Cleaning up 3D prints.

[stewartingram]

What do others find is the best way to clean up 3D prints? I have a small number of prints from Shapeways in white plastic. Although fairly smooth, they do need smoothing down. However I find the plastic fairly hard, hardly responding to sandpaer and small files, which are difficult to manipulate on a panelled coach side.

 

Stewart

[chris p bacon]

Do you know what the material is they've been printed in ?

 

I only use/get stuff in Fine detail plastic (used to be FUD/FXD) for that you only needed a fibreglass pen or some 800/1000 wet & dry.

 

Make sure you degrease/clean it thoroughly first, I use fairy and a toothbrush and others use IPA (not Greene King) although if you're not sure, try a test on some fret.  

[rue_d_etropal]

Sounds like WSF.

Firstly avoid getting it wet, don't even paint it before attempting to smooth. It appears to bind/harden when it gets slightly wet. However if there is any fine detail(thin and breakable), I advice some cheap liquid superglue on those bits.

Then use a good non clogging(green?) sandpaper. Problem is the clogging which blocks the abrasive surface of sandpaper or any file. .If you have ever tried stripping varnish off old wooden furniture you would have encountered the same problem.

Once it is smoothed diown, you can paint with ANY water based paint. Don't waste your money on expensive modelling paints, certainly not enamel, and even  acryllic is unnecessary. I use matchpots of emulsion paint, available in most colours, and not only cheap, they are easy to mix.

 

For even rougher parts such as printing ridges , scrape it off with edge of a modelling knife blade, nothing fancy, just one of those cheap pound shop ones.

Edited September 23, 2018 by rue_d_etropal

[Quarryscapes]

A Fibreglass Pencil works wonders over paint to smooth out around details, such as panelling in this case. 

[Atso]

As others have said, it really depends on which material you've purchased.

 

The 'Versatile Plastic' (formerly the 'strong and flexible' family) is made from laser sintered nylon particles. The resulting print is (as per its former name) strong and flexible but suffers from a grainy texture on the surface; Shapeways offers a polishing service but this can remove fine detail. Because of its porous  nature, this material is difficult to seal and, in my experience, more difficult to sand. I still use this material but only on structural parts where the detail and surface finish is very much the secondary concern (i.e. parts that cannot be easily seen).

 

The 'Fine Detail Plastic' (formerly FUD and FXD) are much better in my experience, but more expensive. These are made in a UV reactive acrylic resin that is deposited in layers using a similar technology to an inkjet print. The surface finish is much better than 'Versatile Plastic' but still benefits from sanding/scraping. For my models, this is usually my material of choice and for parts where the cosmetic look is the primary concern, only offer these materials.

 

If you can get a copy, I wrote an article in the May edition of BRM covering the techniques I use for cleaning up N Gauge 'Fine Detail Plastic' prints. However, there are a couple of good threads on the forum covering bits and pieces in 4mm scale in both 'Versatile' and 'Fine Detail' plastics.

 

http://www.rmweb.co.uk/community/index.php?/topic/99937-kitbuild-challenge-entry-lner-f5-2-4-2t/

 

A thread covering the building of an 4mm scale GER/LNER F5 locomotive in 'Versatile Plastic'.

 

http://www.rmweb.co.uk/community/index.php?/topic/58891-ajmodels-ner-horsebox-ivatt-n1-aspinall-27/page-2

 

This thread covers (among other things) the finishing of an 4mm scale LNER N1 in 'Fine Detail Plastic'.

 

Hope this helps.

Edited September 24, 2018 by Atso

[rue_d_etropal]

Techniques for painting and preparing fine detail plastic are totally different towhat you do on  the nylon grainy plastic(WSF). I have been using it for nearly 5 years so have worked out what works and what does not work.

[Atso]

Techniques for painting and preparing fine detail plastic are totally different towhat you do on  the nylon grainy plastic(WSF). I have been using it for nearly 5 years so have worked out what works and what does not work.

 

Yes, there are some differences in how to clean up 'Versatile Plastics' and 'Fine Detail Plastics' but some kind of sanding/polishing/filling is required for both and it is down to the personal preference of the designer which materials are offered. For N gauge work, I've largely discarded what are now called 'Versatile Plastics' for N Gauge models in 2008 when I discovered the then detailed plastics (since withdrawn by Shapeways in preference for their newer 'Fine Detail Plastics') as I found that, even when I could get the bodies smooth, I lost far too much detail that needed to be replaced. The advent of FUD (now 'Fine Detailed Plastic') changed the way I looked at 3D printing and the level of detail that could be included in an N Gauge model with a better than good chance of retaining it throughout the cleaning/sanding process. I also found it quicker to obtain the results I wanted, although the down side is the increased price - more than offset by the reduced cleaning up time in my opinion.

 

As  I have indicated, my experience is almost exclusively with N Gauge models, but I hope that the below shows my experience in the difference in finish between 'Versatile Plastic' and 'Fine Detailed Plastics' in this scale.

 

 

Above are the bodies for an LNER V1 and a Gresley non-corridor full brake in 'Versatile Plastic'. The full brake is a few years old now and was printed as an experiment to test the polishing option when it was first launched. Unfortunately much of the detail was lost and so I didn't pursue this printing process any further. Incidentally, the V1 was printed from the same CAD file as the ones printed in 'Fine Detail Plastics' shown later.

 

 

These bodies were produced in 'Fine Detail Plastic' (the V3 at the back) and 'Finest Detail Plastic' the other two and, other than a wash in water (they received a scrub with white spirit before priming), are as they arrived. The Stanier 2P is fully riveted with 0.25mm diameter rivets.

 

 

Above are 'Versatile Plastics' following extensive cleaning up. Quite a bit of the original detail didn't make it through the printing process and more was lost during cleaning up. The V1 shown here is an earlier incarnation of the CAD from the others shown in both materials.

 

 

The above are 'Finest Detail Plastics' after two sanding/priming sessions.

 

Finally, a some of examples of models completed or in progress printed in 'Fine Detail Plastics'

 

 

The V1 print shown earlier with turned handrail knobs, buffers and etched lamp brackets. The rear pony truck was printed in 'Versatile Plastic' as the strength and flexibility of the material lent itself well to being pushed over the pin at the back of the Farish N Class donor chassis. I also took advantage of this material by being able to clip the wheelset into the pony truck (although this and the hole for the pin needed opening up/polishing with hand drills and/or needle files before they would fit).

 

 

GNR Six Wheel Full Brake in 'Fine Detail Plastic' this is one of a couple of models that have in development as a kit for some time. However, models of this and the other prototype now exist and are on sale by another designer so I am unsure whether these will be released or not and this one will be finished for myself (although some omissions on the development model have been added since). Disheartening considering the time amount of time expended but such things happen and I'm unsure if there is a benefit to offering a competing product in a small market place.

 

These are N Gauge models and therefore not necessarily representative of what could be achieved in 4mm or 7mm scales. However, my personal opinion is that 'Fine Detailed Plastics' are the best starting point (from Shapeways) for achieving a smooth finish and are easier to work with but at a higher price. I can only go on what I have learnt over the last twelve years, but for me 'Versatile Plastics' aren't the best material for producing detailed models in N Gauge. However, others will have different experiences of the materials Shapeways offer and if they and others are happy with these then that is great.

 

Regardless on methods, material choices and experiences, happy modelling!

 

Edit: With thanks to Tony Wright for taking many of the above photographs.

Edited September 24, 2018 by Atso

[rue_d_etropal]

What has to be remembered is the MUCH higher cost for 4mm scale models in finer plastic, one reason I only offer it if asked for,but now only do N scale in finer plastic, as that is what most seem to want. I can stiil modify my designs for WSF, but it takes a bit longer to do.

Each type of plastic has its advantages, yes WSF is better for some things, so should not be dismissed . As I keep saying, it is not difficult to smooth down , just different, and far far easier (and cheaper) to paint. All too easy to blame the material, when it is the person who needs to adapt. Think household/DIY materials and tools, not purely modelling ones.

[Atso]

Indeed, Fine Detail plastics will cost more that Versatile Plastics, something I did allude out in my previous post. However, the same is also true of resin, white metal, laser cut and etched (or a combination of one or more of these materials) kits. It is a decision by the designer if they are looking to sell a cheaper model that requires more work or a more expensive and more detailed model. The materials are what they are and will do what their respective methods of production will allow them to do; no blaming here, just the realities of the production methods and what they can (and cannot) do.

 

My own design philosophy is to identify the best material for the job at the design phase. If I would like to have detail, the it is a Fine Detail plastic. If I am looking for strength and flexibility then it would have to be Versatile Plastic. The test building phase the validates (or not) my material choices and I can alter these if necessary. I always test build my designs to prove that they will work, make any amendments to the design and/or materials as necessary and will not put a design on sale if I haven't proven it first. If the material choices push up the cost, then, as with everything in life, that is what the model will cost.

 

From what I have seen and (limited) experienced, I believe that WSF is a suitable material for 7mm (and larger) models as the detail is quite substantial (just as well as many models in these scales couldn't be printed in Fine Detail anyway) and easily retained during clean up and borderline ok for 4mm models. Again from experience, I generally do not design down to the minimum level of detail level that each material is theoretically capable of as I've found that the results are often disappointing and/or inconsistent - the missing steps on the C12 print done in Versatile Plastic in my previous post is a case in point (while they printed perfectly in Fine Detail).

 

However, fascinating as this discussion is, I feel that it has now moved far beyond the original poster's request. They have received several contrasting views and I wish them all the best in finding which method best suits their own requirements and expectations. As it is clear that we have differing design philosophies and ideas, I think it best that we agree to disagree at this point and spend our energies on designing models.

 

All the best with your work.

Edited September 25, 2018 by Atso

[Guy Rixon]

Concerning Shapeways detail plastics: little or no smoothing of detail accessories is needed, but the wax that support overhangs during printing must be carefully cleaned off, otherwise paint won't stick. My process:

 

• Wash the parts in soapy water, activated by an Ultrasound tank.
• Pick wax out of crevices with a cocktail stick.
• Ream wax out of round bores with drills.
• Polish (abrasive paper or fibre-glass brush) any parts with printing issues.
• Wash again, as before.
• Prime ASAP with Halford's car primer (other brands available).

The cleaning and priming should be done as soon as possible after receipt of the parts, firstly because the wax become harder to shift as it ages and secondly because the resin degrades if left exposed to UV light.

 

I find that the finish of detail plastic is generally good enough that the primer gives a decent surface. I only need to polish where the wax has been against an external surface or if there are minor printing errors. In the latter case, I sometimes send the print back and ask Shapeways to do it again, but sometime accept the print and fix it myself.