Looking to Print a Caboose...

[wm3798]

Thanks!

[brill27mcb]

From a wish to a reality, and it only took 20 pages of discussion here to make it happen!

Rich K.

[Maletrain]

From a wish to a reality, and it only took 20 pages of discussion here to make it happen!

Rich K.

Actually, it only took 7 pages, even with Ed's drift into "frankencaboose".  We spend some good time trying to figure out how small we could make board spacing and such for N scale models, and then Skipgear ran with it all the way to a finished kit. The next 13 pages are basically progress reports.

This forum is an amazing place of serious collaboration.  Thank you Tom!

Looking forward to some B&O I-5 cabooses and C-15 express cars already. 

As more of us become facile with 3D printers and CAD programs, this will only get more exciting! 

[wm3798]

If nothing else, this thread clearly demonstrates how lazy I am! 

My original hope was for a file that I could tinker with on the printer that presently sits idle not 5 feet away from me at this writing.

And instead, I walk the dog, stop by the mailbox, slap a little spray paint around, and BAM!

You guys are genuinely the BEST.
Lee

[ncbqguy]

I have been working up to commitIng time to teach myself 3D CAD so I can justify investing in a resin printer....no sense in having another toy in a box here. The software is supposed to arrive tomorrow.   One of the first projects I want for myself are variations of CB&Q wood waycars, so this thread is valuable to me.
One contribution....a soldering pencil with an X-Acto blade to melt thru the supports might be better than a nipper or cut-off saw.  I discovered this on InterMountain kits where the brakewheel and some other parts are easily ruined when trying to free a delicate part from a heavy sprue. Once free of the supports there is no pressure on the part when the nubs are trimmed off, and the part can be positioned so the job is easier.
Charlie Vlk

[Sokramiketes]

I have been working up to commitIng time to teach myself 3D CAD so I can justify investing in a resin printer....no sense in having another toy in a box here. The software is supposed to arrive tomorrow.   One of the first projects I want for myself are variations of CB&Q wood waycars, so this thread is valuable to me.
One contribution....a soldering pencil with an X-Acto blade to melt thru the supports might be better than a nipper or cut-off saw.  I discovered this on InterMountain kits where the brakewheel and some other parts are easily ruined when trying to free a delicate part from a heavy sprue. Once free of the supports there is no pressure on the part when the nubs are trimmed off, and the part can be positioned so the job is easier.
Charlie Vlk

The medium here is more like resin castings than styrene/ABS molded parts, so I'm not sure how heat will work. 

What software did you choose?

[Lemosteam]

Nope. The resin is near glass for heat. I doesn’t melt it just desintegates. I’ve actually ised it for casting lead. No joke. It only works once, but it does work.

[Maletrain]

Nope. The resin is near glass for heat. I doesn’t melt it just desintegates. I’ve actually ised it for casting lead. No joke. It only works once, but it does work.

Now there is an idea.  Maybe use 3D printing to make molds for making shells for locomotives or flat cars or underframes using poured lead.  Having cast some bullets, that seems doable if the mold is not too intricate from the pour point(s).  The casting doesn't have to be perfect as it comes out of the mold (like a rifle bullet) because we can putty it as-needed.  The idea would be to get pulling power into the locomotive assembly or anti-stringlining weight into otherwise too-light cars.

(Of course, it would also require some of those stickers about containing materials known to damage Californians.  )

[robert3985]

Now there is an idea.  Maybe use 3D printing to make molds for making shells for locomotives or flat cars or underframes using poured lead.  Having cast some bullets, that seems doable if the mold is not too intricate from the pour point(s).  The casting doesn't have to be perfect as it comes out of the mold (like a rifle bullet) because we can putty it as-needed.  The idea would be to get pulling power into the locomotive assembly or anti-stringlining weight into otherwise too-light cars.

(Of course, it would also require some of those stickers about containing materials known to damage Californians.  )

You might want to consider using low-melt bismuth alloys instead of lead for casting. 

Micromark offers two types, but their price is pretty high.  You can find them online for much cheaper. 

These melt at 160deg F and 280deg F

Another good candidate is called Rose's Metal and melts around 208deg F and is the best for low toxicity when molten.

Ideally, you'd make the master from a quality resin, then take an RTV or rubber mold off of it, and use the RTV/rubber mold to cast your parts from low-melt metal.  The RTV/rubber mold should last quite a while at temperatures of around 200deg F.

Cheerio!
Bob Gilmore

[ncbqguy]

Mike-
I picked CorelCAD.  It looks to be very SolidWorksy.   Ordered a tutorial manual for it but will be sending it back....it explains how to use it for 2D architectural drafting which I think I can handle.....
Charlie vlk

[Lemosteam]

Now there is an idea.  Maybe use 3D printing to make molds for making shells for locomotives or flat cars or underframes using poured lead.  Having cast some bullets, that seems doable if the mold is not too intricate from the pour point(s).  The casting doesn't have to be perfect as it comes out of the mold (like a rifle bullet) because we can putty it as-needed.  The idea would be to get pulling power into the locomotive assembly or anti-stringlining weight into otherwise too-light cars.

(Of course, it would also require some of those stickers about containing materials known to damage Californians.  )

Also there is another method. Add tungsten powder to normal casting resin before pouring.  It works very well for this purpose.  An  who will remain nameless used this practice on some low volume castings and they were quite fabulous WRT weight, and no dangerous metals to worry about.

[delamaize]

Back in my MSTS days, I was using a program called Amabilis 3D canvas. I was able to pick it up pretty quickly, and had some really nice results. That program is long gone, I'm searching for another program to use now, as this thread has got the juices flowing again.

For those of you that were SPF, and into MSTS, you probably had some of my work over the years. My best, and last works were the I1sa and K-4 that was put out by BLLW. I did the modeling on both, but textures, mapping, and physics were done by others in the group. The files are mostly likely long gone, or trapped on some dead PC somewhere.

[Lemosteam]

Now there is an idea.  Maybe use 3D printing to make molds for making shells for locomotives or flat cars or underframes using poured lead.  Having cast some bullets, that seems doable if the mold is not too intricate from the pour point(s).  The casting doesn't have to be perfect as it comes out of the mold (like a rifle bullet) because we can putty it as-needed.  The idea would be to get pulling power into the locomotive assembly or anti-stringlining weight into otherwise too-light cars.

(Of course, it would also require some of those stickers about containing materials known to damage Californians.  )

y

@Maletrain , here you go... not a complete success, but worthy of additional effort.

The cope and drag:


The flat car needing a weight. Grooves are inside the ribs under deck.


The mold closed and aligned. Center hole is the sprue. Four other holes are vent/ mold full holes


The tools.


Mold closed and clamped.


After pour.


Part from mold;


Mold did not melt, crack or fail. Otherwise decent casing that pulled right out do to the draft angle used. Not sure how many castings it fill handle, but I can always print more.

The casting filled about 75-80% of the mold cavity. Need to figure out a way to get more pressure during the pour. Maybe need to heat up the mold first in an oven so make less diparity in temperature between the mold and the molten metal.

Was worried that the part would not eject but it popped right out of there.

Proof of concept is valid IMHO.

[Maletrain]

Nice test, Lemosteam.

When casting lead alloy with steel molds,  it usually takes a few pours to get the steel up to temperature so that the cast part fully fills the mold with smooth surfaces and no wrinkles.  I don't think that is really feasible with a 3D printed mold and lead alloy like wheel weights because the melting point is well above kitchen oven temperatures.  There are lower melting point metal alloys (some even below 212 degrees F) used for casting (things besides bullets), but they are both expensive and considerably lighter than lead.  But, it would be easy to get the mold up to those temperatures. 

Since the 3D printed resin molds are actually pretty good insulators, compared to steel molds, I am not so sure that mold temperature is that important. The surfaces in your test casting do not look to me like the mold was too cold.  But, if the resin releases any gases when suddenly heated by molten lead, that could keep the mold from completely filling unless there are sufficient vents to let the gas escape fast enough.

There are "bottom pour" melting pots that have gates (valves) that open on the bottom of the pot, so the weight from the full height of the molten alloy in the pot drives the liquid metal into the casting mold.  That might be a good investment for anybody planning to make many castings.  For example: https://www.ebay.com/itm/Lee-Precision-90009-110V-Production-Pot-IV-Electric-Lead-Melter/174662151664?epid=27030518376&hash=item28aaacedf0:g:GNwAAOSwAQ5gPpWT .

People have also mentioned doing the 3D printing shell itself in "metal", but I am not familiar with what that means.  Are they really able to print with a lead alloy, or is it resin with a lot of metal power in it?  What is the physical density of the cured print?

[SkipGear]

Nice test, Lemosteam.

People have also mentioned doing the 3D printing shell itself in "metal", but I am not familiar with what that means.  Are they really able to print with a lead alloy, or is it resin with a lot of metal power in it?  What is the physical density of the cured print?

That is a shapeways process. I believe it is a powdered metal infused with resin that is then fired in a kiln afterwards to fuse the metal together. @bbussey played with it in an effort to make a custom split frame for a diesel but ran into dimensional issues. It shrinks when fired and the change is not uniform. It took 3-4 tries to get the model to print correctly so that it was the expected dimensions after firing.