Pix - E Major

[cad]

thanks Tim and Kit for suggestions on hinges. As the colour scheme is silver/grey I had bought a roll of reinforced tape which has a grey silver finish, so we will see how it matches up. Just received Li-po,slow prop, prop adaptor, and servos from BRC Hobbies excellent service and advice. Not much room from the servos, needs a neat bit of cutting. Tim, on one of your photos you show a small hatch under the servos, did you leave this open? the small wire showing is that the aeriel?

Colin

 

[Kit White]

Posted by cad on 05/02/2011 12:13:20:

thanks Tim and Kit for suggestions on hinges. As the colour scheme is silver/grey I had bought a roll of reinforced tape which has a grey silver finish, so we will see how it matches up. Just received Li-po,slow prop, prop adaptor, and servos from BRC Hobbies excellent service and advice. Not much room from the servos, needs a neat bit of cutting. Tim, on one of your photos you show a small hatch under the servos, did you leave this open? the small wire showing is that the aeriel?

Colin

 

Good call on that gap for the ariel, I noticed that in the picture too.

 

My dillema is that, since I'm rather proud on the job I have done on it, I doubt I can ever bring myself to fly it and risk all that hard work and effort now!!!

Might hang it from the ceiling uncovered for a bit!!!

[Kit White]

Oh, I have two questions also. First is, do you think it would be viable for me to permanently glue the wings on? They're only removable for practical reasons, right? Second question is, does it matter if I put the servos in the tail with the elevator servo on the left, instead of on the right as shown in the plan??

[Tim Hooper]

cad,

 

The small hole under the tail is simply an outlet for the air, after it has passed over the motor, ESC and battery. it's probably not necessary on this sort of model (given it's low amp draw), but I'm a Luddite from the era of over-heating tin-can motors and NiCad batteries, so it's a habit of mine to provide the air with a place to escape from! It also lets the aerial hang free.....

 

Kit,

 

I know what you mean about a model looking good un-clothed (as it were) - there's always a slight regret when I have to start covering up the framework of a new aeroplane!

 

Glue the wings on, by all means, if it's easier for you. Experience tells me, though, that having them removable is a boon when it comes to repairs and maintenance! Not to mention storage and transport.....

You can put the servos where you like! I put mine in the tail just to achieve the correct balance point without having to resort to carrying ballast. Whether they're on the left or right makes no difference.

Pictures anyone?

tim

[cad]

Thanks Tim, I would have filled the hole in assumimg it was only for fitting access. Never quite sure just how large holes affect the aerodynamics on a model. On my early attempts with small scale rubber a hole anywhere seemed to make a difference. Have posted two pics on my profile. You wouldnt want to see it at the moment as it is a sad little Pixie as having covered the wings with a silver finish tissue (not really very strong) and having attempted to spray two yellow bands around the wing, I have torn the covering trying to remove the masking!! At the cross roads do I go for the film covering and make a more durable job, or face a lot repairs with tissue. I think probably the former

[Kit White]

I think what I'll do is screw the wings on, with an additional two screws going into the root rib. These can be undone by removing the top covering between the wings. So they will be less detachable, but still possible to remove. The reason for all this is in my case the wings don't want to sit firm in position; niether the root rib presses against the fuselage.

[Tim Hooper]

cad,

 

If you won't post them then i will! The airframe looks great BTW.

 

Kit,

 

 

You can't expect perfection! Is it possile to build up the root rib with balsa, and then re-shape it to match the fuselage? It's what I do on ocasions.

 

tim

[cad]

Thanks Tim. The reason for not posting was that I had read that photos should not be greater than 500kb. My photos are all 3+ MB, and i was suprised to see that I had loaded two of them into my album. perhaps the limitation is only for the avatar.

 

I am assuming that having fixed the servos at the back you then required extension leads to the receiver. You have made a note about the position of the receiver, but only indicate that you fixed the Li-po securely in place, did you leave the receiver and the ESC "loose" The tip about Kits wing root fittings was usefull, I have a similar problem so your advice was timely.

Colin

[Tim Hooper]

cad,

 

Having the rx. secured to the rear face of F4 velcro, meant that I didn't need to use extention leads on my servos, but that'll depend on the make of servos you use. I did have to use an extention on the ESC though. You can't win 'em all!

 

The ESC is velcroed to the floor of the cowl, whilst the battery is a 'push fit' into the open-ended battery box. The battery is removed for charging after every flight.

 

tim

[Kit White]

I meant the wings sort of sag, not that the shapes of the peices are different

[Tim Hooper]

Kit,

 

You'll need to have the stated dihedral for the model to fly correctly - if at all!   Won't the struts push the wings up to the correct position?

 

tim

Edited By Tim Hooper on 08/02/2011 09:07:20

[cad]

tim. I have tried to load up some more photos but to no avail, I was surprised as I said to see the others appear. I have now removed the tissue, and had a dry run test for the centre of gravity. The model with all the bits except the receiver, and no film covering is 12&7/8 ounces. I am not sure how much the finishing will add, but it shouldn't be more than 15 oz. Is there a max weight not to be exceeded for this size of motor and structure? The frame is a little nose heavy as I have been a bit belt and braces around the front end, and I can rejig the esc, and Li-po further back. If any weight is needed, a little in the tail will be more effective than having to solve a tail heavy problem.

[Tim Hooper]

cad,

 

15oz will be fine, I'm sure! Don't worry about the AUW unduly - you're well in the ballpark.

 

As for photos, I re-size mine to 600 pixels along the top edge before I upload them the gallery here. Give it a go, because Id love to see more pics!

 

tim

[cad]

Tim

About to cover the model with Solartex which will be a first for me so will do a trial on a small wing assembly first. However when covering the wings did you find it easier to cover the wing as a whole stretching it fron the root to the tip, or did you fix and stretch the centre section first between the parallel leading and training edge and then stretching out to the root and the tip as a second and third operation, but still using one single piece of Solartex.

Also having some problems securely adhering the acrylic sheets to the cabin frame. I have sealed the frame with a coat of paint as suggested but having used super glue and now white pva, I am unhappy about the adhesion as it will come away with a little pressure, and am concerned that once I start applying heat with covering that I am going to have a disaster on my hands. what glue did you use please?

Colin

[Tim Hooper]

Colin,

 

Solartex is a definite no-no!! It's way too heavy, and will distort the airframe as it shrinks!

 

If you look back to the previous page in this thread I suggested to Kit White that he uses Solite or Litespan. and I'd urge you to do the same.

 

For gluing the glazing to the frame you should be using canopy glue. It looks like PVA at first glance, but is not inter-changeable with it. You'll be able to obtain a small bottle from the same shop that retails the Solite!

 

tim

[cad]

Tim , thanks for the timely warning

Colin

[Kit White]

Posted by cad on 14/02/2011 19:57:23:

Tim

Also having some problems securely adhering the acrylic sheets to the cabin frame. I have sealed the frame with a coat of paint as suggested but having used super glue and now white pva, I am unhappy about the adhesion as it will come away with a little pressure, and am concerned that once I start applying heat with covering that I am going to have a disaster on my hands. what glue did you use please?

Colin

Me too. I can't for the life of me get the glazing to stick, or for it to fit properly. Is there an alternative to using transparent plastic, like a heatshrink type of glazing I could use?

[Kit White]

Also, what covering did YOU use? I have tried litespan but don't like it. Is solite easier, or can I use simple solarfilm?

[cad]

Kit. I have yet to cover my model. Tim's advice is set out in his article, and recommends the litespan as added decoration over the So-lite. There are articles that suggest that solarfilm is stronger and in the quantities involved on this model would not produce a significant increase in weight. I am still waiting to afford a heat iron. Tried the wife's steam iron but it is too heavy and not enough heat control at the tip. This area of modelling is all new to me so I do not have all the kit to hand. This Pixie is exensive in my terms but you have to start somewhere. My friends have all complimented the model in its basic structural form. Compliments to Tim on scaling the original to electric power

[Tim Hooper]

Kit,

 

Read my previous post about using canopy glue! I've heard of clear Solarfilm being used for glazing, but I think it would look a little odd as it shrank over the cockpit framing.

As for the covering used on my prototype, it goes like this;

White - Litespan. Not only gor saving a bit of weight, but because it can pass for tissue at a first glance, without tissue's fragility.

Silver - Solarfilm. The fuselage is a pretty rigid structure (unlike, say, the tail surfaces), so using Solarfilm here didn't cause any distortion.

Green - A mixture of Solarfilm (on the nose/cowl) and Solartrim for the stripey bits.

 

cad,

 

Thanks for the comments.  Incidentally, I don't possess a posh modelling iron either!  All I use is a simple (non-steam) travel iron, which cost me a tenner or so in Argos some years ago!

 

This might do it 

 

tim

 

 

 

Edited By Tim Hooper on 22/02/2011 13:38:19

Edited By Biggles' Elder Brother - Moderator on 22/02/2011 21:54:10

[cad]

Tim, reserved an iron and picking it up from solihull argos tomorrow so hope to make further progress soon. I appreciate the amount of queries you have fielded so far, but now treading into fresh water. have watched the utube vids on how to use the film, and had a go on a spare wing. but when it comes to the areas around the cabin glazing did you pre cut the film and work away from the glazing or did you have the 1" excess which I assume overlaps the glazing and then carefully cut away to the line you want, did you then need to heat the film onto the glazing as a final action,

colin

[Pat (rActive) Harbord]

Totally forgot about this plan, looks fabulous. Just got to dig out Decembers issue and check that i've got everything I need. Then I'm definitely going to build one. I reckon this could be the aircraft to get my boys interested in flying.

 

Thanks for another great plan Tim. I did your Desoutter when first published and loved that (will probably rob it of kit to go into this one)

 

Got to think of a colour scheme different to but equally fitting to your white, silver and green.

[Biggles' Elder Brother - Moderator]

Tim, please read here

 

Thanks

 

BEB

[Tim Hooper]

BEB,

 

Forgive me, guv'nor. I never meant no 'arm.........

 

tim (message received and understood)

[Tim Hooper]

Posted by rActive on 22/02/2011 21:47:07:

 

Thanks for another great plan Tim. I did your Desoutter when first published and loved that (will probably rob it of kit to go into this one)

 

 

Now then, would you be the gent I met at Old Warden a couple of years ago? We flew these models together, in a sort of loose formation.......

 

 

Colin,

 

Good news about the iron! Yes, added the glazing first, and then carefully worked around the glazed areas when applying the film. Just be acrefully of applying too much heat to the glazing as it can distort if you're not too careful!

 

Nothing's ever easy, is it?

 

tim