3d printing

 
  MtBeenak Train Controller

I am interested in a number of On30 models of VR narrow gauge I spotted on a 3d printing site.  I have read in another forum that the material used to make 3d printouts is not stable and can deteriorate.  Does anyone have experience with this medium?  Is the material stable?  How should it be treated?  Primer, undercoat, spraypack paints or plastic only?  Which of the materials on offer is best?


Mick

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  Aaron The Ghost of George Stephenson

Location: University of Adelaide SA
I am interested in a number of On30 models of VR narrow gauge I spotted on a 3d printing site.  I have read in another forum that the material used to make 3d printouts is not stable and can deteriorate.  Does anyone have experience with this medium?  Is the material stable?  How should it be treated?  Primer, undercoat, spraypack paints or plastic only?  Which of the materials on offer is best?


Mick
"MtBeenak"
It depends on the product and who's doing the printing as to the result you get. For something like a model body one of the variants of ABS would be what you get the part printed in. PLA is potentially a better choice though, typically it will be a finer print, you can get sharper edges and details, if your printer knows what they are doing it will warp less and print quicker than ABS. ABS is a bit harder and will be more resistant to temperature, but neither of these are a great benefit to a model. Both should be stable enough for a model, unstable medium includes (ironically) 'UV stabilised resin' - which IMO is strictly to be considered as rubbish product, eventually this medium has the potential to be a lot better than it currently is, it may well become one of the best mediums in terms of detail and accuracy, but the industry has a lot to learn about it's behaviour first. At present I consider the present accuracy to be about the same as trying to build an HO scale model using a ruler only graduated in cm, that is guessing where the mm are.

A lot of the print result comes down to some things over which you have almost no control. The quality of the filament, the storage method of the filament and the environmental conditions maintained during the print, the skill in set up of the printer and which plane of your model is printed on the Z axis.

Some delamination may occur in the Z axis as the lower layer is often slightly cooled (or even near fully cooled) before the print head gets around to printing the next highest layer. Some methods of 'curing' have been suggested, including exposing the printed product to an atmosphere containing CA (supa glue) vapour, the better method will eventually be to have the product printed faster minimising the temperature differential between layers.

One of the best tips I can offer with 3D printing is to not be too lazy, and consider printing your model as a 'flat pack' and doing the '3D' assembly yourself - much better results.
  MtBeenak Train Controller

Thanks for the reply.  Unfortunately the printer does not refer to the mediums in the same terms you have.  I have seen what they call 'strong, white and flexible'. This behaves a little like white styrene modelling plastic.   I think this is what you refer to as ABS.  I bought one piece to try it out.  I washed it in soapy water and used solvent glue to fix it to flat styrene sheet.  I then painted it with thin layers of spray pack paint, and it appears alright, but I have no idea how long it will last.  The detail is suitable for my purposes.  It is not museum quality, but it is far more detailed than my typical level of work. It is also within tolerances for the model it portrays.

Back to my original question, will it survive for years, having been washed and painted and displayed in an indoor, artificially lit room. I want to buy a engine body and mount it to a mechanism, but it is quite expensive, and I don't want to throw away money.
  Aaron The Ghost of George Stephenson

Location: University of Adelaide SA
Thanks for the reply. Unfortunately the printer does not refer to the mediums in the same terms you have. I have seen what they call 'strong, white and flexible'. This behaves a little like white styrene modelling plastic. I think this is what you refer to as ABS. I bought one piece to try it out. I washed it in soapy water and used solvent glue to fix it to flat styrene sheet. I then painted it with thin layers of spray pack paint, and it appears alright, but I have no idea how long it will last. The detail is suitable for my purposes. It is not museum quality, but it is far more detailed than my typical level of work. It is also within tolerances for the model it portrays.

Back to my original question, will it survive for years, having been washed and painted and displayed in an indoor, artificially lit room. I want to buy a engine body and mount it to a mechanism, but it is quite expensive, and I don't want to throw away money.
MtBeenak

Shapeways? I would normally suggest you try elsewhere. Their 'strong and white' is most likely ABS, colour is misleading, ABS and most platics in general can be nearly any colour. ABS does behave much like modelling styrene - indeed the S is styrene. ABS is sort of 'nitrile cross bonded' via the AB bits, the plastic molecules are more 'locked together' so they don't move around as easily, hence ABS is 'stronger' actually more rigid than normal styrene. All of the same glues and solvents work on each, just possibly with a slightly retarded reaction speed on ABS.

Provided the laminations in the printing remain bonded together there is no reason the ABS will not be around (in one form or another) in three generations time. A really thin coating of CA should be enough to garauntee it's lasting for at least your lifetime. Put the printing in a container (with a clear lid) you no longer want to keep with a squirt of CA at the other end and stick the lid on and place under a decent wattage incandescent lamp for an hour or two - keep an eye on it, you don't want the print to melt. Cool and open outside, don't breathe the vapour, then paint etc.
  tabmow68 Station Master

Location: Brisbane
Otherwise, take the 3D printed article and get someone to cast it into rubber for you.  Then you can use the rubber mould to run off a lot more units from urethane (which a lot of the current kits are made from).  There is a limit to how many units can be taken from one mould before it deteriorates but there are other techniques that might help with that.

Bazza
  MtBeenak Train Controller

I appreciate the input, but the reason I want to use Shapeways (I wasn't sure about using proprietary names on the forum) is that someone else has designed the model already, and that these are truly three dimensional models.  I do not believe that you could take an entire loco and create a rubber mould of it.  I would need to break it down into its individual flat components and cast each separately and then assemble again.  It sort of defeats the purpose!

If they will last more than a few years in normal circumstances, I think they will be suitable.  I am only expecting them to be architectural models, not load bearing in any way.

I will report back on a few things I have ordered and maybe others can compare results.

Mick
  TheBlacksmith Chief Commissioner

Location: Ankh Morpork
Some people have bought items from Shapeways only to find the quality is crap and the plastic very brittle. But some others have had success with their products, or so they say. The truth is somewhere in between. A more accurate assessment is that the resins used in 3D printing have not been around long enough to gauge their lifespan. I have had some extremely finely detailed 3D prints made that were as fragile as tiny pieces of glass.

The best method of using 3D printing has already been touched upon, that is to create the design as a number of flat items that can be cast using durable poly-urethane casting resin and then assembled. Poly-urethane has a pedigree, and its durability, workability and ability to take paint is known.

However if you are buying someone else's design from the Shapeways shop, then you don't have a choice. The problem with 3D printing is that just about everyone thinks they can do it but few actually put any real thought into the process. Just because you can design a one piece model does not mean it is a good idea or even the best approach.

I would be interested to hear what models you are looking at, because there are a couple of absolute shockers for sale at Shapeways.
  MtBeenak Train Controller

I am looking at everything I can find in On30 in VR narrow gauge.  That does not mean I will buy it all.  I have bought a few cheaper pieces to gauge the quality and I will go from there.
  TheBlacksmith Chief Commissioner

Location: Ankh Morpork
I am looking at everything I can find in On30 in VR narrow gauge. That does not mean I will buy it all. I have bought a few cheaper pieces to gauge the quality and I will go from there.
MtBeenak

That's what I suspected. Take care in that regard, as this is precisely what I was talking about.
  Aaron The Ghost of George Stephenson

Location: University of Adelaide SA
Saw some 3D printed articles from Shapeways yesterday, one piece something-or-other prototype bogie hoppers. One piece print, sadly in the wrong material because they were brittle as hell and three were damaged on delivery. The damaged units were returned to Shapeways, but Shapeways refused to reproduce or refund.

Overall quality was not too bad, but I didn't have dimensional data to compare the prints against, even on the models retained by the owner some details were broken, missing or cracked, and these were the prints he kept. I did secretly align all of the prints and note variations in height and length for supposed identical items, so my concerns of Shapeway's repeatability are still current.

Nice product, but I have seen much better print quality, but it is seemingly better than it used to be. I do still maintain a better result could have been achieved by eliminating some of the laziness in modelling by printing flats to assemble by hand and fitting brass laddering rather than trying(!) to print them on the one piece... - Time and money wasted at print for a worse result achieved compared to leaving such details off for addition during assembly.
  MtBeenak Train Controller

I bit the bullet and tried some 3d models from Shapeways.  Attached are the results of my first serious effort with this medium.  The model was designed as the post preservation, Puffing Billy version, with ladders and railings for OH&S.  I wanted a pre-preservation version, so I cut off the ladders and etc.  It sits on 3d Fox pattern trucks (from another designer), with Steam era Models 10.5 mm disc wheels, Kadee No.5 couplers, and stencil style decals from Ian Lindsay Models.

[img]http://i282.photobucket.com/albums/kk272/MtBeenak/2014-09-03153610.jpg[/img]

[img]http://i282.photobucket.com/albums/kk272/MtBeenak/2014-09-03153601.jpg[/img]
  comtrain Chief Commissioner

Location: Near Albury Wodonga
Looks fine from where I am sitting Smile But what do you think about it? How much work was involved?  What did it look like when it first arrived? Smile
Cheers
Rod
  MtBeenak Train Controller

Rod,

There was some noticeable stepping on the curved sections of the tank.  These had to be sanded, but it sands easily with a dremel and a drum sander attachment.  If you look closely at the lower, vertical sections of the tank and the side sills you will see that the printing is not particularly flat, and it cannot be sanded without losing a lot of detail.  I painted it and then applied rust weathering. The rough texture simulates metal that has sweated under the paint.  I am happy with it as there is an enormous amount of rivet detail that I would never have applied if I built it from scratch.

I worked out that with the model, shipping, bogies, wheels, couplers, paint and decals it has cost me a little over $100 to finish, plus about 8 to 10 hours solid work spread out over several evenings.

Mick
  comtrain Chief Commissioner

Location: Near Albury Wodonga
Rod,

There was some noticeable stepping on the curved sections of the tank. These had to be sanded, but it sands easily with a dremel and a drum sander attachment. If you look closely at the lower, vertical sections of the tank and the side sills you will see that the printing is not particularly flat, and it cannot be sanded without losing a lot of detail. I painted it and then applied rust weathering. The rough texture simulates metal that has sweated under the paint. I am happy with it as there is an enormous amount of rivet detail that I would never have applied if I built it from scratch.

I worked out that with the model, shipping, bogies, wheels, couplers, paint and decals it has cost me a little over $100 to finish, plus about 8 to 10 hours solid work spread out over several evenings.

Mick
MtBeenak

Well you cannot complain about that. It looks like it is doable by a novice, who takes his time and asks for help when needed and may help people replace the Broad Gauge Bodies kits no longer available for Victorians?  Please show more as you go Smile
Cheers
Rod
  MtBeenak Train Controller

Rod,   I do not think 3d printing will take over from any other form of model building.  I tried it as an experiment, as I thought it might have promise.  The limiting factors are the designers skill and the quality of the printing, which to be honest is not quite there yet.  I could have purchased the same model from Ian Lindsay Models [http://ianlindsaymodels.com/rollingstock.html] and it would probably have been easier to prepare and build/paint.  Having said that, it was a fun little project and it has sparked something.  I now feel like detailing the Na s I bought from Haskell and building a few ILM kits I have in the drawer.

Mick
  Iain Chief Commissioner

Location: Concord, NSW
MtBeenak,

I contract to you views I think 3d printing, once it matures as a technology, will take over a fair bit of the market as it has the potential to do high quality low volume runs of items such as the NQ you tried. From my remembrance of Mr Blacksmiths discussion group there were issues of design and quality but that these were being addressed and I think Shapeways was not suggested as the best producer.

The critical part seems to be the question of design as the process is very much GI/GO. But I can see someone like an Ian Lindsay specialising in providing 3d models in the future or even large players like Airfix providing 3D models either on demand like Shapeway or through selling the file (suitable locked) and litting the user do the printing.

The good bit is you have a fine looking NQ.

Iain
  TheBlacksmith Chief Commissioner

Location: Ankh Morpork
Rod, I do not think 3d printing will take over from any other form of model building. I tried it as an experiment, as I thought it might have promise. The limiting factors are the designers skill and the quality of the printing, which to be honest is not quite there yet. I could have purchased the same model from Ian Lindsay Models [http://ianlindsaymodels.com/rollingstock.html] and it would probably have been easier to prepare and build/paint. Having said that, it was a fun little project and it has sparked something. I now feel like detailing the Na s I bought from Haskell and building a few ILM kits I have in the drawer.

Mick
MtBeenak

Slight correction, the Ian Lindsay model would have been of higher quality, because that is what sets his products apart from others.
  MtBeenak Train Controller

If I have cast aspersions on Ian Lindsay Models, I have been misread.  I know his/their products are of a different medium, and are of far higher quality.  I have several ILM kits built and waiting to be placed on the final layout as well as several still to be built.

On the subject of ILM, they have a new stock of Stencil type decals, which were used on this model.  

Mick
  miktrain Deputy Commissioner

Location: Adelaide SA
But I can see someone like an Ian Lindsay specialising in providing 3d models in the future or even large players like Airfix providing 3D models either on demand like Shapeway or through selling the file (suitable locked) and litting the user do the printing.
Iain

How would you "lock" the file? If you can send it to the printer you can also send it to any computer/storage device in multiple copies.
It is digital, therefore it can be copied/edited.

Tony
  Bogong Chief Commissioner

Location: Essendon Aerodrome circa 1980
Well you can "hire" software like MS Office for a year and download films that can be watched for up to a week. Those things are date dependent and can't be used after a certain date. (And no, you can't get around it by resetting your computer's calendar.)

Likewise I understand it's quite possible to encode a file so that it can only be used a certain number of times before it expires.
  miktrain Deputy Commissioner

Location: Adelaide SA
Well you can "hire" software like MS Office for a year and download films that can be watched for up to a week. Those things are date dependent and can't be used after a certain date. (And no, you can't get around it by resetting your computer's calendar.)

Likewise I understand it's quite possible to encode a file so that it can only be used a certain number of times before it expires.
Bogong

Hiring MS Office etc works because you never have the software on your computer it is done over the internet. If you want to "own" it then there are many access codes all over the net, that is the main reason that many programs are "updated to new vesions" so that you need a new code.

Because you have to send it to the printer to print then it also can be copied multiple times, unless it can only be printed on special printers that will only print those files and who has or would buy one of those if they were made? Just look at the music/movie industry that has lots more money to use for protection but it still gets pirated.

Tony
  lkernan Deputy Commissioner

Location: Melbourne
Well you can "hire" software like MS Office for a year and download films that can be watched for up to a week. Those things are date dependent and can't be used after a certain date. (And no, you can't get around it by resetting your computer's calendar.).
Bogong


If it is able to be displayed on your screen there is normally some way of stealing it.
Most of the time the biggest issue is if it's worth the effort for someone to crack / hack / hijack / decrypt, etc.
  Aaron The Ghost of George Stephenson

Location: University of Adelaide SA
Well you can "hire" software like MS Office for a year and download films that can be watched for up to a week. Those things are date dependent and can't be used after a certain date. (And no, you can't get around it by resetting your computer's calendar.)

Likewise I understand it's quite possible to encode a file so that it can only be used a certain number of times before it expires.
"Bogong"
If it's a file of ones and zeros I can steal it, if it's a file sent to a 3D printer via Bluetooth, wifi, usb I don't care, I can steal it, very easily.
  TheBlacksmith Chief Commissioner

Location: Ankh Morpork
If it's a file of ones and zeros I can steal it, if it's a file sent to a 3D printer via Bluetooth, wifi, usb I don't care, I can steal it, very easily.
Aaron

Have you stolen anything interesting of late?
  lkernan Deputy Commissioner

Location: Melbourne
Have you stolen anything interesting of late?
TheBlacksmith


Someone who knows what they are talking about tries to correct others views on computer security and you assume they are a criminal.  lovely.

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