Thursday 31 October 2013

Enter the world of 3D printing

      Imagine you want to make a plastic gnome or plastic whistle, no, lets start again; imagine you want to make a replacement part for a tool or machine, perhaps a threaded bolt, large flexible washer or toothed belt drive that you can no longer get or takes weeks to arrive in the post, or just want to have some fun making a coffee cup with two handles for your loved one. With 3D printing you can create virtually anything in the known universe in an increasing variety of materials from thermoplastic ABS or bio-degradable PLA to imitation wood, resin, and even titanium or chocolate! All at a cost of course as you can spend a million pounds on  a printer or as little as £300 for a DIY kit that rests on your desktop. I'm intrigued, confused and impatient as it all seems to be happening now as PC World and Maplins announce their first consumer products which by default have to be 'point and squirt'. 

  


Maplins Velleman K2800 3D printer kit for £690 takes three days to
assemble but at least you will know how it works.


     Basically there are several technologies in 'rapid prototyping' or 'additive manufacture' ranging from layered heated filaments (a  kind of robotic hotmelt gluegun) to laser resin and powder forming. I am focusing mainly on the cheapest technology here called FDM (filament deposition manufacturing) found in printers up to about £2,500. They do of course all use computer software and the two elements are the initial design software such as 'Ketchup' and the delivery-to-printer software such as 'Cura', '123D Make', 'Cubify Sculpt' etc. Some printers print remotely from a memory card.

       Now, obviously I've never used CAD in all my years as a furniture designer maker (as I refer to 'Ketchup') but my 3D roots do stretch back to grammar school when I was in class 3D, a reflection perhaps that creativity and academia were (are?) on a different axis! So, this blog really is a total beginners' guide with an attempt to bring together a lot of snippets of information I have picked up and I think my use of the word 'Ketchup' is apt in the importance of attention to detail when making a purchasing choice.

         The burning questions for me are quality, ease of use, variety of print materials, running costs (consumables and energy consumption), reliability and support. The initial cost of machine is secondary as it will pay for itself if these fundamental boxes are ticked. This is where the forums are a very good place to go if you can get a handle on the technical jargon used and of course You Tube helps enormously so my choice of videos here is carefully considered and they are of course mostly brief. But I wish they would use a macro lens on the camcorder!

    I'm going to condense a lot of ideas and snippets of information racing around my head as a result of some prolonged internet research. Needless to say I am still having difficulty actually getting my hands on a 3D printed sample and neither Maplins nor PC World carry printers in stock!!

     We are told the 'Makerbot Replicator 2' is the market leader but is not Open Source which confuses me as it has free shared download designs from a site called Thingiverse. 'Ultimaker 2' (recently released) is Open Source (accessible shared free online design files) and achieves 20 microns accuracy as opposed to the R2's 100 microns (still very good) so these are possibly two of the top contenders. The PC World 'Cubify' achieves passable print resolution at .2mm (200 microns) and does not have a heated bed which is needed for the stronger ABS which in any case is only 30% as strong as injection moulded ABS. 

     The 'Formlabs 1' printer uses a stereolithography resin laser process and achieves 16 microns which is best resolution under £2.5k but you have to dip each component in a cleaning solution and as far as I can see it cannot create rubberised objects that the Ultimaker 2 does. However, I expect that will all change. But it looks a bit laboratory like to me and the resin isn't cheap.  


                                  

Formlabs stereolithography resin printer for around £2,000
 claims the best print resolution at 16 microns  

A recent 'Kickstarter' funding legal battle might cause a bit of caution although I have read somewhere it is a tactic used by Apple to kill off competition even if they lose. 

      Elsewhere on the internet the current 'Top ten reviews' is a bit like 'What's the question but whose asking' as deeper research does not always deem these reviews reliable or meet your particular needs. http://3d-printers.toptenreviews.com/. Interestingly in his 2013 3D printer Guide (http://www.tomsguide.com/us/3d-printer-buyers-guide,news-17651.html) Tom likens the assembly of some 3D printers to putting up IKEA bookshelves - yeah, for some that task takes all of three days! The review is a good read about 3D printing technology.

     So what have I got to add? Well, the deeper I get into this my priorities are quality, ease of print and versatility of materials that can be used.     Speed is a consideration because even if you go off and do something else, if you print ABS it has a smell that will linger for hours. A chess piece as demonstrated in the PC World 'Cubify' printer can take about half an hour. Quietness also counts if you don't want to be driven insane by Darlek sounding noises throughout the night. In this respect the 'Ultimaker 2' operates at under 49 decibels. Size of printed object varies from a coffee cup (typically the Cubify) to a basketball (UM2) and I'm happy with that as I have no plans just yet to print out my next house which of course is already achievable.



The Cubify at around £1,100 is a basic point and squirt 3D printer using PLA filament
and able to create small objects, but not to any great detail. The filament is not cheap. 


                                     

Ultimaker 2, a significant improvement on the original and boasting best print definition,
speed and reliability from the small Dutch company

   
       Here are two videos, slightly longer, that caught my attention as being really interesting. One shows a simple USB and memory stick holder made from an open source design which allows you to tweak it and the other shows flexible belts being produced that have impressive detail and strength. Both use the 'Ultimaker' printer:



Thumb drive holder using rigid PLA filament on the 'Ultimaker' 
from a 'Thingiverse' customisable design




Flexible filament used on the 'Ultimaker Original' 
(3D printer kit) for creating toothed belts.

      The Makerbot Felix 2 is a new printer that boasts impressive accuracy at 50 microns and at (http://www.youtube.com/watch?v=DMz6KzacVQo) can handle a flexible 1.75mm filament called 'Arnitel Flexible Rubber' and this printer has really taken my fancy as it combines accuracy with a modest price. 

      Now, of all the confusing aspects of 3D printing the '1.75mm versus 3mm' filament debate is the most time consuming. All I can do is pass on what is my observation of the current consensus. 1.75mm diameter filament appears to have the edge by requiring less extrusion force, offering more immediate flow, quicker cooling, lighter nozzle head hence faster speed, but costs more! My guess is that shopping around (eg Amazon) and buying in the right quantities filament costs will come down.

     I was all sold on the Ultimaker 2 but am still awaiting replies from emails about delivery not that Makerbot are much better but at least as I write, I received an automatic email stating I should hear within a few days. Nobody seems to use the dog and bone (telephone) any more these day, so it is all a bit of a gamble.


                                       


Makerbot Replicator 2X optimised for ABS uses Thingiverse 
and offers up to 100 micron resolution at £2595 

  Before I wrap all this up, on the subject of finish there is a method, somewhat dubious, called acetone vapour smoothing which at least is worth taking a look at:



Acetone vapour smoothing on ABS which is a petro-chemical based plastic


     Well, apart from the health and fire risks of this method I would be inclined to avoid the extra equipment and time involved in this rather hit or miss smoothing process and invest in the best quality resolution printer. It seems there is already a lot of hit and miss in the technology, a lot of tweaking, such as getting the print bed perfectly aligned with the nozzle, getting speed and temperature settings just right for the model, creating support structures which different softwares go for.

In conclusion, I started out really liking the Ultimaker 2 but the Makerbot Felix 2 also looks promising to me, trading off not quite the print quality but a more confidence boosting service (currently?) for a minimal looking machine (that always grabs my eye). And the bonus of the 'awesome' Makerbot Digitiser scanner, ideal for someone like me before I learn how to use Ketchup. One small observation is that the shorter feedin tube on the Felix for the filament looks as though it won't cause as much friction as some of the other models when using a rubberised filament. I can't see a built- in digital controller, so there will always be plenty of questions and some of the answers only clear after you have taken it your printer out of the box.   






Makerbot Felix version 2 which deliver up to 50 microns in 1.75mm filament at £1440


And what did I say about printing plastic gnomes:




The Makerbot Digitizer Scanner available from Reprap Central for £1295


Some further reference material below but in the meantime don't take any of my ramblings as gospel as the technology will all have changed by tomorrow.