mistermnkim

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I started fitting the gear to mine tonight! My F-4 is the original prototype from Xtreme.

mistermnkim

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Guys looks like Im gonna have a little give and take with the toe on the main gear, I have been playing with the sweet spot but having trouble with making the gear seat deep enough for the doors to close! I will win the fight!!

mistermnkim

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Forgot to ask, is it ok to post on this thread? please let me know!!

joeflyer

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Based on the picture you posted the mains on the wrong sides. The tire should be facing inboard (or up when retracted) and the sissors link to the rear. Switch them left to right.

Joe

mistermnkim

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Yes your right , I switched them last night!! I knew something didn't look right!

mistermnkim

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Here are a few more pics as I go, gonna reinforce the area with carbon fiber after everything is fitted.

joeflyer

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To anwer your other question: If you intend to do much posting as your build continues you might want to start another thread. My F-4 arrived a few days ago and I'm sure I'll have a few questions once I get going.

Joe

mistermnkim

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Yes Joe I think I will, hope to see your there!! Mark

joeflyer

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I'm still putting my F-4 together. Should the elevator throw be measured at the inboard or outboard side of the stab? I'm setting up my control linkage and it makes quite a difference whether I measure the elevator throw at the fuse or at the outer edge of the stab.

I'd like to hear from someone that has flown and Xtreme F-4 or even the large Skymaster one. Do I need 50 mm. of throw and where do I measure it?

Thanks,
Joe

MaJ. Woody

My Feedback: (28)

I always measure mine at the front of the stab. I use a piece of masking tape on the fuse with the neutral point and max deflection marked on the tape. I then tape a t-pin with the pointy part lined up with neutral. It is easy to measure the throw that way.
Dom

joeflyer

My Feedback: (48)

That sounds like a good way to do it.

At this point I'm trying to figure out how much throw I really need. The Skymaster specs. call out +/- 50 mm., but it's not clear exactly where that is measured. Also i can't image needing 50 mm. of down.

MaJ. Woody

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50mm is what I put in mine. My Feibao F-4 and Skymaster F-18, Extreme Hawk all took between 40-50mm of travel.

joeflyer

My Feedback: (48)

Thanks. Exactly where did you measure the 50 mm., leading edge, trailing edge, inboard or outboard?

MaJ. Woody

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Inboard right next to the fuse.

joeflyer

My Feedback: (48)

I finally finished my F-4 and did the maiden flight at Michigan Jets on Sunday, 8/12. I haven't installed the cockpit yet but was suprised that I hadto add 1#, 5oz. of lead to the nose to balance it. Dry weight is 25#, which is heavier than expected. I'm glad thatI went with a Merlin 140sincetake off weight isabout30.5#.

The flight went well except for a collapsed nose gear on landing. CGwas at 245 mm. and control throws at the recommended settings. It needed quite a bit of up elevator tofly level. Once trimmed out it was very stable, flewwell and is quite fast.

The pictures below show the assumed elevator neutral and after trimming (last picture). Since the CG seemed about right I thought that perhaps there was too much downthrust in the pipe.I was able to lower the engine anout 3/16", which reduced the pipe angle by 1-2 degrees. There is still enough down thrust to keep the exhaust away from the stab and tail. I also moved the CG to 250 mm. I'll see what that does on my next flight.

Joe

rhklenke

My Feedback: (24)

Joe,

I was just about to post on this thread because I started the assembly of mine. Thanks for the flight report, PLEASE keep them coming! I'm glad it flew well. I'm going to look into dropping the engine on mine as well.

Did you have to do all of the fiddling around with the gear to get it to retract correctly like Dom did? On mine, the gear came installed on the correct side and I adjusted the tracking to be parallel with the inboard edge of the wing and the gear still retracted into the wing with no problem?

Also, did you use the stock main tank or the 32 oz. DuBro tank like Dom did?

Thanks!
Bob

joeflyer

My Feedback: (48)

Hello Bob,

My gear came installed correctly and no fiddling was required. You should route your airlines and servo leads away from the wheel wells and have them enter the fuse between the two turbine formes, like Dom did. Additionally I didn't like the idea of having to connect 5 airlines for each wing so I used button valves to shut the gear doors. That really cleaned up the plumbing and works fine.. I posted a few pictures at http://www.rcuniverse.com/forum/m_11...m.htm#11129818

I centered the fuel bungs on the saddle tanks just like Dom. The issue he was concerned about with the front tank can only occur if you fly inverted after the saddle tanks are empty and the front tank is about 3/4 full. Since I'm not planning on doing any inverted flight when I'm that low on fuel I used the stock tank. I did move the fuel bung so it is about 1/3 the way up from the bottom. That way I'll be able to use just about all of the fuel in that tank, as long as I'm not inverted.

I initially made some adaptor plates out of 5 mm. plywood to mount the engine. This centered the engine on the air inlet. After my first flight I made new ones out of aluminum plate and lowered the pipe inlet to re-center it on the exhaust cone. The picture above shows the aluminum.

I was going to take more pictures of my build but got rushed to complete it before Michigan Jets. I'll be glad to help if you have any more questions.

Joe

MaJ. Woody

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Congratulations on the first flights Joe!!

joeflyer

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Thanks.I need a few more flights off ofa long runway to getuse to the landing characteristics. My home field has a 380 ft. runway, so I think I'll have to be right on the money to land there.

Joe

rhklenke

My Feedback: (24)

Joe,

Thanks again for the info. I am trying to route my servo lines and airlines like you and Dom did. However, there doesn't appear to be a hole in the wing rib that is on the outside, forward of the landing gear mounts. Thus, when I get the servo lines into the space forward of the box, that is outside the landing gear mounts, I can't figure out how to get it from there to the exit in the wing root where you guys had it.

Dom said that there were holes in all of the ribs necessary to route through there. Were there holes in your's or did you have to drill them somehow? The area around the gear mounts looks different on mine then on Dom's...

Bob

joeflyer

My Feedback: (48)

Bob,

The only holes I had to drill were in the servo boxes. The wires exit the box forward between the two servos. They areroutedby the retract cylinders, just forward of the front retract mountthen towards the root. Clearances were tight and it was a real pain. It's best toroute them with the retracts removed.

Joe

rhklenke

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Thanks Joe. I think I found the path through there with a wire this morning, but I had to go to work [:'(] before I could see if I could get anything through there...

Bob

joeflyer

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Here's my maiden flight. It's my first attempt at posting a video.For some reason Widows Movie Makerwouldn't load the entire flight, but got most of it.

http://www.youtube.com/watch?v=ua2kw...ature=youtu.be

Joe

Ram-bro

My Feedback: (101)

bump

rhklenke

My Feedback: (24)

Bump for what? Heading out to the shop to work on mine for the spring. Do you have one?

Bob