cebrey

Well, I got me one of those Skylarks from eBay. It was advertised as 35MHz (the correct frequency for flying here in the UK). I emailed the seller to confirm that it was 35MHz and not anything else, he assured me that it was. It's here, and it's 40MHz, illegal for aircraft use. Good eh? So, I figure I might as well try chucking in a couple of 35MHz crystals, despite the fact that there's been a good few people who have said that it won't work like that. You know what? They're right. The chopper went nuts, and promptly drove itself into the ground, snapping the swashplate on its way. So, I'm now waiting for a reply from my little seller man to see if I can get that £230 back...

A broken chopper does not a happy Carl make

Hoverup

My Feedback: (11)

Sorry you got burned. Sounds all too familiar. Same thing happened to me (40Mhz delivered to 72Mhz land). Good luck trying to get a refund. They ended up sending me a 25 USD refund to buy xtals that I told them would not solve the problem (the freq boards in the Tx and Rx are completely unique to each band 35/40/72 - not just the crystals). I gave up trying to deal with these guys and equipped the thing with components from my junk box. Good luck and persistance may pay off.............but if it does you will be the first.
Cheers - Boyd

cebrey

Hey Hoverup,

Thanks for the heads-up. I've seen a lot of your posts around here (I've been lurking for some time) and you certainly seem to know your stuff . This was going to be my first outing into the h********r world (I'm a fixed wing junkie at heart) and I stupidly decided to ignore the "don't buy these small choppers as a first chopper" warnings. Bah.

So, anyway, let's talk about converting a Skylark eh? I already have a spare 35MHz receiver that I could prolly make use of. It's for my JR XP652 set, which has heli mode on it, which may or may not be a good thing. What do I need to get this thing in the air (apart from a new bloody swashplate now)?

Cheers,

Carl

Hoverup

My Feedback: (11)

Remove the GWS 40Mhz rcvr and replace it with a light weight (GWS) rcvr in the 35Mhz band. I don't know what your JR rcvr weighs but these little heli's are weight critical. Try the JR and see if you can get airborne. Don't forget the training gear...4 pingpong balls or wiffle practice golf balls mounted on sticks or light weight rods tie-wrapped to the skids will prevent most tipovers. Get a sim and practice, practice, practice.
Hope this helps - Boyd

cebrey

Are GWS and JR compatible then? Should I just throw in the towel and get me a Piccolo?

Carl

Hoverup

My Feedback: (11)

If you end up getting the GWS rcvr, you need to specify positive shift to have it work with your JR Tx. They come in positive and negative shift versions, but the negative shift is for Fytaba, Hitec not JR.
Cheers - Boyd

cebrey

Boyd,

I just weighed my JR receiver, it's 8 grams with the crystal in it. Too heavy? I've managed to get it (mostly) working in the chopper, but I need to get an adapter lead for the tail rotor (the two outer plugs on the original rcvr are the wrong shape for the JR rcvr, but there exists adaptor leads for this)

The only thing that'll leave is fixing the swashplate. Of course, I /say/ it's the swashplate, but I'm kinda assuming that the bit that runs perpendicular to the rotor blades on the rotor head is the swashplate, if you see what I mean Either way, it's that bit that's broken, and I could do with repairing it. Do you think cyano would do the job, or should I see about replacing it with a piccolo spare?

Cheers,

Carl

Hoverup

My Feedback: (11)

The GWs weighs in at 6.1 grams, so your Rcvr should be fine (close enough). Without knowing for sure what the part is or how it is broken it is hard to advise on the repairs. I have repaired swashplates that have lost their antirotation pins with 1mm CF rod, CA adhesive and some thread as a reinforcing wrap. Others have repaired this same failure with paperclip wire or a cutdown tiewrap. I've attached a pic of the swashplate so we can be sure that's what we are discussing.
Cheers - Boyd

cebrey

Excellent! I didn't know what a swashplate was then The part I meant runs at right angles to the rotor blade, spins when the rotor spins and looks like a thin piece of CF with a paddle on each end. See which bit I mean?

I'll see about squeezing that Rx in somewhere (it's light, but it ain't small in comparison to the GWS board).

Oh, and I've had a reply from the seller. He assures me that the Tx is at 35MHz and even then, 40MHz is perfectly legal in the UK. Funny that, given that flying a model aircraft on 40MHz can land you in prison for 6 months and/or a 2000 GBP fine.

Carl

Hoverup

My Feedback: (11)

If it's the flybar that is broken, a 2mm CF rod or a length of 2mm music wire will work. Just remove the paddles, withdraw what's left of the broken flybar and insert the new part cut to the same length as the original and exactly centered. Reattach the paddles, static balance the assy. with the main rotor blades removed and you should be good to go. If it's not the rod and it looks like you can CA the part that is broken without getting any glue in the moving parts then go for it, nothing to lose. I've attached an exploded view of a similar heli (Century Hummingbird) for reference or try:

http://www.centuryheli.com/support/m...20instruct.gif

Hope we are on target now.

BTW they also tried to tell me 40Mhz was legal in the States, so I sent them the Federal Communications Commission regulations and then my $25.00 PayPal deposit arrived.

Cheers - Boyd

cebrey

Aye flybar, that's the one The bar itself is what's snapped (close encounters with a wooden floor) so I'll see about replacing that. I've just managed to get the old GWS Rx out of the heli, so I'm about to start looking at putting my JR in. Should be fun. Just need to find some CF rod or piano wire now. Now where can I get either of those at this time of night?

Cheers Boyd,

Carl

cebrey

Boyd,

One more thing. I've got the new Rx connected up, but when I apply the throttle the main rotor spins but the tail rotor doesn't. Is there some mixing I need to set up somewhere along the line?

Cheers,

Carl

imeins

Hey Boyd, get ready to laugh at me but I ordered a FEDA today. I'm really hanging out to get airborne. I'm still doing the Corona thing but this is my "I want it right now" solution. I won't even curse when I embed it in the wall and you say "I told you so", I just really wanna fly, something!!

Cheers,
Ingmar

Hoverup

My Feedback: (11)

Ingmar - I promise not to say "I told you so". I hope you get it in the air and get the "rush of hovering" that comes with that first time success. Keep us posted.

Carl - What ESC are you using? if you have the Piccolo "clone" board that comes on the Skylark there are two adjusting potentiometers that control sensitivity and mixing % that you will need to adjust to get the T/R responding like it should. For details try this site:
http://www.pgoelz.com/
Even though it is a Piccolo site there is a lot of good and very helpful info ther that will help you.

Cheers - Boyd