Topic: RCRCM SUNBIRD BUILD

Dunno, I asked for a carbon one and had the choice of White  , Red, or Orange...so went for a Tango type...must havE been what was available at the time in the factory...at least there won't be 2 the same

We had our first Sunbird on Tinkers today and I have to say it flew great. Lovely looking model too.

We had our first Sunbird on Tinkers today and I have to say it flew great. Lovely looking model too.

Thats about what it was meant to be.

Seriously though I do hope you lads enjoy it - I always liked mine.

Somehjow I had the feeling that in a good wind I could do anything with it.

Happy flying!

JH

It was the model's maiden and it's owner was very anxious but in the end it just flew straight out with no problems at all. It didn't hang about and seemed pretty nippy. What section does it use, is it one of yours?

Dunno, I asked for a carbon one and had the choice of White  , Red, or Orange...so went for a Tango type...must havE been what was available at the time in the factory...at least there won't be 2 the same

No, looks nice, just my presumption that it was going to be different, you'll love it.

I'm hugely chuffed to have it, and once airworthy I think my Air One Mini Acacia is gonna get a bit dusty...still, I'll make that my mouldie holiday hack 

Is the Air 1 Mini a 4 servo wing? Considered 1 of those when I bought my 1st SB, finish wasn't great on the 1 Zim showed me and a few 'pointers' swayed me to the SB.

Yes it's 4 servo wing, but no rudder...
I still really like it... it's a good finish on this one...

It was the model's maiden and it's owner was very anxious but in the end it just flew straight out with no problems at all. It didn't hang about and seemed pretty nippy. What section does it use, is it one of yours?

Yep its one of mine - JH817

Cheers,

James

I spent last night and today faffing about with the installation of the sunbird...just waiting for the wing servos to arrive, then I'll be good to go. There's not much room to play with in this, but i enjoy the intricate work required to get it just right.

I spent last night and today faffing about with the installation of the sunbird...just waiting for the wing servos to arrive, then I'll be good to go. There's not much room to play with in this, but i enjoy the intricate work required to get it just right.

Now that is looking nice. I've received mine now and I'm starting to think about how to lay it out, reading build threads etc. etc.

What wing servos did you go with in the end? What batteries? Is there still room for enough lead in the nose?

Do you know if the SlopeRacer ballast set is the same size as the factory ballast tube? I vaguely remember something about SlopeRacer supplying a different tube/servo tray but that may have been a different plane...

Yours is definitely the neatest install I've seen, I think I'll be copycatting you.
 

Yours is definitely the neatest install I've seen, I think I'll be copycatting you.

Looking closer, I think I'll have to do the aerials differently - it's the full carbon so I want them to be outside the fuse, and also at right angles to each other.

Yo Yoyo. Did you opt to purchase the ply tray for the model? Makes that install really easy as it sets the position of the battery, ballast, servos etc. Good work, mind you, BG 

Carbon - you should not need to have your aerials outside as the front of the fuse is kevlar/ glass, not carbon. No problem, no need for aerials outside at all.

Ballast sets from SR are to suit the tubes supplied with the SB, Typhoon, Strega, Vector etc etc - all the same gauge i.e. 19mm OD x 35mm long.

Any q's just give Tony a call - he'll be happy to help.


Z

I recieved a ply blank servo tray from Mr Fu when I picked mine up and got a nice carbon ballast tube at the same time. I dunno what size any other ballast tubes etc are.
Not quite sure how I'm going to get any lead in, unless it's lead shot epoxied in...I'll cross that bridge at the time, no worries. I wanted to make sure there wasn't wires all over the place, like my usual standard
The nose is 2.4 friendly, hence the tubes for the aerials alongside the fuz sides...the carbon stops approx at the wing LE

Yo Yoyo. Did you opt to purchase the ply tray for the model? Makes that install really easy as it sets the position of the battery, ballast, servos etc. Good work, mind you, BG 

Carbon - you should not need to have your aerials outside as the front of the fuse is kevlar/ glass, not carbon. No problem, no need for aerials outside at all.

Ballast sets from SR are to suit the tubes supplied with the SB, Typhoon, Strega, Vector etc etc - all the same gauge i.e. 19mm OD x 35mm long.

Any q's just give Tony a call - he'll be happy to help.

I'm sure he'll be as helpful as he was last time I spoke to him, but  I bought this as a second from olerc... so I got the standard factory ply plate and ballast tube. It's been put away by SWMBO until next weekend (my birthday ) so I can't get at it to measure stuff yet... 

Good news about the aerials, inside is always neater. I'll still be aiming for right angles though.

.......Not quite sure how I'm going to get any lead in, unless it's lead shot epoxied in...I'll cross that bridge at the time, no worries. .

If you're really struggling to get enough lead up front, you can always go for the direct method, molten lead poured directly in......should reduce the volume to about 2/3's.

It's a bit scary, but it works well. Make sure you put the nose in cold water, as high as you can without water being able to seep over and get inside. Don't worry about the ply plate. Although it will scorch it, it won't suddenly burst into flames (diclaimer, just in case it bursts into flames-it's not my fault, use at own risk). I've done it to a couple of models, once on the Typhoon and again when I've HAD to (Willow). It doesn't seem to cause a prob with the fuse's integrity. I'm sure I'll get some frowns on the above method but hey ho...

Failing that I've read about Tungsten powder which is twice the weight of lead, so half the amount would be needed, just mix with a bit of epoxy. No idea on price (expensive I bet) or where to get it in the UK tho.

Nice job on the install BG. I wanted to locate my RX where yours is but wasn't happy with it there in the end, I thought the wing joiner might rub on the ariels where they enter the RX  .

Rub on the aerials or leads?

What wing servos did you go with in the end? What batteries?

  Hmm?

I have a couple of HiTec 125MGs in stock that I may as well use if they'll fit, I was quite pleased with the Vigor wing servos in my Speedo but they seem a bit titchy for the SunBird. I can't afford DS095s or Futaba 3150s.

As for batteries I bought a five cell pack of 2/3A's a while ago but when I got round to cycling them, I consistently got 800mAh back out instead of the 1400mAh they were supposed to give. Weird. But it's made me wary of them, especially since you can't get LSD NiMHs in that size yet. So I might stick with a 4AA Eneloop pack.

Rub on the aerials or leads?

I couldn't find a way that I was happy with putting the RX where yours is. I wasn't happy with the mass of servo leads pushing back towards the wing joiner, I thought the joiner would catch and rub on the wires. If I put the servo connections from the RX at the front, by the time I pushed the RX back to give me some access to the ballast tube it looked like the ariel wires would become the problem rubbing/catching on the joiner The mass of servo leads at the front looked a mess too. Maybe the height of my tray and tube is the problem, it's not as low as it could be, but my RX is now tucked under the tray so it needs to be a touch higher. You could just put on 7 servo extensions on the RX and put it in position and see if you think it'll cause you a problem, but they won't sit as awkwardly as a loom and the ele/rudd servo wires IMO. Just check it out before you commit to it as I'm sure it would have caused me probs

I couldn't find a way that I was happy with putting the RX where yours is. I wasn't happy with the mass of servo leads pushing back towards the wing joiner, I thought the joiner would catch and rub on the wires.

You mean that super-clean layout was achieved by not having any wires in place?

Also, BG are the carbon pushrods just glued into the clevises? No adjustment other than the tx centering? If so, what glue did you go for that can be trusted that much?

Wireless install? i should hope
As for the pushrods..yup, no further adjustments, servos centred as are surfaces, any adjustment will be via the Tx centering the servos , although I will have adjustable wing servo connections..Hyperion DS09s.
Glue? Cyano onto abraded carbon...
Rods slightly abraded until the clevi could be screwed on, then a dab of cyano and kicker. No worries, used this previously 

Wireless install? i should hope
As for the pushrods..yup, no further adjustments, servos centred as are surfaces, any adjustment will be via the Tx centering the servos , although I will have adjustable wing servo connections..Hyperion DS09s.
Glue? Cyano onto abraded carbon...
Rods slightly abraded until the clevi could be screwed on, then a dab of cyano and kicker. No worries, used this previously 

Fair enough, I'll go that route. I guess the carbon and embedded bellcrank/clevis aren't going to move, so no need to ever adjust it much.

Are the DS09s an easy fit? Anybody got thoughts on the MKS 460? Looks really fast while being small and strong.. I could use my existing HS125MGs on the flaps and get a couple of decent servos for the ailerons where they really matter.

I think hs125s would be too large, and I've not had my grips on any MKS460s...still waiting for the Hyperions to arrive...

Settings for Yoyo:


RCRCM Sunbird Set-up Guide
 
 
CG at rear edge of joiner – approx 67mm from leading edge to start. Make the permanent weight to 80mm, with four removable weights giving you 67, 71, 75 and 78 as options. Many are now flying 78 and rear. Consider elevator throws may need dropping to 8mm each way when at the rearmost points above.
 
Aileron
 
(measured at tip)
Up 7mm
Down 5mm
 
Aileron (Camber) - see flap notes
Aileron (CROW) – up 5mm
Aileron (Snapflap mix) – see flap notes
Aileron (Reflex) – see flap notes
 
Flap
 
(measured at root)
 
Flap/ Aileron mix – up 8mm, down 7mm
Flap (Camber) – 3mm down worked out along the aileron
Flap (CROW) – 70 degrees
Flap (Snapflap mix) – 3mm up/down worked out along the  aileron
Flap (Reflex) – up 1mm worked out along the aileron
 
Rudder
 
15mm left/ right at base
 
Elevator
 
(measured at trailing edge near root)
Up/ Down 10mm
CROW – down 7mm
 
NB Snapflap mix uses wing trailing edge moving DOWN with UP elevator and UP with DOWN elevator.

Settings for Yoyo:

RCRCM Sunbird Set-up Guide
...

Thanks Zim,

Those look very similar to what I had on the FFish. Except for the rudder, of course...

I wouldn't bother with a setting for 67 or prob even 71mm, up to you but 78mm is still a tad nose heavy IMO, inverted needs more of a push on the stick than I like.

Blimey that's some range setting for CG...67 to 78 and beyond  ...still, further back makes for less nose weight...still weighting for my servos from Ming...

Seems to be a common trait, manufactuers stating a forward CoG. Guess it stops complaints of crashing due to a rearward setting.

My Banana was set at 75mm, recommended from Baudis is 60-70mm. IIRC someone on RCgroups was at about 82mm, but most are between 75-77mm

I'm pretty sure Clifhangers Ocelot is rear of the manufactuers stated CoG too by 10mm or so.

If I was building another I'd set CoG to 82mm and add removeable weights to make it nose heavier. But seeing as I'm into 'extreme rearward CoG's' (comment from RCGroups  ) maybe you shouldn't listen to me 

And IIRC, my ele travel is only about 8mm up/down (low rates, I never use high which are 11mm)

If I was building another I'd set CoG to 82mm and add removeable weights to make it nose heavier. But seeing as I'm into 'extreme rearward CoG's' (comment from RCGroups  ) maybe you shouldn't listen to me 

Are those 'removeable weights' the ballast, or is that separate? Do you make the CoG of the full ballast tube a bit in front of the permanent CoG, on it, or what?

It's also a bit of a booga, when I've installed my ballast tube with the centre of it placed at 68mm 

No the removable weights aren't the ballast.

Ideally you want ballasted and unballasted CoG's to be the same. Problem is you don't know where you like your CoG yet.

My tube takes 4 x 35mm ballast but is about 175mm long, allowing for a 35mm retaining spacer at the front which is held in place with a pozi machine screw.

Like this  ---l-- the vert line is centre of ballast, not tube

I don't take in to account the weight of the spacer and screw as they don't weigh that much, but if you kept them in when the plane is unballasted, it wouldn't then move the cog forward when you do ballast up, because you're adding even weight in front and behind the CoG (hope this makes sense). If the CoG moves forward a touch it seems better to me, as it'll help in windier conditions to move the plane forward. Needle 100 moves back with wing ballast added, but doesn't seem to be a prob according to reports.

The prob comes from deciding on a CoG (lets say 75mm), setting it up so that ballasted and unballasted it's the same. Then finding out you're too nose heavy. Removing nose weight will move CoG back, but ballast will move it forward again. You could opt for a spacer at the back so you can move the ballast back too tho, but it's a fiddly job.

BG, only option if you set CoG too far forward is to reduce the amount of ballast in the tube. Might get lucky if you cut 1 piece in half?

Yeah...I'll sort it out...cheers

If it's any help, here's some notes on fitting the ballast tube from my build (on page 4).

I filled the tube with the ballast & marked its loaded CoG with marker pen, then when fitting the tube lined this point with ~75mm CoG point on the plane (approx the front of the servo-connector hole): I don't think a couple of mm either way will make much difference, and you can always adjust the final pos of the ballast in the tube by cutting the spacers to suit. The actual CoG of the plane ended up near enough identical with & without ballast.

Shame my SB's still a "two for one" at the moment, but rebuild is on the cards shortly 

Think & think again about the fitting of the ballast tube, so that it’s (loaded) balance point is as near as possible on the CofG of the plane. This will be teaching granny to suck eggs to most of you, but needed thinking through for me

With the ballast supplied by Sloperacer, loading the tube works as follows
4 slugs = ½ spacer – 4 slugs – retainer
3 slugs = 1 spacer – 3 slugs – ½ spacer – retainer
2 slugs = 1 ½ spacers – 2 slugs – 1 spacer – retainer
1 slug  = 2 spacers – 1 slug – 1 ½ spacers –  retainer

The end retainer needs cutting to suit the above loading sequence, and the nut epoxied to the underside of the tube. I cut about 10mm off the (cockpit) end of the tube, ensuring that the edge of the cockpit didn’t prevent me getting an allen key to the retaining bolt.

It's the Christmas hols, so time is at last available to finish my 'Bird...
...and with all things balanced and fettled all I now need is a bit of dry weather and a bit of wind to give it some fling...
At a fighting weight of 1.03 kg without ballast, it should be fine for the purposes I have in mind for it.
Pics if I can persuade wifie to trot along on her Birthday

Well, I managed to maiden the Sunbird...i gave it 1 click of down, but apart from that it flew and flew very well.

Cold, damp, drizzley and windy...but I'm a happy camper. 

Looking forwards to the better weather so i can wring it out in comfort 

As it was wifies birthday, we didn't stay out too long, and her uncle (our Xmas lodger) came too 

Glad it all went well 

     cant beat the feeling of a successful Maiden  ( especially if shes a Sun Bird pg3 )


                                               Bob

Well, I managed to maiden the Sunbird...i gave it 1 click of down, but apart from that it flew and flew very well.

Cold, damp, drizzley and windy...but I'm a happy camper. 

Looking forwards to the better weather so i can wring it out in comfort 

As it was wifies birthday, we didn't stay out too long, and her uncle (our Xmas lodger) came too 

Good stuff, hope mine goes as well on its maiden. Have your knees stopped knocking yet?

That will be a while yet though... got to get Christmas out of the way before I can even start building it.

Once I saw it was away and smoothly responding, any nerves left and I tried flinging it about...

Great fun

Nice 1 on the maiden  .

Looked cold tho 

Just in case you weren't looking at the thread about Sloperacer, (Christmas Hols?) and, again, just in case any of you did not know, Sloperacer have some spares for RCRCM. I consulted Tony Fu on a Sunday evening, got a reply within 15 mins., with price and IMMEDIATE availablility for my Sunbird Wing joiner. I sent him a bank transfer and the joiner was posted on the Wednesday and reached me, in Spain, the following Tuesday. "Can't be bad", as my Brummie friends say. Thank you, Tony.

Christopher