Chris Johnson

One of the most powerful things about FreeCAD is that it is a fully scriptable CAD modeling system. This means you can write python scripts to do things.

They call them macros.

Which means they have plugins that do remarkable things. Just wonderful things.

The one I recently started using is the Gridfinity addon. Click the add button, and it will give you a bin. You can click some parameters to get exactly the shape you want.

If all you want is a bin, this works perfectly.

I want to make custom shadow cutouts in bins for some of my tools.

What I can’t do is select the face of the Bin and make direct modifications to it.

More learning to do.

For now, it is getting easier to get things done the way I want to.

When I heard this song on ,Fallout it struck a chord with me. My country is worth fighting for.

The very first thing you need to do when choosing a printer is know what you want to print.

I can’t stress this enough. Sure you can go buy a $2000 11×17 color laser printer. But are you going to print 11×17? Do you need full photographic quality prints?

If what you are doing is printing your tax forms, then a simple $200-$300 black & white printer will do just fine.

The same is true for 3D printers. What do you want to print?

For me there was the “true” driving want, which wasn’t enough to justify a printer. I wanted to be able to print foundry patterns.

With enough research I found that organizational capabilities was high on my list of to-dos that has never gotten done.

To that end I picked MultiBoard as the ultimate pegboard and Gridfinity as my “flat surface” organizer.

Given these three drivers, I could start to list what I required in a printer.

I have tried printing foundry patterns in the past. It didn’t work. Today it should work better.

Most, if not all, of the MultiBoard and Gridfinity can be printed in the cheapest, easiest filament, PLA.

PLA requires a build plate that will support 55°C and a nozzle that supports 220°C. This is every printer out there.

If you need something a bit stronger, PETG is the go-to today. It requires a 70°C build plate and a 230 °C nozzle. Still well within the reach of most 3D printers.

Everything else requires more series printers. ABS, ASA, PA, and PC all require an enclosure. Without an enclosure, your prints will fail. The print will warp, and you will have issues with bed adhesion.

If you need to print something that will be exposed to the elements or that needs to be stronger, you need to go with one of the stronger plastics.

Which leads to the next class of filaments, those with additives. Carbon fiber and glass fiber are two of the common additives.

These fibers will eat your equipment. It will wear your PTFE tubes, but worse, it will eat your extruder and nozzle. You need hardened steel extruder driver gears and nozzle. You just have to plan on replacing the PTFE tubes as they wear. This should already be on your to-do list.

Some new printers come with multiple hotends so you can switch filaments while printing, quickly and easily.

For me, all of this took me to an 3D printer in an enclosure with a series build volume. The build volume I was looking for was 250x250x250 mm.

Because I knew I was going to be printing some CF or GF filament, I knew I wanted to upgrade my hotend to hardened steel.

Finally, I wanted to be able to change the nozzle without messing with cables, wires, or complex procedures.

After doing some back-of-the-envelope research, I started looking for a low cost printer that met my needs.

The printer names that popped up were Elegoo, Flashforge, Creality, and Bambu Lab.

I had never heard of Elegoo or Flashforge, but I had heard of both Creality and Bambu Lab.

The printer I was looking into was a Creality printer, but the Bambu Lab kept showing up with positive reviews. Their P1S met my needs except for the hardened nozzle, but that was an “easy” upgrade. The thing that was blocking me from pulling the trigger was that replacing the nozzle required changing out electronics. Something I did not want.

And then I stumbled on Bambu Lab P2S. This was released in late 2025. The reviews were all positive, but more than that, the reviewers were surprised at the types of improvements.

The P2S came with a hardened extruder and a hardened nozzle. They had also ditched the old hotend and gone with the hotend from one of their higher-end printers. They went with the H2D hotend.

This hotend has a quick replace system for the nozzle. You no longer need to replace electronics or mess with cables; you remove a silicon boot from the nozzle, release two spring clips with your fingers, remove the old nozzle, put the new nozzle in, close the clips, put the boot back on, tell the printer what nozzle you have installed.

I’ve done this twice. The first time took about 5 minutes, the second time about 30 seconds.

This left the ecosystem.

Bambu Lab is a closed ecosystem. They recently updated all their printers. With this update, 3rd party software tools lost the ability to control the printer. You could still move files to and from the printer, but you couldn’t initiate a print.

I had also read that Bambu Lab was using AI to evaluate the things being printed and would refuse to print some models from the cloud.

You could move the files by USB drive, but that gets painful.

They did have a LAN-only mode. That is what I am currently using. In LAN only mode you get full control of your printer. Your printer no longer talks to the Cloud. Your printer is yours.

It also turns out that the OrcaSlicer, which is a fork of the Bambu Studio slicer just works in LAN-only mode.

In addition, the price for the printer and the Automatic Material System (AMS) was less that the Creality printer I was looking for.

Conclusions

Am I happy with my purchase? Yes.

Is there anything I regret? Yes, I didn’t get enough filament out of the gate. I’ve gone through about 10 pounds of filament so far, and I’m not slowing down.

I don’t like finding out that I need a seperate dryer. And the amount of effort it takes to get dry filament.

I don’t like that I can’t directly move files from the Bambu Cloud to my printer; I have to move it through OrcaSlicer.

Would I do it again? Yes. Would I get a different printer? No.

My printer has been printing nearly non-stop since I got it. There were a couple of days when it was busy drying filament and not printing.

They offer the A1 combo at $399. That is the A1 and the AMS light. The AMS light handles four spools and you can have upto four AMS connected to your printer.

They also have the A1-Mini which comes in at $219 but only has a 180x180x180 build volume.

Please remember that I’m a Unix/Linux geek with to much experience in too many fields. What works for me might not work for you. Do your own research, but remember the first rule, have a reason you are going to spend some money. If you aren’t sure, look for a used A1 or A1-Mini or the most popular 3D printer, the Creality Ender 3.

I went with a Bambu Lab P2S printer. It is an enclosed printer; it has excellent support and ecosystem. And it has strong vertical integration.

In order to 3D print something, you need the printer, a build plate, filament, a model, and a slicer.

The build plate is a surface that the filament will adhere to when you want it to and release your printed part when you want it to release.

Filament is a thermoset plastic. I.e., a plastic that melts when heated and can be reshaped and then will hold that new shape after it cools.

The model is a digital 3D solid. It is normally generated with a CAD package.

The slicer take the 3D solid and slices it into layers, then creates a sequence of g-code instructions to recreate that solid in plastic.

The First Print

To start with, I purchased filament from Bambu Lab to use on my printer. Their filament spools come with RFID tags. When you put the spool in the AMS, it will read the RFID, which tells the AMS what type of filament it is and what color. It also says it is Bambu Lab filament, but nobody else has permission (cryptographic) to create RFID tags that the printer/AMS will read.

I selected a useful “print” from the prints that are preloaded in the printer. Then I pressed “go”.
It printed exactly what I wanted, and it has been in use ever since.

The Second Print

It is nice to have models preloaded to print, but that would get boring rapidly. The next step was to use their phone app to print something.

This consisted of starting their app, pointing my phone camera at a QR code on a box. That QR took me to a model in the Bambu Lab cloud. I clicked the print button and a short time later I had a 3D version of that print.

There were more things I printed this way, but it was time to move up.

The slicer

The approved software is Bambu Studio. Which is an Apple or Windows program, no Linux version. I choose to go with OrcaSlicer because it is well respected and integrates nicely with Bambu Lab printers.

Using the slicer, I was able to download models from other sites, outside of the Bambu Lab cloud, slice them, and then send them to the printer. I could then use the Bambu App to start the print, or print directly from the printer control panel.

Over time, I’ve moved away from the Bambu Lab Cloud. I’m doing everything locally now. I still use their cloud to find models ready to print, but that is only because it is easy. I can use their phone app, search for a model, tag it, then download and print it later.

ReMix

My first major print was a riser for the AMS. This was printed in four large parts and a set of TPU gaskets. Yes, I can print custom gaskets.

The riser holds two drawers. I printed those drawers with a Gridfinity base.

All is good so far. I then print a deburring tool Gridfinity bin. It should fit perfectly. It does, except it is too tall. I can’t close the drawer.

This lead to me doing my first remix. I pulled the STL into FreeCAD, then created a sold cube the right size. Intersected the two solids and ended up with a shortened version.

This worked. My deburring tool now fits perfectly in my Gridfinity drawer.

This type of remix is simple. More complex remixes take more time. I’m not good at it yet because it requires me to create a solid from an STL or STEP file.

My First Model

I wanted a Gridfinity box to hold my ultra-precision torque screwdriver. I did all the right things, except I did a shit job of my B-splines. I also took a bad picture. I was too close, so lines that should have been straight were not.

Regardless, I printed it. What came out fit the Gridfinity base. The bin was short enough that the drawer would close.

The issue? The finger holes to lift the tool out were way too small. I’ve learned that I need between 20 mm and 30 mm to bake it easy to grip.

I have a second attempt ready to go, but I haven’t printed it yet. It was cool to see. It is a disappointment for it to not work.

My Latest Model

To control the path of filament, 3D printers use lots of PTFE tubing. This is 4 mm OD and about 2 mm ID pneumatic tubing. These fit into PTFE couplers. One of the coupler/connectors I’m using is a PC4-M10. This has a push connector on one side and is threaded M10 on the other.

I’m using a printed replacement cap for a cereal container. A 4L cereal container will hold a 1 KG spool on rollers with space for a hygrometer and desiccant. With a hole in the container, you can feed your filament out and directly to your printer without ever exposing your filament to the moisture in the air.

One method is to drill a 10 mm hole in the side of the container and use a PC4-M10 screwed into the side. A better method is to put a M10 flanged nut on the backside.

I would rather not drill holes, so I went with the replacement cap with a socket for the PC4-M10.

The model prints the cap, a sealing plug, a threaded and knurled screw-on cap. The cap proper has an inset threaded boss for the knurled cap to screw onto to seal the container.

That boss holds a PC4-M10. The model also contains a printed nut for the PC5-M10. Now here is my issue: the person that printed this seems to have found PC4-M10 with M10x1.5 threads. The PC4-M10 I have is measured with M10x1.0 threads.

I went into FreeCAD, I created a solid with a flange, 17mm hex nut, and a proper M10x1.0 threaded hole.

And it worked. Those nuts are now in use.

I am that much closer to being able to print my patterns for castings.

It has been a learning week for me. I’ve actually gotten to the point where I’m printing things for me rather than for the printer and the printing process.

Every part of the process is so much better than it was the last time I was attempting 3D prints. I have one confirmed model that is a failure. I’ll work with the least failed print to get the tool I need.

The two biggest issues in 3D printing today are bed adhesion and bad filament. Now bad filament isn’t always bad, sometimes it is just that it has absorbed too much water from the air.

There is a relatively simple fix for that: dry your filament.

My printer came with an AMS (automatic material system). It consists of a chamber that holds four spools of filament; each spool has its extruder/feeder. The printer controls the AMS. When the printer wants a particular filament, it unloads the current filament, then it tells the feed motor to push the filament down a sequence of PTFE tubes and Y connectors until the filament is at the extruder proper.

The printer then pushes out the old plastic from the hot end with the new filament, leaving the nozzle loaded with the new filament. It is cool to watch.

The AMS is designed for four small packages of silica desiccant. One of the first things I printed was a set of boxes to hold more desiccant. The AMS now has about between 10 and 20 times as much desiccant as it started with.

The AMS is sealed, has circulating fans and a heater. This means it can be used to dry filament as well as feed it.

There is one small issue: you can’t print while it is drying. You have to have a separate power supply for the AMS to dry while printing.

Which takes me to my “quick” fix, a SunLu S1 Plus filament dryer. This holds one spool of filament, it can run at up to 55°C, and it does a good job of PLA, PETG, and one or two other filaments.

Using it I have been able to rescue some 10 year old PLA that was stored open. It has all just printed, after it was dryed.

Now the fix to this temperature issue is to use a “blast oven”. A blast oven means an oven that can maintain a constant temperature for an extended period of time while air is forced around the filament.

I don’t have a blast oven. What I do have is a printer that can maintain a constant temperature but doesn’t have a fan.

The manufacturer recommends printing a cover in Polycarbonate (PC). But PC is extremely hygroscopic. Straight from the package, it has to be dried at 90°C. Which my SunLU can’t do.

If I had a PC drying cover, I could dry the PC in the printer. All I need is some dry PC but what I have is wet PC.

And this issue exists for every filament I have. So I’m doing a bootstrap.

I did a printer bed drying of some ASA. This took around 12 hours. I used a cardboard box, as recommended. To make a fake cover.

With the ASA dry enough to print, I’m printing a blast oven. This is a two part filament dryer that uses the printer bed for the heat source and a carefully designed drying chamber with forced air.

Now all I have to do is hope that part two prints successfully tonight.

What is the stupidest thing you’ve heard somebody say in the last two weeks?

When I make a statement, I know that I am correct. The proper temperature for the bed of my 3D printer for PLA is 55°C. As far as I know, this is correct.

If someone were to question that statement, I would consider that I am wrong. Being wrong is part of being human.

Assuming that I am wrong, I will go verify the statement. And what I would find is that there are more pieces that go into that statement, for example, the build plate I’m using.

Having an open, learning mind allows me to self-correct when I am wrong. I actually do this so fast, in real time, that people don’t even notice that I had something wrong. Somebody says I’m wrong because of a particular reason. I evaluate and change my position, taking in the new information.

People remember the outcome, where I’m usually correct; they don’t remember the incorrect starting point. It is a process to get to the correct answer.

I’ve done this here. I’ve made a statement; one of you has corrected me or added more information. I verify, then move forward with the new information.

Unfortunately, we are surrounded by people that are incapable of doing this.

These people cannot conceive that they might be wrong. They argue by expert.

My second wife used argument by expert constantly in our interactions. Since she wasn’t able to support her opinions, she turned to an expert and would tell me I was wrong because this expert was saying what she was saying.

This would require me to locate experts who she would accept, which she never did.

The problem with this style of argument is that you are not looking at the subject. You are not investigating the subject. Instead, you are vetting a third party. You have lost the point of the discussion.

I don’t need an expert to tell me that dropping hot glass into cold water is a good way to end up with shards of glass.

The need for people that are so stupid they require an “expert” to tell them what they should think drives me bonkers.

An example. NH has no income tax. Most of the tax revenue comes from property taxes. You are taxed a certain amount per $1000 of value your property has.

For one area of the state, the tax rate is $34.37/$1000. With an average home/property assessed at $215,000, giving an annual tax of $7389.55.

Now consider a small farm with 40 acres at $5,000/acre. That puts the value at $200,000. The assessed value at around $120,000 with an annual tax of $4124.40.

Now NH wants to protect farmers from heavy taxes so they have an option for your land to be put into “current use.” This covers undeveloped land (hunting, fishing areas) and farmland. If your land is in current use, you only pay taxes on 10% of your assessed value. So the farmer won’t be paying $4124; instead, he’ll be paying $412.40. A significant savings.

This is all well documented in the state’s laws. There are people who do nothing but defend current use cases. The gist is that if you have at least 10 acres in current use, you get this tax break.

A person I knew worked for a town. The town was having a shortfall. They were attempting to raise revenue by getting more land pulled out of current use. This person was concerned about their land, 125 acres, 123 of which were in current use. They asked the town lawyer about their concerns about putting up a small 10×20 hunting cabin in the woods.

The city lawyer told her that the hunting cabin would cause all 123 acres to come out of current use.

Even when I showed her the statutes, even when she was presented with the literature from the current use defenders, she took the word of her “expert” over what the plain text of the law said.

Nothing I said would convince her that she was wrong. She didn’t need to consider that she was wrong because it wasn’t her opinion; it was her “experts” opinion.

She was stupid.

On the other hand, she wanted to post the land as no hunting. That would have taken the acres out of current use.

Because she never learned to read the law for herself, nor did she hire a lawyer to advise her, she didn’t know that posting the land could have taken it out of current use.

The left is full of stupid people. People that can’t think, but they can certainly regurgitate what they have been told.

COVID-19 is so deadly that healthy children must be vaccinated against COVID-19. And you should wear your mask when in your car alone or out on a surfboard or in a boat in the middle of a lake.

They could never apply logic to their position because they never evaluated how they got there.

The other day I heard from a teacher friend that they had observed ICE removing a student from the middle school. Except it turned out that she hadn’t observed it. Two of her fellow teachers had observed it.

I was concerned. Was this the mythical unicorn ICE action? ICE agents storming schools to grab kids, throw them into handcuffs, and drag them out?

Well, no. It turns out that the kid was an illegal alien. His parents have removal orders against them. They had been picked up while the kid was in school.

ICE came to the school, told the admin that they needed to pick up the kid. The admin walked the agents to the classroom; the ICE agents and the kid walked out together. No muss, no fuss.

They were making sure the kid didn’t come home to an empty home.

Still no unicorns.

These people do not know how to think for themselves. They are too stupid to hold an opinion, so they borrow other people’s opinions.

They think they know the law because they had a one-hour seminar taught by radical activists.

A deportation enforcement officer will have between 100 and 200 HOURS of training in the law, focusing on immigration law. ICE agents are required to be college graduates. Their training is provided by actual experts in the law, and they are tested to confirm their knowledge.

You can’t fix stupid.

Mobs are an organism. They act like a living creature. They might be made of people, but they react in known and predictable ways.

Mobs move in the path of least resistance towards their goal. If one person chooses a different path, others in the mob will follow, not a lot. But more people will follow those, and pretty soon there is a significant part of the mob moving in that new direction.

This is why breaking contact with the mob can be difficult. You need to fade out of the mob, not attract attention that causes parts to follow.

When there is a junction, the mob will flow down multiple paths from that junction unless guided. This is how multiple blocks can become involved with the mob: they move in the same general direction, but they fill all available space.

Mobs avoid hard points. They will flow around those hard points, but hard points cause a pain-like response, and the mob recoils from contact.

Riots are a type of mob behavior. My mentor told the story of how he and his Johns Hopkins buddies rushed to the rowhouse of one of the buddy’s moms. There they set up in the front window with long guns.

As the story was recounted to me, every rowhouse on that block suffered serious damage except for three. The rowhouse they were in and the two rowhouses directly across the street from them.

The mob avoided that hardpoint. It wasn’t worth the pain, and the organism retreated.

Mobs are dangerous. People get caught up in them and don’t know how to extract themselves. People that would never dream of being violent or vandalizing property will do it without even a thought. They follow anybody who acts like a leader.

During student protests that turned into riots at my University in the 60s, before I got there, there was no vandalism until one person threw a brick through the plate glass window of an upscale store. The student newspaper ran a picture of the man throwing that brick through the window to go with the story of the police vowing to track down the student who did it.

Oh, the man throwing the brick? He was dressed as a police officer.

The REST of the windows, those were broken by students who followed suit. Once one act of violence happened, the rest of the mob followed suit.

During the January 6th march to the Capitol, instigators changed the protest into a mob. That mob did not turn into a riot; they just did things that, as individuals, they would not normally do.

The reason that it didn’t turn into a riot was because there was no drive among the people to be violent.

We compare that to the BLM riots.

In Kenosha, we saw protests turn to mobs turn to riots. One of the interesting things that was caught on camera was people in all-black clothing, carrying umbrellas, throwing those first bricks. Starting the process of turning the mob into a riot.

The people in the streets were already angry. The media had been stirring up hate and anger for days and weeks. It took very little to drive the protests into mobs and the mobs into riots.

But there are things that mobs don’t do. They don’t have Command and Control structures. They don’t have security details. They don’t have assigned tasks for different units. They don’t have units.

One of the interesting, but not surprising, features of the “mobs” in MN is just how well organized they are.

All of which leads me to believe that they are not organic. There are parts that are useful fools/tools. But there are other parts that are most definitely acting to destabilize societal norms in the area. To foment a revolution.

We have some good delivery drivers, but my goodness, some are horrible.

I’ve had a half dozen packages delivered to my “porch or front door”. With pictures of boxes, or packages in a white garbage bag sitting in a pile of snow under my mailbox. 2 feet from where the melt puddle forms.

On Saturday they promised a delivery. They then told me they couldn’t deliver because of severe weather.

The cause? They didn’t want to go up the driveway.

Sunday they delivered up the same driveway with no changes.

I’m sad to say that USPS does a better job of package delivery. Amazon drivers will flat-out lie.

That’s nto to say we don’t have some good ones, Saturday and Sunday drivers are bad, in general.