Here's a workaround to achieve the same thing. You 3-D print a pattern and use that to cast the parts. I saw this on one of the British steam sites in the last month (can't remember which one); I believe they were using this process to cast cylinders.

This saves the manual labor of fabricating the pattern and makes the pattern easily reproducible.

a) In my experience, yes, you can 3-D print, but as was said, the elements will take a toll.

b) Why bother with the expense of the 3-D process when you can make a mold out of cheap latex and cast your own durable parts with resin? We did this with parts on our narrow gauge boxcar several years ago and the parts are still like new.

Here is a link to the work:

http://www.tarheelpress.com/LawndaleBox ... dware.html


Matt Bumgarner
Alexander Chapter-NRHS

Hi,

I was looking at a 3D printer for some hobby items. The spec is the resolution (thikness of a line is about 0.1mm or about 0.039" tall and wide.

If you 3D print a very large item, it will take days to print. This is not cheap or fast. What most people call 3D printing is a process I first learned of called Rapid Prototyping. This is for new produce development (i.e. not having to go through designing and building injection molding dies).

3D printing does have its place but be sure you understand its limitations also. Just a warning - do not discount 3D printing as a possibility.

Shapeways has a 3D printing that (I think) is printing the object in wax (i.e. lost wax castings) and then casting them in brass or silver or gold.

Doug vV

Many schools nowadays (mine being one) have high quality 3d printer(s) as a part of their engineering courses. You could politely explain what you are trying to do, and probably have some stuff printed up for next to nothing, if nothing at all. Could be a project for the students themselves (hmmmm).

Just a suggestion.

Also consider CNC milling or routing such as with the Shopbot. It can't do ornate 3-D work but it can mill several layers of pieces you subsequently glue together. A quality epoxy such as West System will be stronger than any substrate short of metal.

The piece can be worked in a variety of materials and should then be primed with a penetrating cure-without-air primer, and topcoated with a tough topcoat. That way weather damage won't be a factor.

I continue to be surprised by how many cities have maker spaces such as Techshop.,which have 3d printers, laser cutters, Shopbot, waterknife, CNC metal mills etc. I laid over in Phoenix on my way from Detroit to SF, and on a lark I checked if they had one, sure enough there was a Techshop. There are several other types, often local affairs.

Hi,

Another item similat to Shopbot is eMachineshop. They have a CAD that is free to download to use and will price your design.

I've used it to make custom HO scale items including a PRR DD1 chassis (not single piece).

Doug vV

Emachineshop is a service. You send a design and money, their staff runs your job on their machine, and you get the finished product in parcel post.

Shopbot is a machine. Once you buy the machine initially, it's yours. You can use it indefinitely in any manner you please, on any material. Your only cost is materials and bits (and maintenance and purchase, and learning to use the machine). Machines like the Shopbot, Tormach, Epilog laser cutters etc. are cheap enough that serious hobbysists can afford their own.

Maker spaces like Techshop are sort of like gym memberships - a monthly fee then unmetered access to the machines to do all the work you please, using your bits and your material. A few machines with high costs on shop supplied consumables may have a charge per minute or per cubic inch (notably, garnet for the waterknife).

One big difference is iteration - when you discover the part is wrong and needs to be altered. At your own machine or a maker space, you simply make the change and print again, provided you have material. With mail-order machine shops like emachineshop, you get the part in a week or two, discover the fault, redesign, pay again, and wait another week. Another is, obviously, your time; you may not fancy loading stock, spending endless hours watching machines, and sweeping up chips... and mail order machine shops (or any machine shop) will do that for you for money.

Thanks for the clarification. I'll look into shopbot.

Doug vV