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Old Jan 06, 2013, 04:15 AM
GLGofLB is offline
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United States, CA, Long Beach
Joined Jan 2012
168 Posts
Back to work on the Navajo. As you can see by the picture below things are tight in the servo compartment. Spent awhile thinking about the situation and realized that the servo wheel bottom was interfering with the underside of the top sheeting.

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Description: Opened servo compartment.  Servo wheel so to large to fit into aileron link and align perpendicular and attach to servo spline.Name: Image00003.jpg
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Description: Swapping out servo wheel for single sided cut down servo arm with custom placed hole for ball connector solved binding problem.Name: Image00004.jpg
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Description: Once I realized everything would fit, it was time to fabricate a servo tray.  I start with 1/16th ply
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Description: I scored and cracked ply to match dihedral of wing, then added hardwood mounting blocksName: Image00006.jpg
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Description: Tray cemented and braced firmly, servo screwed into place and everything lines up

The next thing to do was to complete the aileron linkages then attach to bellcranks and check the entire mechanism. I the final pushrods are quite short and have three separate bends close together. I only had to make four to get two that worked.

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Description: Laying out servo pushrod exits on sheetingName: Image00008.jpg
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Description: I drill two holes with a 1/8 inch drill then connect holes with sharp knife to make slotName: Image00009.jpg
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Description: Finished slot and pushrod.  Aileron control horns glued into control surfaceName: Image00010.jpg
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Description: A view from the inside.  I only had to make four pushrods to get two good ones

The kit lists two options for mounting the wing. The plans show the wing being held down with dowels and rubber bands; but liner notes explain how to go with nylon bolt hold downs. I am going with the second option. Besides the wing would get crushed on the delicate sheeting by all that rubber band pressure and it looks horrible.

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Description: Here is some extra die cut ply wood that can be used to inlay the trailing edge.  Notice the hole that is formed, this is to accommodate  inch hardware dowel.Name: Image00013.jpg
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Description: Trailing edge sheeting removed and plywood inlayedName: Image00014.jpg
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Description: The leading edge needs hardwood blocks added as wellName: Image00016.jpg
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Description: Leading edge bays were filled with balsa blocks then a liberal amount of epoxy and micro balloon mix was poured inName: Image00017.jpg
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Description:  inch plywood was inlayed over the top of the glue.
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Description: Meanwhile to finish the modifications plywood mounting plates had to be fabricated to fit in the fuselage to accommodate the mounting bolts. Here is the dry fit

All the hard points of the mounting are finished and the wing can now be reinforced with fiberglass. This wing had only a few spar joiners and basically nothing behind the main spar to hold things together so I chose to glass it. The following sequence of pictures shows the method I have developed to get a neat center glass job.

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Description: First cut a strip wide enough and long enough cover the entire center section with one piece.  Also lay out an over sized piece of wax paperName: Image00020.jpg
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Description: Using a light coat of 3M spray mount on one side of the glass coat smooth the fabric out on the wax paper over a sheet of glass. In this case my work table.Name: Image00021.jpg
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Description: Use a metal straight edge and a new razor blade to get a clean fished edgeName: Image00022.jpg
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Description: Make a second cut to get a perfectly squared up strip.  Apply a second heavier coat of spray mount to the exposed cloth.Name: Image00023.jpg
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Description: Using the wax paper as a transfer media, flip the glass over on to the wing and press the glass to place the adhesive will hold things in place
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Description: Peel the wax paper off and use your fingers to smooth the wrinkles outName: Image00025.jpg
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Description: Fiberglass cloth smoothed down ready to add resin.  Note no frayed edgesName: Image00026.jpg
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Description: I also place a piece of masking tape parallel to each edge all the way around about 3/16 of an inch off to the sideName: Image00027.jpg
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Description: Since this wing is going to get a MonoKote covering I am using epoxy resin instead of polyester.  Here all the suppliesName: Image00028.jpg
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Description: I mix the resin pour it on top and brush it through using an acid brush that I dispose of later
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Description: I then squeegee off the excess resin using a credit card and pressure to really glue the glass down firmly.  The right side is done the left still has excessName: Image00030.jpg
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Description: Flip wing over and do the bottomName: Image00031.jpg
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Description: Finished job will be ready to sand tomorrow

I really wanted to get the resin on the wing before I called it a day and I managed to do that.
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