Adventures in 3d Printing.

[Keith Hayes]

I have had mixed success over the past year with 3d printing. I got an Elegoo Saturn 5 almost on a lark, to help with parts for a model for a friend. With that project completed, I decided to go back to the beginning,  calibrate my printer and tune up my modelling skills. A constituent issue is that I think SketchUp is agnostic regarding the solidity of 3d forms. But there is an add-on for that.

An upcoming project is telegraph and electrical insulators. I decided to start small and simple, and in conjunction to the insulators, I developed some NBWs. You can see these tests in the middle. This is my second batch of insulators, and the new ones rendered very nicely,  about 5" tall and 4" at the bottom. The NBWs are okay: these have 1" bolts, which printed fine,  but are not as fine as Grandt 100s. The larger bridge washers are neat: the raised ridges, about 1/2" tall and 1/2" wide came out well.

Many 3d printer types are gamers, and use their machines to make miniatures and figures for fantasy games. Consequently, one of the calibration parts, "cones of calibration, " has a fantasy spin. If everything is correct,  the beer snaps off and fits in the ale tankard, and the sword snaps off and fits in the skull.

Someone else created a model where three small boxes fit into one another.

The successful prints are at the rear of the scene on the right, and two raw parts are on the left.

The Saturn 5 has a routine that allows me to print 8 parts at the same time, each with a different exposure setting. The successful prints exposed the resin to the UV light for just 3 seconds per layer.

The whole process is a balance of the exposure, how far the build plate lifts, and how fast and how long, and how fast it moves back for the next exposure. Even though the plate is moving a short distance (1-2 mm) the forces within the liquid can be significant. Also, these prints are small (short), so only took about 30 minutes. A Sn3 boxcar,  rotated to optimize all these factors could take 4-6 hours.

I am bouyed by my results. I plan to order some clear resin to produce the insulators. I understand this introduces som othe complications in that the UV light bounces places it is not wanted. In any case,  these could turn out to be neat details. I have started to model windows for the Breck depot, and the Climax mine office windows, doors and formers will not be far behind.

[drgwcs]

Great work Keith. It is amazing what 3D printing is doing. I do not have one myself but have a friend at the club Dylan that has done several projects for me.
He just printed the Forks Creek Section House from Charles Dollins' plans
The grounded boxcar next to it was the first test print on a boxcar that the width was off and the roof didn't work right- but it was perfect for this with some tarpaper and a bit of modification. Even mistakes can work great. (The stone building that is not prototypical is an old Morse Productions plaster casting)


These are all done with modified files from Thingiverse- they are not exact (especially in the stakes) but not bad- I also have a boxcar in progress.

[Chris Walker]

I've been known to do a little 3D printing with my welder and grinder, every now and then.

A West Side Lumber groundthrow for those who don't recognise such mundane hardware; suitably reduced by 25% to match my 18" gauge Tramway.

[Paul R.]

Neat!

[pizlinard72]

Wonderful results Keith.
3D printing is really an incredible technology. Even larger printers that can be used for O scale give great results. Here is a fishbelly flat car after the printing and curing process. I only have to add some brakelines, stakes and it is ready for painting.

Had a steep learning curve but that is inherent all new technologies.

[Keith Hayes]

Years ago we had a frequent poster in these parts who suddenly and thoroughly removed all of his posts. I know he was real because he stopped by to visit Leadville once when he was in town. I  would like to think he is a covert agent and is wandering around dark and rainy places chasing bad guys.

Anyhow,  he asked if I could create the parts for the Fort Logan depot, a sweet little structure that was also used at Dome Rock and Estabrook.

He provided the plans--Blazek, I think--and I got to work. The doors and windows have Italinate trim, as was the fashion,  along with some scroll work in the pediment. We consulted several extant examples,  including Como and Osier. I was able to find a clear enough image of one to trace the pattern.

The parts in question were to be printed in 1:20.3, hence the attention to detail. Shapeways priced the parts at over $100 each--I withered at the cost, but I guess it was okay, because the guy bought a set.

Fast forward a decade and Shapeways...has changed...but I still have the drawing file. I have been thinking of building Dome Rock or Estabrook in 1:48, just to do something different. With the recent telegraph insulator project completed,  I thought I would give the Dome Rock parts a go. (Breckenridge is in the queue in1:64).

So far, I have some of the windows. The scroll printed! These are really big, but I think this will make for a nice display model for the RPM.

[Chris Walker]

Those look awesome.  Don't forget Riverview had them also.

[Keith Hayes]

The roof brackets and doors are printed.

Overall,  I am pleased. 3d printing is the best for the complex shapes of roof brackets, including the ogees and fire cuts. The two Leadville depots have 3d printed brackets.

This is the first time I have been successful printing a bevel in the door panels--a win!

Then there is the delicate scroll work. In retrospect,  I should have made this deeper to improve the shadow line. I will need to pick this out with panel liner on the finished model.

I have all the parts now, so can proceed with the model. I had about 5 window fails, but the vast majority of the parts printed successfully, and the details are crisp and nicely rendered. One window mullion came out of the resin warped,  but shrink back to place during curing.

Some of you might ask why I didn't print the whole wall out? I don't know: I guess I think of my process like building older models with door and window castings in styrene or wood siding. So that is what I am doing.

[Keith Hayes]

...And Breck depot parts fresh off the sprues.

Overall,  I am pleased. The freight doors have an issue with a solid, linear support. This shows up from time to time.

I have been using the auto support generator in my slicer. Those are the truss-like things that support the part as it is printed. I was surprised today that I don't need to use nippers to remove the parts. Some gentle movement lest the part break free.

[Keith Hayes]

The odyssey continues.

In spite of filling the build plate with parts, somehow I was short a couple of Dome Rock windows.

So, I printed some more. Some of you might have seen me suggest to Jeff McKee in other places that he needed to add a brake club on the platform of his RGS caboose to really trick it out. Well, I thought that would be easy enough to model and print. I am also working on a mine for Fremont Pass--tenetively named the Walker-McCourtney--and it will have an aerial tram. I needed a bullwheel for the lower terminal,  so I modeled one of those:

While those were printing,  I remembered Bob Stears had done a drawing of the Phase II coals that were converted to cinder cars. I figured this would be an easy project. So I found the plans and modeled the hinges.

There is a right side, and a left one, and by golly,  they printed. I also did a second batch of brake clubs, this time vertical for easier painting and handling. Those are just over 1/2" long!

Studying the cinder car plans, I noted an A-Frame was constructed down the middle of the car. I designed the long beam and the sloping supports, and the deck will be made of real wood,  cut to fit. This was by far my longest print at 7 hours--it ran all night.

So, enough of this for now. Time to get back to the bench and build some models!

(FYI, now that I have embarked on the Phase II Cinder Car project,  that means Bill Meredith will bring out a kit for the rest of you late in 2026. )

[Keith Hayes]

I still have a lit of clean up to do, but here is the part.

And here is how it fits into the car.

[Chris Walker]

Are ya going to stencil MTY RETURN TO PENROSE on the sides?

Any idea on how the Doors were latched? The 0206 may have had the latches removed in this image.

[Keith Hayes]

The brake Clubs in action.

[Mike Trent]

Good one, Keith! Never saw that modeled before.

[Keith Hayes]

Here is a better example for this group.

Pat Student thought a toothpick would make a good start. Elsewhere, someone has tried turning a micro brush to create a brake club. These are such fine pieces, 3d printing is really ideal.

As Doug Jolley pointed out to me, a broom to clear snow out of switch points would also be a good addition.

[Keith Hayes]

One of the projects in the queue is an ore bin served by a spur atop Fremont Pass. A Crystal River Primos kit has been started,  and I  am pondering how to add additional capacity and develop a tramway terminal above the bins.

A tramway terminal needs a bull wheels, so I made some sketches and moved the project into SketchUp and on to slicing and printing. The aspect of 3d printing I find most amazing is how fast I can move from idea to print. A couple of weeks later, here is the print, now painted. I made an extra for a flatcar or coal load.

I figured a new part would be painted nicely and pinstripes. The decal stash happens to have some Microscale white HO 1" pinstripes. Turned out neat!

[Chris Walker]

Keith Hayes wrote

As Doug Jolley pointed out to me, a broom to clear snow out of switch points would also be a good addition.

What Switch points.  

[Keith Hayes]

I have been pondering what to print with the better part of a kilo of clear resin. I thought some bottles would do.

I found the geometry for a coke bottle and a beer and wine bottle and a square liquor bottle.

Printing on larger rafts meant the parts didn't slip through the wash unit strainer.

These took a couple hours to model and less than an hour to print. You tell me if the end result is worth it.

[Keith Hayes]

I have been printing using an Elegoo ABS- like product. I have been very happy with the detail and, this is a brittle material. For reasons I don't know,  I turn into fumble fingers when I am handling these parts and drop them. The parts generally survived the fall to the carpet tiles on the floor,  but then there is the matter if me rolling my chair across the dropped part. The result is not good: ask me how I know. And the resulting break doesn't want to glue up.

I continue to be amazed at how a very complex photo-chemical process has been brought to the hobby world.

Many 3d hobbiests advocate rotating parts. This accomplishes two things: it reduces the suction force within the resin bath as the print is pulled away from the FEP film; it also allows successive layers to cantilever off the previous layer, with possibly fewer supports. Game printers also claim the resolution is better,  though I have been very pleased with the resolution of my models.

At the NNGC convention,  I learned that resin parts are the most accurate in the X-Y plane, so dimensionally-critical parts should be printed flat to the bottom of the tub. My parts have been more dimensionally tolerant,  so this has not been an issue for me. I can tell visually that the bull wheel is not perfectly round, it is pretty close.

Speaking supports, the slicing software has an auto-support feature,  but I have found it over-does. So I have been hand-placing supports. I don't have this down to a science,  and have had failures where I did not provide enough supports. The middle prints above--I was rushing and felt the low end of the parts did not need as much support: wrong. The resin  is exposed to the light, but without a support,  floats in the resin like a flag in the wind, with the results being the prints shown. The higher parts had enough support and printer fine.

Print time is a factor of the Z dimension. The more severe rotations results in a taller part and a longer print. This time I only rotated the parts 15 degrees, which reduces the print time by half.

Once the part is printed, you are only halfway-there. Next comes removing the part and washing the excess resin off. Most folks seem to use a two-step process with a dirty wash, followed by a rinse in cleaner alcohol or detergent. On an earlier print, I thought a longer wash would be better, but I found that the detergent I have warped the mullions, so now I only wash the parts for a couple minutes and rinse them off in warm water.

I also am discovering that it is not necessary to cure the parts for very long, either. I have been taking the supports off after cleaning, as the resin is still soft, and then curing parts for only a minute or two. Earlier parts I would cure for five or more minutes, or set in the sun. I have found with clear parts, UV curing can cause yellowing, so I a sticking with a light touch.

Now I have all the parts for one depot, and can continue the build.

[Al Pomeroy]

Keith,

i am surprised an ABS like material is Brittle. My printer is more of a commercial unit (form 4) and i use a material called tough 2000, which maintains its flexibility after curing. i do find i have to adjust orientation other than what the software provides to get the best prints, and always position the front facing detail away from the supports. to many supports is an issue i fight as well but as you have seen removing them in some cases causes print failures.

Al P.