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Old Aug 06, 2010, 09:01 AM
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USA, UT, Orem
Joined Jul 2004
9,917 Posts
I trimmed in new Assassins for a newer flyer and his wife last night. They had done great build jobs and the planes fly great. They had some building questions and I thought that I would also address them here. I think that if someone here has problems that some of you out there may be having the same problems.

These are the most common problems I see so it is good to take a look at them again.

The instructions and videos discuss the alignment of the pushrods and horns but are a little difficult to understand. They watched the building videos but still had some questions.

Their servos were tall and they had them mounted with the servo arms high enough above the wing that they couldn't glue the wire guides to the top of the wing.

Some ways to fix this are to put the servos as deep in the wing as possible and install the Z bend end of the push rod underneath the servo arm. To do this you have to take the servo arm off the servo and push the Z bend up though the arm. The EZ connector is then on the horn on the elevon.

We have been experimenting with a new wire guide idea. Try using a 3/4" (1.5" wire bent in half) bent wire and gluing it in a hole you melt with the soldering iron in the wing at the middle of the pushrod. It slides well, looks better and is stronger than the straw guides. A common paper clip makes a good wire guide wire. Just don't get glue on the pushrod that restricts movement of the rod though the guide.

They also had not pointed the horns on the control rods at the servos but had installed them at 90 degrees to the hinge line. This is a common problem. It allows the pushrod to shift back and forth as the servo moves the pushrod and it puts push or pull on the horn. Make sure to aim the horn at the servo.

Their planes had tons of movement on the elevons. We cut the throws in half and still had a lot of throw. I recommended moving the pushrod into a hole closer to the servo to decrease the stress on the servo to decrease the throw on the elevons. This adds mechanical advantage to the servo that just turning down the throw in the transmitter program does not add.

Also remember for starters align the bottom of the elevons with the bottom angle of the wing after you have turned on the radio and zeroed the trims.

For most builders these are the most common problems they have. I hope the videos add some insight into the building process.

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Last edited by Lee; Aug 06, 2010 at 09:24 AM.
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