Investment Casting Costs

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Dick_Morris
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Investment Casting Costs

Post by Dick_Morris »

I started to post a response on the Nathan check valve thread, but the cost of making castings wasn't relevant to the original post.
Especially when you consider what people are doing with a $300 resin printer to make their waxes I don't understand why the service is not more affordable?
The opportunities of a resin printer and investment casting in model building are truly amazing. I can't speak on the cost of contracting for castings but I do have a good feeling for what it costs in a home shop. maybe this will put the costs in perspective. The simple truth is that there can be considerable expense in time and money beyond the printer.

Although free 3D software (like Freecad) is available and has awesome capabilities, it takes a significant time investment to go beyond the basic functions. Unless one is very skilled, it can also take considerable time to design a complex part for 3D printing.

The actual 3D printing involves another skill set with its own learning curve that takes an investment in time. When staring out, it's common to experience repeated failures as part of the learning curve. Castable resins tend to be a bit more difficult to cast successfully than utility resin.

An example, here are some variable costs for a a 1/8 scale laird crosshead. The resin suitable for casting cost 3-4 times the cost of a utility resin. Not a massive expense, but crosshead used about $2.00 in resin. It also took about 2.3 pounds of investment powder at a cost of just under $5. I'm guessing that electricity for running the burn out oven through a cycle and melting the metal may cost another $5 to $10, although it's typically split over several castings. Virgin silicon bronze would cost about $10. Crucibles are expendable and the wear and tear for one melt probably costs about $1 to $2.

A new, small burn out oven will start at $600. My first one had a 6" cube chamber which only allowed me to burn out and out a couple of flasks at a time. After a couple of years of watching the ads I found one used that would hold 6 to 8 flasks. It cost $200 plus about another $200 and 50 hours of time to repair it and do some modifications. New, it would have cost $2,100.

A casting station which includes the bell jar, pump, and place for doing the vacuum casting will cost about $650. By buying a vacuum pump and chamber and making the casting table you can get by for about $300. Depending on the style and size of flask, they will cost $15 to $35 each. They are reusable, but you will probably want several sizes and possibly several of the size you use most.

An electric furnace with crucible for melting the metal will cost $250 to $350 depending on size.

Adding sprues to a part and putting it into the flask will take at least ten minutes, more if there is a tree of a number of parts. Mixing the investment, vacuuming it, pouring it into the flask, vacuuming it again, getting it ready for burn out, and cleaning up the utensils before the investment sets up takes about 20 minutes.

It can take an hour for the metal to melt, but the actual time for casting and cooling the flask in a bucket of water only takes about five minutes. Cleaning the investment from the flask and casting takes me 10 to 20 minutes per flask in the summer when I can use a pressure washer and 30 minutes to an hour if I have to do it in a bucket water and using picks. It's nice to have the option of bead blasting to remove the remaining investment and oxidation on the surface of the castings and it doesn't take very long, but that's another several hundred dollar expense, not including the compressor.

Investment casting parts adds a lot of capabilities over sand casting, fabrication, or hogging parts out of a chunk of metal. It's not cheap, but I'm glad I made the investment. It's made me look differently at how I attack many of the parts that I model and allows me to do things that weren't practical with the other methods. I'm glad to have it as another tool in the tool box.
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Harold_V
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Re: Investment Casting Costs

Post by Harold_V »

Thanks, Dick. That was an excellent presentation.

H
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Bill Shields
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Re: Investment Casting Costs

Post by Bill Shields »

dick:

so quick, stick thumb up in air.

to do it reasonably well, what $$$ to make your first part?
Too many things going on to bother listing them.
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Dick_Morris
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Re: Investment Casting Costs

Post by Dick_Morris »

You could probably get started on tight budget for about $500, maybe a less, if you are creative, build some of your own equipment, and have some luck. A big part of the cost is a vacuum pump, which is a must, and a burn out oven with a programable controller. That doesn't include about $250 to $300 for a printer. An old kiln upgraded with about $100 in electronics will serve as a burn out oven. Or one can be made from firebricks or ceramic fiber board and some Kanthal or nichrome wire, which you can wind into coils. Metal could be melted with the proper type of propane burner which can be made fairly cheaply and some fire brick or castable refractory.

$1,000 or $1,500 is probably in the ball park when you have to buy stuff (not including the 3D printer), but can still be a bit creative.

My first time cost isn't a good indicator. 35 years ago for $500, I bought all of a friend's investment casting equipment (a couple of small burn out ovens, a few flasks, a vacuum table with bell jar, and a spin caster. I also got about 40 pounds of investment powder (which surprisingly was still good when I used it). 32 years later when 3D printers became available and affordable and some good Youtube sites appeared, I finally got around to using it.
hanermo
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Re: Investment Casting Costs

Post by hanermo »

Excellent thread !
Looking at above data, I would guesstimate around 1800$-2500$-3500$ for a system for doing castings, given a suitable free propane/heat source.

Including gloves, boots, gauntlets, helmets, sand for protecting the base area, etc etc.
And tubes, valve, connectors, for the propane.

Burn out oven, vac. pump, flasks, stands, gauntlets -- these are pretty much mandatory.

For less than half the price skilled people doing fab can do a ghetto version -- for a first try or proof of concept.
I build stuff In steel, and have plenty of tools to hand.

Using a shop vac, welded unions, builders sand, and a one-time clay jar I might make a single casting of 60%-70% quality for not much in extra materials .
Lots of hours.

For any *real* casting I would estimate about 2000$ minimum cost for someone already doing metalwork and having ppe and skills and stuff.
For me to do a first "proper" silicon bronze casting my cost might end up slightly below the 2000$ mark.

And every additional cast costs in the 0.5 kg / 1.1 pound category around 10€ each in various bits.

Plus about 50€ / each piece in additional desired equipment like thermometers, etc etc etc.
Plus about 1500€+ in various kit if I want to do it seriously or in any quantity or for others.

So for 200€ or so I could "have a go" of low quality --
2000€ to make a really good one-off,
4000€ to make stuff well, reliably, and be able to supply others with bits and bobs they want.

Add patterns or 3d models of choice.
Add work hours of choice.
RONALD
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Re: Investment Casting Costs

Post by RONALD »

RONALD
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Re: Investment Casting Costs

Post by RONALD »

Looks like a number of the Rio Grande items are now listed as Wholesale Only.

Have no idea when that changed, but you should be able to find those items somewhere for retail sale, once you see what is of interest.

Most of my stuff was purchased many years ago, except for any 3D stuff..

I’m putting together a CNC Router Kit for doing some work toward 3D.

Will post photos when it is up and running.
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JBodenmann
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Re: Investment Casting Costs

Post by JBodenmann »

Hello My Friends
Very informative thread. Now you know why I just make waxes and then send them, or take them to the foundry. I am more than happy to pay what I am charged for castings :D . Making consistent good castings is not easy.
Jack
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Bill Shields
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Re: Investment Casting Costs

Post by Bill Shields »

A very true statement

After Anthony's comments a while back regarding porous injector castings, and the general problems I have had with bad live steam casting over the decades, my hat is off for anyone in that business.

It is not something that I would consider doing half a**ed and getting a good product.

Everyone says "that is too much $" until they try to do it themselves.
Too many things going on to bother listing them.
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Dick_Morris
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Re: Investment Casting Costs

Post by Dick_Morris »

I'm happy with my castings and they meet my needs, but on my best day my castings aren't as good as Anthony's.

There is a another cost to consider when you are buying or contracting for investment castings. Sometimes you just have a bad day. A couple of days ago I burned out and cast eight flasks with about 20 parts. All total, I had about 30 hours and $40 in materials invested. Two of the 20 parts came out, the rest were a total failure. A few days like that can be a real drag on a small business, for me it's just a learning experience
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Greg_Lewis
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Re: Investment Casting Costs

Post by Greg_Lewis »

Dick_Morris wrote: Sat Feb 04, 2023 1:15 am ...
Sometimes you just have a bad day.
...

In my shop it's, "Sometimes you have a good day." :shock:
Greg Lewis, Prop.
Eyeball Engineering — Home of the dull toolbit.
Our motto: "That looks about right."
Celebrating 35 years of turning perfectly good metal into bits of useless scrap.
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Bill Shields
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Re: Investment Casting Costs

Post by Bill Shields »

Then you get to the point where you are thankful for hours.
Too many things going on to bother listing them.
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