Proposed Member Group Donation: Small Part Casting Equipment

[Kevin McLeod]

Hi Hive13 family, and happy post-holidays to you all!

For years there have been whispers of people's desires to be able to cast metal at Hive13.  To that end, I have done the research to develop a list of what equipment would be required to establish a casting station at the hive.  

There are many, many different methods and techniques for casting metal.  The setup I propose we start out with is a simple investment casting setup, with a torch for melting small volumes of metal.  This setup is limited to melting about 4 oz. of metal at a time, so the maximum size of parts that can be cast are limited, however, the quality of the castings you get are extremely good, suitable for things like Jewelry with fine engraved details and prongs for stone setting.  The setup would also be suitable for casting small mechanical parts for things like RC Model Engines, Drone parts, etc.  It could also be used to cast metal tabletop minis and other toy-like items.

The process required to make a part by this process starts with a wax model.  The wax model can be carved by hand, machined on a CNC mill (the Roland would be perfect), cast in a silicone mold, or even 3D printed with a wax casting 3D printer filament or resin.

The wax model is then attached to a wax sprue, inserted in a metal casting flask, and a ceramic slurry material, called investment, is poured around it.  The ceramic cures to solid around the wax, leaving the wax model and sprue embedded in the investment. 

The investment mold and model are then placed in a kiln (which we already have in the glass area) to "burn out" the wax from the investment.  This process melts and burns off the wax, and it cures and preheats the ceramic investment making it ready for pouring metal into the cavity.

Once the burnout is done, and the investment is ready,  the metal is then heated with an small hand held oxygen/propane torch in a crucible.  This process can be used for melting gold, silver, bronze, silicon bronze, white metal, aluminum, and many other precious metals and engineered metals.  Up to about 4 oz. of metal can be melted and cast at a time using this method.

Once the metal is molten and ready for pouring, the investment mold is removed from the kiln and placed on a vacuum machine.  the investment material is porous, so the vacuum allows air to be sucked out of the mold, pulling the molten metal deep into the mold cavities, fast enough to prevent it solidifying before the mold is filled.  The metal is poured from the crucible into the mold with the vacuum running. 

After the pour is complete, the vacuum machine is turned off, the metal allowed to cool enough to solidify, and then the investment flask and casting are quenched in water.  The water dissolves the investment, revealing the finished casting.  The part can then be removed from the sprue with a jeweler's saw, and cleaned up with files and emery paper, and polished if desired.  Mechanical parts can also be machined on the mills and lathe in the machine shop to ensure accurate functional surfaces if needed for the application.

Here is a good video that steps through the majority of the process:  https://www.youtube.com/watch?v=Dbj41zl57aw

I have put together a list of all the equipment we would need to get started with this, sufficiently to make it enjoyable, and with enough consumables to allow members to learn the process and get certified.  the full list can be viewed here:  https://docs.google.com/spreadsheets/d/1zVvEHwLEBngNbHcibRAZBm_dvLo1fvwxKBkMSeI5oQo/edit?usp=sharing

On that list, the largest items are the Vacuum Investing & Casting Machine, and the torch (w/ associated plumbing and tips).  It's worth noting that both those items can be used for much more than this investment casting.  The vacuum table is also suitable for degassing resins (epoxy, silicone, etc.), stabilizing wood, and other activities requiring a vacuum chamber.  The torch is also extremely useful for fine detail work in the glass area, a perfect companion for the big Carlisle CC bench torch we have, and doing glass assembly work. The torch would also be suitable for many soldering and brazing tasks, like jewelry assembly soldering, ring resizing soldering, making brazed carbide mill and lathe tools for the machine shop, hardening and tempering tool steel for custom form tools, or brazing parts for things like model engines/boilers, etc.

The total cost for the equipment and starting stock of consumables, including wax stock, investment, and a stock of bronze casting grain, comes to about $2600.  In the spirit of the holidays (and avoiding spending Hive13's money till we get AC installed), I am hoping we can get enough members interested in chipping in donations to cover this purchase.  

I'll start off by committing to donating $700 (enough to cover the torch and associated equipment) toward this.  Please, if you are interested in getting this type of equipment set up at Hive13, consider contributing to this purchase.  My plan is to hold off on collecting any money till we know if we have enough people interested to cover the whole cost.  If you are interested in contributing, feel free to post here with what you are willing to contribute, or if you would like to remain anonymous, send me a private message on slack or email me at kmc...@hive13.org.

Thanks to every one of you for making Hive13 an amazing place!  As hard as this year has been for everyone, our maker community has truly had an impressive and wonderful year.  It's so nice being in the new place, and Hive13 is a genuine joy of a place to make things, thanks to all of your efforts!

Happy holidays,

Kevin McLeod

Hive13 Glass & Metal Work Warden

[Dave Schwinn]

Thanks Kevin for putting together this proposal.  Please put me down for a pledge of $200 for this.

Also I think it is worth adding that I have purchased and will be donating to Hive13 a 6L Ultrasonic Cleaner and a small rock/jewelry tumbler.  Like some of the tools proposed by Kevin, these will be very useful for a variety of purposes including casting.

[James Hartley]

Kevin,

    Awesome!  I’m not sure I have a need for it NOW but the year is young...  I do have some thoughts.

    Put me down for $100 specifically for this.

Regards,

James

On Jan 2, 2021, at 11:41, Kevin McLeod <kmc...@hive13.org> wrote:

Hi Hive13 family, and happy post-holidays to you all!

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[Kevin McLeod]

Thanks Dave and Mark!  Is anyone else interested in pitching in on this?  

If not, I think it may be worth it to go ahead and order everything except the vacuum machine and the electric wax worker tool, and reduce the quantities of the metal stock to ~2 lb each.  that would bring the total initial buy down to ~$1k, which is what we have commited now. 

The casting can be done without the vacuum table, just not with as small sections, as fine detail, or as reliably.  I would say we get everything else, and maybe the material to DIY a shitty vacuum table, then keep an eye out in auctions and craigslist/FB marketplace, the vacuum machines pop up every now and then for far less than new.

Thoughts?

[Kevin McLeod]

err.. sorry, Dave and James, don't know how I messed that up...

[Kevin McLeod]

Thanks everyone who has decided to chip in on this!  We currently have 5 people willing to chip in, for a total of about $1200.  That is enough for us to get the basics, with a small stock of starting consumables.  This would not include the investment-specific vacuum casting machine, but would include a 3 gallon vacuum pot for degassing investment (could also be used for resin casting degassing, wood stabilization, etc.) and a vacuum casting table gasket so that we can DIY a casting table.

if anyone else would be interested in chipping in, please let me know!  all it would take is 3-4 more people willing to chip in about $200 each to be able to get a proper casting machine without having to hack together a DIY solution.  Alternately, if we don't have enough people contributing to get the machine, any additional contributions can be used to order additional consumables so that more people can give it a try!

I'll plan on ordering next friday, so if you would like to participate, please let me know by then!

Thanks,

Kevin M.

[Kevin McLeod]

Update:  I have received a very generous offer of a $500 donation toward this effort from a member who would prefer to remain anonymous.  This puts us VERY close to being able to afford the full, proper vacuum casting machine which would enable the use of any size flask, and both solid wall and perforated flasks, setting us up to be able to do larger and more complex castings.  Thanks again to everyone who is pitching in!

[Kevin McLeod]

Bump for interest.  We are currently at $1720 funded thanks to everyone who has offered to donate, we are only ~$550 away from the goal we need to hit to be able to get the nice casting machine, anyone else willing to help us meet that goal?

as an FYI, I have already ordered the Torch and associated plumbing, it should be in this week.  Dave has also purchased and brought in the materials and equipment to do petrobond casd casting, so hopefully as early as the end of the week we will be pouring some metal!

Thanks again to everyone who helps make the hive a great place!

[Tim Yelvington]

Hey Kevin,

I can donate $150 to the cause. Please let me know how to send the money.

Tim

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[Kevin McLeod]

I'll send a message to everyone who has said they will contribute on Slack in just a minute

[Kevin McLeod]

bumpety bump...   we only need $400 more to meet the goal!  That's just one more person at $400, 2 more people at $200, or 4 more people at $100 each!  Totally achievable to add a great completely new capability to the hive that can't easily be done at home or found elsewhere in Cincy!

Who is excited to be that last person that get's us there?  Thanks again to everyone who is contributing!  I've already got the space set up in the hive to support this, we have power, a workbench, and I got the big vacuum pump that's been around forever running!

[Chris Davis]

Kevin,

Put me down for $100

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[John Clark]

Put me down for $50 and let me know how to get it to you.

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John Clark

[Kevin McLeod]

Thanks! I'll send y'all messages on Slack in a moment.

Also, Tim, I sent you a message on Slack but haven't gotten a response.  If you don't want to use Slack, send me an email to kmc...@hive13.org, I'd send you an email, but the new google groups apparently has broken the ability to message people directly, I can't get your email from your post. 

[Kevin McLeod]

Great news everyone!  I've received another donation of $200! that puts us JUST under the goal by $50!

I would LOVE for us to be able to meet and exceed the goal so we can get this moving forward!  If anyone else is willing to chip in, at whatever amount, please let me know!  any and all we get above the goal will be used to cover additional related materials, tools, and parts for casting.

[Jim Dallam]

Kevin:  Kudos to you for your initiative and leadership towards bringing small parts casting equipment to the Hive!  

Small parts casting is not so much my thing (yet?) but it is interesting to see a member champion with an interest assemble an independent group of interested folks to share their interest and make something interesting happen.  That is one of the great things about the Hive.  It reminds me of the backstory on how the Hive's CNC came to be.

I can only offer to help in small ways.  You are likely fine on-your-own-as-is, but if you want to run your assembled project money in-and-out through the Hive finances I can offer to help to support that process as Treasurer.  It may have some benefit to formalize the record keeping, but it is also a likely complication that is not really necessary for a one-time effort.  I can also offer to help on the Wiki project documentation in small ways.  Back channel me if you would welcome either of these, or if you are fine on-your-own.

Meanwhile, on behalf of all of the rest of us, here is a public thank you again for your continued good efforts and good job.  JimD

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[Rob Wetterer]

Put me down for $50. 

Thank you,

Rob

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Thanks, Rob

[Kevin McLeod]

Thanks Rob!  I'll send you a message on Slack.

Jim - I'll gladly take help getting everything documented on the wiki!

To everyone: thanks so much for your contributions!  We met the goal, and I have ordered everything!

I will admit, if anyone still feels like contributing, I'll gladly still accept more, as between shipping (the shipping for the casting machine and other stuff from contenti ended up being $127 by itself!), the stuff to get our old vacuum pump usable, and various fittings and hose I thought we had, but needed to order, I have put about $500 more of my own money into this than I had anticipated (I'm comfortable with that, but if anyone is willing to help me reduce my personal overage a little by sharing the load, I'd be just as thankful as to everyone who helped us meet the base goal).

The stuff should all start rolling in over the next week, I'll keep everyone posted!

Thanks again! Stuff like this is what makes Hive13 awesome!

[Kevin McLeod]

I posted lots of pictures on Slack, but just so everyone knows, the vacuum machine, the waxes, and carving tools are all here and ready to use!  Kayla and I have already carved items to cast, and invested them. here is a photo album of the pictures we took so far: https://photos.app.goo.gl/EmcEozS66j1gBW1v8

We have two more flasks if more people would like to carve items to be sprued up, invested, and cast!  The torch has not yet arrived, it is stuck in USPS libo, but as soon as it arrives, I will plan to run a burnout cycle and cast the first parts!

Please, feel free to pick out some wax, play with the carving tools, and make something to cast, if you do it before the torch arrives, I'll add your carving to a sprue and we can get it cast in the first batch!

Thanks,

Kevin m.

[Chris Anderson]

Is this for resin casting? Can I make keycaps with it?

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~chris
ch...@chrizzle23.com

www.chrizzle23.com
(513)633-2323

I tried to break down the essential position for him. "You're arguing for a universe with fewer waffles in it," I said. "I'm prepared to call that cowardice." --Tycho Brahe, Penny Arcade

[Kevin McLeod]

Chris,

This group purchase was for the equipment to do metal (silver, gold, bronze, etc.) casting.  That said,  we did also buy a 3 gallon stainless steel vacuum pot with this that can be used for resin (epoxy, urethane, silicone, etc.) degassing.  I also got out old big vacuum pump cleaned up and got all the fittings sorted out so that it can be hooked up to the vacuum pot easily.

Bottom line though, YES! you absolutely could make key caps with this equipment!  You would use the vacuum pot and silicone to make a master mold, and then you could either cast your plastic/rubber resin in that mold, or you could inject wax into that mold, invest the wax, burn it out, and cast it in metal! A mechanical keyboard with all cast metal keycaps would be incredibly badass. 

Hit me up if you want me to teach you how to use everything!

Thanks,

Kevin

[Kevin McLeod]

I have received the last shipment of our casting equipment! We now have a torch for melting our metal and are ready to cast!  I plan on doing an investment burnout starting Sunday morning, the burnout cycle takes about 8 hours, so I will be doing the actual melt and castinging Sunday evening.  If anyone would like to have an item cast at the same time, please get your wax carved by Saturday evening!  We have 2 more flasks that items can be invested in, so please, grab some wax, carve or CNC something you want to cast, and let's do it!  we have a small stock of bronze (1 lb.) that anyone is welcome to use to cast a test piece or to learn, or Dave Schwinn and I both have Silver on hand that we are willing to share for the price we paid for it (about $30/oz).  let me know if you need help getting a wax item ready to cast!

Here is a photo album of our setup, and some wax carving, spruing, and investment that Kayla and I have already done in preparation for our first metal pour.

and here is a pic of the cute little torch:

and our casting machine: