PATTERN PARTS

Component scanning and rapid prototyping is still the preserve of the experts

John Smitherman asks for details of the company who are making the patterns for my Martinsyde cylinder head (Fixes December), as he needs one cast for his 1934 BSA W34/12 Sloper.

Ah, now... this is a bigger deal that I’ve maybe made clear. Initially, I naively thought perhaps I could make the patterns myself, with guidance from my clever mate Bruce, but soon realised it was way out of my league and Bruce very kindly took over. Without his help, it would have been completely impossible – normally cost thousand Although scanning an typing are helpful, at pr what is there. The plasti ‘printed’ is a model of B an original head, giving of what’s needed from w design the pattern.

The next step is for B design and make pattern produce a casting of tha model. These will need several interlocking piec Chinese puzzle – solid enough to withstand the sand being rammed around them, but readily dismantled for removal from the sand without disturbing the imprint. It’s a complex task; Bruce has been at it for over a year now, and we’re only doing it because Chris Tait only managed to find two sets of Quick Six top ends in 70 years and neither of them are available. For John’s BSA, I don’t think able. There must barrels and there somewhere wonder if ng like a BSA p end could be to work; it shares ke’s 85mm bore. nwhile, if anyone barrel and head 1935 550cc BSA er, let me know; ould make John happy man!