Info needed on current 3D printers

[simplyloco]

Hi folks.
I'm seriously considering buying a 3D printer when I get home, both to play with and possibly produce some one-off scale fittings for the Brit. Budget about £1k. Any up-to-date suggestions and experiences would be most welcome.
Regards
John

[Cro]

John,

From the point of the detail at that price I would save your money (no I'm not trying to sell you my stuff instead). Reason being is you can only buy hobbyist printers for this sort of budget and they won't produce decent prints to do either castings or patterns from. What you find with printers at this price which are typically PLA printers that print in one material have to build their own support structure and this is what ruins these prints because a lot of effort has to go into cleaning them up after and its never quite how you wanted it.

If you were printing things like axleboxes or very simple wheels then they are ok because you have little to no over hang on parts that need supporting. Another common issue is getting the print to stick to the bed. In a lot of cases these are glass but the material doesn't always stick and you can use a variety of method to try and get it to work - at work with our Ultimaker we still haven't found a perfect solution.

There is a printer on the market for around 3K I think that is a resin based printer than can be used for casting although I have not tried it but a friend uses it to produce lamps and scenery detail in 7mm. He did my very first speedo prints on it and despite a lot of time spent trying to calibrate it to the best resolution it was a good print. This is one other thing you find with the cheaper printers they are not always self levelling and need calibration quite often to get the best out of them.

Hope this helps and is not too negative.
Adam

[simplyloco]

That's good to hear Adam, I'll continue making up bits out of pieces!
John

[mattb]

John,

There are number of good online print houses where you can upload your models get instant quotes in multiple materials including metals now, I have used these for both work and home projects. This gives you access to the latest printers and materials without all the hassle that Adam describes. I have had well known 3D printing companies scrap multiple prints after hundreds of hours build time. If you just want a few parts it is probably a better option from a financial point of view. If you do this its worth understanding how they cost the jobs as I have perilously put small parts onto a tree (like airfix models) and got significantly cheaper prints. I expect you could get quite a few models printed for £1000

Were you planning on printing a PLA/ABS pattern and then sand casting or maybe investment casting?

[simplyloco]

Hi Matt. You are quite correct: I can get a lot of models printed for £1000. Thanks for the info.
John

[r707]

Hi John -
Only just seen this thread - and I would simply echo Adams comments about the justification of cost for a `desktop 3D printer´ vs the print resolution and post-finishing required to make patterns suitable for invest casting. I have been producing invest cast parts from 3D printed models for a few years now - and having previously worked in-house for Europe's biggest online 3D printing company here in the Netherlands, I can say with confidence that parts anywhere near the dimensional tolerance and surface finish required for detail parts only come out of machines that are ± USD$25k printing in high detail resin material (FDM machines printing @ 33um UHD & 16um XHD), and SLS nylon (selective laser sintering @100um in PA6 or PA12 material).

What is fundamental to the 3D print process is the 3D printer file (.stl) required to print the part in the first place -

So I would also say; save yourself the 1000 pounds and spend it on 3D models produced via Shapeways/ Imaterialize / 3D Hubs - (or another local to the UK is Impossible Creations). Although you may not get a perfect print *every* time from an online 3D print company - user control over print orientation (critical to determining which faces have "stepping" or print lines) has improved markedly over the past couple of years. So at least now these issues have been somewhat reduced.

However, that is all to say that if you just want a 3D printer to play around with and do fun stuff with kids - then by all means go out an buy an Ultimaker (or similar) and you can have a lot of fun. It will even produce some basic low detail patterns that with some clean-up would be suitable for invest-casting or sand-casting (such as horns or cylinder blocks) - so I can encourage you to purchase one for self-learning purposes.
All I'm really saying is just to manage your expectations :-)

The last point I would make is - 3D printing is just a tool - and its not the 'core-business' of model engineers. Personally, I would take that money and invest into improving or upgrading your machine tools. A thousand pounds goes a long way toward fitting digital read-outs (DRO) - and therefore infinitely more useful in the long run to produce a more accurate and precision-made steam locomotive.

If you're a complete beginner to 3D CAD -> why not enrol in a local beginners course in 3D modelling? Nowadays I would expect these kinds of courses to contain a portion on 3D printing and optimising / exporting model files anyway...
Best of luck whatever choices you make -
Cheers,
± Phil

[simplyloco]

Thanks Phil, all useful advice. Or should I say Danke Vel! I'll give it a miss this time round, and as I have a full set of slip gauges and Autocad 3D I'll spend the money on some more riotous living!
Regards John

[daveburrage]

Someone was selling a 3D printer at the Midlands show last year, I think it was only £350 ish. The models looked quite good to me. It used a plastic wire of some sort. If I hadn't already made all my patterns I would have been sorely tempted.

Is there a problem with this sort of printer?

regards

Dave Burrage

[Cro]

Dave,

These are the types of printers Phil and I have mentioned and although they look good at exhibitions they are printing models that typically favour the process for demo reasons for example low to little overhang so no support required and a small footprint so less chance of lifting from the bed. They also spend a lot of time calibrating the machines to produce the optimum print which is all well and good when you know how and the printer you have designed but it's not the easiest thing to get right.

At £350 they may be ok but like with any tools, if it's so cheap why? - quality? That's how I see it anyway.

Adam

[abby]

I would also consider the cost of the print media , like 2D printers the cost of the ink eventually outstripped the cost of the printer.
Whilst owning your own 3D printer might be very convenient the online agencies offer a very fast and economical service supplying prints of far superior quality than any current home machine output.
If you want metal parts from your 3D home print you would need a printer capable of printing wax or at the very least a plastic media that can be burned away without damage to the investment mould.
Metal sintering laser printers are very expensive !
If you can't print wax which is the easy route but not necessarily the cheapest, then you need to produce your wax patterns by the conventional flexible mould and liquid wax route which is not as easy as might be thought
I am of course assuming that we are talking of producing highly detailed parts that can only be cast by investment moulding.

[terryhowlett]

Hi John,
Never thought I would ever be offering views or advice to you sir!
Two of my sons are quite into 3D modelling and printing. One has actually earned some revenue using it, however he tends to do his modelling via 3D software and uses agencies like Shapeways et al to print his models. He has done mostly figures and Jewellry, as he is more on the artistic side of the family, but he did do me a couple of very small scale model aircraft components, which I subsequently took moulds from and cast in resin. He and his older brother have looked into getting a 3D printer and even tried to persuade "the bank of Dad" that the investment would be worthwhile, but his and my own conclusions are in line with the good advise I read above, certainly for the moment.
I'm sure the new technology will evolve into higher quality and quite capable home printers. Meanwhile as Phil suggests above, 3D software packages would be great way to get into this more and the end results can always be produced through a third party albeit at some expense!.
If you get down to Dorset in the summer you can see and feel some of the stuff he has printed ................. I will get those drill bits sharpened yet! :-)
Terry

[simplyloco]

Jan 10, 2017 13:44:28 GMT terryhowlett said:

Hi John,
Never thought I would ever be offering views or advice to you sir!
SNIP
If you get down to Dorset in the summer you can see and feel some of the stuff he has printed ................. I will get those drill bits sharpened yet! :-)
Terry

Hi Terry, and your compliment is well received though not deserved! I'll stick with brass fabrication for the time being. We are selling Hugo the Hymer when we get home in the Spring, and we will be staying in the UK for the foreseeable future, so hopefully we will see you. Jan's son has been living with us for three years, together with all of his  possessions scattered around our property - including the pottery and most of the garage - but he moves out this month having received  a most favourable judgement at Court enabling him to buy a house locally, so I really will be able to get at the Brit on my return. Jan tells me that I will have to sell the 911 as the Brit won't fit in the boot - sorry, bonnet - and I have to get something practical but boring, perhaps a Honda CRV...
See you soon.
Regards
John

[mrmoo]

And I am going to disagree with quite a lot of this. I have a prusa i3 mk2. It will and has printed to a resolution of 50 microns. Yes, it takes a little time and "fettling" to get it to print nicely at these levels but there are so many variables to play with. Oh yes and the kit was a shade over 600 quid, built, calibrated and printing in around 8 hours.
i will post pictures, if anybody would like to see.

cheers
ben

[mrmoo]

I feel I need to expand on my last post. Please bear with me, I really struggle putting my words/thoughts into the written form.

All my prints, so far, have been done in 1.75mm PLA with a 0.4mm nozzle. Other nozzles are available from 0.15mm to 0.8mm and in a variety of materials from plain brass to stainless steel to hardened steel and now in ruby! Yep, industrial ruby. Some filaments, such as carbon fibre and the metal fill, copper/brass/bronze filaments are very abrasive and will wear a nozzle away very quickly. And ive just found stainless steel fill too.... I mean they even 3d print chocolate!!!! As well as concrete, an enterprising bunch have taken a very large printer and have printer mud huts with a traditional mud/straw mix in Africa.
This technology is really still in its infancy and improvemnets/advances are being made almost daily. Agreed that for some things, like the beautiful small scaled parts that Adam makes, the tech is not there yet......

i'll sign this off with, for the money my money would be on the Prusa, every time. If you dont like it, it will sell. And probably very quickly. There are currently shifting 6000 units a month, with a 7 week wait list the last time i looked. they now also do a 4 colour MMU setup that is retrofittable to the i3.....
As with any machinery purchase....research, research, research

HTH
ben

[Roger]

Hi Ben,
I just looked up the printer you mentioned and there's an interesting development they have which allows you to vary the resolution on selected areas. It would be better if it figured out the roughness for you, but being able to shade in an area for better resolution is a good start.

Personally, I don't see anything that stands out in the design of this printer, maybe it's a bit more rigid than some? A friend has a printer and he spent ages adding braces to stiffen it up, and made the bed stiffer too. It's transformed the quality.
I get the impression that most printers are pretty dire when it comes to rigidity, and there's not much to tell between them other than that. Most of them certainly look pretty feeble. I suppose the designers think that because there are only small forces on the nozzle, the whole thing can be weak. That's not actually the case when you start to increase the drive speeds, because the accel/decel forces come into play. There are also small forces created when the filament is being pulled from the reel. All deflections are going to be greater if the structure is weak.
Unbraced frames are likely to move over time with temperature too, so these gantry machines would probably all benefit from additional bracing.
It's easy enough go beef them up though, so I'm not sure you need to spend all that much money on one if you're prepared to put in a bit of effort. All you need is the basic drive system with reasonably good quality leadscrews and linear bearings, the rest can be improved.

[mrmoo]

Hello Roger,

i'll agree with all of that. When i get 5 minutes i will take some pictures of mine and some of the items i have printed and start a thread so all can have a gander.
All the extra bracing you have mentioned is in the future pipeline as i start to want better and better prints. The i3 is quite heavy, 5 or 6kg i reckon, and isnt too bad on the rigidity but there is always room for improvment ! Speed does indeed have a huge impact on the quality of prints. I have read of people using speeds of 100 mm/s but i dont really go above 50 mm/s unless its for infill at 60 mm/s, fine detail is done at 25 mm/s. It is not a quick process.....

cheers
ben


I would like to say, I like the discussion on this board, each side has their say without the "brat" mentality i usually end up seeing on forums.

[mrmoo]

20170922_230050 by , on Flickr


20170411_225454 by , on Flickr

[Roger]

Thanks for posting the pictures Ben, the print quality looks excellent. The distance between the two rails on the head carriage is quite large, so that's a plus. It's a pity they don't make them with larger sized linear bearings, that would help a lot too. It's tempting to just buy a head and make the rest, it all looks pretty simple. Do you know if it's possible to buy the control electronics less the steppers?

[mrmoo]

The frog is done at 50 microns, IIRC he was the first one i did.  I now use that model as a test for new colours.  Filament pigment "can" have a slight effect on how it prints.  I must have printed a dozen or more by now.  The other is the parts for a rotating scanning table that uses a mobile phone to take picture before stitching them all together to make a 3d model.

yep. You can buy all the components seperatly from i believe.... you might have to have a chat with the online support to open some of the "secret" shop for you, from what ive heard....
Personnally, I would buy a kit. Build it, then use it to print its upgrades..... machines making machines....
i think that that would probably be the cheapest way forward and you know its all going to work together. Spare parts and support are very good. The heated PEI build platter is considered to be one of the best available and has mesh bed levelling built in. Its one hell of a clever bit of kit. Can you tell i love mine...

cheers
ben

[kellymaybury]

the quality of the print will reflect in the quality of the castings. FDM printers leave visible print lines. These lines can be mitigated somewhat by a post process where a solvent is misted onto the printed part as it is turned on a turntable to ensure even coating. This process is often refereed to as polishing, however the process is not polishing but dissolving the outer most surface layer. This process is fine for the larger prints however for very small stuff or writing may not give the result you are looking for. The process with the highest resolution is know as SLA. This is where a resin is placed in a heated tank and a laser solidifies the resin and the part is drawn out of the resin. Of course quality comes at a price. I recently bought one of these printers and i am producing stuff for the home market ( down under) and also for the US market. My suggestion would be to have a look around and find somebody to print them for you. I am currently making some parts for a US supplier who was using shapeways. His cost price for the part from shapeways was $US265 in silicone bronze. My price to him was $A26. Working from home and low overheads make all the difference in the world. I have given up trying with photos here(( i am too stupid so you can PM me if I can help.