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Sailplane Construction Project Session #5

Shown below are the Carl Goldberg composite T-Mounts mounted to the Sailplane's (SP) firewall along with the vertical location of the thrust line.


The picture below shows how the forward landing gear 1/8" right leg (looking aft) will be positioned on the 1/4" plywood firewall behind the composite T-Mount. A 1/2" square spacer goes between the T-Mount and the firewall and has an 1/8" inclined slot that will trap the lower portion of the 1/8" piano wire against the firewall. Of course there will be a metal clip bolted to the firewall at the apex to further secure the 1/8" piano wire to the firewall.
Here is the 3-view drawing of the spacer on the right. Of course the inclination of the 1/8" slot is reversed on the left spacer as Note (b) points out. I am currently trying to get these spacers machined out of aluminum.
For the last couple of days I have been working through the details of a design for the SP's ignition system that integrates all of the system's components into a single package or unit. The back side of the unit is shown below under the drill press. The two small plywood tabs are being drilled out for holes to be tapped with 2-56 threads.
This view shows the unit's compartment for the ModelElectric coil with the removable end in the foreground.
Here the ModelElectric coil is installed in foam in unit's coil compartment.
This shows the unit bolted to back of the SP's firewall. Notice the clearance cut outs in the unit's base for the T-Mounts 6-32 blind nut flanges on the back of the firewall. Notice also the larger hole in the removable end that secures the coil in the unit's coil compartment.
The wood on this unit was given five coats of clear doped to seal all of its surfaces. Then Velcro was applied to back side of the unit's coil compartment for shock mounting Marv Stern's Aero Tech IGN-SW ignition module and to the unit's base in front of the coil compartment for shock mounting the 3-cell ignition battery as shown below.  
Here is a picture of the underneath side of Marv Stern's Aero Tech IGN-SW ignition module with the wiring instruction shown. Notice this is one of Marv's earlier modules retrofitted with wires for booster battery capability as shown below. The black "Booster (-)" wire is module's common ground that is connected directly to the engine.
This is a nice shot of the Aero Tech IGN-SW ignition module and the 3-cell ignition battery installed on the unit and partially wired up.
This is a view of the unit's other side showing the ModelElectric coil installation. This design makes for a nice clean compact removable ignition system that can be easily removed as a single unit through a hatch in the bottom of the SP's fuselage............................Tandy

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