After chatting with some of the guys on the MYCNCUK forum it seems steel is a lot cheaper than I thought it was. In fact 50x50x4 mild steel box section can be had for almost the same price as and equivalent piece of PAR pine. When you consider what goes into steel construction compared to wood production that is quite astonishing.

Anyway, after chatting for a bit about where to get the steel from a very kind guy has offered to source and cut the steel for me. His work builds steel frames so they have a full workshop and get a decent discount on prices. Suddenly the steel frame looks like it won’t break the bank.

I had been working from the sizes (and prices) I found at metals4u which seem to do 6m lengths max. I’ms sure they provide a good service but the price is astronomical compared to what you could pay. Since the maximum length metals4u did was 6m I shortened the X-axis to 1480mm in an effort to get all four long pieces out of a single run. I realized that I wouldn’t be able to hit my 1220mm cutting target on X though so I’ve stretched the frame up to 1800mm and added an extra support column. It really brings home how important it is to design before building.

With the X-axis rails extended to 1800mm I’ll need to do a serious re-arrangement in the workshop. Bracing, in the form of 50x5mm plate, has been added to help prevent the frame from distorting. I think the bracing could be better but it should help once it’s bolted down tight. The only other change is to move the long stretcher (at least that’s what it would be called in woodwork) to the inside of the leg as I think it looks better that way. The weight comes in a at around 100kg which I can live with.