RE: SkyMaster MB339 Build Thread
 

only one flame from uat fitting letting air intank. flys well.

RE: SkyMaster MB339 Build Thread
 

is that R2D2 in the top right corner of that picture !!! :D:D ?


Voy

RE: SkyMaster MB339 Build Thread
 

Yes

RE: SkyMaster MB339 Build Thread
 

This is what mine looks like, it's a 170G , the inlets of the 339 are relatively small, and there is a ridge in ducting, for wing pipe, which I think deflects the air over tturbine my fuel piping is checked 100%

RE: SkyMaster MB339 Build Thread
 

In my MB-339, the air ducting goes straight into the turbine so the air is not going all over the fuselage. The fuselage has also some other openings on the side that could help with some extra flow of air and that could help to cool down some other components.

RE: SkyMaster MB339 Build Thread
 

That's interesting Gonzalo, is yours a Skymaster MB?
pls take a pic of holes on side as you mentioned

RE: SkyMaster MB339 Build Thread
 

It is a Skymaster.

Don't have a better picture right now, but you can still see that the plane has a couple of holes. Not too big, but at high speed it should provide some air flow.

RE: SkyMaster MB339 Build Thread
 

Had my maiden  on the weekend with my mb . Needed up elevator trim 4mm checked when landed .
CG was set on middle of wing tube .
 flew well .
Is this normal ?

RE: SkyMaster MB339 Build Thread
 

if you can borrow or buy a cable you can download your memory and we can look at your flame out run and previous runs . The ecu records throttle position,rpm,pump pulse width, and exhaust temp every 1/2 second. xicoy or kingtech sells the cable. not very expensive.you can print a graph to see easier.

Set up my new Jeti transmitter in the MB-339.. love the both of them.http://www.rcuniverse.com/forum/atta...mentid=1945525http://www.rcuniverse.com/forum/atta...mentid=1945526http://www.rcuniverse.com/forum/atta...mentid=1945527http://www.rcuniverse.com/forum/atta...mentid=1945528

Had trouble keeping the outer gear door closed so added second
air cinder. http://www.rcuniverse.com/forum/atta...mentid=1946090

I just dug up this older thread.
The last flight well over three Years ago I (my son) had an engine failure and when the gear was selected down during the final glide the whole nose gear strut fell out. Murphy's law. The only lock screw had loosened. Not too bad though, but some damage to the nose gear bay and doors.
First I sent the engine to JetCat to have it updated, a fault could not be determined however. Then I got too busy and some other projects passed, the MB collected a lot of dust.

Now I took it up again, ordered a new thrust tube from IQ Hammer and UP mechanical gear valves.
I took out all the radio components and most air and fuel tubing, I am gonna retrofit it all.
In the mean time I improved myself in installing the radio components, which was not always my favourite part of the building. Whenever it functioned, I was OK, didn't care too much about excess wiring, or neat installing.
Now I discovered the fun about that part, plus learned some more tricks the last few years since building the MB.

Plus I bought and built a Pirotti Tuono in the mean time, with which a have flown a lot now, so I feel more confident to fly a large scale jet. A few Years ago I was always stressed when flying it.

I wonder You guys are still owning and flying the MB?

I will post some pics during the update.

Here are the modifications to the fuel system, I'd never liked the rubber stoppers in the tanks.
I had one friend make me some alu rings with stops, with M7 threads, so I could use FESTO 6mm connectors, I try to have 6mm all the way to the pump.

For a vent for the saddle tanks I glued a strip of thick alu, drilled a hole and provided it with a M7 thread to take the FESTO 6mm right angle connectors. For the main tank, which has no room for a top mounted vent, I had my friend made a bigger unit that could take two FESTO couplings.

To be able to get the tubes in from behind I drilled an M7 screw (difficult to find, even in EUR) so that I had a kind of "collar" which I could solder onto the pipes that go on the inside part of the tank.
http://www.rcuniverse.com/forum/atta...mentid=2073648http://www.rcuniverse.com/forum/atta...mentid=2073649http://www.rcuniverse.com/forum/atta...mentid=2073650http://www.rcuniverse.com/forum/atta...mentid=2073651http://www.rcuniverse.com/forum/atta...mentid=2073652http://www.rcuniverse.com/forum/atta...mentid=2073653http://www.rcuniverse.com/forum/atta...mentid=2073654http://www.rcuniverse.com/forum/atta...mentid=2073655http://www.rcuniverse.com/forum/atta...mentid=2073656http://www.rcuniverse.com/forum/atta...mentid=2073657http://www.rcuniverse.com/forum/atta...mentid=2073658

Now I need to thoroughly clean them, add the rubber ring, screw tight and press test them.

Made all internal piping, rinsed the tanks with water and compressed air and then with fuel.
After mounting the stoppers I leak checked the with one bar, not even the slightest bubble to be seen..
http://www.rcuniverse.com/forum/atta...mentid=2073966http://www.rcuniverse.com/forum/atta...mentid=2073967http://www.rcuniverse.com/forum/atta...mentid=2073968http://www.rcuniverse.com/forum/atta...mentid=2073969

I bought a used fb mb-339 last year and had a couple of flights on it so far. Floats on landing but all my Jets floats on landing ;-)

CG
 

Hello,
I'm currently building 2 of the MB339.

I have read the thread to find out what the best CG will be. As so often I found different CG's.

I would be more than happy if pilots who has made some experiences with the MB will post it's CG.

Many thanks in advance

Philip

CG
 

Philip, the thread is not very active anymore as You can see. I still have it but fly it not very much because of several reasons. It is stowed right now for winter storage, and would take a lot of time to get it out and to put it together.
If You can wait, in December I have more time....

after wing tube 15mm for the CG of MB-339

Hello Anton,
many thanks!
Best regadrs
Philip

I too have bought a used 339.... and would like to bring this thread back too life...get some others out there that might have one.... get going again on it...and get more pics on here and if others added nose weight what type of weight and how much was added....

Dear ???
Yes I still fly my MB339, it is in perfect shape, all is working very nice, and still looks very new.
It was once heavily modified a few years ago. A complete redo of the air systems and electronics. I moved all the batteries as far as possible to the front, I even put the engine as far as possible forward, so I had to order a new thrust tube, which they made even lighter by using only a double skin in the last part. So I could take out all the lead from the nose!
The CG is now right under the backside of the main spar tube.
Just in case You have to add nose weight, I glued lead plates (the material they use on roofs, that You can shape and bend easily) directly to the fuse's skin in the nose wheel bay, well above the nose gear when retracted. There is ample room there.
The engine is still a P160 but whenever I can get a good P180, I will probably change it. I sometimes fly it off grass and then I could use some more ooommpff. Because the weight has gone somewhere between 24 and 25 kgs over the years.
The Unilight.at light system is awesome, even in bright daylight visible. It greatly enhances the sight of its bank angle during flights in winter time, close to sunset.

I still like to add a few more scale details, like antennae, pitot tubes in front of the cockpit, tank stabilization screws. And better quality cockpit "tubs"plus instruments, plus larger pilots, as the original ones are too small.
Below pictures on my regular airfield, a disused part on a full size runway.
Richard

https://cimg3.ibsrv.net/gimg/www.rcu...8f7df02cf3.jpg
https://cimg4.ibsrv.net/gimg/www.rcu...91146ac94d.jpg

Still buzzing around my MB-339 ;-) not fast but very scale looking in the air.

Wow, that is a scary field, surrounded by trees!!!!

Yes it.is lol..I thought I was a good pilot until I start flying at this f

Landing gear help
 

https://cimg9.ibsrv.net/gimg/www.rcu...9f03c0a07e.jpg
I have now set my MB-339 on its wheels... and I have noticed that it does not sit up on its gear correctly.
its acts like it does NOT have enough air in the gear... I have taken them apart 2 times added oil
put back together and added Air... the gauge tells me I have 120psi but its still not sitting high enough
and its not holding the plane up
so I read the thread earlier as to how to charge the gear but that little tank that I am using...
how much air can it handle before it blows up in my face ? lol
can I add 150 psi ? should I have to add that much ??
in that pic I lifted the plane up its sitting were its suppose to but as soon as I touch it .... it falls some
were its not holding its self up.