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PSS MB339 Aermacchi Build


David Gilder
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Well last year at a PSSA flyin on the Gt Orme in North Wales, we were joined by a fantastic Builder and owner of www.islandmodels.ie - John Pearson.

John had become the owner of the Ray Jones MB339 Aermacchi Fuselage moulds and was pleased to announce that he would be trying to make kits available as soon as possible.. Needless to say that there was immediate and great interest from a number of PSS flyers and I caved in also and placed my order!

Unfortunately, John had issues with the company who were producing the fuselages for him resulting in a considerable delay to production... SO. Not to be outdone, John took it upon himself to go back to school - well, fibre-glassing school!!

John now produces the fuselages himself at home in his small garden workshop at a rate of a few a week and it has to be said, he has outdone himself and produces a fantastic solid fuselage. Well Done John.

 

So about a month ago, I received an email from John to let me know my Kit was ready for dispatch! A short 2 hour phone call to John and everything was paid up and sent over. 2 days later I returned home from work to find a very large box in the lounge!

dsc03615.jpg

 

Well I couldn't wait to see what I had got so out it all came and was checked over for damage and for a general "role call".

dsc03619.jpg

 

That was all I could do as we were selling our house and it had to be kept clean and clear for viewings etc!

Well the house got sold but our new house purchase fell through so we have ended up staying with mum whilst we look for another house... (parents really can be a godsend!!!)

So back in the box the kit had been placed and off into storage!!

frown

 

 

Edited By David Gilder on 15/11/2013 22:25:52

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2 days ago I was chatting to mum about the model and how I would like to get it built for the next season starting in April 2014, but to do this and have time to spend making it right (I have a fantastic colour Scheme set for this one!) I would need to start the build soon!! (hint hint)

Surprise - Shock!! Mum agreed I could start on the build as long as it came "Nowhere near the Dining Room Table!"

 

I hastily agreed and with a few hours today, retrieved the box from storage and made a start!

So what have I got done!!??

Stage 1:

Trailing Edges and Leading Edges glued on!

dsc06855.jpg

 

Then out with the sandpaper and both shaped to profile! :

dsc06856.jpg

 

So having both halves of the wings sorted out they had to be joined!

dsc06864.jpg

 

Following this, I made up the Horizontal Stab and the Elevators but silly me, I forgot to take a picture of them being glued!!!

Never Mind...

I decided to give the moulded canopy a trim down so it was a close fit and just needs final trimming closer to the end!

So all in all, quite a productive few hours work!

Okay, okay.. I couldn't help myself.... I just had to have a dry fit!!

 

mb339.jpg

 

So there we have it... Started and well under way.

Progress will be in limited blasts as I don't want to take advantage of mums kind offer!!

I will update when able!!

 

Dave

cheeky

Edited By David Gilder on 15/11/2013 22:26:14

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Nice one Dave, I look forward to seeing your build take form on this one - it's a lovely kit as you've already stated.

One point I'd mention, there's plenty of room in the fus so do make sure you plan out your Rx fit. I had 2 issues on mine - getting the Rx battery far enough forward once I had sealed the cockpit area (mine has a fixed canopy for strength) and my elevator pushrod got very close to clashing with the wing mount where I had fitted it so that's one to watch for nearer the time!

Keep them updates coming!!

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Hey BBC. Yes, The kit is very comprehensive and even came with a pilot and all the hardware you could want!

Extremely good value for money. I have to say also that John is more than helpfull and if you were lookingto do a colour scheme that is not in the list, he is known to offer a decal design and manufacture at VERY reasonable cost!

Phil. Thanks for looking in. What battery did you put in yours? I am looking at making my canopy fixed also but may have to come up with a device to make removing the battery easier incase of replacement / ease of charging!

Will update as and when I can!!

Cheers

Davewink

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I devised and fitted a sliding tray for mine, formed in light ply, runs on bearers fitted to the fus sides and effectively holds the battery (cantilevered) at the front of the fuselage where you cant get your hands in.

As for the battery itself I went for a 5 cell NiMH of 2500maH so it will last all weekend driving just 3 servos

Let me know if you want a piccie of the tray/rails.

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No probs Dave, here's the battery tray in position, its pushed forward on its ply rails and secured with the 2 little self tappers...battery tray 1.jpg

If you unscrew the self tappers the tray 'slides' back to the full extent shown, filling the wing bay. You can access the battery like this, of course if you need to you can remove the tray completely through the wing bay...

battery tray 2.jpg

Here it is out of the model. Note the battery is securely velcro'd and there is a bump stop to keep it in place. All 1/8th light ply.

battery tray 3.jpg

Edited By Phil Cooke on 16/11/2013 18:48:08

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Thanks very much Phil.

That looks like a good design which I may have to steal ! I am however looking a using Lipo Power 11.1v 2200MhA with a regulator (like in my OV10)!

I had come up with this design to mount under the cockpit!

tray.jpg

The tray locked in place with a pin and D clip as constantly putting a screw in and out would rip the wood apart and get loose over time!

So today I arrived home to find 2 more parcels.. 1 from Leeds model shop with covering, CA glues, 6v 5A Lipo Regulator and a brand new receiver for the model....

And the second from Steve Webb Models (servo shop) with my choice of servos..

What have I gone for I hear you ponder!!! Well...

dsc06886.jpg

They were a good price and are high torque metal gears so should do very nicely thank you.

Will update further as I progress!!

Dave

smiley

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Quick Update...

Have spent the morning pondering the Aileron set-up... Centrally Mounted Servos with Torque Rods, OR, Countersunk into wings providing direct linkage to Aileron Surface.

After much deliberation and head scratching, I have decided to go with the Torque Rods and 2 servos mounted centrally in the wing.

This will give an overall better appearance to the model as none of the linkages or servo horns will be on show giving the model its true clean lines!

Unfortunately, I don't have any torque rods in my box so I have ordered some online along with some pin hinges.

Is not that the hinges supplied in the kit are not up to the job... Its just my personal choice for this model!

Will let you all know more as I progress

Dave

cheeky

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  • 2 months later...

Hello again everyone,

Sorry its been a while since my last update but I have been very busy at work and trying to sort out a new house!!!

The good news is that if everything goes to plan, SWMBO and I will be moving home in the next 3 weeks but on a down side that does mean that there will be a natural stop in model building whilst we get everything sorted out!!

That said, I have done a little more over the last few weeks so here we go again!!

The first thing to do was to fit, trim and glue in the Fin Post.

Onto this will be glued the "fixed" rudder but that's a little way off yet!

fin post.jpg

I think these plastic pegs are a godsend to us modellers. Very adaptable and nothing sticks to them!!

Next was to sort out the torque rods for the Ailerons and then sort out the wing tips!

Easy stuff, So I wont bore you all with the details on this!!

Once this was done, the wing was lined up on the fuselage and the centre marked front and back. The wing locating dowel at the front was then drilled and glued in!

Following on from this is was time to cover the wing.

As I am going to be spraying the model up later, I decided to cover the wings in Solartex so I can just spray onto it direct later.

wing 1.jpg

More to follow shortly!

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Next was to sort out the wing bolt mounting plate.

I decided to strengthen this slightly with a brace either side which should be plenty strong enough for general slope flying with some selective scale(ish) aerobatics!!

Once this was glued in with 5 Min Epoxy, the wing was placed back in position and then drilled straight through.

The captive nut was then placed onto the plate.

Unfortunately, I clearly failed to maintain a vertical alignment with the drill as can be seen from the next pic. You can see where the drill was expected to go through!!! Never Mind, Its close enough!!!

mounting plate.jpg

So with this all done, I decided to work on the front end!

I plan to put in a sliding tray under the cockpit to mount the battery on (removable through the fuselage into the wing mounting area in case of needing to change or check) so in order to make both access for doing this and to square up the cockpit area ready for installing a false cockpit base, I marked out a line 1 cm all around the cockpit floor and then carefully cut this out with a rotary cutter!

So here is the bit I cut out (in 2 parts!)

cutout 1.jpg

and the resultant enlarged cockpit area.

cutout 2.jpg

By leaving a 1cm lip all around, this has ensured that the structural strength around this area has not been compromised,

Back to the wings now and the wing fences.

So careful measuring and trimming to the Solartex left me in a position to attach the fences.

What a change this makes to the look of the model!

top view 1.jpg

Lastly,

I looked to sort out the under wing belly fairing.

This comes as a pre moulded part made of ABS complete with indented moulded lines to ease initial cutting.

So having cut this along the lines I hit a snag.

The mould appears to have been done for a semi symmetrical wing when these wings have an almost flat bottom.

Dilemma Time!!!!!!!

Do I call John at Island Models and request a new part, or do I try and work with the over trimmed one I have!!

Answer in the next part!!!!!

(mini cliff hanger !!!!)

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Okay...

I decided to work with what I had!!!face 10

Maybe I will regret this, Maybe I wont!!

I pulled out some triangular balsa stock and cut to length to fit inside.

With some Epoxy, I glued them along the sides to replace the cut out section and plan to use filler to build it back out along the wood flush to where it would have been!!

Strangely, Even with it built back to it original depth, I found that when sat in place, it was at the correct height at the front end but still quite low to the rear!

I glued a fillet either side at the rear to lift it so it all became flush with the rearward fuselage and again, will use filler on the resulting small gap!

This has now been glued in place but you can see the issue on the following 2 pics.

(John, If you see this, can you have a look at the moulding for me and see if there is an issue or is it that I have made a complete and utter hash of understanding the mould linesblush Cheers)

dsc07534.jpg

dsc07537.jpg

So that's where I am now up to.

Quite a bit further on than before but still a long way to go!!

I will update again when I have something to tell, but with the impending house move, this could be a little way off yet!

Cheers

Dave

wink

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  • 2 weeks later...

Thanks Rez.

I am trying to do quite a complete report as I go in order that mistakes can be seen and learnt from by both myself and others!

This leads me nicely into my first "error"!

This is the first time I have built a model with a moulded fuselage. Having read the earlier parts of this build blog, a fellow model flyer contacted me with concerns about the epoxy I had used to secure the wing bolt plate etc.

With my "limited knowledge" (none) of gluing to a Moulded Fuselage, and he instructions stating to "epoxy in place" I had used 5 Min epoxy......

It was pointed out to me that this would not have created a secure bond with the inside of the fuselage and although it may appear to have stuck ell initially, would soon loosen under stress and with a few landings which could ultimately result in a departure from standard flight!!

This of course is something to be avoided wherever possible!!

A suitable replacement glue was selected (Aero Tech 24hr Epoxy) and ordered! This arrived the very next day! Great service from deluxematerials.com

So now to release the already glued in plate! Actually this was easier than I imagined. Some gently pressure against the inside of the fuselage pushing outwards saw the 5 min epoxy release from the fuselage with almost no resistance!

The plate was then sanded back to the wood and re epoxied into place with the new stuff!!

Over the next few days, the other wooden parts were released, cleaned back and re-glued into position!

So there we go... First proper mistake - Lesson Learnt!! wink

More shortly!!

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What to do whilst these parts re-glued??!!

Well there was nothing else to do but move back to the wing and the Under Belly Pan!

As you recall, I had to adjust this with wooden sides and chocks that would need to be filled and sanded down!

I purchased some P38 car body filler from my local Halfords (other vehicle repair / accessory shops are available!) and set to filling and sanding!!

Here we are after filling:

belly fill rough.jpg

and then after some sanding!

belly fill smooth.jpg

Not too shabby if I do say so myself!!

So with the belly pan sorted I could put it off no longer!

It was time to move onto the ENGINE NACELLE'S!!!

Luckily, on a previous fit up, I had drawn lines around the fuselage onto the upper wing surface so didn't need the fuselage fitted whilst putting the nacelles on!

The nacelles, like the under-wing belly pan needed trimming down from the moulds. This gives 3 pieces per nacelle: Upper, Lower and Front.

Once the were cut out, I lightly sanded along the inside edges of the upper and lower and glued some balsa strip inside. This would be used to give a wider gluing area when attaching them to the wings!

Once done these were trimmed flush and then the upper and lower parts were glued to the front piece.

nacelle insides.jpg

Having put together both of the nacelle's, It was time to glue them in position.

For this I opted for some General Purpose Contact Adhesive (similar to UHU!). Having done a dry fit, the glue was put on both parts, wing and nacelle, left for 10 min's then held in place for a few min's to ensure complete adhesion had taken place.

This did result in a few gaps by the leading edge, but again the wonderful P38 filler soon got rid of these.

I also used the P38 around the sides and rear edge of the nacelle's to give a smooth run onto the wing!

So this is the wing just before I filled the Nacelle Gaps with P38

nacelles glued.jpg

And with everything dried on the fuselage, it was time for another full mock up!

full mock 1.jpg

So there we have it!

There will not be any more updates for a while now as we should be moving home on Friday so will be very busy elsewhere!indecision

Will let you all know obviously when I have more to tell.

Cheers

Dave

laugh

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  • 2 months later...

Hello again everyone!

I'm back and cracking on!!!!

Where to start...... Obviously.. Where I left off!!

The next stage saw me making good use of some P38 Filler to fill the gaps around the engine nacelles followed by copious amounts of sanding saw the wings ready for primer coating! (more about that in a bit though!)

The Horizontal Stab was glued on with 24 hr epoxy along with the balsa fillet, remembering to insert the elevator control rod!

h stab and fillet.jpg

Once dried, the rear cover was fitted over all of this and the rudder glued in place. Then the balsa fillet was sanded down to produce the classic Pen Nib shape.

h stab and fillet 2.jpg

Once all dried, the Horizontal Stab and Rudder were covered with Solar Tex before some more P38 was used to smooth everything out!

The fuselage was sanded down to smooth ready for primer coating, then fitted with a hanging chord from the elevator horn inside!!

fus hang pre spray.jpg

For the primer I opted for Halfords own Grey Primer and the results can be seen below!!

fus hang grey.jpg

Not to shabby if I do say so!!

Next was to top coat the fuselage in its Base colour and once dried, I couldn't resist a mock up!!

black fus yellow wings.jpg

More in a bit....!!!!

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Okay then.

Forgot to mention that before the black spray on the fuselage I fitted the strakes. I marked up where they would go then carefully sanded off the primer for the glue to make good contact.

ventral fins.jpg

Once glued on, these were also primer sprayed!

So next was to tackle the wings!

Primer first (grey) - No pic I'm afraid!

Then the fun really started...

The wing is Black on top with "some" black on the underside so it was out with the masking tape and old newspaper to cover over the areas that are not black then out with the Black Spray paint (Halfords again).

Once dried all the masking was carefully removed and the results were quite pleasing!

All will be revealed in a moment but first I wanted to do some of the next colour on the fuselage...

John at Island Models had kindly provided me with a roll of gold sticky backed covering but I decided that this could detract from the overall finish, so a trip to Hobby Craft, more masking up and 30 min's with the airbrush gave the fuselage its first bit of final colouring!

Once dried and masking removed, I couldn't resist a quick mock up!

So with out further ado, here are pics of the current state of play, topside then bottom side!!

Enjoy!

All comments welcomed!

Dave

black mock up.jpg

black mock up underside.jpg

smiley

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Thanks for the sugestion and concern over the strakes Matt, However, I have followed the design as specified for this one.

The strakes are designed to be knocked off in the event of a less than acceptable arrival to prevent the risk of damage to the fuselage!
I spoke to John about afixing these a bit before attaching and he stated that his are attached in the same way and have yet to detatch, despite a few "very firm" arrivals!

Its something I will bear in mind though for future reference.

By the way, That lightning looks amazing in the air!

Dave
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Sorry to say that I have not been able to do any work on the model tonight....

Its not my fault... Honest.... BUT....

Someone mentioned SUMMER!!!!! So to go with the new house, we needed a new Bar-B-Que!!

So I spent all the daylight after work putting this little beauty together!!

dsc08508a.jpg

I'm sure you'll all agree though.... Every modeller needs a hearty meal.. and this promises just that!!

Oh and it even has a built in bottle opener on the side!!

Roll on those summer nights after a good days flying!

smiley

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