Assembling the Sceadu Evo 50 head
| Author: | Rob Turnbull |
|---|---|
| Article Date: | 30th April 2007 |
Fitting the headblock is simply a reversal of the removal process.
The main shaft has three holes in it. At one end, there is a single hole, while at the other end there are two holes 90° apart, and one above the other. The end of the shaft with the single hole should be inserted into the head block. This choice is made easier by that end of the shaft having a ribbed section, which grips the radius block when fitted. You can fit the radius block before or after fitting the main shaft into the head block, if you fitted it before don't over tighten it as you will need to move this later when setting up.
Insert the main shaft into the head block, trying to keep the bolt hole aligned with the holes in the head block. With the holes lined up pop the bolt through and tighten the nyloc nut onto the back - do not use threadlock with a nyloc nut. If you do not use a nyloc nut, make sure you use thread lock.
Head block fitted to the main shaft
Two holes at the opposite end of the shaft
If you have not already fitted the radius block, do so now by sliding it up the main shaft and roughly into position on the ribbed area just below the head block. There is no need to tighten our accurately position the radius block at this stage, as this will be done later in setup. As a worthwhile side note, rotor phasing is adjusted on the Sceadu by the positioning the radius block.
The washout base, mixer arms and swashplate should still be connected together and can now be slid onto the main shaft, guiding the radius block pins into the washout base and sliding it up.
Radius block, washout base and swashplate fitted
Radius block, washout base and swashplate fitted
We can now reconnect the long rods from the upper mixing arms to the swash plate again, and also the shorter rods from the flybar carrier to the lower mixing arms. Make sure the washout base does not twist around 180° before fitting onto the main shaft as this will incorrectly position the lower mixing arms. (It's quite obvious if you get it twisted by accident).
Next, fit the main shaft locking collar loosely to the shaft and lock it in place fairly high squashing the swashplate, and all above it upwards to keep things out of the way for now.
Mast locking collar fitted
Once you're done with this stage, the next step is to fit the completed head assembly back onto the heli.