read past posts and had the same problems f-770 not fitting and cracked the conical bend this is what i found to add to the past posts i read. i had sawhorses at 704, 705 706 and tail all level. When i had clecos in side skin at 704 and 705 holes were out of alinement at 706 by 1 inch and longerons were short.Had to drop tail 8 inchs and lift at 706 to get holes to line up then longerons were long at firewall end. I had wood shim wedges from the lumber yard that made good shims to then get all sawhorses bearing weight at this time if you run one shimfrom one direction and the other from the other on top of each other you get any thickness of shim. for the conical bend i cracked the first one but could see what i was doing wrong as i cracked it. get the f-770 clamped as in the picture in the manual but make sure you file the edge of the top angel round i thought the bend would be hard and would need a sharp edge because my thumb would be too weak and the bend would move out from the clamp but the opposite is what happens. this is a very easy bend but you need to push with your thumb at 90 degrees to the bend line your natural tendency is to push in a side tearing motion because the other angle that you are twisting runs at an angle to the bend line and you need to concentrate on the bend angle and roll and push with your thumb in relation to this line and not the twist line. for my first bend i pushed in a dirction that had a element of side pressure that ripped the skin right at the start of the bend had tostop drill it. also this bend is very short once the end is at 90 degrees the bend is done. 2nd one didnot crack but i will put a glob of pro-seal behind it when i rivet the skin on per past posts
