Over the past few weeks, I have noticed a number of details for HO scale that have been popping up. It's just amazing to see the clarity and fidelity of drtail of these pieces. Unlike castings, they also eem incredibly cheap in comparison.
Recently I got over 85 pieces for less than $35. There were dumpsters, trash cans, fire hydrants. Window air conditioners. Park benches, all sorts of goodies.
3D printing is a game changer. It's rewriting the rules in so many industries. I believe a whole new era of modeling is before us.
Fifth Dave to the right
Quote from: Dave Buchholz on February 02, 2025, 09:17:51 AMOver the past few weeks, I have noticed a number of details for HO scale that have been popping up. It's just amazing to see the clarity and fidelity of retail of these pieces. Unlike castings, the seem incredibly cheap in comparison.
Recently I got over 85 pieces for less than $35. There were dumpsters, trash cans, fire hydrants. Window air conditioners. Park benches, all sorts of goodies.
I believe a whole new era of modeling is before us.
I wholeheartedly agree! It's a wonderful advancement for the hobby. Also, consider that the quality of metal/hydrocal/resin castings deteriorates as the molds age whereas that won't happen with 3D printed detail parts. :)
As a 3d maker in O scale I must attest some larger prints will develop cracks after a year or so. Smaller details seem to hold up better but sometime warp. Why I have no idea and I'm no expert. I foresee a future where no print lines are visible, which can be masked with a bit of sanding and priming.
Quote from: ReadingBob on February 02, 2025, 09:25:23 AMQuote from: Dave Buchholz on February 02, 2025, 09:17:51 AMOver the past few weeks, I have noticed a number of details for HO scale that have been popping up. It's just amazing to see the clarity and fidelity of retail of these pieces. Unlike castings, the seem incredibly cheap in comparison.
Recently I got over 85 pieces for less than $35. There were dumpsters, trash cans, fire hydrants. Window air conditioners. Park benches, all sorts of goodies.
I believe a whole new era of modeling is before us.
I wholeheartedly agree! It's a wonderful advancement for the hobby. Also, consider that the quality of metal/hydrocal/resin castings deteriorates as the molds age whereas that won't happen with 3D printed detail parts. :)
Use the 3D printer to make a new master mold every time the mold wears out. The mold will be the same in tolerances due to the fact it was designed on a computer. You can make parts faster that way then 3D printing them all.
Bernd
I f that was the case of using 3d Printing to create the mold, it strikes me that the choice of plastic to print the "mold" would seem critical to that process, as it would need to be flexible enough to pop out the final part, without a loss of shape. out.
I could see where a number of people who 3D print could just start the cycle before they go to bed, and in the morning have a wealth of new parts available the next morning. But, I'm just a modeler without those skills, that admires the results of whose who do the programming and printing.
Fifth Dave on the right
Quote from: Dave Buchholz on February 02, 2025, 10:40:20 AMI f that was the case of using 3d Printing to create the mold, it strikes me that the choice of plastic to print the "mold" would seem critical to that process, as it would need to be flexible enough to pop out the final part, without a loss of shape. out.
I could see where a number of people who 3D print could just start the cycle before they go to bed, and in the morning have a wealth of new parts available the next morning. But, I'm just a modeler without those skills, that admires the results of whose who do the programming and printing.
Fifth Dave on the right
Ok, seems like I didn't get the message across. First you print a master in 3D. You use that master to make a rubber mold. You use the mold to cast several hundred copies, which could be done in a day or so. That's what I meant about using a 3D printer in making a mold.
Bernd
Quote from: Bernd on February 03, 2025, 10:39:38 AMQuote from: Dave Buchholz on February 02, 2025, 10:40:20 AMI f that was the case of using 3d Printing to create the mold, it strikes me that the choice of plastic to print the "mold" would seem critical to that process, as it would need to be flexible enough to pop out the final part, without a loss of shape. out.
I could see where a number of people who 3D print could just start the cycle before they go to bed, and in the morning have a wealth of new parts available the next morning. But, I'm just a modeler without those skills, that admires the results of whose who do the programming and printing.
Fifth Dave on the right
Ok, seems like I didn't get the message across. First you print a master in 3D. You use that master to make a rubber mold. You use the mold to cast several hundred copies, which could be done in a day or so. That's what I meant about using a 3D printer in making a mold.
Bernd
It's interesting to consider the economics of this. 3D printing is getting to the point where the initial costs of making the mold and then the material costs for the resin would be more than the cost of the equivalent number of 3D printed products.
dave
Quote from: deemery on February 03, 2025, 11:13:28 AMQuote from: Bernd on February 03, 2025, 10:39:38 AMQuote from: Dave Buchholz on February 02, 2025, 10:40:20 AMI f that was the case of using 3d Printing to create the mold, it strikes me that the choice of plastic to print the "mold" would seem critical to that process, as it would need to be flexible enough to pop out the final part, without a loss of shape. out.
I could see where a number of people who 3D print could just start the cycle before they go to bed, and in the morning have a wealth of new parts available the next morning. But, I'm just a modeler without those skills, that admires the results of whose who do the programming and printing.
Fifth Dave on the right
Ok, seems like I didn't get the message across. First you print a master in 3D. You use that master to make a rubber mold. You use the mold to cast several hundred copies, which could be done in a day or so. That's what I meant about using a 3D printer in making a mold.
Bernd
It's interesting to consider the economics of this. 3D printing is getting to the point where the initial costs of making the mold and then the material costs for the resin would be more than the cost of the equivalent number of 3D printed products.
dave
Consider the time. How long for a print? How long to pour a resin casting and have it ready to pop out of the mold? Have you ever done any resin casting?
Here's a short step by step I did when I was in TT scale. I made my own track patterned after Central Valley Ties strips.
The master mold.
(https://www.kingstonemodelworks.com/TT/TTnut/track/ResTrack22.jpg)
The rubber product I used.
(https://www.kingstonemodelworks.com/TT/TTnut/track/ResTrack23.jpg)
"Squish molding", the resin has been poured. To get a nice flat back a piece of plastic was placed on the back and pushed down to squish out the access resin.
(https://www.kingstonemodelworks.com/TT/TTnut/track/ResTrack24.jpg)
Approximately 3 to 5 minutes later the resin has hardened.
(https://www.kingstonemodelworks.com/TT/TTnut/track/ResTrack25.jpg)
Close up view.
(https://www.kingstonemodelworks.com/TT/TTnut/track/ResTrack26.jpg)
Removed from the mold.
(https://www.kingstonemodelworks.com/TT/TTnut/track/ResTrack27.jpg)
Some clean up of the flashing.
(https://www.kingstonemodelworks.com/TT/TTnut/track/ResTrack28.jpg)
Four pieces of resin casting make up one 3 foot section of track. Toke at the max one whole day. How long would it have taken to that on a #d printer? Asking for a friend.
(https://www.kingstonemodelworks.com/TT/TTnut/track/ResTrack46.jpg)
And if I want more track, I don't need to 3D print more and wait for them to be printed. I've already did all the front-end work. I just pull out the molds and have mold pouring party.
Bernd
Bernd, good point! Castings cure faster than 3D printers print and cure (at least right now.)
dave
Thanks for the clarification.
Quote from: deemery on February 03, 2025, 12:51:32 PMBernd, good point! Castings cure faster than 3D printers print and cure (at least right now.)
dave
That may be so. But from my research into 3D printing there's also the cleaning in IP to get what resin is left on the part off and then it needs to get a suntan in an ultraviolet tanning booth to cure even more.
The first I heard about resin printing was a guy by the name of Don Lancaster. Quite an interesting guy. I beleive he used to write articles in electronic magazines such as "Nuts-n-Volts". That had to be back in the 70's. It took from then till now to get tabletop printers for modelers to use. I think it'll take maybe half as long to get to where you are talking about.
My opinion of 3D printers is that they are good for prototype work and making master molds. As far as production work, maybe not so much. Must be that age thing with me now. :o ;D
Bernd
Quote from: Dave Buchholz on February 03, 2025, 02:15:46 PMThanks for the clarification.
Want to make sure you get good information.
Bernd
Some folks in 3d printing on a commercial basis may have numerous machines, "printer farms" they use. Some filament machines are getting their print quality fairly fine that eliminates post processing clean and cure.
Lots of innovation going into these products.
I came across this subject and as a heavy user of 3D printing in my own modeling I thought I would put my two cents forward. I have both a filament printer and resin. The resin is an Anycubic Mono 5. It has a big print plate and each layer prints at .05 mm so no print lines. It has become the goto printer with the Anycubic filament printer getting dusty.
What I use the printer for is two areas of modeling. The first a filament printer could do equally well, that being making the 'bones' of a structure. Using the simple to learn on line program CAD (tinkercad) program I design the interior framework of the building. Usually wood siding is then attached. If I intend for the roof to be removable I often make that with the printer as well since the shape is ridged and has tight tolerances.
The more exciting purpose is printing complex items. As I write this the printer is making two detailed 1910 coal stoves and ovens that include details like door hinges, tool hangers, even manufacture name. All in HO scale.
The door handles are .2mm thick and the resin printer handles it no problem. The file was downloaded from Thingverse. They are free but I tip the designer up to 5 dollars if design is very complex. I do have to resize, attach other items (chimney in this case). It allows for detailing not often seen. I will post a photo when complete.
Resin printing does require cutting the parts from supports, washing them in an alcohol bath (ten minutes) and UV light final curing (either sun for an hour or an inexpensive UV machine for 30 minutes). I wear gloves and work only in a vented area doing this. Much like fiberglass the resin is toxic when in liquid form and smells if not vented. This drawback puts many people off, which is fine, it is a complex machine process and not for everyone. For this reason I think its advantage for a home modeler is in making unique parts not mass production of hundreds of the same part. Still, my printer could print hundreds or thousands per day of simpler designs(barrels, trash cans and such) fairly inexpensively if set up to do so.
Later today I post photos showing the support structure idea and complex details idea I mentioned.
Jim
As a manufacture of detail parts, structures, vehicles, etc. I have experience in both resin casting and resin 3D printing and I have to say that the cost of production is getting cheaper on the 3d printing side of things. No molds to wear out and replace, no resin and mold making materials going stale. 3D printer equipment costs are now cheaper than buying pressure pots and vacuum chambers for bubble free production castings. For some more detailed casting, making 2 part and 3 part molds was quite tedious. Part warpage is always an issue too.
3D printing does have the mess of cleaning and sprue removal, but resin casting has flash problems as well. Frankly I found it more messy than resin casting overall along with the panic pressure of getting the resin mixed, vacuumed, poured and into the pressure pot in time.
I am sure there are a lot of pros and cons of both methods, I can say from our point of view, 3D printing is the way of the future for small, highly detailed, complex production parts for sure.
We paid $4500 for our first 3D resin printer back in 2014 which had 30 micron resolution and a 2.5" x 3" print platform. Now our farm of printers has 20 micron resolution with 6" x 4" print platforms and are a fraction of the cost of our first printer.
Quote from: Rail and Tie on September 23, 2025, 05:50:26 PM3D printer equipment costs are now cheaper than buying pressure pots and vacuum chambers for bubble free production castings. For some more detailed casting, making 2 part and 3 part molds was quite tedious. Part warpage is always an issue too.
3D printing does have the mess of cleaning and sprue removal, but resin casting has flash problems as well. Frankly I found it more messy than resin casting overall along with the panic pressure of getting the resin mixed, vacuumed, poured and into the pressure pot in time.
Edited to just casting subject.
I don't have a problem using Smooth-On products for resin casting or plaster. I don't use a pressure pot or vacuum chamber. I did use a pressure pot once and found that when you dropped the casting it was almost like a tiny explosion. If you think about it, where does the air go to under pressure? You compress all those bubbles into tiny little grenades.
Here's some pictures of a mold I made for a structure. Note all the bubbles in the mix.
crusher-84.JPG
Pour the rubber in from a height of about a foot.
crusher-86.JPG
Let the thin layer set for a minuet so that any bubbles have a chance to come to the surface. Then pour in the rest of the rubber. Let cure. No bubbles.
crusher-89.JPG
crusher-90.JPG
I agree with the shelf life of the product as you said. What's the shelf life of printing resin?
That's been my experience making molds.
B~
Quote from: Bernd on September 25, 2025, 10:19:14 AMI don't have a problem using Smooth-On products for resin casting or plaster. I don't use a pressure pot or vacuum chamber. I did use a pressure pot once and found that when you dropped the casting it was almost like a tiny explosion. If you think about it, where does the air go to under pressure? You compress all those bubbles into tiny little grenades.
Actually, I have found through experience and testing that the vacuum degassing process pulls all the nasty bubbles out of the resin before pouring. The bubbles formed while pouring are nominal compared to the mixing process. Where the pressure pot process shines is with small cavities and thin details in the mold where you might get air trapped in thin and long cavities. In fact, compressing the tiny bubbles makes the whole part more homogenous and actually stronger, since all the bubbles are gone and the resin is forced together during curing. If you have exploding /brittle parts after demolding, it is likely due to the mixing process and curing with a bit too much catalyst. Also expired resin usually flashes hotter and much more brittle, at least with smooth-on products.
If your resin is mixed with too much catalyst the part will cure on the outer surfaces of the casting first and create increased internal stresses when the core cures. With Smooth on products such as Smooth Cast 300 series products, if you get the mix perfect (even though it is quite forgiving on mix ratios) you can watch as the mixed resin turns from clear to white and see the core of the casting turn white first then heading to the outside surfaces. This creates a stress free casting with very little warpage.
As for 3d Printing resin shelf life, it is usually over a year depending on where you order it from. I have some lesser used colors that are over 3 years old and seems to work just fine. It does take a bit more to mix prior to using as the pigment and UV starches settle to the bottom of the bottle. I am also finding the UV resins are not as picky when coming to storage temperature swings.
Sorry about the digression down the resin casting rabbit hole. This thread is about 3D printed details, which I can't get enough of! That is why our motto is "Detail Insanity". If it can be modeled in HO, than it should be modeled!
Regarding layer lines, here is a good example showing the difference in printing orientation to minimize the lines. (printed on my old dental printer) The photo on the left is printing with the wheel laying flat on the build platform. On the right it is standing up. You can see the supports still attached to the wheel on the right. Both these are printed at 25 micron X,Y and the same build layer thickness.
This is one of the potential disadvantages of 3D resin printing, you always have on face on the part that will not be as good of finish because of the little support nubs. Usually I make that surface on the bottom of the part or the gluing face of the part where it is not visible after assembly.