The MGA With An Attitude
BODY SILL Replacement Part Drawings - RT-223

On 2/1/2010, Jon Tillman wrote:
"Do you have a drawing file large enough for me to print out a full size copy of the sill pattern? I want to take it to a sheet metal shop and find out what they would charge to make me two sets".

A job shop will kill you on price to make one or two pieces of anything.

I do have full scale AutoCAD drawings of most of the parts. I have some of the drawings posted on my web site in somewhat condensed form, but not full scale templates. Most of it is composed to be viewed on a computer screen or printed on 8-1/2x11 paper (or 11x17). You can find the drawings mixed in with 35 web page of my body sill documentation with articles RT-601 thru RT-635.

Drawings with dimensions are here: plate2.gif - box_dwg.gif - box_left_end.gif - gussets.gif - box_weld.gif - gusset_fr.gif - gusset_rear.gif
And location of sill trim strip attachment holes at RT-627A

When I made the B-post rear plates I used a cardboard template traced off of the car body during disassembly. I used this to trace the shape onto sheet metal, and to be cut out of 1-inch boards which I used as forming dies to hammer form the flanges. See details at RT-605.

Curvature on top edge of the inner sill plate came from a cardboard tracing template, measured carefully to determine coordinates shown on the drawing. Then I used the drawing to lay out the pattern on sheet metal to be cut out. The finished part matched shape of the original inner sill flange perfectly, so the drawing is verified to be correct.

Since I was only doing one car and have no intention of mass producing parts, what you see is what you get. At least I took the time to transcribe my AutoCAD drawings into web pages. When I was cutting out the sheet metal I just used the small scale drawings for reference and drew the patterns right on the sheet metal.

Most of the inner sill pieces are very simple to make by hand, being flat with simple bends and/or flanges on the edges. The pieces that will kill a fab shop are the two large box panels. Two of the long bends are simple bends or 85-d and 110-d, easy enough to do on a press brake or a large bending brake. The lower two bends have a progressive bend angle that changes angle by 20-d over length of the part, resulting in one not-flat panel having a 20-d twist over the length. To do these with standard tooling in a fab shop you can make two simple bends of 23-d and 48-d, but then the final 20-d twist has to be hand formed (unless someone has a better idea than I do).

Sometime in 2009 someone commissioned a sheet metal shop to make a pair of these box panels. I'm sure the shop guy didn't understand what he was getting into. He quoted a pittance for the price, then took several hours screwing around and scrapping a few parts before he got them close enough to work on the car. In the end he said he didn't want to ever try those parts again (and I don't blame him).

I saw pictures of the parts supplied by Moss Motors, and they seem to have the same forming problems, trying to make these complex lower bends by hand on standard tools, and ending up with somewhat distorted bottom edge.

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