Hello Dennis, I also have the 251 but have not started it yet. I have a question for you, what method are you using to install the rivets? The rivet snap tool? or something else...
All I have done is made up a brass former as per photo using a 4mm drill just deep enough to leave the shoulder of the rivet just proud of the surface and then rivetted the rivet flat on the other side. A note of caution when you are ready to start rivetting make sure you do it in the right order as you want to be able to get the ball peen hammer in there to rivet. You will have to cut the rivets down in length and you will have to experiment to get that right, I use a pair of heavy side cutters. The dummy rivets of which there are only a few as they only go through one layer will need to be shorter.
Make sure you put the plates that hold the visors on goes on with the counter sink on the outside.
Also I have attached a photo of the track rod position underneath not on top as shown on the plan as it fouls the tierods if put on top.
Dennis,
Your 251 is looking awesome! Very smooth motion on gun rotation and elevation. Will be a very unique model. Really enjoy all of your projects.
Best regards,
Bob
First photo shows method of rotating gun platform, a bit rough but it does the job. Just a standard servo but I cut the top off the shaft that turns the pot from the final drive and also the limit lugs. This means that the servo will stay in the position driven to even when stick is returned to center. Gears are from my R/C racing car days. Cable go to elevation servo and led in barrel.
Second photo, I want to fit super bright led in end of barrel and I couldn't drill the barrel for the cables as too long and thin. So I cut a slot with the Dremel and disc and used car body filler P38 to cover up the slot.