As I am fitting a DA-50 the installation is pretty simple - just follow the manual. I started by marking out the bulkhead for the DA-50 mounts and then mounted the engine. This allowed me to mark on the bulkhead the openings required for the throttle linkages and also the extra material that needs to be removed for the header to clear the firewall. These areas were removed and the bulkhead fitted in place. A very good starting point for right thrust comes about by fitting the bulkhead in the fuselage at a slight angle. In this case 151mm and 157mm to from the front surface of the bulkhead to the front lip of the fuselage. It was then simply a case of aeropoxying the bulkhead in place and creating a nice fillet of glue to hold everything in place. The horizontal supporting ply former was then aeropoxied in place behind the bulkhead.
Next was the cowling. First of all I removed the excess material from the fuselage and cowl by simply 'dragging' a 2mm drill through the material and cleaning up afterwards with a dremel sanding drum and sandpaper.
The next job was to secure the cowling in place. This is probably the most boring job of the whole build but still only took a couple of hours. If you follow the instructions and take things slowly you should be fine. First, the slots are marked out for the plywood 'tongues', cut and filed to shape. The 3mm plywood squares were then glued directly beneath these slots and as close to upright as possible. With these in place I drilled through the centre of each ply square to allow the 3mm allen bolts to pass through. With all this done, I held the cowl in place and transposed the positions of the cowling slots onto the fuselage and cut these slots out.
Next up the 3mm captive nuts were glued into the pre shaped ply tongues and bolted to the lower cowling using the 3mm allen bolts. All the areas around the slots were waxed or masked off and the cowl taped in place. I then used aeropoxy applied with a stick through the front of the cowl opening to glue the plywood tongues that protrude into the fuselage slots in place. This was left overnight to cure and the bolts then undone to remove the cowl. Done this way ensures that everything sets aligned. Two additional phenolic tongues were glued to the rear faces of the cowl to hold the cowl to the correct width of the fuselage. Finally, the holes in the fibreglass for the mounting bolts were enlarged to allow the bolt heads to fit and thus tighten up against the ply squares glued to the inside of the cowl rather than squashing against the cowl.
The next task was to get the cowl to fit over the engine nicely. I temporarily fixed the DA50 in place and through a trial and error process, marked and dremeled my way through the process until everything fitted nicely. The results are below. (Note that you may need to trim a little of the cowl away at the front for the prop hub.
Whilst I was waiting for some glue to dry I knocked together the tank tray / RX support. Took about 5mins - everything slotted together very nicely. I decided that maintenance on this model would be a lot easier if the tank tray was somehow removable so I set about making it so! Rather than glass the bottom of the upright balsa piece to the fuselage floor as suggested in the manual, I used two 3mm captive nuts and bolts to have it bolted in place. The 3mm plywood strip through which the allen bolts pass was all that got epoxied to the fuselage floor. This stops the tray from moving left and right as well as up and down but was, obviously, not strong enough on its own so I came up with a way of hold the main tray to the wing tube. This was done by creating ply pieces the same shape as the balsa parts that glue onto the wing tube on the underside of the wing tray. Captive nuts were glued to these ply pieces and the balsa tray is then bolted to these ply pieces! Works kinda well!
The following pics show details of the way in which the supplied former was cut and installed to suit the MTW cannister available from C-ARF.
I also cut the cooling air exit hole in the fuselage and cut a slot into the front of the fuselage for the cannister exhaust outlet to fit into. The dimensions of the hole I cut can be seen in the pics below