[chbot] 3D printer kit recommendations, and quick start help

Mon Sep 22 11:54:10 BST 2014

Peter,

Thank you very much, this will be an excellent start for my mate.

Regards,

Mark

At 07:47 p.m. 22/09/2014, you wrote:
>This is a very big subject....
>
>>1) Get or create a design.
>
>Yes, most 3d printers use STL files to define the 3d object.  Lots 
>of cad program can export to STL, and even if they dont meshlab can 
>import a lot of 3d format files and can save as STL
>>
>>
>>1a) Assume that the starting point is to print a simple object from 
>><http://www.thingiverse.com/>http://www.thingiverse.com/ - learning 
>>to design items can be left as a later activity.
>Correct, but quickly you find you want to tweak the file a little.
>Most simple things are designed in opencad. but can be any CAD 
>program that exports STL
>I would recommend anyone with a 3d printer to learn basic openscad
>
>>
>>2) Convert to some kind of motion vectors
>Commonly called slicing
>
>>
>>2a) What is the most common intermediate format, is it G code - if 
>>not, then what ?
>gcode is the final format, its is what is passed to the controller 
>to implement all machine functions. From heating up the hot end to 
>movements of and axis.
>
>>
>>2b) What are the recommendations for the best free/open source 
>>solutions to convert from design to printing motion activities ?
>
>Many people swear by slic3r and may other at 
>slic3r....  <http://slic3r.org/>http://slic3r.org/
>The main contender in my view is cura 
><http://software.ultimaker.com/>http://software.ultimaker.com/
>There are others...
>>
>>3) Convert the output of 2) into a format that can be carried to 
>>the hardware controller.
>
>3d printers such a reprap have intelligent controllers, they 
>interpret the gcode on the micro controller.
>>
>>3a) Presumably there is a name for the physical link, and payload, 
>>again, name please.
>
>not really. Its just gcode.
>>
>>
>>3b) What are the recommendations for the best free/open source 
>>solution, or does 2) also drive the interface ?
>
>pronterface is a popular minimalist GUI. It allows you to load the 
>STL file, call up slic3r and then spool the generated gcode to the printer.
>Cura is also a GUI, looks fancier but is limited when it comes to 
>tweaking settings.
>
>>3c) What is the currently most popular physical interface (USB, LPT, etc.)
>
>USB, really its serial over USB.
>>
>>4) Controller interface to hardware
>>
>>4a) Plugs into 3c).. What are the names of popular, low cost, 
>>readily available controllers, and suppliers ?
>There are two types... arduino based and the newer arm based 
>board..  all arm board should be considered experimental.
>
>RAMP's is the most popular, its is modular, being a PCB stack. Is 
>available all over the internet. But I would not go for a cheap 
>board. 'They' do nasty things like inferior MOSFETs and thin pcb 
>tracks and connector plugs that are not up the currents required.
>
>There are many boards that are basically a ramps but all on one 
>board solutions.  These are good in some ways, except if you have to 
>repair 
>it... 
><http://reprap.org/wiki/Comparison_of_Electronics>http://reprap.org/wiki/Comparison_of_Electronics
>NB this is editable, and unscrupulous sellers add in their 
>proprietary boards...
>
>The cheapest board is the Sanguinololu (but get 1284p chip not the 
>smaller 644p)
>These work well, but are the minimal solution..  no extras.
>
>Gen7 is also good, if you want to make your electronics from scratch.
>
>I personaly like reprapdiscount.com   they are really good, and 
>their representative is available on the #reprap irc channel. They 
>are also good at returns etc if there should be an issue.
>
>>
>>4b) I think older interfaces used a pretty dumb motor controller 
>>using an LPT port. Are smarter controllers now used ?
>3d printers require real time movements. Operating systems where 
>found to be dreadful at this, so all timings are on the smart 
>controller. A delay in movement == a blob in the 3d printing world
>>
>>4c) What not to buy, and suppliers to avoid ?
>
>Avoid most cheap reprap stuff from china, especially controllers and 
>hotends.
>>
>>5) Hardware interface
>>
>>5a) A collection of stepper motors are attach to 4a). Which stepper 
>>motor type is more popular, bipolar of unipolar ?
>
>Bipolar
>>5b) recommendations for typical stepper motor size, NMEA type etc.
>Most printers are designed around nema17
>
>>
>>
>>5c) Any special features for the stepper motors (voltage, dual shafts etc)
>
>
>ideal stepper is ideal stepper is NEMA17 size, rated 1.5A to 1.8A or 
>less, 1-4 volts, 3 to 8 mH, 62oz.in (0.44Nm, 4.5kg.cm) or more of 
>torque, 1.8 or 0.9 degrees per step (200/400 steps/rev 
>respectively), for example the kysan 1124090/42BYGH4803 or the rattm 
>17HS8401 or Wantai 42BYGHW609
>
>Single shaft, 5mm diameter.
>
>>
>>6) Mechanical frame
>>
>>6a) From first hand experience, recommendations and warnings about 
>>current designs.
>
>Most currently recommend the I3, there are two models, the plate and 
>the box. The original plate is cut from 6mm aluminium, but has no 
>support in the Y direction. It wobbles and needs bracing.
>Modern laser cut wood frames are good as long as they have the braces.
>Box is also fine. (but looks primitive)
>Stay away from acrylic printers, looks pretty but it fractures at 
>all stress points
>
>the mendel 90 is also a good printer.
>
>Delta type machine look cool and will print faster, but are 
>exponentially hard to get working properly. If you go delta get a 
>laser cut kit, you need the accuracy.
>
>>
>>7) Omissions, corrections
>>
>>7a) Anything I have forgotten
>
>This is a big subject... One that comes to mind is what materials do 
>you want to print.
>Main contenders are ABS and PLA, but there are others, and some that 
>require higher temperatures which dictate what type of hot ends you need.
>
>Hot ends, very important you do not get a jhead clone from china
>Jheads and aluhotends are good for PLA and ABS (hotends.com and 
><http://3d-industries.myshopify.com>http://3d-industries.myshopify.com)
>If your wanting hotter things such as nylon, you need a all metal 
>hotend. but these do not like PLA
>
>Nozzle sizes
>
>0.5 0.4 0.35 0.3 are all commonly available. The smaller the nozzle 
>the finer the detail you can print. But the smaller the nozzle the 
>longer prints take to print.   I would recommend .4 for most new 
>printers.. you can change it out later if you want.
>
>>7b) Things I have got wrong ?
>>
>>7c) Pointers to a web site, quick start guide document, or book 
>>that may cover these questions in more detail ?
>Everything in on <http://reprap.org>http://reprap.org and 
>discussions and question on the forums. 
><http://forums.reprap.org/index.php>http://forums.reprap.org/index.php 
>live chat on irc://freenode/reprap
>
>Documentation. All documentation is just a rough guide. Since its 
>maintained by the community its is always one step behind the latest gear
>
>>
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