Chris's Bella Ballerina HD

[McG 6969]

Hello everybody,

I had a bit of progression despite all those ‘finishing’ jobs to handle.

It was about time to have the fuselage bottom ‘closed’ now. I first made a very simple rectangular foam plate for the front section and curved it to follow the fuselage line. Really simple & no magical tricks required here.

I also cut away the heatsink covering of the ESC to expose it better to the cowl’s ‘mouth’ airflow.

The aft part of the fuselage bottom is in fact a ‘longish’ triangular foam piece running from F6 to the tail bottom plate. Easy as well but when trying to find a position for the belly flashing light, I realized that I had a carbon strip running exactly there in the centreline of the aft fuselage…

I’m afraid I had to replace my inherited desire for symmetry by a thrilling amount of ‘artistic licence’ in this case.

I also had to make a cut out in the foam and glue a thin plastic card roundel as the thickness of the foam wouldn’t allow the LED to stick out of the surface.

When dry, my intention is to give both foam bottoms a coat of V33 and the ply sides of the fuse a layer of sanding sealer before their final sanding and film covering.

Hakuna matata

Chris

BRU - BE / CTR Symmetry Control

[Simon Chaddock]

Chris

Just remember the heat sink is actually held on to the mosfets by the heat shrink. Once you cut it away it is only retained by the heat conducting paste so it does not take much for it to fall off.

Where I remove the ESC heat shrink to improve the cooling (which it at least doubles!) I 'tie' the heat sink down with nylon fishing line.

When done up tight it positively compresses the heat sink down onto the mosfets to ensure good conductivity through the heat paste but does not significantly restrict the airflow over the surface.

In those situations where the ESC is working really hard (EDF) I replace the flat heat sink with a fingered one (better by a factor of 3!) which is also tied down with fishing line..

[McG 6969]

Thank you for the tip, Simon.

To be honest, I thought naively that the conductivity paste also acted as a 'glue' for the heat sink to the PCB.

My intention was to use a tie wrap - cfr. the two drilled tabs at both sides of the ESC - to hold the speed controller to the frame. So, that will maintain/block the heat sink in position as well.

Do you think I still need your 'fishing line' trick as well?

Hakuna matata

Chris

BRU - BE / CTR Naivity Control

[McG 6969]

Hello again,

Since a while, I’ve been having a lot of web-reading concerning the best deco scheme(s) or colours to obtain an easy way to ensure instant recognition of attitude and heading of a mid size RC plane.

I guess I’d better spend some time trying to find ‘the best servo’ or ‘the best TX’… at least that seems to be of ‘high’ priority and interest here at the forum lately…

What I can say is that some pieces of advice were just completely… contradictory. As an example, a given combination of orange, green, blue and red was supposed to give a ‘bright’ view for the aircraft in question. IMHO, from a distance, it just shows a ‘dark’ spot in an often grey surrounding, at least here in BE.

On the other end, I found some valid advice regarding the total differentiation in colours between top and bottom wing, also using high contrast colours for both. Also quite logic seems to be the use of a contrasting colour for the LE, allowing an easier visual wing alignment at landing.

As you all probably know by now, the top half of Bella’s fuselage is weathered ‘Bright Silver’ and the bottom half will be white film with some ‘markings’ like registration (PM-169, of course) and other usual 'aviation' stuff.

The wing and tailplanes are white as well, so I’m thinking of some red fluo (dayglow) longitudinal stripes for their bottom, somehow like the Yak 55 hereunder…

… and some contrasting black to the white for the top of the flying surfaces. No ‘checkered’ effect tough as I’ve seen enough of those flags in my earlier days. Still pondering about that one.

Comments always welcome, gents.

Hakuna matata

Chris

BRU - BE / CTR Deco Control

[Simon Chaddock]

Chris

If your retaining method actually holds the heat sink itself down no problem but to ensure the best heat transfer the heat conducting layer needs to be as thin as possible.

In most ESCs the heat transfer medium is a 'pad' which is squashed down by the action of the heat shrink. There is a danger than the act of cutting the heat shrink may have allowed this pad to have 'relaxed' a bit so the heat sink and mosfets are no longer in such intimate contact.

When I replace a heat sink I do away with the original pad, apply new heat conducting paste and then carefully 'bind' the heat sink down with the line.

For many of my installations (like the super light Petiterina) a finned heat sink is probably over kill, in fact with my usual power off glide approach the ESC heat sink is stone cold (using my cheek!) when you pick up the plane.

[McG 6969]

Thank you once more, Simon.

Yes, with the use of the tie wrap method, my heat sink will be maintained firmly in position.

Even with a 'pressure' against the mosfets as there is a difference in height between the sink surface and the mounting holes for the binder.

But just to be on the safe side, I'll use your wire method as well.

Just need to find some fishing line now.

Hakuna matata

Chris

BRU - BE / CTR Fishing Line Control

[McG 6969]

Hi everybody,

I wasn’t really hoping to receive a massive amount of ideas or suggestions to my intended colour scheme, but with the extreme absence of proposals, I took the decision to go ahead and just to use what I had in mind.

So, starting with the bottom of the wing, I’m simply using the white background and a triple row of red fluo at the wingtips.

As it makes me think a little of the Allied Forces back in ’44, I decided to name the combination of colours ‘D-Day Glow’.

At least, it combines perfectly with Gaston’s pull-over…

The LotH’s Foundation doubtless remains the major partner/sponsor of the Bella project, but my ‘old’ friend and sign-man Roger definitely helps me a lot as well with the supply of the needed markings, spare vinyl material, transfer tape and lamination tape. I used to be his second ‘racing’ customer way back in the seventies and we remained friends since then. So, no further reasons needed to give his company - Publiaplic - a ‘dominant’ place in the middle of the wing bottom.

I guess I’ll better stop playing with vinyl now as half the fuselage is still waiting for its final sanding and I would like to have something done at the looks of that tiny tail wheel as well.

Hakuna matata

Chris

BRU - BE / CTR Sticker Control

[Peter Miller]

Very nice. I like simple but won't the logo be covered in the middle when the wing is bolted to the fuselage?

Er, Don't forget. Rude words are not allowed on the forum!

[AndyD]

looking good.

[McG 6969]

Thank you, Andy.

No worries, Peter. As your fuselage design isn't that overly wide, I don't think it would hide enough letters to make it prohibited or unacceptable in 'Pub | | lic'...

On the other end, this really is the bottom of the wing.

So, unless I try to modify the Bella into a 'high wing' like your Harlequin, the fuselage isn't going to hide anything...

Hakuna matata

Chris

BRU - BE / CTR Low WIng Control

 

Edited By McG 6969 on 23/03/2017 12:12:43

[Peter Miller]

Ah! Sorry I got mixed up.

[Colin Leighfield]

Continuing to look good Chris! On the subject of colour, a number of years back the RAF did tests to determine which colour gave the maximum visibility in the air and they found it was black! That is the reason why Hawks and Tucanos have been black for a number of years. It seems to be counter intuitive but I have found that black with yellow flashes for orientation reference works well. I'm not suggesting that it is a good choice for night flying though!

 

Edited By Colin Leighfield on 23/03/2017 23:12:11

[McG 6969]

Hello to all, gents,

No apologies needed, Peter. If you knew how many times I got “mixed up” since I started the Bella build.

You’re right regarding that RAF test result seeming somehow “counter intuitive”, Colin.

I had been thinking about using some ‘black & white” for the top of the wings but now I will ad a bit of yellow as well to make it a bit more ‘vivid’. Thanks for the tip.

After some final sanding job, I had a start at the fuselage covering with white HK film. Bella’s fuse has Depron side walls between the ply center box and the Deply tail sides. All went well while covering the wooden parts but I ended with a huge amount of bubbles over the Depron part.

Even increasing the temperature for the shrinking job didn’t seem to resolve the situation.

I can’t see why as when I covered the cockpit hatch - also foam - I obtained a nice tensile surface. The only difference was that I used some ‘Bright Silver’ there which seems to be somehow thicker.

Right now I prefer to concentrate on other tasks and leave the second side uncovered until I can see some light in the ‘film-tunnel’.

Hakuna matata

Chris

BRU - BE / CTR Bubbles Control

[Simon Chaddock]

Chris

I have never covered Depron with anything but tissue but could it be that applying heat causes the air in the Depron bubbles near the surface to expand and escape?

Polystyrene has a very low 'softening' temperature as well.

[McG 6969]

Thank you for your analyse, Simon.

I think you might be spot on with the possible explanation.

As it was really 'ugly', I had a try with a tiny needle to prick in the center of the largest bubbles and they 'removed' themselves (partially) just keeping a low temp iron next to it.

So, I guess I originally created a succession of trapped 'hot air balloons' with the air escaping from the foam cells.

I had a test at the bottom of the fuselage where the foam received a light layer of hard floor varnish. The result was as flat and neat as can be. But I still don't understand why it perfectly worked some time ago with the cockpit / hatch.

As there is still some vinyl deco sticking to be done to the sides, I might get away with some 'camouflage' process instead of starting the covering all over again.

Did I mention the term "Steep Learning Curve" already?

Thank you again, Simon.

Hakuna matata

Chris

BRU - BE / CTR Bubbles #2 Control

[McG 6969]

Hello to all,

As I was still pondering to find a solution to avoid further ‘covering’ issues, I went back to the wing deco scheme.

I suppose the main part of you all will know about the ‘soapy water’ - or window cleaner - trick to use when applying vinyl stickers.

It works really well but one can’t use water for all possible backgrounds, especially when the adhesive size is larger than just a model roundel or flag size. Imagine the full cover process for a concrete mixing truck with a spray of window cleaner.

So, I thought it would be worth a bit of explanation for another workable method.

In my example, I first measured and positioned the ‘Publiaplic’ sticker to the surface with a piece of masking tape at each corner (see pic in my earlier post). The sticker then gets a vertical piece of tape near the center of its length.

One half of the sticker - in this case the left side - is then lifted from the surface up to its center, the backing is removed and the sticky side flipped over upside down to the right side.

The left backing part is then cut away with your preferred brand of scissors before lifting the folded sticker back to his place at the left but without letting it make contact with the background.

With a vinyl spatula or plastic card, apply the sticker gently down starting at the center and scraping away any bubble till you get at the left ending. ‘Gently’ is the keyword here as you don’t want to distort the transfer paper on top.

You can now lift the right side of the vinyl and remove the backing. Next step is to apply the vinyl in a similar way as for the left side.

Before removing the transfer tape, I apply some finger pressure to the edges of all the letters to ensure a good contact and remove the transfer keeping it parallel to the surface to avoid lifting up some letter corners.

Well, we’re finally done and I hope John could say: “Jobs a good un me thinks”…

I just realized this was a quite ‘long’ and ‘very probably boring’ story, but I hope it was at least helpful for a handful of readers… and apologies to the other visitors.

Hakuna matata

Chris

BRU - BE / CTR Sticky Control

[john stones 1 - Moderator]

Aye "jobs a good un lad"

Nothing wrong with an how to post either,educating the masses is why we're here

John

[McG 6969]

Thanks, lad - aka John.

"Nowt wrong" then, except that I'm the one supposed to get 'educated' here...

Hakuna matata

Chris

BRU - BE / CTR "Good un" Control

[Peter Miller]

The point is this Chris.

You are coming at it from a different angle and applying thechniques that you leart i other fields.

We can all learn from new ideas so it is a two way exchange.

Keep up the good work.

[McG 6969]

Thank you for visiting, Peter.

You're totally right regarding my approach to modelling as I'm trying to use some experience gathered in totally different "fields".

Sometimes it works really well just by 'reducing the scale' . And in other cases it really doesn't at all and it feels like busting into the mountain.

At least, I hope I'm contributing a tiny bit to that "exchange" you are mentioning.

By the way, the 'flip over' dry method works perfectly for smaller stickers as well. And it is a lot more precise in pre-positioning than trying to get your roundel accurately placed on a wet background.

You can even combine both methods, positioning dry and have the background wet just before flipping the half over and use the vinyl spatula.

Hakuna matata

Chris

BRU - BE / CTR Exchange Control

[Rosco]

Hi Chris, Sorry I haven't dropped by lately, Work and Life in general have taken over the last few weeks! I even had a holiday in there somewhere but it's just a blur now because I was still working my second job whilst on leave from my first job!!!!! I have got some flying in though

anyway................The Bella looks to still be coming along nicely my friend. I'm still looking forwards to the finished product.

Rosco

[McG 6969]

Great to have you for a visit, Rosco.

And, no apologies needed, young man. Life and work goes first, especially if combined with some flying fun.

Thank for your nice words regarding the Bella. Still plodding on slowly, but believe me, really looking forward to see her 'finished' now as well.

Hakuna matata

Chris

BRU - BE / CTR Top of the Mountain Control

[Rosco]

Hi Chris, funny how I haven't dropped by in the last few weeks but it's been twice now!.......

Sorry to hijack your build but this might inspire you?

Here is a quick YouTube clip I put together after our last fly. I tend to do the filming/photo's all the time so I don't get any footage of my models flying 99% of the time. Occasionally someone will film me flying and in this clip, my model is the EDF F18. Once again, sorry to hijack your build thread, I hope you don't mind................

 

Rosco

 

Edited By Rosco on 29/03/2017 10:57:17

[McG 6969]

You are welcome to hijack Bella's thread whenever you want, Rosco. No props at all.

Of course, all that flying makes me a bit envious as I still have everything to learn.

Even common things like binding (trying to) my Tx or having my first ever range test...

But then when I see that Mossie 'landing', I try to convince myself that the right time hasn't come yet.

Hakuna matata

Chris

BRU - BE / CTR Patience Control

[McG 6969]

Hello again,

Not an awful lot done, but at least some progression with the Bella.

For the second fuselage side, I tried to avoid the ‘ballooning’ problem by pricking some holes into the Depron. I used a chequered pattern to prick a 0,5mm hole every 10mm in square.

The covering result is that I can confirm Simon’s hypothesis: the foam was releasing some ‘hot air’ that couldn’t escape but with the holes allowing the air to escape to the ‘inside’, the ballooning became ‘nihil’. I will certainly not pretend it was an easy one, but iron covering can be done to Depron.

"Gaston saw every thing that he had made; and, behold, it was very good" (Gastonesis 1:31).

But, in my very personal opinion (even) as an apprentice, to get a coherent finish with Depron, I’ll stick to 25gr/m² glassing with WB hard varnish in the future.

Hakuna matata

Chris

BRU - BE / CTR 1:31 Control