hogflyer
Posts: 1450
Joined: 3/23/2005 From: Wichita,
KS, USA Status: offline
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I just recently an F-22 PTS NIB for not much more than a trainer box could be had. I needed the transmitter for buddy box (tired of constantly resetting the servo direction and trims between 3 different students) and the engine as a spare for the club trainer, which leaves me an airframe to play with. From experience I know the plane would have poor performance with a .45 trying to fly 7-1/2 pounds on such a low aspect ratio wing (no training aides on this plane!), so some changes are in order. I’m changing the receiver out and will use a Futaba 7C, so the flaps will function on a rotary knob, not a switch. I’m still indecisive about the engine. I have an old K&B .61 (late 70’s vintage with Perry carb) that has a few bench runs on it that I could use, and it doesn’t look much larger than the Evolution that is currently on it. But since this is an older engine, it won’t have the power of the new .61’s, so I’m also considering either an OS .55 AX or OS .61 FX. I’m guessing the K&B and OS .55 will have about the same power, but the K&B may have the edge on torque. I’m probably going to change the landing gear out. Use a Dubro unit for the front and bend new rears to have them angled back. I hope to get a 1” to 1-1/2” more ground clearance to swing a 12” prop, and fair in the intakes similar to the ones in the picture posted by MinnFlyer. Here’s a few questions for you guys who have moded yours. Has anybody installed a larger fuel tank? It doesn’t look like there is a lot of area in there to install a larger tank beyond the 11 ounce tank H9 installed, so I may be stuck with limited flights. Does the OS .55 fit the stock engine mount, or require a new one like the K&B or .61FX will? How much vertical will the OS .55 allow? I’m still unsure of which way to go with the engine (.61 FX is only $10.00 more than a .55 AX, has more power but weighs more, but I have the K&B .61). It would nice to be able to use the stock mount if possible too. Since have a couple of planes on the table right now to finish, it’ll be a few weeks before I have this one ready to fly – just want to get everything lined up for an easier assembly. Hogflyer
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Flight Training Coordinator - Wichita Radio Control Club - AMA Intro Pilot www.wichitaradiocontrolclub.org AMA 47317
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