RE: What do you think about JETLEGEND L39?
Jeremy,
Yes, that is correct. I had the same observation when building mine. There are very thin rectangle alu corrective shims included in the kit to put under the retract units to get them in the correct angle, so they lock properly without friction at all when retracted, and having the struts still perpendicular when the bird stands on its legs. It is described earlier in this thread.
You will have to repeat this "trial and error" sequence a few times, in combination with the correct toe-in of the wheels. It is quite time consuming, but worth it to spend a lot of attention to it.
Nicolas.