Stability, etc

Tony Rodda

Yes Andrew, lots of questions about strength, stability, etc. but we have to start somewhere and even my little printer duplicates in about six different materials.  There’ll be one (or more) that proves suitable. 

Plus, as you say, it’s the manufacturing process that is revolutionary but if we need a part that needs high strength (and say “Carbon” won’t do) such as the ‘scope end plate that takes a lot of weight, then I can make specific/individual parts in metal or buy/adapt ready available screw adapters.  But that’s a bit of plate work – you don’t need an experienced lathe operator for the complex stuff. (McClaren are printing complex gas flowed inlet manifolds in titanium if you fancy a £500k printer but that defeats the object!).

My current ‘production run’ is only to construct test beds.  One to use and evaluate the actual practicality and accuracy of the spectra produced (and it’s resolution, etc.) in various materials and one to ‘hack about’ with different lenses/grating, etc.  I hope to do that for each design ‘out there’.

I produced three small ‘blocks’ of material with identical dimensions except for wall thickness and infill density.  Then carried out a very scientific test called ‘hitting it with a two pound hammer’.  (OK a bit more controlled – identical drop height, etc).  I increased the wall depth but kept the infill to 80% on one block as per PG’s instruction and had to physically pick up the hammer and belt it two or three times to destroy it.  I’m printing larger parts this week so I’ll begin testing rigidity, etc.  If, in the end, I have to brace the sides with one or two metal struts (Meccano style) or thicken sides/bases, etc I’ll do that.

As for the chemical /photo stability of PLA, ABS, etc I think a bit of practical use and testing will point the way.

I think a composite will be a short term reality and the dramatically cheaper cost will tempt more people into trying more serious spectroscopy before a large outlay is required.