Hobby King SunBird Motorized Glider Build Thread

[Jesmond Falzon]

Here is my sunbird wing.... but I'm thinking for reinforced more especially in the middle part where attached with the fuselage.

 

[TooJung2Die]

Here is my sunbird wing.... but I'm thinking for reinforced more especially in the middle part where attached with the fuselage.

That looks great. It will get a lot stronger in the center when the balsa sheeting is glued in. There's a video on YT of a Sunbird folding a wing under high G's. It broke about halfway out one of the center sections, not in the middle.

I never posted the video of my Sunbird. Good flying days are rare during winter here and this wasn't one of them. It handled the wind well enough. I can see it performing well as a slope soarer. I can't wait for warmer weather and columns of hot rising air.

Jon

 

[Jesmond Falzon]

middle part of the sundird wing.

hi nice video well done for you build.....so is your wing especially the middle part is the original fit or added some reinforce ? and how was attached to the fuselage ???.....I m thinking to make quick realise like dowels ...you understand ?...tks.

 

[TooJung2Die]

I didn't do anything special when joining the wing at the center. I followed the plans except where folks like Joker said to do different.

I thought about holding the wing on with rubber bands over dowels. The wing is attached to the fuselage with two nylon screws. I thought the blind nuts that came in the kit for that purpose were too small. I tapped threads into the plywood wing hold-down blocks included in the kit. Drill holes to fit the tap then shoot some CA glue down the hole to harden the wood. The tap will cut threads in the wood like it was plastic. Drip some more CA down the holes and chase the threads with the tap again.



Jon

 

[Jesmond Falzon]

Re wing

tks for reply......ok i will do like you I like job well done.

 

[Jesmond Falzon]

I didn't do anything special when joining the wing at the center. I followed the plans except where folks like Joker said to do different.

I thought about holding the wing on with rubber bands over dowels. The wing is attached to the fuselage with two nylon screws. I thought the blind nuts that came in the kit for that purpose were too small. I tapped threads into the plywood wing hold-down blocks included in the kit. Drill holes to fit the tap then shoot some CA glue down the hole to harden the wood. The tap will cut threads in the wood like it was plastic. Drip some more CA down the holes and chase the threads with the tap again.

View attachment 105695

Jon

here is my job.

 

[Joker 53150]

I didn't do anything special when joining the wing at the center. I followed the plans except where folks like Joker said to do different.

I thought about holding the wing on with rubber bands over dowels. The wing is attached to the fuselage with two nylon screws. I thought the blind nuts that came in the kit for that purpose were too small. I tapped threads into the plywood wing hold-down blocks included in the kit. Drill holes to fit the tap then shoot some CA glue down the hole to harden the wood. The tap will cut threads in the wood like it was plastic. Drip some more CA down the holes and chase the threads with the tap again.

View attachment 105695

Jon

Rubber bands could work if the wing and saddle were modified a bit to keep the wing steady. From what I saw building mine it appears that the wing would pivot or move fairly easily. Some blocks mounted to the bottom of the wing that fit inside the fuselage to locate the wing would be an easy solution. You'd probably also need to beef up the fuselage a bit where dowels go through, but again nothing too major with that. But it's hard to beat the cleaner lines you'll get with a couple screws holding the wing in place. Just my opinion...

 

[Jesmond Falzon]

 

[Jesmond Falzon]

 

[Morgan]

Looking good!

Be careful with that style pin, I've had that round head break when I'm pushing on it and had the pin's flat end stick in my finger before, not pleasant at all...! Yours may be better quality than the ones I had, but they still make me nervous to the point I threw mine away.

Year I've had the blunt end stuck into me before and it not very pleasant .☺

 

[TooJung2Die]

Wow, lots of progress. I haven't been receiving email notifications to my subscribed threads.
I see you filled the gap in the fuselage behind the wing. That bothered me too so it's filled like you did. There's another gap in front of the wing at the back of the cabin hatch I felt needed a piece of balsa to fill.

 

[Jesmond Falzon]

MORE PROGRESSIVE PHOTOS ON COVERING.

 

[TooJung2Die]

Nice. What are you going to use for hinges on the control surfaces? The hinges that came with the kit were too stiff.

 

[Jesmond Falzon]

Nice. What are you going to use for hinges on the control surfaces? The hinges that came with the kit were too stiff.

TKS MATE...

SO YES IS TO MUCH STIFF ..... I STILL USE THEM BUT WITH A THE DIFFERENCE .......CUT IT IN TWO PARTS BECAUSE IS TO MUCH BIG.... AND FOLDING BEFORE I USED THEM FROM THE MIDDLE
.

 

[Jesmond Falzon]

More progressive photos with white wing tip , servo installed and aileron in place too.

 

[TooJung2Die]

You'll be flying your Sunbird soon!
We had some perfect flying weather here last week and I took out the Sunbird. Mysteriously she gained weight over the winter. She now weighed 434 grams, up from 425. Even with the 1000 mAh 3S battery all the way to the rear of the cabin she flew nose heavy. I had to add up elevator or she kept going nose down in the glide. Shimming up the leading edge of the wing probably would've helped. Instead, I took off the 8x4.5 folding prop (29 grams) put on a lighter folding prop, 7x6 (15 grams) from HobbyKing. Now she weighs a svelte 420 grams AUW and the CG is at the rear edge of the wing spar. Nose heavy problem solved and it climbs great with the 7x6 prop. Let's go thermal hunting!
Jon

 

[Jesmond Falzon]

 

[Jesmond Falzon]

 

[Jesmond Falzon]

You'll be flying your Sunbird soon!
We had some perfect flying weather here last week and I took out the Sunbird. Mysteriously she gained weight over the winter. She now weighed 434 grams, up from 425. Even with the 1000 mAh 3S battery all the way to the rear of the cabin she flew nose heavy. I had to add up elevator or she kept going nose down in the glide. Shimming up the leading edge of the wing probably would've helped. Instead, I took off the 8x4.5 folding prop (29 grams) put on a lighter folding prop, 7x6 (15 grams) from HobbyKing. Now she weighs a svelte 420 grams AUW and the CG is at the rear edge of the wing spar. Nose heavy problem solved and it climbs great with the 7x6 prop. Let's go thermal hunting!
Jon

h

hi mate tks for replying.


now my sunbird is read for median flight.... so mine is about 644 grams but with 1300mah 3s lipo battery. with folding prop 8.5 size , metal gear servos , 30 A ESC..... So as a CG under the spar 55mm from the leading adge of the wing. i add some weight 15 grams on the back.

now need a god weather for the test flight.... hope will fly good.

let you now for sure mate!!!.

 

[TooJung2Die]

I see you put the control horns on the top side of the wing. Interesting. I think you are going to have a fast Sunbird with that power setup and weight. Hope you have a long runway to land on.
Jon