Hello world,
I am restoring a 1959 MGA Coupe here in Sydney Australia. The car is a barn find that was put neatly away in 1979 until I bought it from the estate in 2018. The great part is that the car is pretty much straight and amazingly rust free. The bad part is that someone decided to take out the original motor, transmission and drive-train and shoehorn in an Australian straight six Holden engine and parts from an EH. So when I took that all apart I had a gaping hole where the top goalpost should have been as well as no lower front tube and no drop-box-section cross-member! (There were additional braces welded in ... so the car had been roadworthy ... just!)
Anyway after searching I couldn't find anyone who made a new goalpost section and the only place to make the other sections was in Europe and prohibitively expensive for me. So in true Aussie fashion, I figured no worries she'll be right mate and went about making my own. So what I have come up with is a design to be made in galvanized sheet metal that comes in two pieces.
I did this so it can be bent on a sheet metal brake and then spot welded together. This makes manufacture much easier but also allows someone to individually tack weld in captive nuts if they choose. (after bending but before they spot weld on the "lid"). Personally I have chosen to use the Rivnut method and it looks just the job plus is very neat and super fast.
The holes take 5/16” UNF Rivnuts for the most part, aside from four smaller ones which are 1/4" UNF.
I've updated and amended the design after great input and suggestions of improvement. The cut design now allows for the correct bend radius for 1 mm (0.0393701") galvanized mild steel with a k-factor of .44! (and no I had no idea what that meant either so I had to go learn it up!)
The finished piece weighs just over 7 lbs.
Once I have cut out the pieces of the old remaining part and welded in the new goalpost I will begin work on the lower two sections. I plan to do a similar job on the box section with the drop in it ... make a design in CAD, cut it out, fold it and weld it.
I want to thank both Barney Gaylord (the MGA Guru!) as well as Chris (HURSST from this very forum!) who have helped greatly with the design process and giving me measurements and such. I am happy to share the complete CAD with anyone who wants it as a way of giving back. Plus if anyone needs a goalpost now, at least there is one backyard Aussie who will see you right mate.
Goodonyas
Rich