Skymaster F5 questions
10-20-2014, 04:20 PM
#51
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Jeffpro,
I was the owner of the F-5 that broke in half at Kentucky Jets a few years ago. Thanks to Mike at Global Jets, I was able to get a new airframe. This new airframe from Fei Bao has two spar braces, one for the front wing spar and one for the rear wing spar. Only two flights on it so far, and I really like the way it flies. Now if only someone would produce a larger one that's affordable.
I was the owner of the F-5 that broke in half at Kentucky Jets a few years ago. Thanks to Mike at Global Jets, I was able to get a new airframe. This new airframe from Fei Bao has two spar braces, one for the front wing spar and one for the rear wing spar. Only two flights on it so far, and I really like the way it flies. Now if only someone would produce a larger one that's affordable.
10-20-2014, 05:19 PM
#52
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Now I wonder if I need a second wing spar. :-)
What do you do about the rotation problem? It's the single biggest weakness of this jet IMHO.
Somebody flew a *huge* F-5 at Super Jet South a few weeks ago. I wasn't there, so I don't know whose airframe it was, but the guys at Georgia Jets were still talking about it last week.
What do you do about the rotation problem? It's the single biggest weakness of this jet IMHO.
Somebody flew a *huge* F-5 at Super Jet South a few weeks ago. I wasn't there, so I don't know whose airframe it was, but the guys at Georgia Jets were still talking about it last week.
10-20-2014, 06:28 PM
#53
How many fuel tanks does the skymaster F5 have? I have 2 tanks that fit between the inlets (one on top of the other) and there is a funny shaped 3rd tank that I got with mine that I cannot figure out where it would fit at all. It is about 10" wide, 5" tall, 5" deep, with the 2 rear corners having about a 2.5" radius and the opening for the clunk is dead center on the largest flat face (10"Wx5" tall) which is a horrible place as a clunk line could never possibly actually reach any of the corners.
10-21-2014, 11:09 AM
#56
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Now I wonder if I need a second wing spar. :-)
What do you do about the rotation problem? It's the single biggest weakness of this jet IMHO.
Somebody flew a *huge* F-5 at Super Jet South a few weeks ago. I wasn't there, so I don't know whose airframe it was, but the guys at Georgia Jets were still talking about it last week.
What do you do about the rotation problem? It's the single biggest weakness of this jet IMHO.
Somebody flew a *huge* F-5 at Super Jet South a few weeks ago. I wasn't there, so I don't know whose airframe it was, but the guys at Georgia Jets were still talking about it last week.
10-23-2014, 07:53 AM
#59
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Question: would you mind letting me know how high the bottom of the nose sits off the ground with your nose gear deployed? Skymaster has changed the nose gear for this jet at least once, and I suspect the one I have is slightly shorter than the one most others have. If I can use spacers to get my nose the same distance off the ground as yours, I'll do it.
10-23-2014, 04:15 PM
#60
So I spent a few minutes today looking at how to get the tailpipe into the jet and after some frustrating grinding and cutting of the inlets I was finally able to get it most of the way in however......... The fin mounts are hitting the pipe and not allowing me to get it centered. The bolts are hitting the outer layer of the pipe hard enough to deform it and the rear fin bolt is getting caught on the pipe so I can't push it back far enough. Now I should clarify that this is a Tam's pipe but should be the same dimension. My thought is that I'm going to have to find a counter sink head bolt for the fin mounts and do away with the standard bolts and the giant thick washer that's on there. Has anyone else gone the route of a countersunk bolt in there? I didn't build the airplane but the hardwood blocks that are in this airplane seem ridiculously big considering the fin only goes into them about 3/4". Were the mounts something the builder had to put in or were they done by skymaster? I would assume they were done by skymaster with some sort of jig.
10-24-2014, 07:04 AM
#61
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I had to grind away part of the lip on the fuselage to get the tailpipe in, too. It fit (it's the stock Skymaster pipe), but there is some interference between the bolt that holds the vertical stabilizer on and the tailpipe. (I had to build a mounting bracket to bolt the fin on, but apparently some models come with that bracket already installed.) Anyway, the bolt presses down slightly on the tailpipe, but only on the "skirt" that surrounds the area where the tailpipe splits, not on the pipes themselves.
10-24-2014, 09:07 AM
#62
Hi Jeffpro,
That's where it's hitting is on the outer layer (skirt) of the pipe. I just don't like the idea of that bolt rubbing any part of the pipe.... I'm thinking a countersink head bolt might be a better solution. The pipe is slightly narrow at the back end as well for the outlets, I'll just need to grind some of the plywood away in the tail cone I guess though I hate when things are not centered but there's not really a chance of widening the pipe I guess.
That's where it's hitting is on the outer layer (skirt) of the pipe. I just don't like the idea of that bolt rubbing any part of the pipe.... I'm thinking a countersink head bolt might be a better solution. The pipe is slightly narrow at the back end as well for the outlets, I'll just need to grind some of the plywood away in the tail cone I guess though I hate when things are not centered but there's not really a chance of widening the pipe I guess.
10-29-2014, 08:12 PM
#63
So I finally got my pipe in but what an ordeal that was...... Turns out the problem was not the fin mounts (though that's what was causing it to catch) but the stab spar box was pushing up on the pipe to much jamming it into the fin mounts. I finally got it slid all the way back, but the pipe was smashed hard against the top of the tail cones and there was no way I could get the bellmouth to line up on center, it was simply to high. I ended up grinding about 3/8" away from the top of the stab box on both the front and back spar and now the pipe fits in perfectly without crushing against anything. To put strength back to the stab spar in the fuse I will glue another piece of 1/8" ply up against it with some carbon cloth in between the two layers. That will make it stronger than the original single ply layer was before grinding it down anyway.
01-04-2015, 10:13 PM
#64
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I have just aquired one of these kits too...im trying to get hold of the manual if anyone has a pdf copy they can share it would be highly appreciated...
Also any clues on how the airbrakes are oprated? servos or air rams? a flying buddy has the f20 from JL and operates those by servos...insallation photos would also be appreciated ;-)
Also any clues on how the airbrakes are oprated? servos or air rams? a flying buddy has the f20 from JL and operates those by servos...insallation photos would also be appreciated ;-)
10-09-2015, 09:51 AM
#65
I know this post is a little old but I have my F5 basically ready and thought I'd just check to make sure I'm not missing anything.
Stock F5 set up with the following:
Tams pipe
I have strengthened the stab spar box as recommended.
I have added a 1/4" ply laminated with fiberglass both sides cross brace to the rear wing former (I wanted to do the front one as well but there is no way I can put one in that would be removable as the back side of the front former has huge blocks glued to it to hold the gear door rams and the front side is simply to tight with the inlet ducting where it is.)
I have added NACA ducts to the rear bottom hatch to help with cooling as I was overheating on the first run.
CG is set at 110mm. Throws are as per skymaster.
Nose gear i THINK is a longer strut, it looks like it was spaced down 1/4" with a wheel collar to change the angle of attack. When the jet sits on the gear and the reat struts compress it has a just slightly nose high attitude.
I think that's all, AMT Pegasus SP for power. I think I need to reinforce the main gear doors though, they flex quite a bit, has there been any issues with them opening in flight due to flexing?
Stock F5 set up with the following:
Tams pipe
I have strengthened the stab spar box as recommended.
I have added a 1/4" ply laminated with fiberglass both sides cross brace to the rear wing former (I wanted to do the front one as well but there is no way I can put one in that would be removable as the back side of the front former has huge blocks glued to it to hold the gear door rams and the front side is simply to tight with the inlet ducting where it is.)
I have added NACA ducts to the rear bottom hatch to help with cooling as I was overheating on the first run.
CG is set at 110mm. Throws are as per skymaster.
Nose gear i THINK is a longer strut, it looks like it was spaced down 1/4" with a wheel collar to change the angle of attack. When the jet sits on the gear and the reat struts compress it has a just slightly nose high attitude.
I think that's all, AMT Pegasus SP for power. I think I need to reinforce the main gear doors though, they flex quite a bit, has there been any issues with them opening in flight due to flexing?
10-09-2015, 12:28 PM
#66
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You can add two small ribs on each door to stiffen them up front and back I also machined a new longer nose gear pin to help with the nose hight stance mine rotated nice and smooth
Good luck
Ted
Good luck
Ted
10-10-2015, 08:25 PM
#68
Here is the wing former brace. It bolts to the former under the fuse top. I'll post more pics. Can only do one at a time on my phone for some reason
Originally Posted by ww2
birds;12111100
birds;12111100
LGM (Jeremy?) .. do you have pictures of your mods to the stab box and rear wing former?
thanks!
Dave
thanks!
Dave
10-11-2015, 03:59 PM
#72
Hmmmm, it appears my picture of the stab box modification isn't showing up?
I should also mention that on my wing joiner, there was no way for me to drill a hole through the existing former so the 1/4" ply brace bolts to a 1/4" ply ear that is glued to the existing former, I drilled and counter bored the gluing surface of the ply ear to hold the blind nut, then that is all glued to the existing former.
I should also mention that on my wing joiner, there was no way for me to drill a hole through the existing former so the 1/4" ply brace bolts to a 1/4" ply ear that is glued to the existing former, I drilled and counter bored the gluing surface of the ply ear to hold the blind nut, then that is all glued to the existing former.
10-29-2016, 02:20 PM
#73
Member
I have ordered this model and it is on the way to home, i noticed everyone is installing minimum 160 size engine, i have only p120se available.. does it enough or i have to get bigger engine?
