FW Ta-154 Moskito

[KeithT]

I started this build from the plan last year and after end-of -year-delays just this weekend made a bit of progress. I'm a total novice builder (Crash-E my only build so far) but this very curved fuselage has been more of a sculpting lesson than a modelling one!

 

Here's where I am: body, wing and nacelles...

 

 

Today, I have also tested the power setup, with all my dubious soldering...

 What you're seeing is a pair of E-Max CF2812's with 12A ESC's driven by a 3s 2250mAh 20C LiPo.

Full power on...

 

Close up on the meter:

 

Thanks to Timbo and others for previous posts on the wiring of a twin electric

I'll try to update the thread as I make some progress, but be warned I work slowly.....

[Terry Whiting]

Keith,

I think you are running too close to the edge here in using 12A ESC, as you are drawing almost 11A per ESC,      and surely that battery pack can not be fully charged

[KeithT]

Hi Terry,

 

Nope the battery pack wasn't full - about half from the last flying sesh.

 

I tend to agree the current draw is high at full throttle and I was slightly surprised by the amperage.  However I do not intend fly at full throttle, for any significant amount of time.

 

You are right though,  it is something to be aware of, and if I find it doesn't fly except at full throttle I could swap down to 2 blade 7x4's, or 6x5's even, but...I'd like to try it with this setup first.

 

 

[Terry Whiting]

Kieth,

 

3 blade props only look nice stationary, and the only time I used them was for static shows. For flying that extra blade is drag which in your case reads in higher amps .

 

E-Max CF 2812  has a continious current rating of 10 amp and really was developed

for fast rpm 5" props.  

 

[KeithT]

Fair point and taken on board. I think the 'structions from brc recommend a 2 blade 6x5 which will lead to a lower draw.  I'll get some 2 bladers before the plane's finished and can fit them for flying. 

 

I need some warmer weather, or a sunny afternoon, for sand sealing the wing. The fuselage and tail is glassed and Poly-C'd apart from the nose, so just the nacelles and wing to go.

[KeithT]

I'm learning a lot from this build - like how I should plan better...

 

I got carried away enjoying covering the plane and completed the wing with glass cloth and Poly-C - beautiful finish. Unfortunately I did forget to cut out the ailerons from said wing, remembered, then forgot again and glued the wing to the fuselage  

 

Still, I got the elevator servo in position and attached it to the fitted elevator using carbon rod.  That bit works at least, making it a two channel model - throttle and elevator...

Edited By KeithT on 07/03/2010 10:14:51

[KeithT]

Here's a piccie from beneath - wing is fixed on, elevator servo in place and hooked up. 

 

This is after I have cut out the first aileron, which has sliced out surprising neatly and ready glass-covered

 

From oblique, you can see the 'shoulder' pieces for the fuselage disappearing into the wing fitted and glassed.

 

I had a generic horn and fixing plate for the elevator but to my surprise the bolts were nigh on an inch long, when the elevator is only 1/8"   so I fitted them, cut them down to size and cyano'd 'em.  I realise it's good to have some leeway in the bolt length but these seem excessive for a 'small' sized horn !!

Next comes the aileron champfering and nacelle fitting, thus the lines on the wing in the top picture.  The ailerons will be on dedicated servos, side mounted into the nacelles rather than the original design of a single servo in the fuselage.

 

I've tested my airbrush on the hatch, just covering it in a couple of layers of white acrylic primer - it's going to take quite a few more to obscure the pencil marks I think. 

 

Then I got hassled by kids to let them have a go with the airbrush so paints were abandoned and we spent the next half an hour spraying water at large sheets of absorbant coloured paper - this makes really good patterns that amuse them endlessly...

 

[Toni Reynaud]

The build looks really good so far, and nothing looks quite as nice as freshly finished balsa covered with glass and resin (or similar). I almost think it's a shame to cover all that nice wood with paint.

That said, it looks as if it will be a goer. Have you a target weight for it?  Also, in that last picture, the clearance between elevator and fin looks just a little bit tight.

[KeithT]

Posted by Toni Reynaud on 17/03/2010 16:18:14:

That said, it looks as if it will be a goer. Have you a target weight for it?  Also, in that last picture, the clearance between elevator and fin looks just a little bit tight.

 

 Thanks for the encouragement  You are quite right the elevator needs a little sanding to make sure any expansion won't make it bind - it doesn't actually at the moment, but its close due to a slightly one-sided elevator build   Very much a learning experience this.

 

Target weight was based on the specified AUW of 30oz - piling all the bits on a balance including motors and LiPo came to around 26-27oz so I think it should be in the right ballpark.

 

I'm now working on the wire routings from the nacelles and lining up the motors perpendicular to the wing - unfortunately my nacelles are not totally symmetrical longitudinally which make it slightly tricky.

Edited By KeithT on 18/03/2010 00:02:16

[SA Allan]

Here is mine , I flew it again on the weekend and it go's really well .

 

It had a big prang on maiden due to signal loss with a Spektrum AR6100 reciever while doing a reversal , patched up really well though . These sheet designs are quite tough .

 

[KeithT]

Hey that's great ! I like the colour scheme too - you seem to have got the nose carved better than mine. I suspect my sculpting skills need more honing.

 

Nice to know it's reasonably tough as it will probably get tested in my hands.  Signal loss shouldn't  be a problem with 2.4GHz, but my flying will I suspect

 

Out of interest which motors / props are you using?  I have just bought some 6x4's to test - I'll post the results at a later date.

 

[KeithT]

Done a bit more since last time I posted some pics;

 

I've carved out the ailerons which came out nicely with the glass/PolyC covering then hinged them in. Nacelles epoxied in place.

 

 

The nacelle fitting took a while due to the need to decide where the wiring was all going - I eventually embedded the wiring in the wing and have semi-embedded the ESCs. The horizontal wiring is from aileron servos (just visible to the sides of the nacelles).

 

This also shows the brushless outrunner mounting which is also modified from the plan.

 

Next came the covering of said wiring - here it is balsa'd in place and glass/PolyC'd. I've started to paint it with white primer.

 

The new 6x4 two-bladers are there ready to be tested soon...

 

 

 

 

 

[SA Allan]

Hi Keith

 

The motors are a pair of Hobbyking TR 28-26B 1350Kv Brushless Outrunner's with 18 Amp speed controls .

I'm using 7*5 Graupner props as you get them in pusher and puller configuration so they are counter rotating , I'm not sure if this is really required .

 

The small spinners are sourced from Hobby-Lobby

 

 

 

 

[KeithT]

Interesting, thanks for that.

 

I'm getting around 20A from the two 6x4's (counter rotating also) in testing.

 

I was just setting up the ailerons and notice the throw is not too great given the thin chord of the ailerons. May I ask how much throw you're getting as my max must only be 7-8mm?

[SA Allan]

Hi

 

The aileron throws are small but they are quite effective , I think its due to the propwash over them . Unfortunetly the plane is at my parents house , I will be visiting over the weekend so I'll get back to you with exact measurements . 

[KeithT]

Hadn't realised my last post was so long ago. I've finished off the Moskito by playing with the airbrush - great fun

 

Here's a few piccies. Underneath showing the finish and light paint over ESC's:

 

 

Other views; I realise the paintjob is not true to scale, but I eventually decided that after the amount of work that went into this I would choose a hybrid semi-scale scheme to suit the semi-scale nature of the model. So mostly the paint job is based around Me109's

 

 

 Given it was my first attempt I'm quite pleased. And if it actually flies (still to be tested) and survives, I might tinker with the detail a bit more - panel lines in soft pencil maybe.

[Toni Reynaud]

Looking good. I just hope you find it easier to see in the sky than my Hurricane sometimes is. Those colours were chosen for a reason!!

[KeithT]

Yeah, that is my main worry - I tried to make the contrast between top and bottom high, but it is reversed from my first plane (Crash-E) where it was white on top and dark blue underneath.  The high contrast has saved me several times at long range with plain orientation - I plan to keep this one deliberately much closer.

 

Maybe black and white stripes under the nacelles might help a lot. Or even just invasion stripes on the wings. I'm not going for total authenticity and it won't help anyone if I plough a field with it

[Erfolg]

Keith

 

Looking at William Greens "Wings of the Luftwaffe", the prototypes pictures, which appear to be V3, V7, and V15, look to have in the case of V3 traditional Dark Green and Light Green splinter, presumably with light blue under surface. the remaining two seem to have the splogged (my description) mottle on upper surfaces. The contrast appears to be high, suggesting perhaps dark gay splogges against light grey . I can only speculate as all the photos are traditional black and white, so interpretation is necessary.

 

In my case I have tried to use the high contrast available from some schemes where the underside is very much lighter than the top. A further non scale aid has been fluorescent orange wing tips, similar to I think carried by RAF jet Provosts. Hardly notice this blatant fudge, yet the combination seems to work generally well. It is winter skies, with there lead grey sky, which are the worst, for providing low contrast and reflective light.

[KeithT]

Thanks for the info; Yes indeed - the prototypes mostly look painted with very hurried splodges or wandering spaghetti of dark grey over light, with continuation underneath. I felt this wouldn't help the contrast in flight and wanted more colour on there.

 

I like the idea of fluorescent orange tips - it is the effect I was after with the yellow tips (above) but I suspect orange would be better and perhaps a greater tip coverage may be in order, possibly with the tail tips done too. I do like that idea. 

[KeithT]

Hurrah! It flies !!

 

Today I took it down to the coast (at Boulmer) to finally get it airborne - remembering the screwdriver to take the hatch off this time - it was a beautiful calm sunny evening and I gave it a push up at 30° with full throttle slightly off-wind (as into wind was out to sea!) and with a slight wobble to port I straightened her up into wind and a level flight.

 

Just a bit of down trim to stop her pulling up and she flies smooth and simple. I kept the first flight short as with two motors on the 3s 2250mAh I didn't know the duration so 4 mins later a belly landing and battery check showed 11.75V remaining (started @ 12.6V ish), so I played for a further 3 mins before alighting - final score 11.55V - before skimming stones with my son.

 

Lovely evening and I'm well chuffed with the plane - it's so smooth and slow flight seems no-problem, though the landing is still a fair pace and skims along on the nacelles and fuselage for quite a ways

 

Thanks Tony Nijhuis for a great plan, plane and interesting subject

 

I'll try to get a photographer for next time

[David Ashby - Moderator]

Nice one keith, a few flying photos would be nice

[philip valente]

Keith

Great build notes

I am contemplating the starting of either the mossie or the mosq .

You have been flying your few for a while . .anything you can offer as things to improve if you were to build another?

Thankk you

[Brian Wilson 2]

Keith, how was yours for balance ?

My build is almost finished and it seems a little tail heavy based on using a 2200mAh battery which I have on hand.

In saying that, it may be self inflicted as I mounted my ESC's in the fuselage immediately behind the COG but I would not have thought that would have much effect.

Thanks,

Brian

Edited By Brian Wilson 2 on 27/11/2014 01:12:31

[J V R]

I've built one & its tough as old boots, 3 heavy arrivals,the last one was very heavy & broke the fuz, I stuck it all back together and it flies just like it did the first time straight as a die with the contra rotating motors...