Buying a 3D printer, but which one?

[Michael CheckleyParticipant @michaelcheckley34085]

Posted by Peter Edwards 5 on 15/04/2016 13:41:30:

Further to my doubts about 3D printing and spoiling the party, I would like to add that I do believe the method can be very useful, and I would really like to believe I can have one on my desktop so I can print parts out from Solidworks. At the moment the machines don't produce sufficient accuracy – they will improve in the future I am sure.

Claims that 3D printing is the manufacturing of the future are a bit far fetched – mass production??

Machines already exist that improve productivity with multiple nozzles printing simultaneously. Mass production in the true sense of the word is achieved using techniques such as injection moulding. 3D printing is already being used to make tooling that increases the speed of injection moulding compared to conventionally machined tools.

Surface finish and accuracy is not an issue any more as hybrid machines can both 3D print the bulk and then machine critical features.

The biggest issue yet to be overcome is the consistency of material properties.

[MuzzerParticipant @muzzer]

Posted by Peter Edwards 5 on 15/04/2016 13:41:30:

Claims that 3D printing is the manufacturing of the future are a bit far fetched – mass production??

Well that's just a dumb claim anyway. Dunno who came out with that one but can't imagine anyone paid much attention to it apart from cynics and children.

3D printing is just one tool of many. SLA printers have been around for decades but the recent excitement centres around the simplicity with which anyone can get involved and the very low cost of doing so.

3D printers, CNC routers, CNC lasers, CNC machine tools, CAD and CAM in the home, robotics, Arduino / RPi etc etc are all taking us in a future direction and have a lot in common. Certainly, you can see that they have a lot more relevance to manufacturing in the future than drawing boards and manual machinery. It's fascinating to wonder what home workshops will look like in 50 or 100 years time….

[AjohnwParticipant @ajohnw51620]

They can be used for fairly large scale production. It just needs lots of them doing the job. There is a strong possibility that is how rep raps etc are currently being manufactured.

John

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[Michael CheckleyParticipant @michaelcheckley34085]

John,
Did you machine the bore of your gears for the bearing or was the print good enough?

[AjohnwParticipant @ajohnw51620]

It's some one else's work off another forum Michael. Some one that has done lots of it. She does a lot of printing often using 2 home made printers. I do know that she also uses this one at times

**LINK**

How ever people get good results from RepRap Prusa's as well.

Frankly I think a lot of the performance that can be obtained with them is down to the user.

John

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Edited By Ajohnw on 15/04/2016 20:11:49

[joeyParticipant @joey]

I obtained a Velleman Vertex and i have excellent results from the start.

[Clive HartlandParticipant @clivehartland94829]

I see someone has just made new feet for a Duck that lost them due to frost bite, TV shows the Duck being able to walk again! So that's one good use for them.

I have been thinking that they could print out plastic honeycomb as a foundation in a hive? It is possible to buy plastic/resin foundation which is made by impressing the image of the comb between two sheets embossed with the honeycomb.

[Ian S CParticipant @iansc]

There is a dentist in Christchurch who is advertising the fact that he is using 3D printing in the manufacture of dental plates.

Clive, if you could print with Bee's wax, you could do the bees out of a job.

Ian S C

[Anonymous]

Posted by Peter Edwards 5 on 15/04/2016 13:41:30:

Further to my doubts about 3D printing and spoiling the party, I would like to add that I do believe the method can be very useful, and I would really like to believe I can have one on my desktop so I can print parts out from Solidworks. At the moment the machines don't produce sufficient accuracy – they will improve in the future I am sure.

Peter: At least you're being consistent in your viewpoint, but I'm afraid you're a bit behind the times.

I use my 3D printer to produce production parts for an air quality gas and particle sensing box. While some of the parts are simple, others are complex and would be very difficult to produce by other means, except possibly injection moulding. And there the cost of moulds is currently prohibitive for our company.

As for accuracy here's a picture of the prototype for the gear change mechanism on my traction engine:

The mechanism was prototyped as I completely redesigned it, since the drawings were in fantasy land. The picture shows the mechanism after the main casting had been machined, originally this was 3D printed too. I had to tap some holes 1/4" BSF in the 3D printed parts, but otherwise everything fitted together pretty much off the printer. I cleaned out some of the holes with drills, but the 3D printed mechanism worked a darn sight better than the fully machined metal version. I've lost count of the hours faffing about with the metal version trying to get it to work smoothly.

Andrew

[AjohnwParticipant @ajohnw51620]

Initially I intended to buy the older Velleman but was unfairly put of by a lady who had destroyed one – lots and lots of use and I expect not cleaning the slides periodically. She just used the bits to build another one. My initial thoughts going on from that idea was to buy one and if needed use the bits in another one but if attention to detail does make any difference I concluded may as well start from scratch because over all it would be cheaper.

For guides I was pointed at this site. The same lady had built 2 other printers using the guides they stock. They have some other interesting bits too.

**LINK**

Instead of using lead screws etc she used a fishing line referred to as braid wound round drums. It uses technical fibres that have very little stretch. It seems they do need retentioning occasionally. It's turning out to be a popular way of obtaining the movements. The braid is wound clockwise and anticlockwise around a single drum plus a pulley at the other end. She used line with a 100lb breaking strain. I'm aiming to use glass reinforced timing belt but I need to check technical data on pulleys sizes etc. Looks like I can get a resolution of 15um / 6/10ths or lower with a bit more complication if needed. It could be that the braid is better than the timing belts usually used on 3d printers.

Some people use 3mm filament. I get the impression that this will need a gear driven extruder. The thinner filament seems to be much easier to extrude going on the more recent extruder designs without gears. Available nozzle diameters seem to be the same – up to 1.2mm and 1kg of material is 1kg what ever diameter it is.

Example parts showing accuracy may be a bit misleading. If I printed a nut and bold and the fit was no good I would simply alter the sizes and print it again. Samples of another sort – who's going to send out a bad one and they might have been printed very slowly and will in any case have been printed by some one who knows what they are doing and they will have printed many before.

I'd guess that they could be used to print honeycomb foundation. Size might be a problem price wise and there may be a need to be careful about the choice of plastic. PLA might be ok but ABS and nylon more recently are possible. I think there are others as well now. The main changes seem to be extruder nozzle temperature changes.

**LINK**

John

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Edited By Ajohnw on 16/04/2016 10:56:00

[Enough!Participant @enough]

Posted by Ian S C on 16/04/2016 10:14:41:

There is a dentist in Christchurch who is advertising the fact that he is using 3D printing in the manufacture of dental plates.

Then there's this.

[Russ BParticipant @russb]

I failed to print the dreamo test (I got most of the way their then accidentally shorted the terminals on the LED light, which cut the machine out!)

I was 85% of the way their but I would call it a failure. Basically, the overhang edges of the part were curling up more than I'm used to. This is likely down to a few factors but this is typical ABS behaviour. The test print is a real overhang stress test!

I can change my nozzle to 0.5 or 0.7 which will help.

I can also increase my infil from 20% to 30% which will give it more rigidity and foundations to anchor to.

I can lower my nozzle temperature to 230 (from 240) so their is physically a lower temperature differential

I can print a wall around the part to keep the heat in.

I can turn up my printed bed to maximum and print the part just off the center as it was covering the sensor so it will have raised the temperature of the bed in the middle, fooling the software to almost turn off the whole heated bed, resulting in a harsh and unexpected temperature differential.

and I could do all this and get the same results.

This test piece is really an overhang stress test – The vertical surfaces are beautiful, nicer than the ultimaker in ABS, maybe on par with the Zortrax, its so smooth better photo's might be required to judge fairly.

EDIT* Also, I was printing very very fast (circa 40 minute print time if it had completed) so I achieved a very fine finish which I wasn't expecting at those speeds although I had a feeling it wouldn't make much difference. I think the Rostock sometimes favours high speed printing as the hot nozzle doesn't dwell as much in one spot.

Mine just looks like its wearing rough trousers (as some of the samples shown do, but worse)

I would like to know the print settings used (shell thickness, infill, print and bed temps etc) so I could compare.

Edited By Russ B on 19/04/2016 09:56:54

[Michael CheckleyParticipant @michaelcheckley34085]

Unfortunately I havnt got the settings used on the Dreamo`s and I cant ask as I have purchased my Ultimaker from someone else

The final decision was between the Zortrax and the Ultimaker. The finish on both was so close that the versatility of the Ultimaker became the deciding factor. The Zortrax is a superior build quality and may have just tipped the balance of the print quality but it is too restrictive for varied hobby use. I was told these two are the biggest sellers and both could be seen printing at MACH, not much point looking at a 3D printer that isn't printing!

I found 4 suppliers selling the Ultimaker and non were particularly bothered about making a sale, even a free roll of filament would have swung the deal. In the end CREAT3D had a show offer at MACH so the purchase was made. I have printed a couple of test prints using PLA and I am very impressed. The possibilities are endless so watch this space for photos of new projects!

Thanks to all that gave useful advice and helped me make my decision. The only request I would make to those that promote their favourite machine would be for them to put photos up of their projects so some real world examples can be seen and compared.

[MuzzerParticipant @muzzer]

There are some examples of parts I made on an Ultimaker2 in my albums.They were used to check out the CAD models I'd created before cutting steel. These were half scale so they would print quicker (presumably almost 8 times quicker).

Also printed some parts for my Bridgeport clone Z-axis CNC drive, to check they fitted the machine as a sort of idiot check.

Did quite a few other parts but these are the ones already in my albums. Despite appearances, not everything was made in garish orange. I probably used it for my own parts, reasoning that nobody else would be wanting it! The clear stuff was pretty good although it would be better described as translucent due to all the voids and inclusions.

As mentioned, ABS was quite a bit trickier, with the extra heated bed parameters to play with. PLA was the default and worked fine for most things. I didn't get to try out any of the flexible materials.

Murray

[Anonymous]

Despite the naysayers here are dozens of 3D printed production parts (in XT) that go into air quality measurement instrumentation, plus a couple of prototype cases (top right) for Cambridge University:

And in PLA prototypes of my hollow pistons before making the real thing in cast iron:

Some press tooling in PLA:

And a prototype gear change mechanism for my traction engine; this 3D printed prototype worked a darn sight better than the final steel/cast iron version!

All the items were designed in Geomagic and printed on an Ultimaker 2.

Andrew

[VicParticipant @vic]

I belong to a model making forum and folks on there looked at but won't use 3D printers because the quality is so poor. Surface finish in particular on hobbyists printers is a joke as ably demonstrated by some of the pictures posted on here. I wouldn't like to predict the future of 3D printing but the poor quality, integrity and mind numbingly slow production means it's got some way to go yet. One day.

[Michael CheckleyParticipant @michaelcheckley34085]

Thankyou Andrew for adding the photos. It was seeing your real life applications that helped me make my mind up.

Surface finish is an interesting debate as given the way the technology works it will never be 'perfectly' smooth. From the samples I have printed I have been impressed with the surface finish given by the Ultimaker (the Zortrax was even better on ABS) and I would say the surface finish is far better than the shockingly bad castings us model engineers are happy to purchase.

No need to predict the future of 3D printing just go in to any major industrial player and see for yourself. I took some samples in to work to show my colleagues and have already been asked to write a proposal for getting a more industrial machine installed.

[MuzzerParticipant @muzzer]

If the superficial appearance is important rather than function and you are the type who spends hours polishing things up, you can get a similar effect with 3D printed items by hanging them in an acetone vapour. Lots of info out there if you are interested. Depends what you are after. No point going for the finest resolutions and surface finishes if you are making a press tool or simply want to check out the outline dimensions of something before making it for real.

There was a fine example on this forum last year(?) of an interesting jewellery ring that shows what can be done if you want.

These are all just tools in our chest. There's a place for them all if you have an open mind.

[VicParticipant @vic]

Chalk and cheese comparing industrial printers to hobbyist machines. One of the best uses I can see for hobby machines is pattern making for castings.

[Anonymous]

Only a few weeks ago in a thread on carbide inserts, Vic airily dismissed my comments, stating that he wasn't interested in what industry did. Now he seems to be dismissing my 3D printed parts solely because they weren't printed on an industrial printer. That seems inconsistent?

Confused of Cambridge

[NJHParticipant @njh]

Never mind Andrew – it's a nice day – go and get the glider out and stooge around for a while admiring the view. All things will return to their right perspective!

Norman

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Muzzer on 23/04/2016 13:28:46:

There was a fine example on this forum last year(?) of an interesting jewellery ring that shows what can be done if you want.

These are all just tools in our chest. There's a place for them all if you have an open mind.

.

Never has a truer comment been made than that ^^^

For reference, the ring photos are here: **LINK**

MichaelG.

[AjohnwParticipant @ajohnw51620]

I think that thread mentions a 20um layer and then finer. This is the problem with them. As the volume being printed increases the time taken goes up rapidly and the only way of speeding things up is thicker layers.

In this area it might be worth bearing in mind that typical reprap prusa offers 4um resolution on the z axis and usually 10 or 11 on x y.

Partly mentioned because I am oscillating between 5,10 and 15um but things like the reprap aren't that  bad really.

John

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Edited By Ajohnw on 24/04/2016 19:27:26

[Anonymous]

Posted by NJH on 24/04/2016 12:17:44:

Never mind Andrew – it's a nice day – go and get the glider out and stooge around for a while admiring the view.

Sadly not in Cambridgeshire. Started off blue and by the time I'd had breakfast it had overdeveloped. And then proceeded to get worse. Looking at the gliding club webcam not a single private glider was being rigged. Unlike yesterday when every man and his dog was rigging. It even induced me to go out to the club yesterday, but I got rained on driving round the peritrack. Which rather sums up the weekend, and most of this week looking at the forecast.

Andrew

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