When mounting undercarriage blocks into foam wings try this idea which has proved worthwhile in service-
Normally the undercarriage fits into a slotted birch rail which is simply epoxied into the wing underside,make a mod by glueing another plywood rail on the upper surface extending the same distance as the lower,now take you drill and make four quarter inch holes from top to bottom,then cut four pieces of hardwood dowel and glue into place with PVA glue,the effect is to spread the load and torsion between the two wooden rails,ideal for foam or built up wings.
There is less chance of the undercarriage being ripped away with this useful tip.
Normally the undercarriage fits into a slotted birch rail which is simply epoxied into the wing underside,make a mod by glueing another plywood rail on the upper surface extending the same distance as the lower,now take you drill and make four quarter inch holes from top to bottom,then cut four pieces of hardwood dowel and glue into place with PVA glue,the effect is to spread the load and torsion between the two wooden rails,ideal for foam or built up wings.
There is less chance of the undercarriage being ripped away with this useful tip.