Monday, May 30, 2016

Wall details, 3D printed in HO scale

For custom details, Shapeways is the way to go.  This assortment is all wall details.  Some of these I had printed before, others, this is the first time.  The set includes a lot of parts.

 There are two different gas meters, two of each.

A selection of pipes to run along the walls. 

 Four different wall vents, four of each.  Three of them are see through, the four smallest are surface mount.

 Four wall fans, and two types of electric meters, four of each.  

 Roof drain scuppers.

Two types, eight of each.  Four coal doors, a set of six mail boxes )note the raised lettering for the apartments).  There are also two size of fire sprinkler connections, four of each.  I have since added four alarm bells to put on the outside wall of the building.

There is a large selection of tension rod washers (sometimes called stars).  Nine styles, eight of each.

Here are a few pictures of the tension rod washers.  These are based on prototype pictures, and are used on most older masonry buildings.  These are HO scale, so the are between 1/8" and 1/4" in size.





There are eight of each of the tension rod washers in the set. 

Here is one installed on a building, an old Roundhouse kit.

 The smaller gas meter, and the piping. 

Here is an example of how I used the pipe, and you can also see more of the tension washers.

 Here are the larger gas meter, and four wall mount fans.  

 At the top of the picture  are the fire alarm bells and the eight fire hose connections.  Next down is the apartment mail boxes with raise lettering. And, at the bottom are the scupper (flat roof downspout drain), two styles.

Here is another shot of the mail boxes and fire apparatus.  To the right are eight electric meters, four of two different styles.  The connections can easily be filed off if needed.  

The electric meters installed on an apartment building.

The mail boxes.

Sixteen vents, four sizes.  The small vents to the right are surface mount, the rest are see through, i.e. real vents. You can see the copper penny through the vents.  The coal doors are in the upper right.

I held the larger vent up to the light for this picture.  One has to be very careful to not fill the vents up when painting.

I added a coal door to this apartment building.

Here is a link to these items on Shapeways, should anyone be interested.  https://www.shapeways.com/structure-exterior-wall-details

I did not expect to ever sell the piano store, it was just something I wanted, but I have sold a couple sets, https://www.shapeways.com/piano-store-stock

Here are some links to other details I have designed and had printed at Shapeways.




Tuesday, May 24, 2016

3D Printing in Copper #2 & #3, weathering

Printing with Copper infused PLA part 2

The copper roof ridge, with natural weathering.

In the previous post, I covered some items I printed in copper infused PLA.  3d-printing-in-copper-model-railroad-details  I wanted to take it a step further, and naturally patina the copper (weathering it by oxidation).  A little research, and one finds that Uric Acid works well, but it a little gross to handle, so I went with the second option, Ammonia and salt.  You don't soak the items in it, but rather you fume the copper.  The fumes from the solution cause the copper to oxidize, much as it does in nature. I also wanted to see what would happen if the items fumed for a long time.  How green would they get.  I wasn't totally satisfied with the roof ridge cap shown above.  It had fumed for about 36 hours.  I did not measure the amount of salt or ammonia, and I assume different ratios would produce different results, but I am just playing, not trying to do a scientific experiment.

I put about a teaspoon of salt in a plastic container, and printed out some angle pieces to hold the printed parts up above the solution.  

I used some raft pieces to make a table to lay the parts on.  

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Since I had a bunch of copper raft laying around, I ground it up in a blender to use it as a pile of scrap in my junk yard.  I put this in a plastic bag, and propped it open to make sure fumes would get in.

 I took this picture after 48 hours, and you could tell it was working, lots of copper leaching out into the solution.  The next evening, I was tired, didn't even look at it.

 After 96 hours, I opened it up to see this.  One piece had collapsed under its own weight, and another had warped.  I did not know what to think, so I took the parts up to wash off in the sink.  I threw a paper towel over the drain to keep the parts from getting away.

 Here is the really cool part, there was not much left, the copper had almost completely oxidised away, leaving only some PLA powder.

 After it dried, you can really see how little is left.

 The scrap in the bag, somehow fared much better, and came out great.

WELL, that got me thinking.  How about a test, put a bunch of items in the fuming chamber, and take some out every 12-24 hours, and see how they fair.  So, here we go on that...

Printing with Copper infused PLA part 3

I made four sets of buckets and tubs, and placed them in the container with ammonia and salt.  Placed the cover on it and let it set for 12 hours.

In 12 hours, the solution was a little blue, but the items did not look like they had oxidized very much.

I rinsed them off, and set them aside to dry.  Wet, they were not impressive.

But dry, dang, the looked good.

And after 24 hours, they showed, obviously, more oxidation.  Quite impressive.

After 48 hours, the solution was very blue, showing a lot of oxidation had occurred. 

No reason to continue the experiment, as the oxidation had deteriorated to the point the parts were falling apart. Once the copper was removed, there was not enough of the PLA left to keep the parts together.

So much of the copper had oxidized away that this copper tub was almost white.  It had almost no strength, and was easily crushed.  I crushed them up, and threw them in the scrap pile.

This is the 12 hour fumed items, and they look great.  If I want a little less patina, I will just fume the products for a shorter time.

The 24 hours fumed items shown here, really show the heavy oxidation.  I can't imagine one could need any more patina than this.

I am planning on picking up a rock tumbler later this week, and we will try polishing the copper....

Sunday, May 15, 2016

3D Printing in Copper, Model Railroad details

This is the first of several posts that will be about 3D printing using Copper infused PLA.  This is PLA (Polylactic Acid) plastic filament with fine copper infused in the plastic, so it prints in copper.  Because it is real copper, it can be chemically weathered to add patina.  

First, I generally print using ABS (Acrylonitrile Butadiene Styrene).  ABS melts at a higher temperature (240 degrees celsius and more) than PLA and it requires a heated bed on the printer to keep the print from warping.  ABS is stronger, more flexible, and will not degrade over time.  It is also solvent weldable to Acrylic, and polystyrene, so it is great for modeling.  (for more on ABS versus PLA).  ABS prints clean, with very little stringing, more on that later.

PLA melts a lot lower temperature, 180-200 degrees celsius.  If you leave an PLA print in your car in the summer, it can sage, warp and get sticky.  PLA is sticky, and tend to string between items.  It, therefore, take more clean up than ABS.  It is brittle, when compared to ABS, and it is biodegradable, even compostable.  According to most sources, it will degrade over time if left outside.  PLA is cheaper.

I bought my roll of Copper infused PLA from Afinia, since I have two of their printers.  FYI, that is wood infused PLA next to the copper.  Yes, I can print in wood too, but that will be a later post.

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One of the first items I printed in copper is a roofing ridge cap.  

I test fit the cap on the roof, before I weathered it.

One of the cool things about copper is that it can be chemically weather to give it a natural patina.  That will probably not get covered much until the second post, as it was quite an experiment. 

Here is a large tub I printed, this would be about the size of a bath tub in HO scale.

To get the copper to oxidize, you fume it in an atmosphere of ammonia and salt.  I threw some salt in a container with a tight let, put in a little ammonia, then used some 3D printed angles to hold the ridge up above the liquid.  I put the lid on and waited a day.

It came out with a nice patina to it. 

It is a fairly new looking roof, so not a lot of patina was required.  If you leave it in the fuming chamber longer, it will oxidize more, and, therefore, have more patina.  MUCH more on that in the next post.
 I also printed a small section of copper roofing,  

In my opinion, PLA does not hold as sharpe of lines at the ABS, so the details are not as clear.  In this case, the roof ridges are just not as clean as with ABS, but then, they don't make ABS infused copper!

Remember the tub in the picture earlier, it had one little string of plastic coming off of it, formed when the print was done and the printer head moved away.  Check out the print above.  I printed the tub with two chimney caps, and note all the stringing and globs of plastic between the models.

These tubs are only about 1/4" in diameter, and you can see all the clean up needed.

They can be cleaned up, but it take a little work.  Much easier than cleaning up a metal casting, since it is plastic.   Here is whole bunch of items I did some tests on.  I wanted to see how long items needed to fume in the ammonia and salt air to get a given patina.  More on that in my next post.  


I also made some skylight frames using the copper, for more on that, click on this link, skylights-copper-3d-printed-frame.

I am also looking at getting a rock tumbler to polish the copper.  If I can make it look old, it would also be nice to make it look new.