Justin has elected to feed the airbox through dual, twin 3" NACA ducts. This is possible since we are swapping out the glass on the side windows with Plexiglass, to enure once again, our fire-rating. The NACA ducts need to be positioned to the rear of the window, as the Plexiglass firewall disects the side windows about one-third of the way along.
I didnt have the ducts with me, so I just made up one out of carboard to see if we had enough free-space aft of the firewall to mount the ducts. Afterall, I didnt want to move the firewall at all if I could help it - heaps of room!!:
More fabrication!! With the beltrail reinforced, and the floor reinforced, it was time to tie the two together. This ensures that any reactive forces get channeled up through the correct load-paths and are therefore shared by as much of the monocoque as possible and as evenly as possible. To do this, vertical members need to be made to tie-in the two other structural members, and make them essentially, into one structural element.
Because the sides of the Mini shell have a definite curve, I decided to use (as Richard and Nik would say) CAD, or Cardboard Aided Design. The curve of the shell exterior is not uniform throughout its length, so best to make a carboard profile, than be wrong and waste steel:
Transferring the profile to the sheet, mark-out, cut-out and bend in the panbrake:
Then, do a test fit to see how close we were - lovely!! As you can see, the vertical bulkheads will be made in two pieces for simplicity, and then welded together:
Grind back the paint, punch out some evenly spaced holes for the plug welds, and then weld:
Making sure that we have good penetrations once more through to the shell:
Do that again to the other side:
The tops of the vertical bulkheads were a bit of a convaluted profile, so hence the reason for doing each side in two parts. It was a case of estanblishing the profile, marking it out on the sheet, cutting it out and then bending it up with the panbrake:
Then once we were happy with the fit, punch some holes for the plug welds, and weld on:
Ensuring one again good penetrations though to the shell:
And same again to the passenger side (bit repetitive I know!!):
More updates soon.
Cheers,
Tricky
)!!