marc s

This is a thread detailing the work to re-fit and upgrade a 'one off' Aermacchi MB339.

Here's the background as I know it, although I am sure there are a few bits missing!

The fuselage was moulded from a plug made for a static display model for Aermacchi by Fritz Heer in Switzerland, the plug was not suitable for a model designed for turbine power, so numerous modifications were made by Fritz before the final fuselage was usable.

The wings were made from a foam core base covered in two layers of carbon fibre cloth.

The fuselage and wings are complete and painted in the 'frecce tricolori', landing gear is machined from solid.

The task ahead is to re-fit this jet and bring it into a position where it can be flown, as to date it has never left the ground under its own power

Turbine is a AMT Olympus, Weatronic rx, air drivern doors and a hydraulic system to run the gear. Also navigation and landing lights are planned, smoke and a few other extras.

Its about 2.9m long and the span (tip to tip) is roughly 2.6m - estimated weight from the original builder was just under 20kg.

First job is to remove all the old remaining equipment, evaluate and upgrade where required.

All the servos appear to be Hitec, so the owner is changing these to JR8711s and others where required.

Here are a few pics to start off, many more as I go along. Any experts on the jet please pipe in as I would be happy to hear about little details, especially on the nav and landing light set-up.

marc.

marc s

more..

schroedm

My Feedback: (1)

You're a busy boy mate!! Look nice - is it for who I think it must be for?

marc s

Think so - how does it compare to the Hawk for size?

marc.

schroedm

My Feedback: (1)

oh, I think mine's a little big bigger than his

SCALEFANATIC

Marc,
www.cuccoloaeromodelli.com make the 1/4 scale kit you have with foam wings and fibreglass fuselage. Retracts are from eurokit. I am waiting for the new Airworld kit when out,
Regards,
Brian Hewson

marc s

Working currently on the front and cockpit areas.

Internally things needed tidying up, some of the cockpit formers were not in horizontal so have had to modify and shim them, removed the front gear door air ram, as I am looking to use a servo to run the doors using a servo slow, to give a better scale look, especially as the gear is hydraulic.

The original cockpit deck was carbon foam sheet, and to me did not look very nice, so as weight is needed in the nose have made the first of two cockpit areas using patterned aluminium sheeting.

Painting the inside of the fuselage in a grey cellulose paint to improve the overall appearance.

Slighlty modified the original air brake servo mounting, sprayed it black and fitted new mounting plates.

Struggling with the rudder set-up (posted a new topic for help)

Weatronics and more gear here in the week so will start to plan the install and equipment.

marc.

marc s

Finished the front gear door mechanism, which I have modified to run from a JR161 servo rather than air, managed to mount the servo nice and neat above where the air cylinder used to mount. The throw is good, and with the Weatronic and Tx programming a 'servo slow' setting will give a nice scale llike operation.

Managed to squeeze an 8411 into the steering cradle, replaced the old secondary door springs with repositioned and longer new items, which are more accessible for routine maintenance than the originals.

Made a battery restraint just aft of the rear front gear former, to house the 3 x 6 cell Nimh 3700's that will power the Rx and hydraulic systems, two aluminium straps will secure the packs down (still to make)

Hydraulic equipment mounted on its own panels, with the distribution valve and oil reservoir yet to be fitted.

Its a treat having space in which to work

marc

marc s

Latest.

Re-made the elevator servo mounts as the originals were secured using heat shrink and a flexible adhesive, which although probably OK was not considered safe enough for the 8411's. Made new servo covers using FR4 board and secured to this with some BVM 'L' brackets and recessed bolts.

Added a hatch spring to the nose door as it kept closing under its own weight, which became a little frustrating!

Nose gear all in, kero pump and solenoid mounting plate made (FR4) and starting to position items on main board.

Smoke tank assembled, although looks to be a tight fit under the turbine (will post pics when test fitted).

Added a few pics of the jet taken today on a very sunny and warm February day!

marc.

ThomasP

Marc,

It is looking really nice, maintaining standards I see.

P.S Did you see my place of work in the news today?

Regards,

Alistair.

marc s

Alistair,

Hi, unfortunately not - what's it in for?

marc.

marc s

Most of the equipment trays now done.

New 'ball' UAT mounted along with smoke pump - wish these things were designed with an easier mounting facility!

Electronic landing light and navigation equipment mounted with dedicated battery, hydraulic system mounted and waiting some modified Festo fittings.

Main battery tray full with compliment of 4 packs, air brake servo and linkage complete.

Added the main Weatronic isolation panel into the front nose section, tidied up the nose gear servo lead routing.

Modified the stab servo mounts and now just need to match the paint!

Onwards.............

marc.

marc s

Back from hols so on with the build.

Moved the Weatronic to the fuselage side, which puts if out of close proximity to pumps and turbine ecu.

Decided to make things really hard for myself and install all the charging (x6) and switches (x4) Weatronic data socket into the front nose section. Don't ask why, it just seemed good to have all the 'electrical stuff' under one hatch. I had already made and mounted all the electrical stuff on a panel in the middle hatch section, but was not happy - so put myself through an evening of pain.

With a little work on the connections, it looks as if it will all go in, hopefully I'll have the sockets and switches mounted tomorrow.

Plumbed the 'ball' UAT.

Later.

marc s

latest:

Switches and charging points all wired and mounted, and the ribbon cable routed to connect the data point and immobiliser panels for the Weatronics.

Servo screw (yet to be fitted!)

Pics of front nose section before and after............and some others

marc s

Install so far.

Have had to do some major work on the main gear legs, the springs supplied were not capable of supporting the jet so have had to work through a plan to experiment with different springs, but in order to do this the internal diameter of the legs needed to be machined out a few mm so that UK metric springs would fit - I want to say a big thanks to Danny Wenham for his help in this job, and for the superb aluminium 'manifolds' he machined up for me as well, they are really slick

Pictures tell the story, but not far to go on the main equipment, then comes turbine and smoke followed by the rudder modification and replacement wing servos..............

MF Boy

Ah its for Ali
or is for you Mark?

Matt

InboundLZ

My Feedback: (10)

The switches you are using, they JR? It looks like heavy duty cable coming out of them. What say you?

The build looks really professional!

marc s

Switches are heavy duty JR ones.

marc s

update.

Main turbine hatch now is hinged and sprung, tried a couple of hinge types had lying around but none gave the right opening spacing so decided to make three hinges from FR4, strengthened each where it mounted to the hatch and worked out a spring fixing point to both fuselage and hatch to give it that sprung feel, now swings open when the release is made and stays there until closed.

Had some issues with a front hinge on the nose leg gear door, one just sheered off while moving the door to the closed position so then had to work out the best way to replace the broken hinge.

As the old hinge was secured very close the the door cut out so I opted to remake the mounting plate for the hinge as there just did not seem to be sufficient 'meat' to refix with screw holes literally on the fuselage edge. Finally made a couple of very 'sharp' pointed triangle fillets which were fixed to the vertical panel immediately behing the door opening, this allowed a greater surface area for glueing and so far seems to have worked out well - after replacing the broken hinge the good one had to come off so it could match the other!

The smoke tank has been causing a headache, and although not yet complete I have decided to have a go at making one to fit the space allocated, if it fails will resort back to plan A.

Made a foam plug from some 1.5" foam which I hot wire cut using two ply formers, then glued 5 together to make the tank shape. Covered in profilm and applied three good layers of wax release. I am now in the process of covering the mould in 5-6 layers of glass cloth and finishing resin. Once this is done plan to cut the tank in half widthwise, remove plug, add fittings with Aeropoxy and re-close using glass bandage and resin.

Phots attached, including the hydraulic distribution manifolds (thanks Danny) now fitted with the festo elbows.

marcs

marc s

Been a bit lax in posting but here are some more picks of the work done over the last few weeks.

The rudder originally connected to the servo via the star type servo horn which was screwed to the base of the rudder itself, when I tried to remove the rudder and servo it was almost impossible to get at the servo, and once finally removed for inspection one lug was totally snapped off so leaving three screws which were not totally secure. More of concern was that there was no real way to check that the rudder was actually seating fully into the splines on the servo, so alternative servo drive was required.

Changed over the wing gear door air opening system to a servo driven one, mainly so the servo slow on the front gear doors will work in conjunction with the main gear doors, giving a better scale opening and closing speed.

Installed the 'fill' panel just aft of the cockpit area under a hatch.

Smoke tank is now made, released from the former plug and cut in half, fitting the BVM hardware now and will re-close and cover in a few more layers of glass cloth and resin before pressure testing etc...

pics...

schroedm

My Feedback: (1)

Marc,

Another work of install art!

So, what you working on next?

M

marc s

Update.

Mounted the fuel pump and two solenoids with plumbing and re-made the hydraulic reservoir mounting plate as the original reservoir has been modified by the manufacturers MTH to simplify the air bleed arrangement (thank you to Peter Hausl), the new system also now incorporates a plastic pouch which helps protect the fluid bag which could be vunerable to damage.

AndyAndrews

My God, that looks like a Refrigeration unit.

marc s

Latest.

Finally finished the smoke tank, it holds 2.5ltrs, had no holes in it (result!) and fits in the space it was made for!

Decided to mount it via carbon rods through brass tubes, which are glued to each side of the tank. The tank sits between two formers so the cf rods pass through the former on one side of the tank, through the brass tubes and out through the second former, seems to work well (copied from the original main tank mounting system) and allows very quick removal etc if reqired - takes a bit of alignment time though.

Added the two overflow vents, and started routing pipework.

marcs

Bob_B

My Feedback: (11)

Marc,

Another fantastic build I see!

Bob