We have just published a paper in the journal Robotica about how RepRap started, its development, and how it has got to where it is now.
It is, of course, a scholarly engineering article intended for academics. But it is - we hope - also a good read for everyone.
You can get a copy from the Cambridge University Press website here.
The citation is:
Jones, R., Haufe, P., Sells, E., Iravani, P., Olliver, V., Palmer, C., and Bowyer, A.,: RepRap – the replicating rapid prototyper, Robotica (2011) volume 29, pp. 177–191. Cambridge University Press.
Very nicely done indeed. Great to see this getting journal recognition.
ReplyDeleteYou mentioned on page 186 that PLA gives much better strength characteristics against delamination than other plastics like ABS, but didn't cite any reference.
I'm aware that there is widespread experience confirming this in general, but I just wondered if anyone has gone to the lengths to test that point in order to quantify it.
As far as I have seen, there are papers in the literature showing the general extent of anisotropy in FDM, and there are papers giving the various properties of PLA, but none that do both at the same time.
I asked my lecturer in materials engineering about performing strength and toughness tests on FFF-printed PLA specimens, though she didn't seem very impressed with the idea. She has done work with PLA in a medical context, but apparently the university would charge high costs to use their machines, unless it was being done as part of a masters project. However, I am very reluctant to go back to university for another taught year for reasons I could fill a lengthy blog post with (in a nutshell, their old-fashioned ways don't suit my 'architect' personality). MSc-by-research placements are simply non-existent up here.
Do you happen to know of any open-source-friendly bodies that would support such simple research?
Otherwise, do you think it could be worth botching together something like Da Vinci's strength test next to a ruler, or a very simplistic analogue Charpy apparatus, and printing out test samples in various orientations?
It seems that accurate load cells can be rather expensive things, and I'm not sure who would trust a strain gauge etched by a reprapper. :)
Hi 4ndy,
ReplyDeleteCurrently we are performing exactly those tests at Bath. We should have some results by the summer.
Cheers,
Andrew
Awesome, Andrew. Sounds like you guys have some cool staff. I hope you have time to do a full set - axial stress/strain, shear, bending, fracture toughness, etc.
ReplyDeleteI'll be very interested to see those results when they come out, and whether/how you manage to sort out any bi-axial tests or anything at 45 degrees. Leaves me with other fun stuff to do though.
Many thanks,
Andy D, UofG
Nice to know the detailled origin of the reprap, that's why I love it... for me it's a perfect exemple of how Design must be (biomimetism ftw).
ReplyDeleteThanks all for your work !