Prop ShaftsThis is only the second set of shafts I have installed, and hopefully I’ve learned from the previous fit.
I am using Raebosch watertight shafts. A bit more expensive but well worth the extra.
Lots of measurements taken, inside and out, marking out hull from plans dimensions.
The big 48 mm props have to be close into the hull profile, with motors positioned within the compartment level and straight.
‘A’ frames were cut to suit the hull and slots made using my Rotacraft. From here sight lines were established parallel to the keel. Hull intersection points marked out with long centrelines as after the initial hole it is important to keep the developing slot centred and in line. Holes drilled, and opened out into the required ellipses with round files. File starts off perpendicular to the hole, then gradually angled to create the ellipse.
A balsa box that was used for frame construction came in handy to positionally locate the inboard shaft ends
The shafts need shortening. 3 mm off the M4 threaded end, then the brass tube and stainless shaft to suit motors & UJ's. The inboard bearing sleeves secure with Loctite.
Recheck evertyhing, hold shafts in place with with Bluetack.
When all OK set in with epoxy, using reinforcing tape inside, and finish with filler.