3-D Printing

I'd like to start a thread discussing the best way of covering the field of 3-D printing in MEW. It's probably the most revolutionary of the 'new' technologies available to model engineers. Although it requires us to think in new ways, the basic principles are easily understood and my understanding is that it is not difficult for anyone familiar with CAD/CAM/CNC techniques to achieve results with it.

I'm aware that this is probably a rather short term debate. By 2020 I would not be surprised to see constructional series that included turned, milled and printed parts as a matter of course. But the next five years or so will see the further maturation of this technology,. and some of the things on offer now will turn out to be dead ends or a waste of money and effort. I'd like MEW to take a role in helping readers make the right choices, to know if it's right for them and to make sure they don't end up with expensive white elephants gathering dust in the workshop.

So, what are the questions you have on 3-D printing? What aspects of it are generally understood and what needs to be explained?

What sort of things might you use a 3-D printer for and what sort of articles would interest you?

What level of coverage should we give 3-D printing in MEW?

What are the popular machines 'out there' and which are the ones that offer most to home workshops? What sort of budget are people likely to invest in 3-D printers? Should we focus on the RepRap type machines or look at the next level up?

What sort of software do you use, and what would you recommend for the beginner?

So, over to you...

Neil

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Neil,

Your post is an excellent "starter", but I will respond to that one question, if I may:

Please concentrate MEW coverage on the next level up

The web is loaded with information about RepRap, and there is no hope of MEW matching that content. So please put our coverage in the areas where we have the special abilities.

MichaelG.

Neil;

In some ways, I think MEW is about 5 years too late. Reasons below:

I do subscribe to Digital Machinists Workshop, and enjoy the writings of Ed Nisley - he also has a blog **LINK**

I think a lot of the home tinkering for 3D printing is now covered well by other publications, catering to the younger generations.

Me? I'm into the 3D software behind computer graphics, and CNC applications for model engineering. My blog, for those interested: **LINK**

I do have a friend/colleague who is very involved in Shapeways, a 3D printing shop of choice. (we worked on standards for the underlying graphics they use, and on many other graphics-related things). Shapeways, and equivalents, produce very good work, much better than home machines can. And of materials that produce acceptable results for model engineers and coal fired steam locomotives, of course!

If you want a question, I wonder why the heck STL file formats still exist, when other formats (e.g., X3D) exist that can describe geometry mathematically, (allowing the printer to choose the resolution) and colour areas, and even texture map for colourization of the printed item.

So, while MY focus is in producing models using more modern techniques, I'm sure that your readers would be interested in the "modern techniques" side of things.

I hope you read many rays of optimism in the above, sometimes the printed word can be emotionally interpreted in many ways.

One final note: presented "Model Engineering" at the Ottawa (Canada) Maker Faire last September, and noted the reactions to my CNC-ized Unimat SL lathe.

Reaction 1) People approximately 40 and under. "LinuxCNC and a G540, but what's that machine it's moving?"

Reaction 2) People approximately 50 and older "Unimat SL - I had one of these, and a Mark1 model, too. But, how come it's moving on its own? Is that magic?"

John A. Stewart.

You should print a complete how to make a 3D printer in your home workshop series.

It needs to be rigid and strong. The aluminium sections would probably be fine but I think it needs to be a portal machine rather than a single upright with the head on.

Most of them now are far to flimsy.

Next you need to cover the software. I think many model engineers and home workshop enthusiasts can do 2D cad but, like me have never had time to learn 3D cad. To make some thing useful such as a pattern you need to be able to draw something in 3D then put it through the slicer software to turn it into a 3D printing program.

You also need to be able to produce a pattern with a smoother outside than currently done.

I think this comes down to rigidity. I suspect that if you have a rigid 3D printer the resulting object will have smother sides.

regards David

Hi Neil and welcome!

I saw the 3D printing displays at Sandown and was very much reminded of the early days of microcomputing (1970's 6502/Z80). I spent a lot of money on a Z80 based Nascom II and then time building it and even more time typing programs into it. This 3D printing tech seems to me to be at a similar stage. These days the idea of building a PC from component level would seem somewhat bizarre.

So whilst my immediate reaction was that 3DP might be useful to me for the smaller model components (either for use directly or as patterns) that I currently have to fabricate - with my current grasp of 3D CAD it is probably faster for me to just make these bits rather than print them.

So I don't think I will be too interested in owning one of these devices until I am able to download a (pre-designed) 'part', simply scale it to my requirement and just print it. It may well be in the future that MEW/ME articles will have links provided where the author makes some component parts of the design available for download (and printing).- and this would be a real incentive to adopt the technology.

What I wouldn't want to see is (to me) the rather annoying separation of 'hardware' from 'software' such as the homebrew DRO recently published. I might never build one but I would have been interested in the Arduino code used (as I have a Uno). So design/construction articles where 3DP is used but you have to (metaphorically) "type" in your own design code would be a big turnoff.

I'm sure however that this technology will be driven by (other mass) markets and I'm sure new standards and norms will emerge - especially in these days of Open Source.

Regards,

IanT

IanT has summed it up. After spending many thousands of pound on (now defunct) computer hardware, especially in the very beginnings of the PC my attitude is quite simply, Give me a call when it all works.

I will not be spending any money on a 3D printer anytime soon and IF i need anything 3D printed I will just continue to send a drawing + money to one of the reputable printshops.

At this stage of the game, I have absolutely zero interest in learning 3D CAD. I have far too many other things going on. So, having said all of that, I am always interested in reading about the latest developments.

graham.

As a small company that uses 3D Printing as part of our manufacturing process, I can see that there is a distinct lack of good quality 3D printing at an affordable price out there. There are 3D printers, and there are 3D printers!

The one thing that unites them all is the high cost of the consumables, but unlike ink, these are unlikely to reduce by much as the years go by, simply because of what they are made of.

The 3D printer we use is very high resolution, and can print down to 14 micron layers - this is damn fine, but is very expensive to run and maintain. The cheaper the printer, the worse the quality.

Then there are all the different types of 3D printing - FDM (powder), smudgy plastic wire melting blobby stuff, and liquid poly resin (the hi res stuff) - maintaining quality and dimensional stability as time goes by is also important in model making/engineering.

Post edited by JasonB to remove possible commercial interest

Edited By JasonB on 11/02/2014 14:21:54

How are you going to send a drawing to a 3D printers if you then say you won't learn how to produce a 3D Cad drawing to send

I'd like to see something along the lines of what Andrew posted showing the various finishes that can be obtained from different levels of machine, type of media and resolution plus ways to refine the printed surface such a susing solvents.

Would also be interested in seeing the process from print to finished casting using both sand and lost PLA/wax methods.

I'm unlikely to want to build one so that side of things would not have much interest but the things mentioned above would help me decide what sort of machine to buy and what results to expect from it.

J

Personally I am not interested in knowing about the different file types, I can't control or change them.

Cheap machine building is already coved but the main differences I see are there are open sourced programs what do the slicer routine or the high up machines that have dedicated software to the machine [ usually incorporating their own mother board ] Again whilst you can be made aware of these you can't do nothing with them.

Readers of the mag are more interested in practicalities than theory, Andrew has shown some good examples.

I have two applications in the pipeline at the moment. One is very simple and it's just a 3D printed pattern that has gone to the foundry for casting, not even a complex part but it's far quicker to print it as a pattern that faff about with the brown stuff. unfortunately it's proprietary so I can't show a picture but I could soon do another part I could show.

Second one is a 3D printed part that was done to try a design out and it's not that complex but would be hard to make in a home shop workshop by virtue of it's shape.

I then realised that this part is so lightly stressed that if it was made thicker I could actually use the 3D plastic part in the finished design, Each piece would take 40 minutes to print but the metal parts would, even when geared up take 2 to 3 times as long.

3D CAD is a mine field, Ask 10 people what CAD program they recommend and you will get 12 answers.

Problem with 3D CAD is it's expensive so the choices are reduced, You will get people with ripped off copies of solid works saying use this but it you don't want to break the law you are looking at £5,000 plus about £1,000 in annual maintenance.

Then there are free version of 3D CAD but because they are free they are usually a home written work in progress [ remember no free lunches ] that only the most determined can get to grips with.

So end of day out of all the programs out there it boils down to about 3 or 4 affordable ones, and of these no two people are going to agree which one is best or easiest to use.

So my views on this are yes there is need for an article but it will have to be that generic to suit everyone.

I'm still a real newbie here, and still trying to get to grips with the ME/MEW scope (e.g. "modifying your ML7" in ME recently?) so whatever is done with 3D printing across the two publications needs to (should?) surely respect the differences.

Some/a lot of the above seem to be more ME-related i.e. actually making things?

But I'm more than happy to be corrected

Edited By Martin Millener on 11/02/2014 17:30:12

Congrats Neil and very many thanks to David. Nearly all home made 3D printers are extruders. As a user I would suggest that the stiffness of many machines is not a great issue, the material is deposited at very low pressure in a molten state. Rather there are many other reasons for poor finish, stringing and striations. The last Sandown showed a few different ideas in extruding machine design, although there are some good commercial models some of the home made ones are every bit as good. A machine of this kind is a whole lot of challenges for home workshops, it's bits we all have with some cheap other parts. It's turning and simple milling but more it's using your brain and hands to make a better one.

Extrusion and plastic are not the only options, for example you can shape a hard wax block to produce a lost wax casting with very high precision. You don't need to use a cast iron machine weighing 100Kg to do the shaping, a home made wax shaper could well be an interesting project. Hot wires or heated blades for cutting linear features, conventional milling / drilling or heated tubes for recesses/ holes. The wax is re-useable too! Aluminium and other non-ferrous casting is well inside the ME domain and practiced by many.

There are many other 3D printing methods, plaster powder and water drops, UV cured liquids and metal spraying are just a few different forms. There are a great variety of different ways of making 3D objects but what is very striking is that a lot of the actively interested young people have the ideas but not the engineering experience or facilities to produce great machines while those older people have a vast skillset and machining abilities that the young need . Pity the two groups don't get together more.

In the UK we have the additional irony that -having removed machine tools from schools- kids don't get hands on ( and therefore brains on ) with milling and turning while the machines that are ex-school are in the hands of the people who now don't have industrial jobs but have a super abundance of fabrication skills and technical knowledge.

So my take on 3D in MEW is to suggest that MEW have a competition to make a machine that can produce a variety of complex shapes by addition or subtraction directly or can then be cast via resin, wax or metal by any method up to the sides of a 150mm cube ( say 6", machine weight to be under 30Kg. So a CNC mill would be too heavy, A 3D extruder could do it but another type might win out on sheer finish or build speed. Perhaps the competition could specify a test object that should be printed to qualify, then anyone who could would be challenged to print a new mystery object at the next Show. Or is that too hard?

Billy.

The same way I do right now Jason, pay someone.

I really do not mean to be contentious about this, and this is not directed at anyone. But to become really competent at CAD, any version, is not an overnight 3D CAD (or 2D CAD) for Dummies read. It takes a long time to become very competent AND quick. Also, as has been pointed out, good software is not cheap.

I am very interested in the technology and I think that the possibilities are very, very exciting. I would much rather just give one of my (now infamous) pencil sketches to someone and let them come up with the drawing, usually before I can get the compfuser turned on.

As an exercise I think a 3D printer would be 'fun' but to get the accuracy I need for anything a £500 box of bits assemble it yourself RepRap machine will not cut it. I don't need another hobby right now and I have a finite amount of time for the ones I do have.

graham.

I don't have the space in my shop for another machine, so I am looking at making a print head for my little Denford Novamill. There is a plugin for Mach3 allowing it to run a 3d printer, so the controller can be dual purpose. So far have made the filament feeder which is a "Bowden" type that will go atop the spindle with the feed tube down the bore to an extruder fitted to a taper mandrel. (Must remember not to turn on the drive motor!)

This suggests that a good approach for a maker's workshop could be a router that could do light aluminium milling, plastics and wood of course, or the spindle could be replaced with a print head for 3D printing. One could also print an object then clean it up to size by milling.

People keep harping on about the accuracy needed but if you know what it is before hand then how can this be a fault if it fits into your sphere of working ?

Does your local foundry work to tenths ? Is the finish absolutely smooth and blemish free ?

No, if you are making parts fully machined all over then it's a valid excuse if they won't fit tolerances but does everyone fit into this slot ?

How many times did we hear in the early days of CNC that quote " This isn't for me " but later they tread the path.

Things move on machines change and most importantly software gets simpler to use.

Perhaps a more truthful statement is "It's not for me at present but I an keeping an open mind "

I see MEW214 will have an article (1 or likely more installments, I suspect) on "Making a heavy duty REPRAP 3D printer"...

edit: MEW, not ME

Edited By Martin Millener on 11/02/2014 22:08:54

Notwithstanding the self replicating concept of RepRap and other simple machines the plastic & threaded rod from B&Q are weaknesses. Perhpaps a valid series would show the upgrading of such a machine with Model Engineering skills ie milled metal and turned leadscrews. With cost/time/space contsraints there might be an opportunity for joint projects between Model Engineers and computer buffs

no interest to me at all,

and i am sure your advertisers (of castings) wont be too happy either.

cheers,

julian