Thread Tools
Sep 15, 2008, 02:38 PM
Registered User
Synergy1's Avatar
Thread OP
Build Log

Phoenix Model Products Aermacchi MB339


Phoenix Model Products Aermacchi MB339 build in progress
(EPP PSS slope soaring jet trainer..)

http://www.phoenixmp.com/models/aermacchi.htm

Its not a very scale model but its cheap enough, Ive found stans' models are nice to build.

I plan to Assemble it, spackle it, X-weave tape it, sand it, then cover it in profilm for a good finish.

In addition to the kit I needed:
-12 Minute Epoxy
-Polycell no sanding polyfiller (the stuff that feels like the tub is empty)..From B+Q
-Evo Stick Impact adhesive (From homebase), its a bit more expensive than other brands but comes out of the can far less stringy. (I couldnt find a local source of 3M77).

I won't go into step by step detail as you can see the instructions here: http://www.phoenixmp.com/epp%20instructions/aermacchi.htm

Ill be adding photos of interest showing various stages and any noteworthy comments.

In order for the Fin not to be "floppy" I added some spare EPP into the hollow tail section (made of EPP sheets) below the fin, allowing me to add a carbon fibre tube / wooden kebab stick up through the EPP and into one of the chloroplast flutes in the fin

3x Hitec HS82MG servo's will be used, one for ellevator and one in each side of the wing, facilitating a spoileron setting. Standard servo's can be used; One for the ellevator and one for the wing, (using torque rods) but you can't then have a spoileron setting as one servo will operate both ailerons). The wings are too thin to use 2 standard sized sevos in them.

If you can build a beginners / trainer glider, like an orion or a gentle lady, from a kit of parts, following instructions and a plan you'll have no problems with this kit, its pretty simple.
Last edited by Synergy1; Oct 13, 2008 at 02:26 PM.
Sign up now
to remove ads between posts
Sep 18, 2008, 02:11 PM
Registered User
Synergy1's Avatar
Thread OP
Fuselage assembled prior to sanding to shape.

The fuselage construction involved popping some 3mm plywood "doublers" out of a pre-cut sheet, sanding them, super glue on some 12mm square balsa bearers that separate the two sides, fit a servo, the outer surfaces of the plywood are then sprayed with impact adhesive and the EPP fuselage sides glued on. More EPP is glued in between the nose and tail and both ends pulled in and glued making sure the fuselage is straight. Chloroplast Tailplane sheet is glued on with epoxy and fin added (using cross weave tape between tailplane and fin). The servo snake is then routed to the ellevator. Sheet top and bottom with EPP using impact adhesive (the fin becomes a lot less floppy at this stage, as its held either side by the EPP).
Last edited by Synergy1; Oct 13, 2008 at 03:13 PM.
Sep 18, 2008, 02:15 PM
Registered User
Synergy1's Avatar
Thread OP
Sand: I used a medium grit wet and dry paper. I did it by hand using a sanding block rather than resorting to power tools as i didnt want to go at it like a hot knife through butter !
Last edited by Synergy1; Sep 18, 2008 at 02:24 PM.
Sep 18, 2008, 02:22 PM
Registered User
Synergy1's Avatar
Thread OP
Id spent a while on the fuselage by now, so i thought for a change id do some work on the wing.

Learning point: do not eat sticky baked goods in the same room you've been sanding EPP in.

Figuring out the layout and fitting the spars: (these are glued in with epoxy). the spar slots are tapered so you have to square them up with a sharp blade. I made a sanding block the same width as the spar and glued on some wet and dry paper onto the sanding block, so that the spar slot was nice and square, and so the the spar could sit just below the top of the wing surface (it will later be covered in spackle (lightweight filler) and you won't be able to see any impression of it through the covering)

When epoxying the trailing edge reinforcer onto the EPP, its important that it sets absolutely flat or it'd be a nightmare when trying to fit the ailerons. I used masking tape to hold it in place and stood the wing up on its edge on a flat surface, then taped the wing down onto that surface so it wouldnt move or creep as the glue sets. Spars must also be glued in so as not to deform the shape of the wing. I glued in the lower spar first with the wing upside down (curved side down), and plenty of weight on top, then flipped it over and glued in the upper spar with weight on top of the spar. This may or may not be the best method but it worked for me and I came out with a nice straight wing, with ease :-)
Last edited by Synergy1; Sep 19, 2008 at 02:19 PM.
Sep 18, 2008, 02:29 PM
Registered User
Synergy1's Avatar
Thread OP
before id sanded the fuselage i couldnt resist fitting it all together to get an idea of its proportions
Sep 18, 2008, 03:49 PM
Registered User
QUIKSILVER's Avatar
Oh Yea! I Swear It Said Jp Before My Bad!

I Think my POS will fly ok!
Last edited by QUIKSILVER; Sep 19, 2008 at 09:12 AM.
Sep 19, 2008, 02:21 AM
AKA Cactus
Phillybaby's Avatar
stan never made that pos, it's a pekins job
Sep 19, 2008, 02:41 AM
Registered User
julianb's Avatar
Quote:
Originally Posted by Phillybaby
stan never made that pos, it's a pekins job

S'funny though. That link takes me right to it.

Perhaps I was imagining it...

Sep 19, 2008, 09:14 AM
AKA Cactus
Phillybaby's Avatar
no, but you did miss the post i was replying too
crafty ruggers edited it now
Sep 19, 2008, 01:45 PM
Registered User
Synergy1's Avatar
Thread OP
Ok so whats happening on the build:

I've got a couple of wing spars to glue in, that should take all of 10 minutes (+ glue time). Ill cut some aileron servo holes in the wing and then its Spackle time.

To the unitiated "spackle" can greatly improve the look of the model and its overall "slipperyness" in the air. The fibreglass purists may even raise an eyebrow as to the finish or your EPP "blob". Spackle helps reduce that unfortunate aerodynamic syndrome known as drag, which so ruined my attempts at self-propelled flights as a child. "Spackle" is actually an american term and for those of us living on the Queens fair island then I'm actually referring to filler. But not your average domestic polyfiller: we use a lightweight polyfiller, and if your wondering what to buy you could do far worse than a tub of Polycell One fill Pollyfilla, light weight formulation. All B+Q stores sell it. Its fast dryng, non sagging and non shrinking.

The principle is simple: once your EPP model is assembled the manufaturer normally says to spray it with a coat of impact adhesive to "prime the surface" and then lay on cross-weave tape. But here we deviate from the hallowed manual a tad, and cover our creation in the "spackle" first. You can use a decorators scraper, an old credit card, a new one if money is no object, or other similar application tool. The idea is to fill all the lumps and pits in the foam and make a smoother surface before you add the tape. It helps if you are generous with the application, don't skimp and spread it too thin, but then dont "butter" your model like my father does his bread either. You dont really need to "prime" the EPP surface first either.

Somehow, slobbering all over your lovingly sanded model with a white paste will feel wrong, but be steadfast and spackle away. Aim for a uniformly smooth surace but dont worry if theres the odd dimple, pimple or imperfection, lets face it, we all have them. Once dry (overnight in the living room at least, more if you live somewhere wet and humid, like a caravan during british summertime).

You use a fine grade wet and dry paper and sand the model to a smoother surface. Now re-spackle any cracked bits, or bits you missed, or anything not smoother than james bond in silk pajamas. Sand again with fine grade wet and dry. dust off with a brush or hoover with brush attachment, Now prime the surface with impact adhesive and let it dry. Then go forth with the cross-weave tape.

Thats my weekend planned: expect lots of fine white dust. A good shed or an undertanding partner are handy at this point.
Last edited by Synergy1; Oct 06, 2008 at 11:33 AM.
Sep 20, 2008, 05:15 AM
Registered User
With my Phoenix Tucano I extended the fuselage doublers with 1/32nd ply the stiffen the rear fus. I've gotten to the spackle stage when my attention wandered. Taping EPP is NOT my favourite chore.
Sep 21, 2008, 10:01 AM
Registered User
Synergy1's Avatar
Thread OP
ok folks, well its been a sunny weekend, so I thought id make the most of the weather and have not done as much as planned.. but the fuselage is now fully spackled and im about half way through the wings.

Spackling was a bit time consuming as to get it good and proper, you have to do it a couple of times and make sure all the lumps and bumps are filled in properly. I found that for the second application, a slighltly watered down spackle worked well, that is.. a few drops of water to make the paste a bit smoother but it shouldnt be too wet! when you apply the spackle, first off youll be thinking..oh god, what am i doing to my model, but stick with it. I also noticed that once dried, the fuelage feels stiffer seomehow.

You can see from the photo just how many lumps and bumps the spackle has filled in the foam. If the foam was perfectly smooth and uniform like a moulded model, almost no spackle at all would stick, so its suddenly very clear just how un-aerodynamic bare EPP is.

Now sanded i have to spray the entire fuselage with a coat of impact adhesive and let it set. This primes the surface ready for the cross-weave tape.

How much time and care you spend spackling the model is up to you. But If you are trying to make it look like a moulded model, then why not buy a moulded model?. With the exception of racers, I dont really see the point of spending ages and ages spackling an EPP model to absolute perfection if you then plan to combat fly it or bounce it off the slope etc, Sure make it a bit better and smoother etc but dont stress too much if its not totally perfect, consider the type of flying you do and how you treat your models. Why go for a perfect finish if you then try and do four point rolls 2 feet off the ground on a boulder strewn slope.
Last edited by Synergy1; Oct 13, 2008 at 03:18 PM.
Sep 21, 2008, 10:06 AM
Registered User
Synergy1's Avatar
Thread OP
Quote:
Originally Posted by Windknot
With my Phoenix Tucano I extended the fuselage doublers with 1/32nd ply the stiffen the rear fus. I've gotten to the spackle stage when my attention wandered. Taping EPP is NOT my favourite chore.
Indeed: taping the fuselage is my next job and im procrastinating by being on RC groups!
Sep 21, 2008, 10:17 AM
Registered User


The sooner I finish the job that's on my bench at the mo the sooner I can start on my Ki-61. So now neither is getting done!
Quote:
Originally Posted by Synergy1
Indeed: taping the fuselage is my next job and im procrastinating by being on RC groups!
Sep 21, 2008, 12:50 PM
Registered User
Synergy1's Avatar
Thread OP
the fuselage is now cross-weaved...thank goodness thats over and done with!

This was a fiddly job ,,especially around the canopy and nose. It involved lots of little cuts into the side of the EPP strips to let it to pull around the compound curves. I used an iron and managed to shrink out a few minor creases in the cross weave tape, some will dissapear when the fuselage gets a light sanding again, and i may even use a wee bit more spackle to tidy up a few spots that were particularly irksome.
Last edited by Synergy1; Sep 21, 2008 at 01:56 PM.


Quick Reply
Message:

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Yippee! Phoenix Model Products - online shopping satinet Slope 6 Feb 06, 2007 05:05 PM
Gary Wright Model Products E3D Robert Wick Electric Plane Talk 8 Apr 18, 2002 03:19 PM
Set-Up Instructions for Speed Demon 202 ESC (Viper Model Products) Kevin Murray Electric Plane Talk 0 Feb 24, 2002 02:09 AM
Gary Wright Model Products Q&A WilliamSettle Sport Planes 379 Feb 07, 2002 04:03 AM
Mountain Model Products has beyond excellent service!! Don Sims Vendor Talk 0 Jan 17, 2002 05:56 AM