When using this ensure it runs true by locking on the propshaft against the nut and a small washer then if necessary move this a quarter turn at a time until it is aligned correctly (this can be necessary on threaded shafts).
This only needs to be glued on. First tack in place with a little superglue. Then run a small amount of epoxy around each side of the collar on the tube, then after drilling when installing into the model be sure to have this tilted to one side (at least 45 degrees) because if you install this upright it will obstruct the movement of the battery tray.
Stress Marks On Styrene Plastic
This can occur when cutting or shaping particularly with scissors and turns the colours pale and white. This can easily be rectified by heating slowly with a hairdryer or hot air gun a little at a time, but please be careful not to over do it and distort the plastic which can happen, Eventually the colour will return.