Sebart Katana (similar weight, but I don't think it'll be particularly suited to launching unless I build a new adaptor plate, and that's just more delay!), and a UMX micro beast lol.

I think it'll have to be Steve's cat.

Double wing spars now all set in place, wings are feeling good. Now all that's left pre-maiden is a quick and dirty glassing of the belly and wings, sorting out the wing servo/light connectors and retaining mechanism, elevon servo linkages and then a quick check of CG and electronics.

Getting there chaps!

Here are a couple of pics where you can see how the wings fit... happy with how it's come out as it all lines up nicely. Hope it's all up to the job!

[Funky Diver]

Looking pretty swish there.  The catapult video did make me cackle, that moment where you'd pulled the catapult back and seemingly contemplating "is this going to go all very Peter Tong when I let go?"

Excellent machine there dude :)

[Zeeflyboy]

lol, how did you know what I was thinking?

I was also wondering how far the sled would end up going if it didn't stop...

[Zeeflyboy]

this eve I glassed and roughly painted a wing... still needs a sand/coat/sand/coat...

This stuff is really nice to work with - as you can see I even managed to keep panel lines where I wanted to... I think I'm slowly getting a bit better at glassing too, it's far from perfect but I think it's coming out reasonably!

You can also make out my Flytron strobes (crazy bright) and my little nav light led that I piggybacked onto the board.










Only a little more to go.... sigh.




I've also found out something nice about this technique... while it's a lot tougher than just the foam on it's own, it's still easy to dent a little if you drop something heavy on it (like I did by accident lol). A little boiling water poured over the dent magically lifts it back out as though it were never there. I always used to use this technique on my foam models, but of course it never worked quite so well as the foam would always look a bit damaged. Here the layer of glass protects the foam and it just gets crushed... with boiling water it pops straight out and looks perfect.

[Zeeflyboy]

very kind thanks.

I managed to give it's durability a real test yesterday... I stepped on the front on my tail because I had it off next to the plane and didn't see it as I picked the plane up and walked off. Unbelievable!

The front part below the APU intake was completely squished. Some boiling water poured over it for 20-30 seconds and it was almost back like new. A quick go over with some sand paper and a thin coat of paint, and you'd probably never know it happened. I'd say it passes the ruggedness test!

So, other than destroying my work, I've glassed the other wing and changed the servo connector over to my quick plug type. Both wings now flight ready (lacking a control rod in pics, hence the elevon position!)... just the belly left.






And, I've been wondering how best to make a small foot pedal release for the catapult that can be removed for storage, and doesn't mind what angle the ramp is at (since the angle is adjustable). I was walking around the hardware store the other day and I suddenly stopped and laughed... there was a MASSIVE oversized novelty clothes peg on the shelf and I had been hit with a moment of inspiration!

As it happens, it's perfect with a few little mods (please excuse the rough and ready appearance, it's just proof of concept thus far lol). The sprung nature also means it's very difficult for it to be depressed accidentally. Works great! Who would have thought... a clothes peg.... Crazy...





quick video (this end could do with being pegged down I think).

Foot release pedal


So what's left before maiden? Postman needs to deliver my EZUHF rx and my new higher powered bungees, I then need to run through some electronics setup again and make sure it's all working correctly. I also need to fit some wing retaining screws, Glass the belly, then go fly!

[SouthPawPaul]

That's the biggest friggin clothes peg I've ever seen!

Nice work

[FPVSteve]

Wouldn't like to meet the lady who's pants require a clothes peg that big ... :o

Nice work Zee, I really can't wait to see this bird fly.

[Zeeflyboy]

I've run a few tests today with my new bungees and it all looks pretty good! The release mechanism, while simple, works just perfectly every time... the power looks pretty good too, It's certainly going to launch it with more speed than you could ever hope to accomplish with the most powerful hand launch.

So we're getting there gentlemen! I'm hoping to get the rest of the minimum necessary glassing done over the next few days, the replacement EZUHF rx should hopefully arrive in short order, and then we're getting very close to maiden time with just a few odds and sods to sort out before hand... I'm getting excited!