I didn’t have a 10mm x 1mm die so the machining of the blanking plugs stalled until next week when it should arrive.
I thought I would get on with my case saver instead.
Some while ago I ordered some 2mm SS sheet sufficient to make 4 case savers (1 x M900, 2 x S4 and 1 x 750SS –my Ducati fleet). I looked up old threads on here and found a drawing but one critical dimension was missing – overall length. I wanted to provide maximum protection so using some masking tape worked out the total length ( xxmm) then cut the sheet with a 1mm cutting disc in an angle grinder at 46.5mm wide, 30mm for the saver and 15mm for the 2 attachment tabs (allowing 1.5mm for the bending of the tabs).
With rare insight I marked the cut sheet with a Sharpie pen corresponding to 2 reference points on the crankcase where I judged the curve part should start and finish. This proved invaluable later when trying to adjust the radius of the curve.
The first bend was made by putting the sheet in the vice and bending manually advancing the sheet about 3mm at a time until the required c125 degree bend was made. This method gives you one chance to get it right because the workpiece once bent will not go back in the vice. I didn’t really expect to get it right first time and I was not disappointed.
The bend required a radius of c 52mm and I had nothing that big to act as a former. First I tried adjusting the radius of the bend around two 10mm bolts projecting about 50mm through some 8mm steel flat about 50mm apart all held in a vice but this ended up with threepenny bit bends.
This is what gave the best results:
The hammers are hard rubber, shot filled and one of my favourite tools as they give a dead blow and do not damage what you hit – highly recommended.
It took about 2 hours of adjustment to get the curve to match the crankcase as closely as possible and maximise the clearance for the chain. All that remains now is to mark out where the tabs are needed, angle grind off the material not needed and to bend and drill the tabs.
I will not use the 2mm stainless for the other bikes it is just too difficult to work and getting the clearance for the chain is a real challenge, I will buy some 1.5mm instead