During the construction of the plane (except painting, haven't done that yet) these are the tasks I found the
I find making sure that everything is level and without any twist before drilling/rivetting is the most difficult for me. In fact, I live in dread fear that the plane is going to be very out-of-trim/rig on its first flight.
UPDATE: The plane appears to have come out trimmed pretty well. So I'm changing the most difficult task to THE CANOPY. Bleah. I broke two of the rear tubes while trying to make everything fit, and it still doesn't fit very well.
Installing the landing gear in the center wing section. This took a lot of trial fitting, then grinding, then fitting, then adjusting, etc, etc.
The canopy was pretty darn time-consuming also.
Sawing the supplied 1.5 x 1" aluminum extrusions down to 1.5 x 0.75" for the landing gear slides. Installing the 30 nuts/washers inside of the landing gear (by sticking them to the end of a flat-bladed screwdriver with plumber's putty) was rather tiresome also.
Probably the landing gears, just because they are the first thing I've made that moves! I can't wait to get to the control systems.
I enjoyed the instrument panel work a lot also.
Most Expensive Replacement Part
That would be the main gear leg I replaced because I (somehow) managed to drill it to the wheel fork backwards. The gear leg cost less to replace than the wheel fork. Actually, at $58 for the leg I can't complain.
Most Dreaded Thing Still to Do
I'm told that manually bending the forward longerons, without wrecking them, is not fun. And I'm not really looking forward to painting this thing either.
UPDATE: Actually bending the longerons wasn't bad, only took about an hour. So that leaves painting...
I'm giving this award to my $54 pneumatic rivet puller from Central Pneumatic (Harbour Freight). I have noticed the the holes in the Zenith-modified nosepieces are starting to distort, however... and after only about 4,000 rivets!
An engine. Ok, I guess that's not really a tool. I can't really think of any exotic tool that I think I need, except for maybe a quality HVLP spray gun/blower.