Thanks for the question about fixed gear.  Here in Florida I fly off of grass strips and most flyers fly 1/4 scale or larger.  Fixed gear works the best.

The pictures above will give you an idea of what I do.  I am sure this is not the only way, but is one way.

1.  I cut the bottom of the fuse with a dremel cutoff disk to give the opening for the gear.  Save that piece as you will use it to close up the space as the last step. 

2.  Set the gear on the fuse and see that the vertical fin is 90 deg to the table

3.  Wrap the gear in waxed paper and glue  the wood brace inside the fuse with slow cure expoxy. I use West Systems epoxy.  There may be better b but you can get pumps that will give a proper mix every time.  Thicken with milled glass  (Great Planes) and apply.

4.  After all is dry set the gear on the fuse.  Install a T pin at the bottom of the vertical fin use a length of thread that does not stretch use a slip not at the end and attach to the T pin.  Put a short piece of masking tape on the thread where the edge of the gear is and drill one hole through the gear and wood plate install a blind nut and (suggest 6-32) tighten to hold in place.  Remeasure tighten and remeasure then drill second hole opposite side of fuse. Install 5 bolts, 2 on each side and 1 in the center.

5.  Now work on the piece of fuse you cut out.  Most likely the sides will be to long adjust to fit.  Use 1/8 ply to attach to fuse with 4 -40 bolts

The last picture is what happened when I used retracts on a test bird (LA-2 with one piece wing).  It was pilot error, I was too fast at touchdown and caught a small rut.

Any questions please call any time.  If I am not in the shop call my cell.  239.821.4195

Jim Graham
www.rccityfl.com