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Retracts in a scratch built A-10

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Retracts in a scratch built A-10

Old 10-15-2004, 09:44 PM
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sina
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Default Retracts in a scratch built A-10

I just got started building an A-10 from the Keith Spark plans. It is difficult to follow as he assumes that you already know everything! I strongly recommend Mike Pastorel's plans from RCM.

Anyway, I am wondering if anyone out there has built one from Keith's plan and if they have been able to successfully add retracts to it?

Any help is appreciated.

Thanks,

Sina

P.S. i have since ordered a set of robart pneumatic retracts. I have been pouring over the plans trying to figure a way to have the retracts installed forward of CG as this is a tail heavy design. the mains will have to fold forward into wheel nacelles at mid wing. CG is at mid-spar. I have no choice but to install the retracts behind the main spar as otherwise my wheels will be to far forward when deployed.

so the question to the retracts experts is the following:

How far aft of the CG do the main wheels have to be? Can they be forward of CG? I have been studying my ARFs and Kits and all appear to have the mains aft of CG. Also, what will happen when the wheels are retracted - will the shift in weight cause any instability after I pull them in?

As you can tell this is my first time adding retracts to a scratch built and i have a lot to figure out. Again, any help is appreciated.

I'll post pictures of my main wing section if you think that would help.
Old 10-19-2004, 01:47 PM
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Johng
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Default RE: Retracts in a scratch built A-10

Hummm, if you put the retracts ahead of the CG, it will tip back on it's tail. Almost by definition, the main LG need to be behind the CG.

The placement of the retracts behind the cg will have minimal effect on balance, becasue they are a minimal distance from the CG.

B
The weight shift will be forward, so the plane will get more stable with the gear retracted. Balance it with teh gear down.

Place the gear in a more-or-less scale location and it will all work out. Have a look at the 3-view.
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Old 10-20-2004, 06:40 PM
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sina
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Default RE: Retracts in a scratch built A-10

Well just got the retracts in the mail. The main gears (605HD) are 3/16" they look too big for this plane! The nose gear (607) came with a smaller 5/32". That is all tower had for sale on retracts.

I expect my finished weight to be around 7 lbs at the most. Are these oversize? Should I return them or keep and change the struts to 5/32" ?

Any help is appreciated.
Old 10-21-2004, 10:35 PM
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Default RE: Retracts in a scratch built A-10

That's exactly what Robart recomoends for that size plane. I'd use 'em.

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