SkyMaster MB339 Build Thread
05-31-2012, 08:56 AM
#301
RE: SkyMaster MB339 Build Thread
ORIGINAL: wojtek
The wing fences do come with the kit. They usually come wrapped up in foil. 2 big ones, and 4 of the smaller ones. They should match your paint scheme pattern where they are to be mounted. You will need to glue these on yourself. It can be a pain, so you will need to tape the area off, and make a nice filet with the glue ..
~V~
The wing fences do come with the kit. They usually come wrapped up in foil. 2 big ones, and 4 of the smaller ones. They should match your paint scheme pattern where they are to be mounted. You will need to glue these on yourself. It can be a pain, so you will need to tape the area off, and make a nice filet with the glue ..
~V~
I will check the packaging material again, it can be stuck there...
Yes, i found them! Thanks again.
Best regards,
Robert
06-01-2012, 12:11 AM
#302
RE: SkyMaster MB339 Build Thread
Just acquired one of these second hand. Anyone had problems with oil leaking from the struts? Is there a known issue? I need to do some testing over the weekend to find out specifically where its coming from. I'm guessing regular hydraulic fluid is a good replacement.
06-30-2012, 11:04 AM
#305
RE: SkyMaster MB339 Build Thread
Bruno, gorgeous! How did you do to get the pilot clothing and helmet detailing so nice?? Which scale is the pilot (1:4 or 1:5)? How long is the pilot in cm?
07-01-2012, 06:21 AM
#307
RE: SkyMaster MB339 Build Thread
Looking forward to flying my newly acquired MB339 next weekend. Had to have it after seeing the scheme. I like the traditional Tricolore scheme but I think this scheme is awesome. Programmed my new DX18 for it this morning and did retract, brake and engine testing. Love the sound of the P160SX. Surprisingly quiet.
07-30-2012, 01:48 AM
#308
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RE: SkyMaster MB339 Build Thread
got me a secod hand MB, refiited everything internaly with Kingtech 16 etc and test flew it on saturday.
WOW, what a gracious a/c, sits well and very neat. had to add more weight upfront for second flight, which was better.
Battled to slow her down thouigh for landing, not enough Flap throw , 25mm, so i need to go up to say 40mm deflection.
Can you guys please give me some pointers on slowing her down for landing. i did a clean stall configuration test, and she can be slowed down a lot without dropping a wing, so im wodering if im coming in too fast to start off with.
WOW, what a gracious a/c, sits well and very neat. had to add more weight upfront for second flight, which was better.
Battled to slow her down thouigh for landing, not enough Flap throw , 25mm, so i need to go up to say 40mm deflection.
Can you guys please give me some pointers on slowing her down for landing. i did a clean stall configuration test, and she can be slowed down a lot without dropping a wing, so im wodering if im coming in too fast to start off with.
07-30-2012, 02:23 AM
#309
RE: SkyMaster MB339 Build Thread
25mm flap is indeed a more lift producing as a drag increasing setting.
Combine the enlarged flapsetting with a few mm UP ailerons (crow brake). Don't overdo the aileron UP value as it greatly diminishes roll control. Find by testflying the elevator correction for this setting so You don't need to correct on final Yrself.
Activate the belly speedbrake, not too much of a work, the extra speedbrake panel is normally a part of the kit, maybe the previous owner still has it lying around. Or it might be ordered with Skymaster.
Indeed, testfly slower approach speeds, a system like the Eagle Tree which gives airspeed values can be of great help learning to fly slower. GPS speeds can only be used at wind-less days, as GPS gives groundspeed that varies with windspeed. As soon as You have been accustomed to the angle of the fuselage on final that gives a safe final speed, You can forget about telemetry.
Good Luck,
Combine the enlarged flapsetting with a few mm UP ailerons (crow brake). Don't overdo the aileron UP value as it greatly diminishes roll control. Find by testflying the elevator correction for this setting so You don't need to correct on final Yrself.
Activate the belly speedbrake, not too much of a work, the extra speedbrake panel is normally a part of the kit, maybe the previous owner still has it lying around. Or it might be ordered with Skymaster.
Indeed, testfly slower approach speeds, a system like the Eagle Tree which gives airspeed values can be of great help learning to fly slower. GPS speeds can only be used at wind-less days, as GPS gives groundspeed that varies with windspeed. As soon as You have been accustomed to the angle of the fuselage on final that gives a safe final speed, You can forget about telemetry.
Good Luck,
07-30-2012, 03:15 AM
#310
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RE: SkyMaster MB339 Build Thread
hi Richard, thanks for quick reply, much appreciated.
It makes perfect sense, that 25mm flap, would be more lift enhancing than drag , so hopefully more flap, will slow her down.
the belly speed brake is there and actually connected, BUT did not apply as dont know what to expect from that deploy, Up pitch or DOWNpitch, what did you experience?
I still think that this SM model can sloooowww down much more, as wing profile works for design.
Can you also tell me, what was your length of Oleo damping, only with the oil in oleos, somewhere i read, 10mm ?
How is your model flying
It makes perfect sense, that 25mm flap, would be more lift enhancing than drag , so hopefully more flap, will slow her down.
the belly speed brake is there and actually connected, BUT did not apply as dont know what to expect from that deploy, Up pitch or DOWNpitch, what did you experience?
I still think that this SM model can sloooowww down much more, as wing profile works for design.
Can you also tell me, what was your length of Oleo damping, only with the oil in oleos, somewhere i read, 10mm ?
How is your model flying
07-30-2012, 03:36 AM
#311
RE: SkyMaster MB339 Build Thread
Take a look at http://www.skymasterjet.com/arf339.htm for more information on this model.
You can go up to 40 mm with your flaps.
The typical static ride height for main gear is about 16mm from filling valve center to seal and 14 mm for nose gear from M3 bolt center of fork to seal.
I have my belly speed brake working and it does helps to slow down the plane, but as you have mentioned before, the key is to not approach at a high speed to start with. In mine, typically when I'm turning to base, my turbine is already in idle. This jet keeps so much energy that I find that most time I don't need my turbine keeping power during the approach.
Try you speed brake while flying high and with flaps to see what kind of reaction you get in your plane.
You can go up to 40 mm with your flaps.
The typical static ride height for main gear is about 16mm from filling valve center to seal and 14 mm for nose gear from M3 bolt center of fork to seal.
I have my belly speed brake working and it does helps to slow down the plane, but as you have mentioned before, the key is to not approach at a high speed to start with. In mine, typically when I'm turning to base, my turbine is already in idle. This jet keeps so much energy that I find that most time I don't need my turbine keeping power during the approach.
Try you speed brake while flying high and with flaps to see what kind of reaction you get in your plane.
07-30-2012, 03:49 AM
#312
RE: SkyMaster MB339 Build Thread
Currently I am not at home (holidays) and I cannot recall what the pitch Up or Down I felt when giving speedbrake. If there was any, it was little pitch effect. As always, try these first at altitude.
Due to several circumstances I did not fly the MB a lot, neither recently (over a Year now).
I am planning to redo the innards of the MB first this winter before reflying it. Not that there are problems, but when I built my last jet (Pirotti Tuono) it was the first time I really spent enough time getting all electrics and pneumatics NEATLY inside. Now looking at my MB I feel more ore less embarrassed when looking inside.
I have a building report on my Tuono http://www.flytobiggs.com/index.php?...gen&Itemid=137
Sorry, only in Dutch, but lots of piccies.
Now with a lot more experience with all systems I have a better idea of how and where installing components, plus I might opt again for mechanical air valves, in hindsight (and my new Tuono has them also) I prefer the mechanical valves like the ones from UP over the electric ones.
I see, I have the mains on 14mm with oil, then 10 bar. The nose is difficult, my settings were too high, one friend of mine uses lower pressures, as the MB needs to sit nose low.
Of course You are familiar with higher true air speeds due to the elevation at Jo'burg....
Due to several circumstances I did not fly the MB a lot, neither recently (over a Year now).
I am planning to redo the innards of the MB first this winter before reflying it. Not that there are problems, but when I built my last jet (Pirotti Tuono) it was the first time I really spent enough time getting all electrics and pneumatics NEATLY inside. Now looking at my MB I feel more ore less embarrassed when looking inside.
I have a building report on my Tuono http://www.flytobiggs.com/index.php?...gen&Itemid=137
Sorry, only in Dutch, but lots of piccies.
Now with a lot more experience with all systems I have a better idea of how and where installing components, plus I might opt again for mechanical air valves, in hindsight (and my new Tuono has them also) I prefer the mechanical valves like the ones from UP over the electric ones.
I see, I have the mains on 14mm with oil, then 10 bar. The nose is difficult, my settings were too high, one friend of mine uses lower pressures, as the MB needs to sit nose low.
Of course You are familiar with higher true air speeds due to the elevation at Jo'burg....
07-30-2012, 11:15 AM
#313
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RE: SkyMaster MB339 Build Thread
Be careful when using lots of flap throw, if you get to a point where the flap leading edge wiper disengages from the trailing edge of the wing it could get bound up and stall the movement of the flap...ask me how I know...
07-30-2012, 11:59 AM
#314
RE: SkyMaster MB339 Build Thread
ORIGINAL: InboundLZ
Be careful when using lots of flap throw, if you get to a point where the flap leading edge wiper disengages from the trailing edge of the wing it could get bound up and stall the movement of the flap...ask me how I know...
Be careful when using lots of flap throw, if you get to a point where the flap leading edge wiper disengages from the trailing edge of the wing it could get bound up and stall the movement of the flap...ask me how I know...
Very good point..... one thing is what the manual says and other thing is what mechanically you can do. I always try to set up to factory expects but then I check that everything works with no problems.
07-30-2012, 12:08 PM
#315
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RE: SkyMaster MB339 Build Thread
I have sold my 339 (HUGE MISTAKE) but I know the guy who has it now, he cut the flaps loose and re-hinged them in a more traditional way. Now, there is no way they can get hung up. He was flying her at Speed World last year and I was totally amazed on how slow he could get her on approach. Flaps and Crow and it work like a charm!
Did I mention how much I miss mine????[&o][&o][&o]
Did I mention how much I miss mine????[&o][&o][&o]
07-30-2012, 10:42 PM
#316
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RE: SkyMaster MB339 Build Thread
hey Dave, i have only had 2 flights , and i can see how you could miss the MB, it really looks and feels solid. i even had a flameout on 2nd flight (air in lines/old hopper), and dead stick on runway was no issue.
last nite, i managed to slice away Trailing edge of wing, and now flaps have a clean 40mm throw, thks for advice, checked that flap wont get stuck too.
my MB, is the one on Anton's site,, the model that our SAteam member "Morne" flew at Worlds 2007............now its mine
last nite, i managed to slice away Trailing edge of wing, and now flaps have a clean 40mm throw, thks for advice, checked that flap wont get stuck too.
my MB, is the one on Anton's site,, the model that our SAteam member "Morne" flew at Worlds 2007............now its mine
12-01-2012, 02:53 AM
#322
RE: SkyMaster MB339 Build Thread
Hello guys,
I have the Skymaster MB339 2.4m kit. The servo rods. the servo arm and the aileron and flap horns are supposed to be in line with each other, and in line with the aircraft longitudinal line. This is the case with the flaps servo boxes with covers/hatches, but the aileron boxes are really out of line/skewed (same problem on both wings). The wing trailing edge and hinge lines are exactly square to the aircraft longitudinal line. I have seen these skewed aileron servo boxes on several other Skymaster kits, e.g. Hawk. It looks like this offset design has a purpose, but I have no clue which (and it looks ugly).
Has anybody an explanation?
Best regards,
Robert
I have the Skymaster MB339 2.4m kit. The servo rods. the servo arm and the aileron and flap horns are supposed to be in line with each other, and in line with the aircraft longitudinal line. This is the case with the flaps servo boxes with covers/hatches, but the aileron boxes are really out of line/skewed (same problem on both wings). The wing trailing edge and hinge lines are exactly square to the aircraft longitudinal line. I have seen these skewed aileron servo boxes on several other Skymaster kits, e.g. Hawk. It looks like this offset design has a purpose, but I have no clue which (and it looks ugly).
Has anybody an explanation?
Best regards,
Robert
]
12-03-2012, 05:36 PM
#324
RE: SkyMaster MB339 Build Thread
Robert, there is usually enough material on the SkyMaster servo mounts to grind away some of the mounting tab and get the servo in there square. Square up the servo and get the linkages 90* like they should be. Dont know why SMaster does this.
12-03-2012, 08:44 PM
#325
RE: SkyMaster MB339 Build Thread
Robert,
this is a design flaw .... they lined the servo pockets up with the LE, and not the TE ... If you have pre-drilled pylon mount holes, check those too if they are lined up with wing root, or LE .
I was able to mount my servos up at an angle and trimmed the servo pocket covers to match ...
~V~
this is a design flaw .... they lined the servo pockets up with the LE, and not the TE ... If you have pre-drilled pylon mount holes, check those too if they are lined up with wing root, or LE .
I was able to mount my servos up at an angle and trimmed the servo pocket covers to match ...
~V~