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Old Jul 10, 2012, 10:03 PM
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Airspeed would be my guess as well. Unless your plane is set up for aerobatics or has full trailing edge camber control, the amount of elevator trim needed to maintain level flight in relation to airspeed will be more pronounced.
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Old Jul 12, 2012, 09:44 PM
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Joined Jul 2009
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Thrust line location

I'm trying to figure out the neutral horizontal level of the fuse, as I need to establish a horizontal level thrust line for my nose motor installation. Is it a line that passes thru the center of the leading and trailing edge, as is the case with most of my other planes? With them, I just mount the incidence meter on the leading and trailing edges, and level the plane. None of the joiners seem to line up with this location, and the necessary extension arms for the meter are all on back order. So, I need to establish and draw the line on the fuse wing root, so I can make sure the motor is level, or neutral. (I don't want it down, and Rt., as usually done on electrics. So, Where is the level thrust Line?? Just through the center of leading and trailing edge? I've got the servo trays, fillers, etc. all hogged out for the motor install mods --what a job. I'll post pictures of the install soon as I figure how to attach pictures. Thanks, Bob.
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Old Jul 12, 2012, 11:34 PM
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Bob, I've done a bunch of these motor in the nose conversions so I can say with some confidence to put down the rulers, etc. and simply mount the motor in the nose in a position that looks good and allows the props to fold back in a reasonable and appropriate looking manner e.g. straight back towards the tail.

No matter what you do, you'll need to add elevator compensation so just be prepared for it and create the appropriate mix once you've developed a little experience with the K8 on power.

Regards,

Steve
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Old Jul 13, 2012, 12:05 AM
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Quote:
Originally Posted by SteveR View Post
Bob, I've done a bunch of these motor in the nose conversions so I can say with some confidence to put down the rulers, etc. and simply mount the motor in the nose in a position that looks good and allows the props to fold back in a reasonable and appropriate looking manner e.g. straight back towards the tail.

No matter what you do, you'll need to add elevator compensation so just be prepared for it and create the appropriate mix once you've developed a little experience with the K8 on power.

Regards,

Steve
Thanks Steve. Will do. I set the fuse up on the bench so tth stab platform is level, and the front 2 bulkheads are vertical, 90* , so I'll use the 1st bulkhead behind the nose block as the starting point for the succeding "firewalls" and reinformements. It was that wing root rib shape and orientation with all those connecting rod holes that threw me off. I have to machine some aluminum parts for the shaft extension and bearing support next. Got it drawn out, now just have to do it. Thanks again. Bob.
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Old Jul 13, 2012, 07:45 AM
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Bob, there's a Japanese site called Thermal Studio. This is a small, one man company that makes a 5 meter Ka-8c kit and offers an in-nose electric conversion. Here are some photos that may prove helpful.He also offers a 1/3 scale Minimoa powered the same way.

He has some nice videos showing both planes in action. Here's a link to one of them.

Minimoa & Ka-8 1/3 RC scale sail planes (4 min 55 sec)


Please let us know how you progress as I'm planning to convert to self-launch over the winter.

Steve
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Old Jul 14, 2012, 11:40 PM
robdyan Rob
Joined Mar 2007
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The weaving you guys are describing is almost certainly due to being towed at too high an airspeed. Depending on their experience the tow pilots may not realise that they need to adjust their climb angle for the airspeed and/or weight of the glider they are towing. As the glider pilot you should be talking to them during the tow and tell them to slow down their airspeed ie pitch their nose up, during the tow. The most common time for the tow pilot to speed up without realising is when they have completed the first 180 and are flying downwind - don't know quite why it is but I've seen it happen a lot both here in New Zealand and in the US at Visalia. Often when you tell a power pilot to slow down they'll say they'll throttle back but that's not what you're asking for- you need the power to climb and them to use their nose attitude to control the airspeed. Exactly like gliding upwards- nose up to slow down, nose down to speed up.
If you want the tow to look more scale or the glider pilot doesn't want to climb at a really steep angle if the glider is light in weight and/or slow flying you might want the tow pilot to climb with reduced power. The same rule applies to controlling the airspeed.
Our 1/3 Piper Cub with a 3W 120 can quite happily tow a 2 kg 1/6 scale anywhere from about 1/3 to full throttle depending on how the glider pilot wants to climb right through to an 18 kg 1/3 scale at full throttle climbing a bit steeper than scale.
Hope that makes sense and apologies to those who already know but hopefully sharing the info around makes everyones flying more enjoyable.
Rob Johnston
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Old Jul 15, 2012, 07:04 AM
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Excellent post Rob. Right on the money, Just like full scale, pitch controls airspeed, throttle controls decent.

LEN



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www.RcAerotowing.com/forum
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Old Jul 15, 2012, 11:22 AM
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Corner Ketch, DE
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Just started on mine
Picked up spoilers from Alex at Warbirds over De
They are a little to tall
What spoilers are you guys using
Would like to stay away from the electric ones
I didn't see any on Tower
16mm are to tall
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Old Jul 15, 2012, 11:23 AM
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I also thought they had top and bottom slots so I got four
Opps
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Old Jul 15, 2012, 11:58 AM
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No bottom slots and you need to cut out the bottom of the spoiler bay to fit them......next thing you need to because you didn't get the electric ones is you need to cut and fabricate a servo opening on the bottom of the wing for the spoiler servo......that's the main reason why I bought the electric ones.
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Old Jul 15, 2012, 12:46 PM
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Steve,

I am looking into the EMA system from Florian to put on the plane. Probably easier to use. The Japanese motor on the nose launch usually requires a dolly or a short bungee. The prop is too big to get off the ground.

Brian, an EAJ
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Old Jul 15, 2012, 02:14 PM
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Quote:
Originally Posted by SZD16 View Post
No bottom slots and you need to cut out the bottom of the spoiler bay to fit them......next thing you need to because you didn't get the electric ones is you need to cut and fabricate a servo opening on the bottom of the wing for the spoiler servo......that's the main reason why I bought the electric ones.
Tom what about mounting the servo under the door against the rib and using a push rod?
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Old Jul 15, 2012, 03:54 PM
Vintage wood is the best!
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Originally Posted by creeve View Post
Tom what about mounting the servo under the door against the rib and using a push rod?
That should work.
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Old Jul 15, 2012, 04:49 PM
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What kind of spoiler is everybody using?

Brian, an EAJ
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Old Jul 15, 2012, 05:03 PM
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Going with top and bottom
opened up the bottom and cut the ribs
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