Hi All - Milli is starting to permeate my gray matter (and grey hair) again. The aim was to make cold cast parts but that has not worked out. Another was to take advantage of a big mill at one of the machinists I use and another was to develop a new machinable E70 material and that didn't work. So in short we are back using aluminium, maybe laminated then finish machined in the big mill. There are three pathways to do this:
1) billet machine
2) bolted plate construction
3) fabricated heavy extrusions and finish machine - this has not been on the menu before

Billet machining makes a lot of expensive swarf to get to my 50kg per part rule. Bolted plates have various issues and edge bolting is expensive due to the double handling required to do edges. The machinist does a lot of aluminium welding and does regular solution heat treating to T6 of these assemblies. But for machines I don't think that's necessary although it would fulfil the same function as a thermal stress relief.. many of the large parts when run through the form finder have triangulated internal shapes which a plate build can't achieve.

The steel trussed mill is really interesting and this brings me to an aluminium version. Recently I had to design a large dolly for moving a large machine and I did it in heavy aluminium sections welded and machined and it worked out quite good weight and cost wise. So my thoughts mashed around the idea of taking advantage of the laser cut sections (tube and plate) then welding, then finish machining. Also using laminated aluminium wherever possible for vibration mitigation... I think this is a valid path. It uses the aluminium with minimum swarf production, keeps the manufacture within two companies and the welding and machining is done by one company which means they understand what the outcome target is... I have to check what the max thickness they think they can weld easily...

So philosophically the Mazak VTC 200 config is the sort of thing to aim at. Its pyramidal in structure and can be long. My things tend to be long. Since my aim is to make aluminium moulds and mill composites I can neglect the cutting steel requirement briefly and spec a high speed spindle.... so starting at the spindle I can work up a minimum size aluminium truss mill to see what happens...

Also I have news that the chinese company with chopped carbon is sending me a sample but it would be 150g. I need 500g to make Plank3 so have asked for 1000g.... see what happens...

A new Milli chapter begins - Peter