3D printing - a home production revolution?

[Olly P]

Peter,

Try Auto-cads 123D program, believe it works on Vista - I'm on W7 and W10 so can't guarantee.

Olly

[Peter Miller]

Thanks. I will give it a go

[MaxG]

This is slightly off topic but still associated with 3D printing.

Rolls Royce are now using it albeit in metal, particularly high temperature alloys for their aero engines. Lasers are used for heat sources and metal powders as the material. It is known in their case as additive engineering and they are now designing parts with this production method in mind, as a way of avoiding wasteful machining of high cost alloys. Turning high cost metal into swarf is not good economics.

Here is another thing that lots of people on this forum should be interested in but perhaps not willingly!

A company I am associated with is looking at scanning people's hip and knee joints and then using that data to fabricate replacements that will fit the recipients body exactly without forcing the body to adapt to a one size for all which is where we are at present.

Just thought you may be interested.

Maxg

[Peter Miller]

Hopefully it will not affect me but sounds very good for those who do need it.

[Erfolg]

Max

The RR system sounds dead easy. Although in reality i suspect a lot more involved than a simple description implies.

Taking the process at face value, it seems no different to say adding metal to a worn shaft, as an example as an additive process. Or another way of looking at what is being done, a form of continuos casting. Both of these approaches, suffer from the generation of a grain structure, that is not ideal.

Continuos casting casting often getting around the issue by having a rolling mill type operation to create a favourable structure.

I am assuming that RR has been able to develop a process that has long range order at the atomic level, as in a single crystal structure. As these structures are significantly stronger than the common structures found.

I keep hoping that RCM&E will run an article, or a series on the various aspects of 3d printing, as there does seem to be lot of potential, as well as whatever the limitations are. Never mind the machines themselves, the computational aspects. Seems a big subject where most of us, if I represent the majority know nothing, other than a headline and some vague notions.

[MaxG]

Posted by Erfolg on 05/04/2016 13:50:31:

The RR system sounds dead easy. Although in reality i suspect a lot more involved than a simple description implies.

Taking the process at face value, it seems no different to say adding metal to a worn shaft, as an example as an additive process. Or another way of looking at what is being done, a form of continuos casting. Both of these approaches, suffer from the generation of a grain structure, that is not ideal.

Continuos casting casting often getting around the issue by having a rolling mill type operation to create a favourable structure.

I am assuming that RR has been able to develop a process that has long range order at the atomic level, as in a single crystal structure. As these structures are significantly stronger than the common structures found.

I keep hoping that RCM&E will run an article, or a series on the various aspects of 3d printing, as there does seem to be lot of potential, as well as whatever the limitations are. Never mind the machines themselves, the computational aspects. Seems a big subject where most of us, if I represent the majority know nothing, other than a headline and some vague notions.

Erfolg

Yes Erfolg you are right, it is in principle no different to building up a worn shaft, whether that be by oxy-acetylene, tig welding or laser. The process merely needs a heat source and a material source. What is different in the metal 3D printinng as used by RR and others is the precision of the very small heat source in a focussed laser beam and the precision with which you can manipulate the beam by robots and software.

I can see where you are going with your thoughts as to grain structure but not all as cast structures are not fit for the purpose for which they are used. If that was the case you would never use a casting and that is definately not the case. I do not know whether the RR additive manufacture has long range order but if it is not necessary then just use it as is. Single crystals are not desireable in all instances even if they are in the hot end blades. In reality single crystal structures are often weaker than their multi crystal counterparts it depends on how you want to use it.

Like you I might like to see a series of articles on the type of hobby 3D printing to give me a much better idea of the technology.

Maxg

[Ian Jones]

I can see the day when the RCM&E free plan will be on an SD card, perhaps not even that, more likely a download that you then send to your printer.

[Richard Harris]

I am in the middle of building a 3D printed Spitfire, willing to try anything new I have to admit my balsa bashing head has had to be unscrewed. Although in its infancy it is very clever, I am sure there will be a market for it in the future and if it brings in new blood that is a good thing.

Rich

[john stones 1 - Moderator]

Aint got a clue what you're on about or how it works....looks good though

John

[Olly P]

John, There are about half a dozen '3D printing' techniques out there.

The one we seem to be talking about is what is called 'Fused Deposition Modelling' (FDM).

It's really very simple, a thin 'bead' of solid plastic is pulled into the print head, heated up until it melts, and is pushed out of a small hole by plastic coming in at the back. This is smeared onto a print surface (known as a print bed) to make a shape by moving the nozzle about. The prnt head then lifts a bit and the process repeats, building up lots of layers that stick together.

Another way of thing about it is to imagine printing something with a normal printer. now put the paper in again and print more ink on it, and keep going. now instead of ink add layers of plastic 0.1-0.4mm thick. There you have FDM in simple terms.

[Olly P]

Posted by Ian Jones on 01/03/2016 00:26:31:

I'll be buying a 3D printer sometime this year, there's no end to the uses I hope to use it for, though it will be quite small scale stuff.

As for the future, they will be as common as TVs and microwaves. Instead of warehouses full of physical objects there will be data warehouses frull of 3D plans. When you need something new or to replace a broken part you will donload the data and print it. Of course there will probably still be a cost in the down load but it's an attractive business model.

Ian

Ian - I missed this one, if you want anything doing upto about 150 mm x 150 mm x 200 mm give me a shout, but won't be quick turn around!

My print volume should go up when I sort some niggles with the machine set up....

[Andy Meade]

In reality - the build size isn't the limiting factor of course, just how good your 3D modelling gets. The biggest of objects can always be broken down into structurally sound, easily-jigged items, so that once printed you can bond them together to form a great whole.

[Ian Jones]

Posted by Olly P on 05/04/2016 22:29:31:

Posted by Ian Jones on 01/03/2016 00:26:31:

I'll be buying a 3D printer sometime this year, there's no end to the uses I hope to use it for, though it will be quite small scale stuff.

As for the future, they will be as common as TVs and microwaves. Instead of warehouses full of physical objects there will be data warehouses frull of 3D plans. When you need something new or to replace a broken part you will donload the data and print it. Of course there will probably still be a cost in the down load but it's an attractive business model.

Ian

Ian - I missed this one, if you want anything doing upto about 150 mm x 150 mm x 200 mm give me a shout, but won't be quick turn around!

My print volume should go up when I sort some niggles with the machine set up....

Thanks Olly, I'll bear that in mind though there's nothing requiring urgent attention. I gather that these printers cabn take quite a lot of setting up but after that should p[roduce good results.

I've been looking at quite a few 3D printers and found myself drawn to the Malyan M180, typically around £400 though just today I've come across the CTC 3D printer going under several different names and versions, typically around £275.

I'm quite put off the CTC by highly variable reviews and the price might be just too good to be true for a dual head machine but the Malyan appears to be okay. Anyone any experince with these particular machines?

Edited By Ian Jones on 06/04/2016 20:20:21

 

Posted by Andy Meade on 06/04/2016 08:59:00:

In reality - the build size isn't the limiting factor of course, just how good your 3D modelling gets. The biggest of objects can always be broken down into structurally sound, easily-jigged items, so that once printed you can bond them together to form a great whole.

Ah, that brings me to a question that always in my mind, bonding pieces together, how's this done?

 

Edited By Ian Jones on 06/04/2016 20:23:02

[Erfolg]

What does dual head mean?

How does the head work. Extruders have been around for a long time, here granules would be typically dropped in a hopper. The hopper was feed into a chamber, with a helical screw (sometimes two) in it, where the lead increased nearer the discharge insert is located, and where the heated zone is located. Something tells me that is not how a 3d printer is arranged.

The other aspect i am struggling with is that plastics, are made of Mers, many of them making Polymers. Although drawn as nice flat chains, the reality is that they have Chirality, that is they are sort of twisted. It is the entanglement of the polymers which provide the strength of the structure as well as the strength of each chain.

Which has lead me to thinking it seems essential to melt the already substrate, get some mixing of the two components, the substrate and the extruded layer if there is not to be a weakness at each layer.

I am assuming that this is achieved, how.

The final aspect how is accurate is the surface of each layer etc.

I am certain that BEB and his fellow academics will know the answers across all the types of materials and devices currently state of the art, the mainstream. I can also envisage that they will be aware of the cutting edge research. Plus the answers to the opportunities and the present limitations.

 

Edited By Erfolg on 06/04/2016 22:11:35

[Andy Meade]

Ian - I usually bond pieces with one of two methods. Thin cyano or a quick wipe of acetone and hold the parts together firmly. I mostly print in ABS, so acetone works fine - if you are using PLA or some other material, you'd have to check first on that as I am unsure.

I don't know the CTC myself, but I do know of people using them. I can't see the need for dual head / extruders in what I use my prints for as yet, mainly because I finish them in other ways rather than relying on bare printed media.

Has anyone tried TinkerCAD? Seems quite good, but not tried it myself as yet - I may give it a whirl on the PC connected to my printer, so I can quickly do tweaks or scaling mods instead of firing up the CAD beast after importing the STL files

There are some printers that need the bed levelling every time you move it, which can be quite a pain. Some have contact probes or other sensors that touch the bed to make sure the machine knows where it is. In essence though, you don't have to do it very often, if at all.

If you do end up printing ABS I'd recommend a thin PEI (type of plastic) print bed to ensure the prints pop-off smartly.

[Dave Hopkin]

Posted by Erfolg on 06/04/2016 22:10:07:

What does dual head mean?

How does the head work. Extruders have been around for a long time, here granules would be typically dropped in a hopper. The hopper was feed into a chamber, with a helical screw (sometimes two) in it, where the lead increased nearer the discharge insert is located, and where the heated zone is located. Something tells me that is not how a 3d printer is arranged.

The other aspect i am struggling with is that plastics, are made of Mers, many of them making Polymers. Although drawn as nice flat chains, the reality is that they have Chirality, that is they are sort of twisted. It is the entanglement of the polymers which provide the strength of the structure as well as the strength of each chain.

Which has lead me to thinking it seems essential to melt the already substrate, get some mixing of the two components, the substrate and the extruded layer if there is not to be a weakness at each layer.

I am assuming that this is achieved, how.

The final aspect how is accurate is the surface of each layer etc.

I am certain that BEB and his fellow academics will know the answers across all the types of materials and devices currently state of the art, the mainstream. I can also envisage that they will be aware of the cutting edge research. Plus the answers to the opportunities and the present limitations.

Edited By Erfolg on 06/04/2016 22:11:35

As I understand it Efrolg - there are several different technologies used in 3D printing, that might end up as being a bit VHS/Betamax-ish in the end.

A decent explaination can be seen here - **LINK**

[Andy Meade]

I don't see that ever coming to pass Dave. The technologies all fit their niches rather well, and that is unlikely to change. Nothing will be obsolete as the source data can always be exported, and filament is far too widespread now to become defunct too. And if that ever does happen, there are plenty of DIY solutions out there to manufacture ones own filament too!

[Erfolg]

I am not sure what to think.

I can see that 3d printers are not a single technology. but a pretty wide range.

At present, I can see that the applications are in some respects niche. For us modellers of non structural, mostly requiring cosmetic items, 3d printers probably have a role.

I have a sum what jaundiced view of the economic and performance suitability for many applications.

Many others will have recognised that for many engineering applications, that the geometry and visual look, are only a fraction of the requirements for many engineering applications.

This really the realm of BEB, or similar well informed person, with access to other experts, to educate many of us. With emphasis on defining the opportunities and the limitations of the generic term 3d printing.

[Ian Jones]

Thanks Andy, that's good to know. If I've got them the right way around then PLA has too low a melting point too be reliable if exposed to a hot sunny day (hah!), so ABS will be more than likely be the way I wil go most of the time.

I'm also curios to know about the filaments that are impregnated with wood dust or even carbon, are these filaments weaker, stronger or unchanged?

Interesting comments re dual heads, I quite see your point, going to have to think about that some more.

My position now is that I have been saving my pennies and the piggy bank is ready for the hammer, the only hold up now is my indecision on what to go for or even wait for a reasonabley priced 3d Scanner/Printer/Copier. I suspect the latter may be a second purchase some years off yet.

[Andy Meade]

Non structural? Complete airframes are being 3D printed currently, with no added structural members to support flight loads. I have also printed offset flap hinges and specially-shaped horns, and they work a treat. I of course followed a bit of due diliegence first and ran some destructive testing first, and compared that to FEA from CAD. Safe to say that my aircraft won't be getting anywhere near the required flight loads to make these parts fail.

[Andy Meade]

Sorry Ian, your reply came in whilst I was typing. The scanning technology is pretty good these days, it depends if that is your primary requirement - replicating parts. If not, I'd steer clear, and maybe even go for a standalone item at a later date when the price comes a bit further south.

The impregnated filaments are a bit of the old curate's egg. If you intend no further finishing processes (i.e. a quick sand/prime/spray) then they are quite pretty. The only one I've found a use for is the conductive (aluminium filled) version to make a small bus bar that fitted around a PCB. Works quite well, but those carbon etc just do not get printed in a way that uses the benefit of their structural properties. I haven't tried the semi-flexible (ninjaflex I think) filaments, but they are intriguing. I quite fancy making some flexible receiver covers, or some customised eye-cups for the SLR.

PLA can indeed warp once printed, not ideal. It doesn't require a heated bed, however, and smells less when printing.

[Dave Hopkin]

As firearms have been produced entirely from 3D Printing, any material that can withstand and contain a 9mm round firing will be well able to withstand any structural loads we place on it providing it is designed correctly

[Erfolg]

Dave

I have read that for instance that firearms have been manufactured using 3D printing.

At face value, pretty impressive. Yet the link does illustrate that the 3d printing is not a single technique, in reality a very wide range in the process and materials.

Accepting that a fire arm has been made, We all assume that the item has at least fired once, or was it several hundred times, Then there is an almost trivial issue, was the design consistent with a conventional fire arm.

I am very happy to be convinced that the 3d printer is a significant step forward in manufacturing technology, beyond the cosmetic appearance.

It is at least an interesting manufacturing method, 3d printing could well be far more than interesting, I just need to know more, to form an informed opinion.

[Ian Jones]

Well this is all really helpful and making me re-think what I need (yes!) and what is "specification creep". Yes I see a 3D printer as a means of scanning and replacing broken items but it's true that I'm more really into custom design of parts or even complete items, hence my bonding question earlier.

So, scanning not really needed, impregnated filaments of limited usefulness and multi colours not top of my list, all pretty much leaves me with a spec of the best single head (fewer parts to maintain) 3D printer I can afford.

Thank you everyone.

 

Edited By Ian Jones on 07/04/2016 22:47:47

[Colin Leighfield]

I'm still watching this subject keenly and waiting to make the right move, it's still a bit confusing for me. Making spinners would be of particular interest, really I'm looking for someone else's good experience that I can follow, both in terms of the kit and methods of use.