Hi Wesley,
At 2018-12-12Wed06:17:43+00, Wesley Brooks sent:
(Active) RepRapLtd: https://reprapltd.com/ RepRapLtd may be able to put together bundles for you. They are very helpful.
Thank you. We were aware of RepRap Ltd. but they don't seem to list the Huxley, let alone the Huxley Duo. Their listing for 3D printers (https://RepRapLtd.com/product-category/3d-printers ) currently only has 3 items, of which all 3 are delta. However, having just had another look now, at https://RepRapLtd.com/shop I see “If there is an item you would like, but can't find, please get in touch.”, which suggests that actually they'll probably sell any RepRap design if asked. The first thing that I noticed when I looked at their homepage, today, was a thumbnail feature of an article about a filament Y joiner: https://RepRapLtd.com/filament-y I find this very interesting because I'd rather have a smaller, lighter extruder which can achieve a higher quality, rather than have a dual or tri extruder as Andy feels are a requirement for the workshops. Although I've suggested 2 techniques to Andy for how to make multicoloured parts without a special mixing extruder, one requires a hot air pen to join coloured parts (with a somewhat poorer colouring resolution like that of Lego, but nonetheless very colourful and with any number of filaments) and the other would have required a special pentachromatic filament, a sensor, and slicer awareness to use unwanted colours on fill, or other parts where the colour does not matter. Today, when looking for the Huxley Duo review forum post I mention below, I accidentally found another forum post (https://aniwaa.com/blog/multicolor-3d-printer-filament ) which indicates that filament very similar to what I describe already exists! Furthermore, it goes on to explain and excellent idea: custom colouring with permanent markers!!! This makes me wonder whether the best multicolour mechanism is to have actuated permanent markers on the Bowden feed. There would be a bit of a delay, but the slicers would merely have to set the colour while its printing the skirt, brim, or raft, and just always actuate each pen early by however long the Bowden cable is. Obviously dithering could be used to create gradients. Having noticed yesterday a key feature of the Huxley “The MiniMendel uses a bowden-extruder that has less moving mass and thus higher speed due to the stepper not being on the print-head.” (https://RepRap.org/wiki/Huxley#Extruder ), thinking about that today in conjunction with the filament Y, I realise also that dual or tri heads are going to have an inherent stability penalty just for the additional moving mass!! So I'm going to say that as long as the machine can reliably print colour by some technique then it does not need to be a Duo, else we may decide to not have all 3 be the exact same model.
(Active) RepRapForums: https://reprap.org/forum/ The mass of different sub forums looks organised but the down side is post in a quiet place and your post will go unanswered.
I'm no fan of posting to Web-based forums, preferring wikis or email, so I'll leave that to my TFMS peers.
Discussion from Bowyer about the closure of RepRapPro (used to sell machine kits through RS): https://reprap.org/forum/read.php?340,610436,830486#msg-830486
Thank you very much! That answers all of my questions about what happened, and also introduces me to the legal mechanism of how an LTD company can ensure that it remains committed to its original mission persistently, through the use of clauses in its Memorandum of Association which define special ‘Ordinary B’ shares with the power to assert the commitment to the original mission. I like that. Perhaps I could submit some wiki edits to RepRap.org in the coming months, especially where I see dead links or other missing information. I'd also like to document my colouring techniques mentioned above, as well as other techniques.
£750 for three machines is tight. You'll probably be relying on Arduino Mega and RAMPs for that rather than the more recent 32 bit controllers.Searching for amd reconditioning second hand might help. If determined to get new then your best shot will be searching for a bill of materials and collecting the parts yourself.
The budget that we've decided for the printers is 750£, but we weren't sure whether we would buy 2 or 3. Andy tells me that prices across the market have plummetted this year, and the Huxley and Huxley Duo appear to have been around for a few years. Last week, I found a 4-year-old price for a Huxley Duo of 290£ on a review forum that came up in a search (http://forum.reprapdiscount.com/threads/introducing-our-new-reprappro-huxley... ), or 237.5£ for a hardware kit of nonprintable parts, so thought that it would be reasonable to expect to get 3 for 750£ 4 years on. 2×290£ + 237.5£ = 817.5£; 290£ + 2×237.5£ = 765£; 3×237.5£ = 712.5£. The decision is complicated slightly by the need to strike a compromise between what is most appropriate for the workshops and the desires of the existing makerspace members. Some aspects align, particularly the size: for the workshops they need to be small and portable; for the makerspace, all of the items that I'm aware have been printed on the Wanhao Duplicator i3 that we currently have are well within the build volume of the Huxley. The largest that I'm aware of were a couple of 10cm×10cm cylindrical beakers which I printed to demonstrate watertightness, and each took about 2 and a half hours to print even though they were just 1mm thick (as measured with a caliper). I'm not sure how much the size contributes to the cost, but we'd rather have a smaller, better-quality machine than a large machine which is too wobbly for small parts. Furthermore, we have participatory overlap with 2 local repair cafés (Shrewsbury and Oakengates) which have a keen demand for small, precise, custom parts. Andy and I didn't manage to successfully print a small replacement involute gear after several attempts of tweaking settings – the teeth were too blunt to mesh. If we could find a Cartesian filament printer which is a bit more precise then I'd be willing to augment the budget with my own money for a Huxley-like model which is more precise.
I could have a look at how long it would take me to print the parts in white PLA. I'm tuning PETG but it is not ready yet.
We do actually have the ability to print PLA at the makerspace already, on a Wanhao Duplicator i3 lent to us by a local supplier of filament, 3D Printz Ltd., but thanks for the offer. And thanks once again for the advice above.
Best regards, James R. Haigh. P.s.: In writing this email, I realise that I had muddled RepRap Ltd. with RepRapPro Ltd. in my previous email:
• Why did RepRap[Pro] Ltd. close?
Sorry, I meant RepRapPro Ltd.. Nonetheless, you already answered as if I had not made that mistake, so thank you. I now understand (from the forum post from Bowyer that you referred to) that RepRap Ltd. is/was a parent company of RepRapPro Ltd., along with eMaker Ltd..