The Home Machinist!

Thought everyone might be interested in some technology that could, at some point when costs go down, be of use to Live Steam builders....

3D printing of sand molds and cores for castings. This be great for a one-off cylinder, cradle, or trailing truck casting, for example.



The video is long and drawn out, but worth watching

LL

Boy would that make my parts a snap.

John B.

Have a look at the company offering the machinery as well as the services:

http://www.exone.com/resources

hudson

Thought everyone might be interested in some technology that could, at some point when costs go down, be of use to Live Steam builders....

Cost are down, well at least in my mind, to the point where I have done around ten parts now for a set of patterns and cores for a Hodges Trailing Truck on my Pacific.

I have been using a company called Shapeways that allows me to upload my drawings as STL files. Within four minutes I have a price quote and once ordered by simply clicking it into my cart I have the part in ten days or less. Fender was the member that took me to the sight and I have not had a bad experiance yet.
This particular pattern was easy and cost me 26.00.

The part was a simple casting

The more complicated set of patterns for the jorurnal box consisted of three parts with four core parts cost closer to 200.00

Charlie.... Costs are down and still coming down for RP/3D printing.... But they are still up there when it comes to printing sand molds.

These molds, after assembly as required, go straight into the foundry from the printer ready for metal pour.... Iron, aluminum, etc. They are not patterns or pattern cores to be rammed in a cope/drag.

Great for larger one-off (or maybe two-off) parts where no additional castings are be made.

LL

Last time I checked the ZCORP process for building sand molds would not handle the heat of molten iron or steel.
Good for bronze or aluminum though. Maybe they have developed better bonding agents.
The size of the casting is limited by the size of the machine

Howard Gorin wrote:Last time I checked the ZCORP process for building sand molds would not handle the heat of molten iron or steel.
Good for bronze or aluminum though. Maybe they have developed better bonding agents.
The size of the casting is limited by the size of the machine

Howard....

The video says the molds outputted by the printer being used are iron capable.

Build sizes by ExOne printers are up to 79x39x27 inches.

LL

Brochure for the largest ExOne printer....
http://www.exone.com/sites/default/file ... ure_EN.pdf

Molds are iron, steel, non-ferrous, and light metal capable.

LL

Very interesting that sand can be processed into molds and cores. I can imagine core printing, but the mold is a little more difficult. I would think mold shipping would be rather iffy.

I have a 3-D printer that makes things out of ABS plastic. Good for patterns and some finished objects that aren't required to be super strong. My printer is a Printrbot and is very small with an effective print area of 4 3/4 x 4 3/4 x 6 high. That is good enough for a lot of pattern times for live steam. The Printrbot can be expanded to about any size, however. It prints objects in layers and 0.004" is about as thin a layer as it will do.

Now if I were any good at Alibre or Solidworks, I'd be all set. I'll get there eventually

JerryK

A buddy of mine works for the manufacturer of the print heads for these machines. There is a couple of companys that are building the parts directly of metal. The Iron ground to powder of 30 picometers ( 30 billionths of a meter) as is brass. Agitatied it flows like a liquid, then layed down in layers as in the video. Sand is laid down in what will become the voids. The whole sand and metal powder block is fired in a furnace, brass melts out into the sand, leaving the iron as a solid structure. The end product looks like a really fine sand casting. I wish I could share the photos, but can not do so.

Theer is a group trying to use it for laying down live cells of human organs to grow replacement parts, bones, kidneys etc.

Very cool stuff

I'll get excited the day they remove "prototyping" and replace it with "production."
Only way they can justify the prices is small quantities.

RB211 wrote:I'll get excited the day they remove "prototyping" and replace it with "production." ....Only way they can justify the prices is small quantities.

I was given access to the speadsheet used to calculate one company's printing costs. I will will not divulge actual cost figures, but I will say that you would be surprised at the mark up price charged vs. actual expenses to make the model/pattern. Not cheap.

The quote I received on a printer a few months ago was big bucks money. It wasn't for the largest size production printer, but one made by a leading manufacturers, with the latest state of the art technology and an extremely high resolution print out in a moderate size print area.... $84,000 less tax, shipping, or install/setup/training. The latter, in it's own right, is expensive. Purchasing an annual maintenance/service contract is $8k..... For this particular printer, media cost per 2.0Kg volume cartridge ranges $575 to almost double that. Support media in the same quantity is around $375.

With the printer I was looking at, the cost to buy it, set it up, train, and other printer related expenses (the unit to remove the support media, service contract, media, etc.) was in the neighborhood of $115,000. Just to get it ready to produce the first printed part.

Printer prices are coming down, but the highest resolution machines still ain't cheap. Especially if it has the largest build size.

LL