A-10 Tankbuster build nearly finished

coolwings

My A-10 Thunderbolt II is moving nearer to completion.
Every time I see one in the gulf I want it ready to fly now!!!
Been working on this on and off for a year now. :cool:
Here are some pics. The wrok was split between myself and a good pal here.
Photos of paint job to follow later.

coolwings

Oooops, I'm not used to the pic attachment routine, I cut the file size down twice and turned it into a thumbnail. :eek:

Here is a better look at the whole model....

RuggieBear

That looks pretty cool. A-10 is my fav warplane....mainly coz its big, ugly and does alot of damage (just like me!!)

Fobia

That is one amazing model you got there....I want it!

coolwings

Fuselage is epoxy fibreglass, wings & tail are built up.
It's covered with silver Oracover (Profilm).
The challenge is to get the paint to stick to both materials equally well.
I've decided on jungle camo for the paint job.

More pics ....
Twin jet nascelles, slightly overscale so as to fit 90mm fans inside.
Closer look at jet nascelle, stator and brushless motor already fitted, ready for rotor.
Tail arrangement, with vertical rudders.

mad m

She is a beaut coolwings,seeing something like this makes me want to get back into the whole model scene again....goodluck with her maiden flight..

coolwings

Elevator & rudder servos inside fuselage ....

coolwings

Twin brushless speed controllers, with 3 cables to each jet nascelle...

coolwings

16 cell battery pack now soldered up and trial fitted ...

coolwings

Here is first of some full view shots of the paint scheme ....

Battery alarm in camera went off, had to stop photo session.

I'll take a couple more soon ... :cool:

RuggieBear

sorry for sounding stoopid...but is that actually going to fly (remote controlled)? I just thought it was a stationary model! :eek:

coolwings

Yep

The ordinance is for display only. It comes off when preparing for flight.

Now I have to do the rotor blades, and work out power and balance. Still got final tests to do and maybe some little bugs to work out before maiden flight.

This A-10 is heavy, and very powerful, just like the real one.
Wingspan 1.3 metres
Weight 2.4 kgs with 16 x 2.2 Amp hour cells or 2.7 kgs with 3.3 Amp Hour cells, I don't know which battery will be best for it just yet.
Size ... similar to a .46 piston engine model Power about the same as a good .50

Cool factor ... incredible ...it's a warbird, a twin , a jet, a modern prototype, and in the news. I'm really worked up about this model, wanted one since I first saw an A-10 in a film.

The kit comes ready for propellers, it would have cost less to do it that way, but I just had to do the impeller jet variant.

RuggieBear

coolwings wrote:

Yep

Awesome

coolwings

I eventually got the camera out again. Here are more pics of the finished model

coolwings

Here they are ....

Jim

Sweetness.

RuggieBear

that looks great.....god i wish i had the patience and the noose to create something like that!!

coolwings

This model was on the slow track ... I began work 18 months ago. I've done maybe 3 other models & flown them since, it moved slowly on.
Then I accepted I needed extra hands, I enlisted the help of a good capable pal, and suddenly progress was very fast.
Now it is only last checks and tests that are left to do. It took a while but it was worth it.

The Real B-man

deadly model!!!

kensutz

nice one

Ciaran_Dub

Coolwings I have to admit RC planes aint my thing even though my Uncle keeps slagging me that he will show me what real rc modelling is about and let me fly some of his planes but that model is looking the business.

I really enjoy seeing what the likes of yourself can turn a lump of balsa into. Keep up the good work (my catch you at an airshow someday if my Uncle can talk me around)

coolwings

I'd like to say "It was all my own work" , but this one was a collaboration between two of us.
I spooled up the (electric) turbines for testing (it sounds brilliant ) but I wont take it out to the field until after Xmas.
Patrick has persuaded me to hang it in the shop for December for folks to look at, before risking it on a maiden flight.
I could take a vid clip, with sound, of motor testing before hanging it up, but I dont know if it can be posted here. Data size limits etc. Maybe Fobia can advise by PM?
If this isn't possible I would be able to put it on my own webpages, but can't leave it there as it is already on the data limit.

coolwings

Well I finally soldered up the "proper" battery pack today.
For the past week & a half I have played with smaller packs from other models.
Charged it up. The results are scary to say the least....
The battery is 22 volts off the charger.

This A-10 has a 55" wingspan, and if done with glow would be expected to need a hot 45 like OSFX or MVVS., for a power of 700 watts.
I hit 700 watts with the stick at about 5% throttle , the papers on the other side of the room were by now all flying round or on the floor.
Throttle back to zero, check all is OK, and go again. (My self imposed limit for power was about 900 watts, or .50 power at 10,000rpm) but I hit 950 watts with throttle below 1/4

Then I took a chance with the turbine blades and went up to 1/3rd, it did 1.23 kilowatts and I chickened out. I didn't want to break fan blades off using the motor as a wind tunnel compressor. That is equal to a hot 60 doing about 14000 rpm. That is if you can get a 60 get up to 14 thou. Our normal models reach about 10 thou max with normal props fitted. This was screaming. The fans were at over 25,000 rpm, more than 400 revs per second, but I still don't know where top is because it is so high it would strip the fan blades off. So I will play with reduced rates on throttle as a limiter-governor.

It is now clear that with a flick of medium throttle for a second or two, this jet will accellerate like mad.

I had radio glitches which have to be eliminated next (receiver right beside power source at present).

Vid clip to follow soon.

Fobia

Coolwings: any news on the video/audio clip idea? After reading that last post it sounds like quite a beast

coolwings

I just put the cam on charge, & will try to get a vid clip done later today.
Trouble is...I'm mad busy ....
If it works OK (as it should) I'll transfer it to digital tonight and post it.

Fobia

Cool

Mutz

If you need space to store a video let me know and I'll gladly lend you some space. I'd love to see that beast in flight!

jack shictt

Peace to the a-10 is deffently one of my fav planes if not my fav, pace to the gau-8 dakka dakka dakkka dakka

jack shictt

Peace to the a-10 is deffently one of my fav planes if not my fav, pace to the gau-8 dakka dakka dakkka dakka and congrats on the model

coolwings

Back to work again ....
At 1.2 kilowatts this A-10 is an absolute animal, and while there was LOTS of power, I knew I could save weight by reducing the 16 cell battery pack, and running on a lower power level.
(I may go back up when all the bugs are removed, and first flights successfully completed.)

So over the past weeks I did tests on 16 cells, then 14 cells, and finally settled on 12 cells for the time being.

coolwings

Here is the battery voltage with no load (before starting the twin jets)

coolwings

And here it is again with full throttle....

coolwings

So we have ... (battery NOT fresh off charger)
Before starting voltage 17.1 amps 0 watts power 0
Full throttle voltage 11.5 amps 65 watts power 762

The 762 watts is about a .50 engine which is about right for this size of model.
Amps 65A is highish, but I got top quality speed controllers, so no worries there...
Voltage of the 12 cell pack is sinking to 11.5 under maximum load, which is .95volts per cell, and that is low but OK, I guess it will rise back higher when throttle is reduced to 1/3 or 1/2 for normal flying.

Weight of the A-10 with the new power pack is 2 1/2 kilos, so I have 300 watts per Kg, and that compares with 150-200watts/Kg for a glow plane on takeoff roll based on an (OS46LA in a 2 1/2 kg model).

The static thrust is very good but maybe not equal to a 40 with 10" prop, I will have to measure it tomorrow. But on the bench the turbines are acting as air compressors and accellerators, there is a vacuum in front of the jets, very noticable, and an impressive rod of airflow behind them. I have a windmeter somewhere, so I will dig it out and measure efflux velocity tomorrow...

In flight air will be feeding into the jets, so thrust should go up a lot, I hope better than 10% improvement actually in flight.

I made a video of todays tests, but the sound is terrible, so I will do another tomorrow, with hopefully better results, and post them either here, or give a weblink to the video file.

Here is the gear as set out for the tests :

coolwings

I have been away from this model for too long.
I bashed a couple of other planes and had to do repairs, to get them back in the air quickly. So the new projects got "put on hold" :mad:

So I got the A-10 out tonight and put it on the table and began finishing off all the little outstanding items that need doing.
Just for inspiration I played my video clips of the fullsize A-10 Thunderbolt.

So now in the words of the song:
I feel good now - I knew that I would .... I feeeel good ....I knew that I would ...

Here is a link to the model and vid clip of the prototype...
Norm_flyer's gallery page with new pics & A-10 vid

I also got some lipoly batteries, so I have a new power - to - weight setup to test out.
It should reduce the all up weight by almost half a kilo. Not to be sneezed at !

g5hn710m4xpdwy

didny know this existed like what done so far

RC-Model-Man

When do you hope to fly her ?

coolwings

As soon as the new runway at the Dublin Kestrel Model Flying Club is ready to take off from, and land on. It's a bit fast and high investment for putting down on the old runway.

that is about 2 weeks from now.

Model is ready to fly.

piraka

Beautiful model. Did you build it from your own plans or from puchased plans

RC-Model-Man

piraka wrote:

Beautiful model. Did you build it from your own plans or from puchased plans

Well as it is a moulded epoxy/glass fuslage and wheel covers, I am guessing it is a kit. By the loosk of the wings they are built up balsa and spruce. The engine covers are foam (moulded ? ? ? ? )

Great lookin model thou and should go well.

coolwings

It is an Aero-Naut kit from Green Hobby in Dublin.
The fuselage is epoxy fibreglass with a little carbon fibre rovings added during the build.
The wings are built up balsa fully sheeted in the centre section and half sheeted tip sections.
The nascelles are an add-on from aeronaut, cut from high density foam, and designed in such a way that they can be done for 90mm impellers as I have done, or OTOH can be done with two x 480 motors with conventional propellers, which would have cost me a lot less, and results in a lighter finished model.
But I just had to do it with fans.
I used Kontronik motors, but Megas would have cost less and still had plenty of power. As it is I am using only 1/2 to 2/3rds of the available power of the motors with the set up I have settled on.
For EDF a normal sort of kit (made all of balsa) is not durable enough to take the stresses, and these type of models wear out in use far faster than a fibreglass model. So for EDF jets in sizes bigger than "400" I would advise always picking a fibreglass model, even if it is more costly, it is well worth it.

zt-OctaviaN

Thats class!!

I was amazed until you said the electric motors put out same as .46 or .50!!
Youll definaltey have a vid or two up when it flys.

Good Luck!

Manic Moran

I have to say, I'm impressed. I look forward to seeing the video of it flying around. You need to find someone with a radio-controlled T-72 so you can do strafing runs.

Only question I have though.. is it really that colour, or is it a trick of the light? I just don't recall ever seeing a real one quite so... um.. vibrant a green.




NTM

coolwings

A bit of both actually .... the "light" green has a tad too much cadmium yellow and a bit less yellow ochre in the mix (with the blue) than would be perfect.

Also - the photo of it in bright sunshine really lights up the yellow in the light green, making it more like "jungle" camo than would be if it were absolutely spot on.

So it could have been better, but I'm happy enough with it for the moment.

The trouble of scale RC warbird planes is visibility, when they go below the horizon, and a wooded area happens to be behind them - they can disappear for a second or three - which can be scary at best, and disastrous at worst. So I try to have red wingtip tanks, or invasion stripes (WWII), or some insignia to pick them out for that difficult moment. I'm hoping the USAF decals will be good enough to see, but the "vibrancy" of the camo will undoubtedly help a little too.

About the vid clips: I am still trying to get my sound card to capture the sound that goes with the picture - lots of nice tests with no sound in my hard drive, all no good - as soon as I get the data capture set up properly I'll post one here.

Edit: Nice pics by the way !