Chris Johnson

The “want” of a 3D printer was to be able to make foundry patterns. This is quickly becoming the standard for small run castings. It is much easier and faster than traditional pattern making, and you don’t require the same set of specialized tools.

The downside is that most 3D printers don’t have a large enough print volume of interesting castings, requiring printing in parts and then assembling the parts to create a whole.

This want was not enough. There had to be something that was a reasonable fit with our household. It isn’t like I’m going to be printing dragons and dice and hoping to pay for the hobby with that. There are hundreds, if not thousands, of people doing that.

My son just showed me a site where he has purchased D&D figures. He and I will see what we can do for him.

One of my issues is organization. If something has a place, it goes back to that place. Most of the stuff in my life lives on a flat surface. And it is time sorted. The oldest stuff is on the bottom.

I want organizational tools.

Enter two 3D solutions. One is a system of displaying things in an organized way for quick access. The other is the worlds fanciest peg board.

I plan to use GridFinity for most of the “flat” storage areas. That means draw and shelf organizers.

The more extensive system if Multiboard. This is much more complex than GridFinity.

Here’s a simple example of what sorts of things can be done. The eco-system consists of MultiBoard, the pegboard, hooks, and simple shelves. MultiBin, containers to hold things that can be attached to the MultiBoard. With MultiPoint me the connection system.

Take the time to watch the introduction video, get some ideas.

Here are three to think about:

1. Is it an assault with a deadly weapon to use a Super Soaker in -7F tempetures?
2. Should Don Lemon be charged for his participation in the invasion of the church in MN?
3. What is the thing your SO will decide they must have once the snow has started?

My first computer was a Litton Automated Business machine. It used drum memory to store data and had an instruction register and maybe two other registers. I purchased it for $100 my first summer home from college.

It was a remarkable machine. It was fun to work with, but you really couldn’t do much with it. It had dual paper tape readers, a printer, and a paper tape punch. I wrote an inventory control program for my father with just that, in something that looked very much like machine code.

It wasn’t a usable machine for my father.

The computer I told my parents to get was a Macintosh. They just worked out of the box. Plug them in and you had a word processor, a paint program, and I think a spreadsheet. It all just worked.

They got a PC and fought with it for years.

Today I can buy a piece of hardware, load an operating system on it, and have it fully functional as a general purpose computer or acting as an embedded machine in just about an hour.

The biggest time sink is removing and inserting screws to hold everything in place.

3D Printer

10 years ago or so I purchased a 3D printer kit. I’m sure I never got a fully successful printout of that damn thing. I had to do so much to just get it to do something. I spent more time trying to make it work than I did printing. And it was fragile.

Today, I believe that the kit instructions had the count of the number of teeth on one of the drivers wrong. Which meant that cubes were squished.

Today we have Macintosh printers. After 6 months of research, I pulled the trigger and purchased a Bambu Lab’s P2S printer with AMS.

Setup took around 2 hours. Every step was clearly documented. All the tools to do setup were included. Mostly setup consisted of removing packing, tape, and shipping screws.

Thereafter, it was plugging in one cable, 2 tubes, and the power. Turning on the power brought up the screen that forced me through an initial setup process that calibrated everything.

Finally, I pressed a few buttons on the control panel, and it printed a tool.

From there I used the phone app to scan a QR code, which took me to a cloud version of a storage box to print. That’s printing as I write this.

Again, there is no effort on my part to do any of this. It is pick, click, and print.

Calibration

My kit had no bed leveler. That was done by putting a piece of paper on the bed, lowering the nozzle until it just touched, and then clicking the next button to repeat. I think there were 20 or more sample points. And I still don’t know if that was enough.

The automated version required the printer to be working to print a new piece for the printer, which would hold a switch. The switch used a paperclip as a probe. This went much faster, but it still didn’t work.

The motors were noisy, but it was a joy to watch them move the hotend around.

Today’s calibration took around 45 minutes. This included using the built-in lidar to measure the distance to the bed, and then I think it used a pressure sensor to determine when it actually touched the build plate. It took samples every centimeter or so in a grid. That went rapidly.

It then went into a noise tuning calibration. For 20 minutes it ran the hothead around in diagonals, working to find the correct stepper speeds at different head speeds and then tuning them to be quiet.

It worked. These are stepper motors you can’t really hear. It blows my mind.

From there it did vibration calibration. This thing can accelerate so fast that it will cause the printer to move. For every action, there is an equal and opposite reaction.

This thing figured out, for this printer, on this surface, just how much the printer reacted to head movement to be able to offset that motion during the deceleration stage.

The first print after calibration took only a few minutes to check calibration before it started printing.

Slicers

To create a 3D print, you start with an idea. You build a 3D model. I use FreeCAD; people use many CAD systems; Fusion 360 is a popular one.

Once you have a “solid”, a completely closed volume, you export that solid as an STL or a STEP file.

An STL is a triangulated file; a STEP file still retains geometry. For example, an STL file will represent a cylinder as a mesh of triangles, while STEP represents the same geometry as a cylinder or as a curved surface; regardless, STEP is the cleaner format.

Now that you have a surface representation of your solid, you import that into a slicer. I’m using OrcaSlicer which is a fork of the Bambu Studios.

This allows some manipulation of stl/STEP objects. The important part is to position the object on the build plate with no overlaps. Once that is done, you can slice the volume.

This is where things have come so far.

The solid is sliced into layers, generally 0.2mm high. The slicer then calculates the path of the print head over the object at the same height. It knows where edges are and uses loops to make solid walls, it adds internal fill to keep the print light yet strong.

3D prints can’t print in thin air, sort of. They can span short distances before the plastic droops too much. To print with an overhang, or to put a top on something, the slicer has the hot end create a raft across infill or across supports. Once that layer is completed, it will put a more finished layer, then an actual finished layer.

The slicers are pure magic. It really is easy.

All the hard work remains back in the CAD package, which is the same package I’m using for all my other engineering builds.

If you are interested in 3D printing, decide why you want it. Then pick any of the plug and play printers out there. I strongly suggest getting one with an enclosure. An enclosure will be needed for certain types of filament.

A good set of starting projects are GridFinity, an organizational system for flat surfaces, including shelves and drawers, and MultiBoard, which is a hyped up pegboard system.

In this analysis, I’m not going to be doing as much quoting. There are others that do so. Instead, I’m going to attempt to distill the argument or line of questioning.

Alan A. Beck, lawyer for the good guy

The Second Amendment is implicated. Hawaii has not met its burden to prove there is a historical tradition of firearms regulation that matches this law. This is a presumptive ban on The People’s right to bear arms, even if not stated explicitly.

Thomas: You argue that the law prevents access to about 97% of public areas? how did you arrive at that?

Beck: The entire package of laws is 96.4%, this law is less. We got that value from an architecture firm that went through public records of the County of Maui.

Sotomayor (interrupting Thomas): It’s not really 97%, right? This law is much less than that. People can carry in other places, Right?

All right. So you say that there is a constitutional right to carry a gun on private property?

Beck: Yes.

Sotomayor: I’ve never seen that right. I mean, I understand that there is a right to carry a gun on private property with an owner’s consent, express or implicit, correct?

Me: I did read it in the Constitution: the right of the people to keep and bear arms shall not be infringed. And she just said it, she gave it away. You have that right if you have the right to carry on public property if you have the owner’s express or implicit consent. And that is what property open to the public means: you have explicit consent to enter, and you have the implicit consent to carry.

The state of Hawaii removes that implicit consent to carry.

Sotomayor then goes on to try to conflate carrying where you are legally allowed to go with trespass. It is difficult to follow because she wants it to be difficult to follow. She is attempting to make the case about property rights. Which is not at question.

Nobody is arguing that private property owners can forbid trespass and can set rules for entering their property. “No shoes, no shirt, no service” is exactly that. A “No Guns” sign means I’m shopping somewhere else.

She then goes on to yap about the “custom” of carrying on private property with implied consent. She then pulls a quick one by trying to say that since Hawaii has a 200 year custom of forbidding firearms, this is the custom that should stand now. Beck fires back that it is a “custom of the nation”, not the state. Falling into her verbal trap.

There are no laws in this Nation’s historical tradition of firearms regulation that takes away that implied consent.

Sotomayor and Beck get into a back and forth regarding a previous Supreme Court case, McKee. Sotomayor claims it was talking about the customs of just the state of Missouri, while Beck points out that Justice Scalia used the term “Nation” multiple times. I’ll take Beck’s word over the second dumbest justice to sit on the Supreme Court.

She then tries to bring in laws from 1721, 1722. There’s a huge issue with this. The laws of 1721, 1722 are the laws of England, not this Nation.
Even if the laws were applicable, they all dwelt with closed lands. Lands that were not open to the public.

Barrett and Beck agree that Hawaii could pass a law that prohibited carrying on closed lands as a property right.

Dumber (Jackson) now opens her mouth. Justice Thomas takes off his glasses, leans back in his chair and waits for the magpie to stop making noise.

This is just a property right issue. Property rights trump Second Amendment rights.

Beck calls her BS saying the issue implicates the right to keep and bear arms. Jackson says it doesn’t. It is just property rights.

Gorsuch: This law destroys the right to bear arms in Hawaii. Where does this fit into the Bruen framework?

Beck: Carrying is implicated by this law. The burden must shift to state to prove a match with this Nation’s historical tradition of firearms regulation.

Sotomayor: So the 96% doesn’t really matter? There’s no means end scrutiny? Hawaii has a right to regulate a custom. That means the Second Amendment isn’t implicated.

Using a 1763 for the colony of New York, they banned trespass on private land; that means Hawaii can ban carry on public land.

Sotomayor’s method is to talk over, to interrupt the lawyers she disagrees with. She doesn’t listen to what Beck has to say.

She is actually doing performative art. She and Jackson are both saying things that can be quoted later and which they will quote in their dissent about why this was wrongly decided.

Sotomayor ran this guy out of time. And even when Chief Justice Roberts says he is out of time, Sotomayor talks over Roberts for another paragraph or two. Beck tries to answer; Sotomayor cuts him off before Roberts cuts Sotomayor’s line of questioning off.

Roberts uses a gas station and a home on the side of the road to highlight that there is a difference between private property closed to the public and private property open to the public. Beck does a fantastic job of pointing out that all other rights extend to the door. As Roberts says, “A stranger can walk off the sidewalk and go up to the door?” Beck, “Yes, up to the door, Your Honor”

Alito asks if there are any other objects besides guns that a person may not possess when they enter private property open to the public.

Sotomayor goes back to the Hawaii custom of denying rights to prove that they should still be able to deny The People the right to keep and bear arms.

And she is snarky about it; it looks like she yanks some number out of her ass: So 78 percent of Hawaii residents and 64 percent of Hawaii gun owners do not think that loaded concealed weapons should be allowed into businesses at all, correct?

Beck: I’m unaware of that statistic, Your Honor.

Sotomayor: “I wasn’t aware of your 97 — 96 point — percent number”

She would have been aware of his numbers if she had read the fillings. Thomas knew. Thomas mentioned it, not Beck.

Kagan: Hasn’t the state met its burden with the many historical regulations it has cited? And they have multiple references to legislation that flipped the default.

Beck: No. The poaching laws limited carrying on private lands for poaching, not for self-defense. The other laws cited are black code laws. Laws designed to discriminate against blacks. We’ve moved past that.

Kagan: Well, yes, they are anti-pouching laws, and yes, they did allow people to carry for self-defense, but that is close enough to banning armed self-defense on private property, right?

Kagan: You see, the anti-poaching laws were about preventing injuries to private property, and Hawaii’s law is about preventing injuries also.

Me: No, anti-poaching laws were to stop people from stealing food on the hoof.

Beck: This entire line of questioning is irrelevant. The laws you are referring to were closed property; Hawaii’s law is for property open to the public.

Gorsuch: The laws being referenced are a New Jersey 1771 anti-poaching law. The other is an 1865 Louisiana law that a Reconstruction governor explained was aimed at the freedmen. A black code law. Do you think that black codes should inform our decision-making?

Beck: Hell no.

Gorsuch: Well, the state claims it is a dead ringer for this statute.

Beck: The 1865 law was expressly passed to discriminate against African Americans that were newly freed slaves. And I just don’t see how a law like that can be used to be analogized to a modern-day law, this modern-day law, Your Honor.

Barrett asks if Beck agrees with everything the government said in their brief. Beck thinks she is talking about the state of Hawaii. Barrett clarifies that she is speaking of the US federal government, which filed supporting The People and will be arguing next. Beck corrects himself and there is a bunch of laughter.

Barrett: The government that’s on your same side.

Beck: Yes, I understand.

(Laughter.)

Beck: I agree with every —

Barrett: I’m not asking you to throw your case away.

(Laughter.)

Beck: I fully endorse the United States’ brief, Your Honor.

Barrett asks for clarification regarding “open to public” and “closed to public” and the 1865 black code law. Beck replies that there might be something to discuss there, but the fact that it is a black code law means it is not part of this Nation’s historical tradition of firearms regulation.

Jackson is back for another whiff at bat: Chief Justice Roberts asked about a gas station on the side of the road. We don’t get to enter that gas station because of a Constitutional right but because the owner of the gas station has given us consent. That consent has limits, and the owner can set those limits, and the state can set limits, right?

Beck: You have a constitutional right to carry your firearm onto that specific gas station.

Good going, Mr. Beck. Don’t let Jackson distract you.

Goodness, is Jackson dumb or just incompetent? She is attempting to set a word trap, and she’s nowhere near as good as Sotomayor, and Sotomayor is bad at it. She denies there is a constitutional right to carry on private property. She then says that there is an implied license. Then claims that there is a historical tradition of requiring a license to enter private property.

This is so convoluted. Nowhere do you need a “license” to enter private property. She is using an obsolete definition where “license” is the same as “permission”. She then continues to use the term “license” to say that you require a license to enter. This type of language will be used in the dissent to justify Hawaii’s licensing (permission) scheme.

Cringe warning

Jackson:

(I had to take a break after that.)

She goes on, saying that when Thomas wrote “this Nation’s historical tradition of firearms regulations” he said that we were bound by history. Since 1865 is part of our history, then that should be part of the Bruen test. Which also means that any law ever passed becomes part of our history and thus becomes justification for all future infringements, even if that law is later struck down.

Ms. Harris is the Principal Deputy Solicitor General for the Federal DOJ. She was acting solicitor general before D. John Sauer was confirmed as solicitor general. She is now the second in command of the office of the solicitor general. John Sauer was presenting on a different case the day this case was argued.

In other words, she’s way the heck up there. Trump->Pam Bondi->John Sauer->Ms. Harris. And she’s arguing for us!

Harris: Hawaii is lying about why they passed this law. It is aimed at only legal gun owners with CCWs. There are no other items these laws affect. Besides, the only law they can use to support their current law is an unconstitutional black code.

There is back and forth regarding pretextual laws. The example given is of English game laws. These laws were to “preserve game” but were designed to prevent commoners from hunting.

The gist is that when looking for an analog firearm regulation, the real reason is looked at, not the pretext. Hawaii says it is protecting property rights for safety reasons. Just because they say it is for safety and property rights doesn’t mean that laws dealing with property rights and safety are a match to this law.

You have to look for the true reason for the law. In this case, the vampire laws are designed to keep people from carrying because there are too many places where it is illegal.

Kagan opines that The Court doesn’t look at the motives a law was passed. Harris fires back that if the stated purpose and the text show a fundamental mismatch, it belies the asserted motive of the legislature.

Kagan says The Court can’t do that because that would be means-ends scrutiny.

It is clear that the three crones of the Supreme Court are trying to neuter Bruen.

Kavanaugh has had enough of this.

Harris: Absolutely!

This is a trap that “smart” people fall into. They get distracted by the details. Instead of focusing on the big picture, they get lost in the weeds, and then instead of deciding based on the big picture, they end in a major fight over details.

Harris is fighting a different battle here, though. She is fighting to make it clear that doing an end run around the limits the Supreme Court sets out is not acceptable to the United States. She is clearly targeting New York, California, and the rest of the states that had Bruen tantrum response bills.

Kavanaugh is say to keep it simple. Hawaii didn’t meet their burden. Done and done.

Gorsuch brings up First Amendment case law that addressed a similar issue. Harris uses Lamont as her example. In Lamont they flipped the script on mail delivery. The rule was that you got mail of all sorts unless you explicitly said “no”. The law in question in Lamont flipped it to require a person to explicitly request mail on a “very easy-to-send postcard”. This was firmly rejected by The Court.

Jackson is back with another attempt to make this only about property rights. Harris gives a perfect example of how stupid this argument is. She points out that today a politician can have somebody come to your door to campaign. But if this law was followed in a First Amendment situation, the homeowner would have to post a large sign on their property before that door knock could take place.

Alito sends a soft pitch asking about why antipoaching laws are not an appropriate analogue. Harris knocks it out of the park. You know why.

Alito then asks what is the purpose of the Second Amendment right is. Harris, self-defense, and other lawful purposes.

Alito focuses on Heller, which he wrote, to point out that the wording was about self-defense but that other lawful purposes also existed. Harris does a good job in the answers.

Sotomayor is back. Still attempting to make it all about property rights and the owner’s consent. She tries to use Hawaii’s tradition of screwing over The People’s right to keep and bear arms over the last 200 years as the tradition that allows Hawaii to pass the vampire laws.

Harris fires back, stating clearly that local customs in a state doesn’t allow that state to have its own Second Amendment. The meaning of the Second Amendment doesn’t change as you move from state to state.

Ok, this is good!

Harris:

It is almost as if Harris had this response lined up before it was asked. Great response.

In an interesting exchange between Kavanaugh and Harris, Kavanaugh asks about sensitive places as mentioned in Heller. He attempts to get Harris to agree with Heller as is. Instead, Harris goes with, We agree with the principle as stated that there are obviously sensitive places. You determine them with respect to the history of firearm regulation.

This is a massive statement by the DoJ. It says they are not arguing that sensitive places do exist, but that it isn’t as easy as saying, “That’s a sensitive place,” to get guns banned. You can’t declare the island of Manhattan a sensitive place. So New York declared Times Square a sensitive place.

Barrett asks about anti-poaching regulations. Harris points out that poaching was and is a problem.

In my state, and most states that I know, you have to post your land to keep hunters out. Hunters are presumed to be able to hunt on any land that is not posted. In my state the limit on where you hunt is 100 yards of an occupied dwelling. And they mean occupied as people living in, not that nobody is home.

JUSTICE JACKSON: So I guess I really don’t understand your response to Justice Gorsuch on the black codes. And here I thought that Jackson had gotten her “I don’t understand” under control. There is so much she doesn’t understand.

She’s arguing that black code laws, laws that have been found unconstitutional, can be used to justify more unconstitutional laws.

More tomorrow.

I’ve been doing to much research into steam locomotives, I feel like I’ve been working on the rail road.

The featured image is of one of my very first sandcastings. It came out better than expected given my level of experience. My later castings were much better.

I used Petrabond for this casting, which gives fine details. The item in the front is a Duplo block, and the part in the back is from a wooden bowl with a handle.

Sand Castings

A sand casting starts with a pattern. The pattern needs to create a void in the sand, which will be filled with molten metal. To allow the sand to hold its shape, fine sand is mixed with a binder and a liquid. When the binder and liquid are in the proper ratios and thoroughly mixed, when compacted, the sand will hold its shape after the pattern is removed.

This means that you must be able to remove the pattern from the sand without damaging the void. Any sand that crumbles from the sides will cause an imperfection in the surface of the casting. Or worse, it can cause a void inside the casting.

Because we need to be able to remove the pattern safely, The pattern is created with “draft” or taper. With proper draft, as soon as the pattern releases, it is no longer in contact with the sand at all. If the pattern is undercut, meaning the sand covers the pattern, there is no way to remove the pattern from the sand without disturbing the sand.

For the parts shown, there is only one piece of the pattern. For a pattern that does not have a flat side, we use two patterns that fit together to form a whole, called a split pattern.

The Flask

The flask is a two piece box that is open on the top and bottom. The bottom piece is called the drag because you drag it across the molding board. The top is called the cope.

You start by placing the drag upside down on the molding board. Then you position the pattern inside the drag with the taper pointing up. The molding sand is then added to the flask until the pattern is covered.

The sand is then “rammed” up. This means compacting the sand by ramming it again and again with the end of a stick. This will force the sand to bind together and bind to the edges of the drag. More sand is added and the next layer is rammed up. This is repeated until the drag is overfull of sand.

Once the drag is full, a stick is used to scrape off the excess sand, called striking off. This leaves a flat sand surface.

A second molding board is placed on top of the drag and then the sandwich of the bottom molding board, drag, and upper molding board is flipped over. This leaves the pattern exposed on top side, sitting in a cavity in the sand. The sand is extremely firm if rammed correctly.

Now the cope is put over the drag to complete the flask.

Ramming Up the Cope

With the cope in place, we can put the other half of our split pattern in place. More parting powder is dusted over the pattern and top of the drag. Think of parting powder as non-stick spray for sand casting.

Once the pattern is in place, we can then ram up the cope the same way we rammed up the drag.

When we finish striking off the cope, we cut a sprue for pouring molten metal into the mold.

The cope can now be lifted straight up, and with a little luck, the top pattern will come away in the cope and the bottom pattern will stay in the drag.

To make sure everything goes back together, the cope has alignment pins, and the drag has alignment holes.

Pattern Extraction

This is the most frustrating part of the process for me. The two halves of the split pattern are firmly held in their sand voids. We need to get them out. The surface of the pattern that is facing us is normally very flat.

If you have made the pattern correctly, there should be threaded holes to insert screws into. Once these screws are in place, you tap and rattle them to cause the pattern to shift slightly in its void. If done correctly, this makes a very thin space between the pattern and the sand.

When you think you have done this enough, you carefully lift the pattern straight up. If you don’t, you can destroy some of the void in the sand.

This is why making patterns is such a high skill level job. The pattern must have enough draft, or it won’t release. The surface needs to be very smooth to reduce the friction between the pattern and the sand. There can be no undercuts. And the pattern must be sturdy enough to withstand being rammed up, over and over again.

Once the patterns are drawn out of the sand, gentle air from a squeeze bulb or from a low pressure air hose is used to remove all the stray sand. Sharp lips of the pattern might be gently touched with a soft brush to remove any sand that might separate from the walls when the casting is poured.

Cutting Runners and Gates

Tools are now used to remove sand from the drag to make channels, called runners, from the sprue hole around the different patterns in the drag. Smaller channels are then cut from the runners to the void/patterns. These are called gates.

Cutting runners and gates is a science unto itself. They have to be large enough for the molten metal to reach all the gates before it starts to freeze. It can’t be so large that you waste metal that is needed for the casting. The metal needs to be a laminar flow; turbulence can cause erosion of the sand of the walls of the runners and gates.

In addition, you want a place for sand carried in from the pour to go and settle out without the loose sand entering the casting.

Closing the Flask

Once all the work is completed on the mold, it is time to prepare the mold for the pour.

The mold needs to be transported to the foundry floor. For large castings, the mold is created right there on the foundry floor. I’ve watched videos of them molding and casting drive wheels for steam locomotives, wheels 5 feet or more in diameter.

The process is the same, except the flask is huge and is rammed up on the floor. Overhead cranes or other types of cranes are used to lift and flip the flask. It is remarkable to watch.

If the mold is small, then the cope is put on the drag, the alignment pins bringing the two parts in to perfect alignment with each other. It is important to note that it is not relevant that the cope and drag be in perfect alignment, just that they align repeatably. That is to say, when the alignment is correct, the voids in the two halves of the flask will be perfectly aligned.

Once closed, the mold is transported to the foundry floor for the pour.

Occasionally the mold is too heavy to be closed and moved. In this situation, the drag is first moved to the foundry floor, then the cope is moved and put into place.

If the mold is truly too heavy to move, even in halves, then the mold will be rammed up on the foundry floor. Cranes will lift the cope off and put it back when required.

Pouring

When the mold(s) are in place, ready for the pour, the furnace is started. The metal is brought up to temperature. Additives will be added to create the correct type of iron or steel or aluminum.

When the metal is up to temperature, the crucible will be lifted out of the furnace and transferred into a pouring gizmo; the word escapes me. For large pours, the furnace has a pour spout at the base; the furnace is opened, metal runs out and is caught in a crucible or ladle.

Regardless of the method of getting the molten metal into the pouring crucible or ladle, the metal is carefully carried to the molds and then poured into the feed sprue.

The metal has to be poured at a constant speed into exactly the correct spot on the mold. If the pour is too slow, the metal will freeze, and you will not get a good pour. If you pour too fast, you risk overrunning the sprue, which will get metal to run out over your flask, which can be very dangerous.

You want to continue pouring until you see metal start to come up the risers. If you don’t see this happen, then you have a short pour, meaning that the casting might not be complete because it didn’t get enough metal to completely fill it.

The pour has to be continuous as well. You can’t stop and start. To do so would be to cause chill spots and potential freezing.

The Wait

After pouring, you need to wait for the metal to completely freeze. To cool enough that it can be handled.

Different metals have different wait times, affected by the mass of the castings.

I was able to observe a bronze bust being poured. I asked when they would break open the mold. They laughed at me because it would soak in the mold for at least 24 hours.

Certain metals perform much better if they are allowed to cool slowly.

Luckily for me, the wait time for aluminum castings is about an hour.

Even after 2 or 3 hours, the castings I make are warm or hot to the touch.

Rough Finishing the Casting

Once the casting is cool enough to work with, the casting is cleaned. The means to remove all the sand that is still attached after breaking the casting out of the mold. If there was a core print, the casting might be soaked in water to help remove the core.

After all the sand has been removed, the casting is cut free from the gates and risers.

The flashing is also removed. The flashing is where metal leaks between the two halves of the mold. You can see the parting line in most objects that are cast or molded.

In some foundries, the casting is then processed to clean up any remaining excess metal.

For some metals, the casting needs to be heat-treated before it can be machined. This consists of putting the casting in a heat treat oven and bringing the metal up to temp. Then the casting is held at that temp for a known amount of time. Finally, it is allowed to cool according to the heat treat instructions.

Most metals have internal stress. I’ve watched a piece of 1/8″ steel curve like a banana when I cut it longways due to the internal stress being removed.

Part 2 tomorrow, about lost sand.

There is a good reason for using internal combustion engines instead of steam engines in our modern world. IC engines are very portable and very fuel efficient. A gasoline engine is about 20-30% efficient, while a steam engine of the type I’m working with will get between 8 and 15%.

In other words, an IC is about twice as efficient as a steam engine.

Having said that, most of the power you use comes from steam. Instead of using a reciprocating engine, we use turbines in the modern era. We still boil water and use the pressure from the steam to get radial motion, which is converted into power. You get that power in the form of electricity.

When you hear about coal power plants, or nuclear power plants, the difference between them is the fuel used to heat the water, not the electrical generators.

The advantage of steam, for me, is that I can use almost any fuel to generate the steam.

Fuel For Steam

Depending on the design of your boiler, it can use wood, coal, propane, natural gas, gasoline (bad), kerosene, diesel, or a host of other fuels. The only requirement is that the firebox be able to handle the fuel and the temperature generated by that fuel.

Coal was often used for locomotives. It produces more BTUs per pound than does wood. It burns hotter and typically longer than wood. Plus, it will keep for a fairly long period of time. The downside of using coal is that it emits sulfur dioxide (SO_2) which will eat at almost anything it touches. It is a primary source for “acid rain”.

This means that burning coal is hard on your firebox, fire tubes, and smoke box/stack. It is why many restored locomotives use wood instead of coal to fire the engines.

I want to be able to use coal or wood but have a burner that can be put into the firebox as needed that will burn liquid fuels. I have an axe, I have trees and fallen branches, I can make steam.

I will buy coal in fifty pound bags and that will provide steam for hours and hours.

Types of Boilers

There are two primary types of boilers and one “toy” boiler. We’ll start with that toy.

With a toy boiler, you have a tube filled with water; you heat the tube up, it creates steam, you tap the steam off the top of the tube.

The boiler I used for my first live steam test was a pressure cooker. I attached a hose to the rocker port and then the other end to the steam engine, a simple double-acting wobbler.

Skip about halfway to see it actually running.

A boiler of this type wastes much of the heat that is put into the system. It can make high pressure steam but at a fairly low rate.

The next type of boiler is a firetube boiler.

A firetube boiler captures more of the heat put into the system by routing the fire through a series of tubes surrounded by water. The goal is to extract as much heat from the fire and gases as possible and still have a good fire.

Water completely covers the firebox. The hot gases then pass up into the first set of fire tubes, which brings the hot gases through the water back to the left side of the image. The hot gases are then mixed back together and pass forward through the third stage before being exhausted to the outside air.

The design criteria include the size of the fire tubes, the length of the tubes, and the surface area of the tubes.

A small diameter tube has more surface area per given length of tube because we are measuring the ID of the tube. For small tubing, the wall thickness adds a larger percentage to the OD than for larger IDs. But as the cross-section of the tube goes down, the velocity through the tube goes up. A smaller pipe requires a faster flow to move the same amount of gas.

As the diameter grows, the required size of the walls of the pipe also goes up. This creates a balancing act. You also need some way to create draft as the fire is starting.

The pressure is working to crush the tubing; this is the right direction for the strongest vessel with the thinnest walls.

This is the standard for boilers from 200 years ago through today. As long as you have enough water in the boiler it will be a very safe boiler.

Water Tube Boiler

This type of boiler runs water through the tubes inside the firebox. It is a faster method of getting to steam pressure but has some downsides.

Water enters at the top left at room temperature or lower. It is pushed through some lazy coils within the firebox to warm it up but not to create steam. It is then added to the very hot, near boiling water in the separating drum. From there it is pulled down and pushed back into the firebox at the bottom.

As the water moves through the coils, it absorbs more and more heat until it wants to boil but can’t because it is held under pressure. When it finally reaches the steam separating drum, again, the steam is free to escape; it boils.

That hot steam is still carrying too much water; it is considered saturated. As it is tapped off the top of the separating drum, it travels back through the firebox for a third time; this time it is being pushed by pressure, not pumps.

During this third trip through the boiler, it is “super heated” which is to say, it becomes so hot and the pressure so high that it is no longer considered saturated.

In other words, it is “dry” steam.

This type of boiler requires two pumps, one that can inject water against high pressure. The other is actually running at “normal” pressures. While the contents of the pipes is at a higher pressure, the inlet pressure and the outlet pressure only differ by a small amount, as compared with the feed pump, which is working against 150 psi or more.

The Ofeldt Boiler

My Ofeldt was attempting to design a better still, for making alcohol; he designed this instead:

In this design there are no circulating pumps. The water is injected into the central drum, where it mixes with the hot, nearly boiling water.

“Cold” water flows to the bottom where it enters the coils. The coils are in the hot gases of the combustion chamber. As the heat transfers to the water, the water starts to rise. As the water absorbs more and more heat, it starts to change phases. As it enters the gas phase it collects at the top of the central drum. From there, a pipe will lead down the side to a pancake coil at the bottom, closest to the burner. This is the superheating stage.

From there, the superheated steam is sent to the engine.

This is a very compact design that works well for small spaces. The firebox can burn any fuel with the correct grating and burners.

This is the boiler or steam generator I plan to make.

Design

I am not a good welder. I will need to be better to make this boiler.

The central tank will be schedule 80 black pipe, as large as I can afford. It will have pairs of threadolets added for each coil, top and bottom.

To the threadolets will be 1/4 NPT, which will connect to an adaptor from 1/4 NPT to double ferrule compression fittings. This means that I will be able to weld the threadolets on with full 360 access to the root. Giving me a higher possibility of success.

After each thradolet or set of threadolets is welded in place, I’ll add the adaptor and then a capped plug. This allows me to do a hydrostatic test of the boiler chamber one weld at a time. And when I start adding the coils, one coil at a time.

I’m hoping for 4, 6 or 8 sets of coils. I think I can do this.

As they say, a grinder and paint makes me the welder I aint.

According to my research, the boiler I’m describing should produce more than enough steam at a high enough pressure to drive the steam engines I’m designing.

If it works, I’ll look into having a real boilermaker make them for me. And be shocked at the price.

P.S.

I read your feedback on this blog. One of the things I realized is that I often write articles that allow me to set down my thoughts and ideas logically. I’m putting my reasoning into words to break cycles of indecision.

Yesterday’s article about cycles is more like how my mind runs normally. I’ll be thinking about something which circles back to the original thought, which will take me in a different direction for another rabbit hole which then cycles back to the same driving force. Frequently without ever reaching a conclusion.

For those that know me in person, it doesn’t look like this from the outside. It just looks like a nearly instantaneous leap to a correct or at least an excellent starting point.

I have an obsession with knowing how to do things. I need to know how things work. And occasionally I get lost in reality.

Years ago, I was working for Cray Research, Inc. We worried about cycles and memory access times. The unit time of accessing memory was a cycle and was 80 ns. I.e., freaking fast.

I became interested in photography. My mentor was already doing some spectacular photography, but I believe I’ve become better than him.

One of the ways I became better was in the concepts of studio lighting. I purchased and was using studio flash, getting good results.

The issue? How the heck did we sync the strobe with the camera? The camera fires, and the flash goes off. There is a propagation delay before the signal reaches the primary light and it fires. There is more delay while the light travels to the next light; there is still more delay before that light can fire. How can this work?

The answer was simple: the real world isn’t the digital world. The lens would be open for 16.6 us. This is 16,600 ms, or 16,600,000 ns. The only requirement was that the flash go off a some point while the lens was fully open. The camera wouldn’t initiate the flash until the lens was fully open, so it was never an issue.

I didn’t wrap my head around reality; I was working in my model of reality. I was wrong.

The Circle

I want to make something. What I would like to make is a steam engine.

To make a steam engine, I need a machine shop. I’ve purchased that. I also need to learn how to use all the machines in my shop. I’ve made a good start at that.

I also require castings for the steam engine. To get castings, I need to purchase or make them. To make a casting, I need to first make a pattern. Once I have made a pattern, I need to “ram” it up, and then cast it.

To make a pattern, I have to design the pattern and then construct it. To construct patterns, I require good woodworking skills and good wood for pattern making. Pine and most common hardwoods are not going to cut it. I’m working on getting those skills.

The pattern design is also a skill; I understand it, but I’m not good at it. CAD can make it easier.

Once I have the design, I need to construct it. This is pattern making, and I don’t have the woodworking skills to do it. But I can CNC or 3D print my patterns.

To get better at woodworking, I have to practice. To practice, I need space. The space has to be heated. I can handle working during the summer; I can no longer handle working in subfreezing weather.

The workshop will be in the first floor of “the hut”. The hut needs to be finished, insulated, and powered. This is a good time to learn about off-grid power systems, like solar. The solar system won’t be enough for this area, so what if I can add supplemental power from a genset? I don’t like the sound of internal combustion engines, but a steam engine? That sounds good to me.

So I want to make a steam engine.

Since I’ve created a cyclic tree, maybe I can break it with something? How about learning to make 3D printed patterns? I’m still doing all the design work, but now I can have a machine turn it into a physical item.

I liked my toy 3D printer, but it was a kit that wasn’t good, and it was never accurate enough. I was never able to build pieces that could fit together. It was retired. But new 3D printers are plug and play, which is what I want. I would rather not build them and tweak them physically; I want to use them to create physical objects.

And look at this, there is a set of modular 3D prints that can be linked together to create a pattern for a flask. The thing that holds the sand that patterns are rammed into. This means I can actually have sturdy flasks that won’t burn.

But all of this requires some skill in CAD. I have years of experience doing 3D solid modeling. What I don’t have is experience in creating the blueprints for translating these models into reality. But a CNC mill would be helpful for some of that. And I have a mini-mill that I got from my father. I can convert that to a CNC machine for certain operations.

And with the ability to make standard flasks of standard sizes, I can then make molding plates for those flasks to simplify casting certain items.

I can use a 3D printer to make runners, gates, spouts, and risers to make it easy to make castings.

The cool thing is that I can make a 3D printed pattern with proper shrink rates, then cast that pattern in aluminum. The aluminum then becomes the working pattern, so we have to allow twice the shrink so the working pattern can then be used to create our final castings.

If I’m going to be making my own patterns, I will need to make core boxes. Cylinders for steam engines are complex; they have ports cast into them as well as steam passages. Which means I will need to machine or print core boxes.

But there is a minimum size that cores can be. You don’t make 1/8 in cores 2.5 inches long. What is the right size steam passage?

Well, the steam passage should be able to transfer the swept volume without ever having a velocity above 6000 ft/minute. Where did they get 6000 ft/minute? Don’t worry, they used it in the age of steam, and it was empirically tested.

What does it mean though? Well, we know the volume in in³/s. If we divide that by 6000*12 in/60s, we will know the cross-sectional area required.

The area required is equal to pi*r^2, where r is the radius of the steam passage. We can use this same area when designing the ports for the valve and cylinder.

But I’d really like to know if this value was any good. Well, the “easy” method is to run a CFD analysis of the steam flow in the engine.

This would seem to be easy, since the workflow is to build a mesh of the domain for the CFD analysis, then set the initial conditions and let someone else’s code do the work.

What the heck is a CFD “domain”? Well, that’s the part that isn’t modeled. Which means I need to make an inverse model of the steam engine parts that are important for a CFD analysis.

But that requires new skills in my CAD program.

And all of this must be done because I want to be able to build steam engines that are fractional HP in size, but big enough to do the work required.

What would it be like if I had a steam engine that was driving a hydraulic pump for a wood splitter? Would that be cool? Motors for hydraulic pumps are built around HP requirements, but steam engines produce excellent torque at low RPMs. Do we really need a 5 HP engine to drive a wood splitter?

Now, If I get a 3D printer, I can use it to print Gridfinity and multiboard systems to organize my reloading room. My reloading room is full. I can’t get to the press, and I need to get there because I require more 9 mm ammo. And I want to reload a few hundred 30-06 and 7.62×51 rounds with something for taking deer.

So having a printer is a good idea. And I know where it will go. All I need to do is throw away the three junk paper printers that are stacked there, and I’ll be good to go.

Are we having fun yet?

I’ve been having a difficult time being motivated to write. I made a promise to myself to post at least once a day when I started writing for Miggy, and I’ve kept that schedule ever since.

The number of readers seems to have dropped to a very few core readers and my guess is that I just don’t write the things people want to read.

At the same time, when I hear about something interesting, it is normally because somebody else has already chimed in.

So the question of the week:

What do you get out of this blog? What is it that gets you to click back to see what is new?

Thank you