SkyMaster MB339 Build Thread
 

Guys,

Going to post my build progress on my 339 here (sorry if I am starting over/posted before as I can't find my own posts! [:@] )

I will post in no particular order...

This is my quick disconnect for my air system. As the wing is installed, the airlines are connected....

RE: SkyMaster MB339 Build Thread
 

Here is the elevator servo installation....

I made a mount that glues into the stab, no hatch panel required....

You will see how I had to add stock to the elevator so the horn had something to glue into....

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The rudder servo mount....

The servo is held in place by a plate the screws on top as well as the hatch cover...it is ROCK solid and does not move at all...

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This is my wing servo wire disconnect.... it has yet to be installed...

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Mocked Up....

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Looks great keep the pics comming.

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The wing QD fittings are complete along with some additional reinforcement to keep the fuse side solid (they flexed a little bit when installing the wing) for positive engagement. NO Comments on my sloppy HySol job...I am still learning!

RE: SkyMaster MB339 Build Thread
 

Those air line quick disconnects look suspiciously like BVM "Easy Air" fittings....................Hmmmmmmm

Harley Condra
BVM REP
JetCat REP

RE: SkyMaster MB339 Build Thread
 

Which look suspiciously like a colder products item. hmmmmmmm :D

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I can assure you they are not BVM...They are modified robart, I made the panels myself...

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Well now that the QD's are done its on to the speed brake. Dremel tool in hand and two minutes I have a VERY big hole in the bottom of my fuse. The cutting of the fuse and cleaning up the hole was quick and easy....the brake itself needed much more work. At first I was cussing it as a major POS but as I began to fit it I realized that it was made oversize so it could be fitted perfectly or at least as best as I can get it... tomorrow I will hing it.

RE: SkyMaster MB339 Build Thread
 

Diamondback

Have you checked to see if your tanks will clear the airlines to the disconnects when they are installed? It is a tight fit.

John

RE: SkyMaster MB339 Build Thread
 

Yep, I have and it is all good.... Tight, but good.

RE: SkyMaster MB339 Build Thread
 

Hi, F-18DiamondBack102

Great Job!!

I have a MB-339 in the R & D for install the servos with turbine, Here are soem pictures,

Best regards

Anton

RE: SkyMaster MB339 Build Thread
 

Anton,
What size and torque is your steering servo?


Rich

RE: SkyMaster MB339 Build Thread
 

Hi, Rich

we use the 8511 for steering servo,

Best Regards

Anton

RE: SkyMaster MB339 Build Thread
 

more pictures..........


Best regards

Anton

RE: SkyMaster MB339 Build Thread
 

Hi Guys, I'm scratch building a 339 so I'll be looking to this thread for clues. Mine is all wood & just 2 metres span for an 18 pound turbine.

Is the steering servo attached to the leg & travels up & down with the nosegear?

Also, Anton, how far does the jetpipe finish inside the fuselage? From the pic it looks quite a bit shorter than the fuselage. - John.

RE: SkyMaster MB339 Build Thread
 

Anton,

Thanks for the pictures! Can you please tell me more about the hinges for the speed brake. Are they custom made or are they available to purchase?

Please Advise.

Also, the bell on my exhaust is considerably larger than the one shown in your pictures, could it be that I have the wrong one?

RE: SkyMaster MB339 Build Thread
 

Work continues....

The speed brake was tough to get hinged. I had to fab up part of the hinge from carbon fiber plate...getting the panel to swing in and out was a total PITA! I get cold sweats thinking about hinging gear doors.....

Anyway, you can see how I did mine....hopefully it works well in actual use.

RE: SkyMaster MB339 Build Thread
 

On to the saddle tanks....

First I plumbed the tanks and I installed a vent nipple at the top of the tanks to make fuel line installation cleaner.

Then I made mounts for each side that tie into the engine mount rails....

RE: SkyMaster MB339 Build Thread
 

F-18D like your work, neat bits and done the way I do my builds - used a similar hook up with the air on a MiG15 I did last year, works well (mine were BVM - EzAirs;))

Thrown in a couple of pics - not trying a hyjack!

I have been asked to re-fit a large scratch built MB339, so will keep an eye on your build for ideas, keep up the nice work.

marc

RE: SkyMaster MB339 Build Thread
 

Exellent work guys. Thanks.

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Hi, F-18DiamondBack102

our builder made modify the hinges for the speed brake

your tailpipe is for P-180 , so, the bell with diameter is larger than my picture (for P-160) ,

Best regards

Anton

RE: SkyMaster MB339 Build Thread
 

I building a Fei Bao MB339 and Im going to try and get the turbine as far forward as possible to reduce the 3 ½ to 4lbs of lead in the nose. My friends mb339 crashed after the nose left the plane doing a normal high G pull up and bank. Hear are some pic of the progress so far.

RE: SkyMaster MB339 Build Thread
 

Anton,
I got the same tail pipe with large bellmouth as F-18 Diamondback, ill it atill work with my Jetcat 160 Titan?
Lawrence

RE: SkyMaster MB339 Build Thread
 

Hi, Lawrence

yes,

your tailpipe is for P-120 to P-160, No, problems, we have no make the F-18 tailpipe for P-180,

Best regards

Anton

RE: SkyMaster MB339 Build Thread
 

OK, the build continues...

The work on the landing gear doors continues...Many thanks to the guys who offered help on hinging them.

The main door is where I started. I have never hinged a door before so it was all a learning process. I now have the doors on the left wing about 80% done. I still need to do a final fitting and set up all the gap seals and whatnot. I employed some "that looks about right" engineering when it came to the ram and link installations. See pictures....

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A few more....

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No more progress on this one ???????

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I am working on the other wing, but it is the same stuff...Had minor setback as other in service jets have had mechanical issues. I should be ramping up on this one soon.

One thing I will throw out there is finishing the jet, as in paint. I have contacted a local painter and he is quoting me 1600 USD to paint it. I have done a lot of painting of glass helicopter canopies so I have some experience but I am not sure about a big project like this. I figure that for 1600 bucks I could own the spray equipment, buy all the supplies and do it myself.

Not sure if I should go pro or home brew...anyone have any advice?

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I went for the fully completed 339 therefore....that is if Anton starts to reply emails, my dealer has not heard from him since the Chinese Holidays started.... The paintwork (i have seen the completed one) is truly a work of art, I guess I cannot get even close....

I spray painted many models and I did not succeed in getting everyone 100%. There is always an area You overdid, (especially near sections where the stab or wing meets the fuse) thus getting drips, or when removing tape and it sticks to fresh painted stuff, or the ONLY fly in the garage that decides to rest on the last paintlayer...
There is a long and steep learning curve with painting. It is not that You have to buy all equipment, if it were only that easy.... At least You need also an area that can be used for spraying, that means: heated, lighted, ventilated....plus a friend who has good experience in let's say painting cars!
I made myself a steel "grill" in which I can alternately fit in a fuse or wings to get an optimum angle for spraying, and helpful tools to hold all small parts etc. Preparation for painting takes a whole day for me......

Btw some shops sell those air compressors with a complete "set", including a spray gun. Give that one right away to Your children for water fights in the garden, absolutely rubbish stuff normally! A good professional spray gun will set You back over 500 U$....

I gues You should shop around more and get some more price proposals. Delivering a model well sanded and prepared for painting saves them a lot on hours.

RE: SkyMaster MB339 Build Thread
 

Diamondback

Before I painted my 339 I had only ever used spray cans for smaller projects. For the 339 I decided to paint it myself in a scale cammo scheme. I bought a compressor and gun at my local B & Q (Home depot in the US?) for £85 ($180) and decided to use latex house paint. I had the paint mixed up to the three colours I needed and also got some matt clear water based laquer for the clear coat. The paint cost me £50 in total. I sprayed the model in primer first using large cans of cellulose primer, I scuffed the model surfaces first with a Scotchbrite pad.

I experimented with thinning the paint with water and found that about 25% water with a gun pressure of 50 PSI seemed to work well. I practiced spraying on some scrap sheetrock, the paint has a pronounced "orange peel" look when first applied but dries quickly to a nice level matt finish, small imperfections can be easily and quickly
touched up either using the gun or with a good artist's brush. I then applied the decals before spraying the clear coat. I used 3M door shut masking tape to separate the cammo colours and this was very effective and easy to use.

The paint has proved to be reasonably durable in sevice and in my view has many advantages in that it is cheap, no breathing equipment is required,cleaning up only needs water, you can spray in fairly low damp temperatures. Refer to the thread "Spraying with emulsion paint" for more info.

If you intend to spray 2 pack type paints etc. you may need a better gun as Richard suggests but I certainly don't think you need to spend $500 on one. I was very pleased with the quality of finish my $70 gun produced.

Best regards

John

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John,
I agree with Your suggestions, but there is a LARGE difference whether You want to dress it with a cammo scheme, or a shiney one like the Frecce Tricolori paint scheme. Any imperfection will be seen on these glossy surfaces. And for durability 2 K lacquers are way better as waterbased ones. To get optimum result You need a high quality spraygun. Of course I started long ago with a cheap one, but after upgrading in steps with better equipment, I found that the end result improved every time. The expensive ones make much better fine spray as do cheap ones, thus reducing the risk of droplets (or is the correct wording "sagging"?)

Professional spray guns operate with 2 Bar pressure, which is 30 PSI

An expensive plane like the MB needs a nice dress :) No good to go the easy way out on this one.

RE: SkyMaster MB339 Build Thread
 

Lots of good sugestions...

I have been planning on doing a "Red Bull" version so it would be a very shiny paint job...I like the military idea as well but I have not found a scheme that really grabs my attention....

Not sure what to do at this point....

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Cammo dressing has a big drawback, eg., you tend to loose sight of it sooner than with a bright colour scheme. With sight I mean a good reference of bank and attitude. No big deal, cammo was exactly made to do this!
Plus, in the end, all camouflaged airplanes start kinda looking the same (no offense meant for those who love them...)
Personally I find more satisfaction in making a new model bright and clear with a perfect finish. Plus You can use Your imagination to any extent to make an exclusive scheme.

Keeping a model as long as possible in such a state requires extra care though, for instance in avoiding hangar rash. On a camouflaged surface a few scratches more add even more to "scale".

RE: SkyMaster MB339 Build Thread
 

Richard

I tend to agree with you on the high gloss finish, I have never tried that so I can't comment. The water based paint works fine for cammo schemes though. The 339 is so big it is quite difficult to get disorientated especially if you fit the tip tanks which really help with the visibility.

Best regards

John

RE: SkyMaster MB339 Build Thread
 

The camouflage on my Spiderjets F16 combined with 5 tailfins and only tiprails installed makes it to be monitored carefully in serveral turns of the pattern. Hazy conditions in the higher layers like last weekend with somewhat milky sunlight, I tend to stay close and low.
But nice it was!

RE: SkyMaster MB339 Build Thread
 

As this thread has been silent for a while, I am picking up the story, as I have received my MB (ready painted in Frecce Tricolori colours) some time ago and now busy working on it.

A few things:
The idea stolen from my friend Leo (who also builds one) I made a temporary stand to accomodate all the gear components and test it. Good idea, as I found out that some Skymaster door cylinders were leaking. (new ones will be sent, good service).
The gear itself proved flawless, not only it looks sturdy and made to a high standard, but it works just perfect. Almost comic to see that gear flap upright on the bench!
The same time I could delve in the software of the Weatronic and adjust it to suit, make the Jettronics (from Sandor) work as they should.


The nosegear main door proved a headache to get it hinged right. First started with the offset hinges, but that did not work due to the double curvature of the door.
Then I looked again at the 1/1 MB pics, and noticed very faintly it has outward hinges.
So I copied that using normal Robart flat hinges.
First I glued some aluminium brackets to the door. Take care to align the vertical panes to be in line.
I removed the hinge pins and replaced it with a long 1mm wire that runs through both of them, to get both hinges working in the same hinge line, very important.
Then I tack glued one side to the alu brackets, taking care the piano wire touches the door just in the middle, any further out mounting of the hinges is not necessary.

Removed some material from the fuse side and made plywood blocks to receive the other side of the hinge. Here too, careful alignment is important
Then tack glued the othe side to the blocks.

The end result is, the door fits like a glove and is easily rotated to more than 180 degrees! You cannot get even close with offset hinges...

Now I need to touch op some parts, and tip paint the hinges, install a bracket to attach the actuator rod. I might cut back the alu brackets a bit if they stick too far inside, hampering the gear.

The long wire will be replaced with shorter hinge pins, but will definitely make them removable to be able to remove the door.

RE: SkyMaster MB339 Build Thread
 

Great post Richard....

Progress on mine has stopped as a King Cat jumped in line...I am working hard to get it finished and then I will be back on to the 339. I like your suggestions on the nose gear door hinges, I will carefully consider what you have done and may use that method as well.

Keep the pictures coming....