Author: jkfirth

Categories
3d printing

My new printer, the Tevo Tornado

I’m Jason Firth.

Late last year, I decided it was time to jump into two technologies I really wanted to play with that I’d been putting off for a long time: Virtual Reality, and 3d printing. At the time I selected what appeared to be good choices for both off of Amazon: The Oculus Rift for VR, and the FLSun Delta Kossel for 3d printing.

At the time, I expected virtual reality to be the thing with staying power and for the 3d printer to be a quick toy. What I quickly realized is that Virtual Reality isn’t really for me in a lot of ways — I’ve played many hours, but never really gotten sucked in the way I thought I would. On the other hand, 3d Printing has become a hobby I really enjoy.

The FLSun Delta Kossel was an inexpensive unit. Today you can buy it on Amazon for about $200 CDN. It was really a cheap unit, and I’ve written about my experiences with that unit.

Plutarch wrote of the Ship of Theseus: “The ship wherein Theseus and the youth of Athens returned from Crete had thirty oars, and was preserved by the Athenians down even to the time of Demetrius Phalereus, for they took away the old planks as they decayed, putting in new and stronger timber in their places, insomuch that this ship became a standing example among the philosophers, for the logical question of things that grow; one side holding that the ship remained the same, and the other contending that it was not the same.”

The printer over the course of the year has become like this. I’ve replaced virtually every component, upgraded everything in some way or another. Is it still an FLSun Delta Kossel? That’s difficult to say. What I can say for certain is it’s now a very impressive printer that tends to put out excellent quality prints.

After my year with the printer, I realized how much I’ve enjoyed 3d printing, and I wanted a larger printer that’s a bit more standard so I can start printing larger things and spend a bit less time tinkering with the printer itself.

To that end, I’ve bought a Tevo Tornado. It is a popular model of printer, lots of support out there, and overall I feel it’s going to be a good choice long-term.

My first impression: I’m really impressed with a lot about this printer. The FLSun came in a million pieces and took me a full 2 days to assemble. By contrast, it took me all of 2 minutes to assemble the Tevo Tornado when it arrived. It homed immediately and I found it simple to level the bed, contrasting the Delta’s bed which was always a pain. I’m really happy with the first 15 minutes with the thing.

Before I even get started with this printer, however, I want to replace the main board. It came with an MKS Gen L, identical to the FLSun. There’s no problem with this board for straight 3d printing, but I want a board with a processor instead of a microcontroller, having seen the limitations of the Atmel mega while using my Delta Kossel, and I want a board with built-in Wifi capability. Using Octoprint on my previous printer was a great experience, running around with a memory stick is ridiculous when I can just press one button to start a print. I purchased a DuetWifi clone board. 

I’ll pass on my notes as I work with this new printer.

Thanks for reading!

Categories
Instrumentation

The Ontario College of Trades is being wound down

I’m Jason Firth.

This week, I read about the news that the Ontario College of Trades is being wound down, to be shut down in 2019.

As a certified tradesman, I’m a little mixed on this, but mostly I’m happy to see it happen.


In every other province, the government administers voluntary trades, and provides a piece of paper saying you’re a certified tradesperson at the end. You pay for the test, you pay for the piece of paper, but then the government is done with the process. You are a journeyman forever. By contrast, the Ontario College of Trades was charging over $100/yr for the privilege of putting your name on a list and sending you a replacement sticker for your piece of paper saying it’s still valid for another year.

This isn’t unprecedented. OACETT and other related associations require an annual payment as well to maintain your certification. However, there’s one big difference in my view: Associations of Certified Engineering Technologists and Technicians provide value to the public and value to certified members for the money. I’ve had opportunities to go to seminars, to participate in really cool activities for National Engineering Month, and more. Also, we vote on our leadership, and get to participate in the rule making process.

By contrast, the Ontario College of Trades doesn’t provide value to tradespeople. I never got any opportunities from the College, only a bill. There were no chances to improve, no chances to participate (all the important people in the College of Trades were appointees, not elected by the membership).

And then there’s the public. In theory, the College of Trades is supposed to give the public somewhere to complain about tradespeople who engage in poor workmanship or who violate the college of trades code of ethics. In practice, this never did happen.

With hundreds of thousands of members each paying over $100 a year, they had a huge pot of money, but they didn’t use it to make the world better. The handful of prosecutions by the college over the years were simply not worth the absurd cost of each one.

In my opinion, the world is better off with this legislation removed. Maybe in the future an association for skilled tradespeople can exist. However, it would have to look a lot different than the college of trades.

Thanks for Reading!

Categories
Process Control

Too many software engineers

I’m Jason Firth.

At one point, most instrument software was written by instrument specialists. As a result, it was small, simple, and specialized.

This was good. Specialized software may be ugly, but it works, and is often designed with specific technician use cases in mind. Moore’s software packages for communicating with their smart instruments are a good example: with one utility and an RS-232 cable, you could configure, query, troubleshoot, and test an instrument.

Software engineer types would rather create flexible platforms to develop software on top of.

Now, that is a very legitimate desire. If you can build that one tool, then you can make it easier to access a large number of devices with one tool, and you simplify the development process for vendors, who can focus on the job, rather than the surrounding elements.

There are problems with creating a flexible platform if it isn’t done carefully.

One problem with this is that flexible platforms add complexity for end-users. PactWARE, for example is a marvelously flexible piece of software. It allows you to not only use a number of point-to-point hardware devices such as HART or Endress+Hauser’s proprietary communication cable with a simple swap of the DTM; it also allows you access every single device in your plant using multiplexers, or to access IP HART devices. The problem is that all this flexibility is extremely cumbersome to navigate.

ProComSol Devcom2000 is a piece of software that only speaks HART through a serial port or USB modem. Its simplicity allows a technician to connect their modem to the PC, connect the modem to the HART instrument, and run the program. The software will immediately connect to the instrument, after which you are ready to go.

By contrast, PactWARE requires you to connect and start the software, followed by installing the HART communication DTM, followed by configuring the module, followed by opening the autodetect window, then running a scan, then selecting the correct DTM, then closing the autodetect window.

This is one example of one software package compared to another, but the fact is that there are countless examples of software trying to do everything, only to be less useful as a result. I try to design anything for that 2am call, and a ridiculously complicated tool isn’t conducive to this.

Another issue with creating these extremely complicated software programs is a simple truism: the more moving pieces you have, the more things there are to fail.

I really like Wonderware Historian for its standard SQL front-end and tight integration with wonderware and application server, but it is a complicated beast. IO Servers speak to the PLC, the Historian mdas service communicates with the IO Server, (assuming the import went correctly), which communicates with the historian storage service. To retrieve, the SQL service links up with the retrieval service. There’s other services involved as well, but the bottom line is that any one of these parts is huge and complicated, and all it takes is one cog in one of these giant machines to break.

Historian isn’t even the worst. I’ve seen instrumentation configuration utilities that require always-on services to be running, a full SQL server instance — just to shoot a couple bits over an RS-232.

The problem is that conceptually on a software development level, using these tools makes a lot of sense — you’ve got this big fancy development package and this big fancy software engineering degree, of course you’ve got to make use of them! A small, simple program that does one thing very well, that’s not going to work. We need a platform. Something that can handle all use cases. Something that can keep me employed fixing it!

Thanks for reading!

Categories
Process Control

An Uber fatality and the limitations of automation — and the amazing powers of your human operators

I’m Jason Firth.

Recently, there was a fatality in the news, as an Uber automated vehicle hit a pedestrian who was crossing the road.

The circumstances seem to be that the pedestrian carrying a bike crossed the road without seeing the car, and the car basically drove right into the young woman.

A lot of people seemed shocked that the car didn’t recognise the young woman was there, and didn’t immediately brake or swerve. One person invoked “fail safety”, the idea that equipment should always default to the safest state.

This case is, in my estimation, more complicated than you’d think. It’s true you want things to fail safe, but it isn’t always clear what a fail safe state is.

I’ll give you an example.

In a commonly told but apocryphal story, boiler maintenance was being done at the paper mill in Fort Frances Ontario Canada. (You’ve heard this story from me before) The design of a boiler (at least a recovery boiler like this) is you have tubes filled with water and steam surrounding a combustion chamber. Usually, you’ll have a drum called the mud drum that contains a certain level of water. If that level is too low, that’s normally considered an emergency situation. In this case, the maintenance they were doing required the mud drum to be empty, and they were still firing the boiler.

The story goes, a new operator came on shift and saw the mud drum was empty and immediately panicked. The operator immediately opened the water valves wide open (what would normally be considered ‘fail safe’), and the boiler immediately exploded.

Why did that happen? What happened is the boiler tubes were red hot and virtually unpressurised. When cold water hit the tubes, the water immediately caused an explosive release of steam which caused an explosion. While the involvement of a person is unusual, boilers routinely experience explosions due to water valves having problems like this. If the boiler was running under normal conditions, perhaps dumping water into the tubes would be a safe option — cooling everything and getting everything to a zero energy state faster.

So despite the valve opening being what you’d normally consider a ‘fail safe’ state, in this case it was a dangerous action to take.

Let’s assume for a moment that both the car and the driver had perfect vision in that moment, and saw the pedestrian long before the moment of impact.

What is the safest action to take if you see someone crossing the street? Everyone here is immediately saying “obviously slam the brakes and swerve!”, but let’s think about that for a second. Most people are not going to walk directly into the path of an oncoming vehicle. Even if crossing, you’d expect a person to stop, so you can’t necessarily use the fact that there’s a person there to predict what’s going to happen. By contrast, what happens if you slam the brakes and swerve every time you see someone crossing the street a little too close? If there’s a car near you, it could cause an accident. If the person was going to stop, then that person could end up getting hit by your actions where they might not otherwise. The driver or passengers in the car might be injured — probably for nothing, because 99 times out of 100, the person will stop before the car hits them. Often, the safest act is to do nothing.

Here’s where there is a divergence between the powers of an AI, and the powers of a human. An AI sees object 15 — perhaps even a human on bike type object — travelling at a certain speed at a certain vector. It has to figure out what it can from relatively limited information. By contrast, a human sees a sketchy looking lady walking in a strange way not paying attention. The AI might not recognise there’s a threat, whereas the human might recognise something isn’t right and take the opportunity to take some of those more aggressive defensive manoeuvres for this isolated case. It isn’t just object types and vectors, it’s a vivid world of information and context.

Our powers of intuition, empathy, and deduction are much more than we give ourselves credit for. We know more than any purpose built AI, and can make connections that no purpose built AI presently can. Humans aren’t perfect, but there’s reasons why we still have humans involved with even the most high tech processes.

It’s ironic to say this as an automation guy, but the world is about to realize the limitations of automation, as it comes closer and closer to our personal lives.

As interesting as this story is on it’s own, I feel it’s also interesting to show the limitations of raw automation in the industrial context as well. Sometimes, operations asks for a system that reacts to something the human knows but the machine does not. If you’re not careful, you cause false positives and react dramatically to situations that don’t exist based on assumptions, causing more problems than you’d prevent.

One I saw for a while was an operator pointing to a spike on a graph and going “That’s because of [event], we need to prevent that.” Then you’d go down the graph and find another spike and go “Is this [event]?”, they’d say “no”. You’d go down a little further and say “how about this? Is this [event]?”, and they’d say “no”. It turns out that the reason the operator knows what’s going on is that the operator is a human with eyes and ears and an incredibly versatile mind that can understand things far beyond a series of numbers plotted along a graph. Short of dramatic changes to the process, the PLC can’t know that [event] has occurred with any sort of certainty.

Thanks for reading!

Categories
Industrial IT

Microsoft is lazy in a bad way.

I’m Jason Firth.

I caught a video about Microsoft Edge today that got me thinking about something.

I find their attitude towards Edge and Windows 10 to be terribly lazy.

Let’s look at some of the basic changes over Windows 7.


There’s a new feature, the PC Settings app. Let’s try to change the IP address:

![undefined](pcsettingsapp_0_o.png)

To change the IP address, you have to open a win32 program. Oops!

To manage the SSID, you have to open a win32 program.

The settings app has many examples like this, where the new OS features are half-baked. If you want to make a change, it’s time to hit the roulette wheel: Which program do you use to change this setting — the original win32 program, or the new metro app?

Assuming, of course that the Metro app decides to work. The reliability of that framework is suspect. I routinely open the calculator to watch a screen with a calculator icon glaring back at me. When I have to head back to the original win32 versions of programs to do simple things like look at a picture or add 1+1, that’s a fundamental breakdown, and Microsoft should be considering any instance of that to be an all-hands-on-deck situation.

That brings us to Edge.

In my experience, Edge just doesn’t work very well, even (as seems to be a developing tradition), with other Microsoft products. I can’t use it at work, because it doesn’t function properly with Sharepoint. My only option is Internet Explorer. (Chrome and Firefox don’t work with Sharepoint either, presumably because of the same problems that keep Edge from working). That essentially makes Edge useless for Enterprise, if it doesn’t work with Sharepoint. That’s lazy of Microsoft to create a new browser and ignore essential functionality for their core users.

Lazy can be good. Lazy can mean you reduce the complexity of tasks. Lazy can mean you make things easier, or that you do things in a less risky manner. In this case, lazy is bad. By half-assing the OS and the browser, you end up with programs that fundamentally can’t complete the tasks they’re supposed to do.

Edge currently has 1/4 of the users Internet Explorer has. Some of this is because Edge is only for Windows 10, but much of it is likely because Edge can’t even do the things Internet Explorer does. Furthermore, Windows 10 has had much slower adoption than Windows 7. By this point after Windows 7 was released, it had a commanding lead over XP. By contrast, Windows 7 and Windows 10 are neck and neck. I believe the biggest reason for this is Microsoft’s lazy behaviour. Windows 7 behaves like a cohesive product. Windows 10 feels like two completely different products have been inexpertly melted together with a heat gun. Unlike Windows 8 it doesn’t scream in your face with its incompetence (The windows 8 start menu really is an excellent example of how not to do navigation), but that doesn’t mean Windows 10 and it’s associated products aren’t still broken.

Sales of Desktop PCs have dropped below 100 Million for the first time in a long time. Some of that is just because laptops are so good these days. (I’ve been using laptops exclusively for years because I travel so much for work. I’m writing this on an Alienware R15) However, I strongly believe another reason is that Windows 10 is a poor OS, and people are choosing not to upgrade their PCs, lest they have to give up their Windows 7.

In other works, Microsoft has the ability to reverse the course of the industry. Come up with a polished OS that actually works in a straightforward manner, and I believe there will be an immediate boost to PCs.

Ironically, some of the changes have been made so Microsoft can emulate tablets and phones in form, but in doing so they’ve moved PCs away from them in terms of function: I can configure my android device from the settings app. I’m sure I could do the same on an iOS device. I can’t do it from Windows 10. I can only imagine the nightmare that using a Windows 10 tablet or phone would be, based on my Windows 10 experience. It is completely understandable that because of their lazy choices, instead of Windows 10 being an advertisement for Microsoft’s phone and tablet products, it is a case against them.

To move forward, Microsoft needs to stop adding new features and chasing the latest craze. They need to take a step back and put the work into building this platform.

It’s simple, but not easy:

  1. Create a team consisting of one person with the authority to make decisions from each software team involved, a few UI designers, and a number of laymen who use Microsoft applications daily. For the laymen, reach out to customers, even! Corporate, personal, industrial, front-line users, IT users, software developers. You need their input. That input would have saved you from Windows 10.
  2. Come up with a list of every basic task users do in Windows. I bet it’ll be a list of the top 1000 tasks between users and power users/sysadmins. Come up with a list of the top 100 tasks people do in each major piece of software such as Edge.
  3. You’ll have a huge list, prioritize them. Personally, I’d focus on tasks that are done routinely, and tasks that are going to be major “pain points”, such as configuring network interfaces. Spend the most time and make sure there’s cross team interaction on the top priority items.
  4. Using the list as a template, enumerate the steps required to do each of these top tasks. Actually do the tasks to prove it.
  5. Ask yourself: “Is this really a reasonably easy way to do this? How would someone know how to do this besides Googling it?” (Being real here, Bing is garbage and you need to fix that too. Google “Windows XP Service Pack 3”, then bing it. What are the top 3 links for each? Clearly, you’ve got problems. One disaster at a time, though) Honestly, if you look at the list of steps required for a lot of relatively basic tasks, there’s absolutely no way you’d know how to do it. “Go ‘run’, then type ‘horrentouslylong -cmdline’, and choose the fourth tab and press the plus and type “arbitraryChars (seriously)”. This is all garbage, and needs to be streamlined.
  6. Look for obvious stupid things. Going online to solve problems with my Internet connection just makes you guys look completely clueless. Keep the updated database of methods to solve problems with Internet connections locally! (That’s just one example, mind you)
  7. Run user tests on users own hardware. Get random users to do the top tasks. I bet you’d be surprised to discover a lot of them don’t actually work! At work, I often use the win32 image previewer because the Metro app doesn’t work! I’ve erased purchased, licensed copies of windows 10 and replaced them with Linux because Windows suffers some of the worst bit rot since Windows ME, and the machine is locked solid from processes that “don’t run while you’re doing anything” but clearly do.
  8. Document the new methods to complete these key tasks.
  9. Ask the same questions about the new methods that you asked about the old ones.
  10. Fix the problems you find, make the changes you need to make. It’s a short line, but most of the work.
  11. Have lay users test each solution to make sure it actually works and is actually intuitive! Don’t use a strict test script, let users try to figure out how to do each task in their own way. In fact, if you can run a test by scenario instead of by task (for example, let IT folks set up a PC for use on their own network, or let a home user set up a PC for their own use)
  12. Use your documentation and the results of user testing to create user documentation for all these top tasks, and include the latest version of these documents offline.

Like I said, it wouldn’t be easy, but in spite of the fact that the form may be different than a tablet or phone, the function would be the same: Finally, all the basic functions of Windows and its major applications would work in a fully functional and intuitive manner.

You want people to use your store? Your phone OS? Your tablets? You need to get your day 0 stuff sorted out. People need to be able to trust your software to be basically competent before they give you license to do more.

If I’m being honest (and I recognise this may be a controversial statement), Google does this very well. People trust their search engine because it does the basics well. Their mail does the basics very well. Youtube does the basics very well. Google maps do the basics very well. Android does the basics very well. Because they do the basics well, they are given license to do more. People are willing to let Google drive their car for them, because their software is generally competent, functional, and easy to use. Nobody is willing to let Microsoft drive their car for them (or their phone, or their tablet, or their search engine, or their web browser) because Microsoft isn’t doing the basics well, and thus lacks license to try more. Microsoft wants to brag about the quality of their work, but their work doesn’t speak for itself.

This can apply to control systems as well. If we don’t do work that is generally competent, functional, and easy to use, then we won’t get license to do more. Managers won’t want to let us try things, front line workers won’t be willing to let controllers stay in auto, and the money will go elsewhere, to other capital projects that perhaps do have histories of being those 3 things.

Thanks for reading!

Categories
3d printing

You can’t take the tradesman out of the…

I’m Jason Firth.

Another quick post to share my latest improvement for my 3d printer (again). I wasn’t very happy with how the cables hanging. In cabinets we often use sticky backs or slotted rail to clean up cables, I decided to use a similar approach on the printer. Here’s the design you can use on tinkercad:

Categories
3d printing

Updated spool holder

I’m Jason Firth.

Here’s an updated spool holder. I took some ideas from Geoff King who printed up a modified version that fit with more spools. It bolts directly onto the screw holes for the original holder.

Categories
3d printing

Next step

I’m Jason Firth.

I printed off a set of braces for the towers of my Delta printer, and after installing them, found that the printer was all of a sudden failing prints. The kapton tape on my bed was utterly destroyed twice in a row, and the print I was trying to do just didn’t work.

My first instinct was to take a look at the home switches. They were wobbling around, so I figured part of the problem could be that my homes weren’t consistent.

I swapped the square bolts that come with the FLSun printer with actual T-Bolts. I immediately realized there was a problem: The bolts were not holding the part in!

I discovered that the back of the switch had these ridges meant to hold them into the 2020 strut.

![undefined](img20180128162318_2_o.jpg)

I realized the easy way to fix it was to cut away part of the ridge. I used a simple razor blade from Home depot:

![undefined](img20180128162528_0_o.jpg)

Afterwards, the t-bolts I purchased fit properly:

![undefined](img20180128162602_0_o.jpg)

The switches locked in solid after this.

problem: My prints were still failing!

So I looked further. Next up I realized a basic maintenance problem: My belts were very loose. It worked much better after that, didn’t slam into the bed.

However, the print still failed, even though all these maintenance items were improved.

The final solution was to increase the layer height of my prints. I had it set to .06mm, but it appears that once I started tightening up everything, the printer simply isn’t capable of printing such thin layers. Perhaps in its sloppiness it was just barely slopping its way into each of the next layers.

Categories
3d printing

3d printers again…

I’m Jason Firth.

Yesterday, I had a revelation about my new printer. I was pretty happy with the prints I was getting (happy to be getting any prints at all, in fact) but the quality wasn’t quite where I wanted it.

I ran a check of the extruder calibration and found it substantially out. I asked for 100mm, but got 57mm instead.

I was already looking at calibrating the extruder, so I switched to the Marlin AC branch. That branch contains the latest developer patches.

Along the way, I had to move my config changes to the new firmware, so I had a deeper look. One change I made is to reduce the “slow” speed while calibrating. The stock settings shook the whole thing. I also increased the number of calibration points and changed the calibration routine to take each measurement 3 times.

One of the additions to the marlin-ac was automatic bed levelling. I assumed the auto calibration took care of levelling, but it seems that’s a different feature.

Someone in the flsun Facebook page suggested that my “delta kossel” and the “mini kossel” I keep reading about might be the same printer. It does seem plausible on second thought. However, it means that the example config is just completely wrong.

The other thing is that the flsun YouTube page appears to call the delta kossel and mini kossel different things. It’s difficult to figure out whether the two are the same or not.

This speaks to a fundamental of maintenance: defining your equipment. Giving it consistent naming, giving it a unique identifying number that functions within a system. For a company with perhaps 9 different products, this ought to be trivial. Perhaps a digit for product category (3d printers), one for product type (delta kossel), one for the subcategory (mini/standard/jumbo), a digit for model number, and a digit for revision number. “3ks1a” – easy. Then everyone can search for “3ks1a” and find Information directly relating to that printer.

In industrial automation, the ISA 5.1 standard defines similar naming. In industries around the world, this convention is used to name instruments in an immediately identifiable fashion.

Let’s look at a typical designation:

66-FIT-123

The 66 part of the above is area number. Very few plants are monolithic. Most consist of a certain number of defined areas with defined functions. These areas often have a single number associated with them. If 66 were for a certain power boiler, for example, anyone in that plant would immediately recognise that the instrument existed in that power boiler.

The second part, “FIT” above, is a standardized designation based on the ISA 5.1 standard. In this case, the first letter tells us the process variable. In this case, “Flow”. Other common process variables are Temperature, Pressure, Analytical, or Density. Each represented by the first letter of the word. The second letter above is “Indicating”. It is a modifier telling us that the instrument has a display. Finally, the last letter is “Transmitter”. This speaks to the function of the device. Often you’ll see Switches, Valves, or Elements. Sometimes you’ll see a Y, which indicates “special function relay”

Finally, the number “123” above represents the unique loop number. Every loop in the area will have a unique number, making it trivial to look for loop sheets, wires in a junction box, or PLC code.

In terms of the name you’d give it, I prefer following a few general rules.

1. Name for humans. This means naming things using natural language, and in a way that people can read. I’ve seen colons, dashes, And underscores in names. There’s no need for that. I’ve also seen things named something nobody calls something. Either correct your name, or change what people call the thing.

2. Name precisely. Calling stuff pump #1 is tempting, but makes things too difficult when trying to refer to something. “Boiler #10 feed water pump #2” tells someone everything they need to know about that device. Calling the printer the “Delta Kossel” is too broad. Every printer of this type is a “Delta Kossel”, and it appears the company has multiple kossel style printers.

3. Name consistently. Create a nomenclature or taxonomy and follow it. Don’t refer to the same device with six different names. In this case, the “Delta Kossel” and “Mini Kossel” might be different things. If they are, that’s fine. If they’re not, that’s a major failure of naming.

Anyway, I’m done playing with the printer until next weekend. Looking forward to the next steps. I’ll keep everyone updated.

Thanks for reading!

Categories
3d printing

3d printer, day 2

I’m Jason Firth.

I apologize in advance for the photos. No idea why they came out so bad.

Last time, I talked a bit about setting up my new 3d printer, an FLSUN Delta Kossel. The first day consisted of fighting with the firmware that was set up without any limits, and with some seriously wonky default settings.

I was able to complete my first 3d print, a ring from thingiverse, and then moved onto my second 3d print, a ball valve I designed:

![undefined](494367944833638131_0_o.jpg)

Unfortunately, it didn’t print very well, and after printing successfully once, I wasn’t able to get it to print at all again.

I still had a few problems. The head wanted to dig into the bed. I tried to tape some magazine stock to the bed to protect the head and I tried to calibrate the bed that way, but that was a pretty poor solution. What I discovered is that there were a few problems with what I was trying.

The unit came with leveling springs, and the instructions on YouTube suggested I install them. This turned out to be a bad idea, because the nozzle contains a spring as well,and the two were fighting each other. I took out the spring, and because I’m concerned about the heated bed touching a bunch of plastic, I took one of the spare square bolts and used it as a spacer:

![undefined](removesprings_0_o.jpg)

Next, I wasn’t happy with the auto calibration. The entire unit shook dramatically as it auto calibrated because of the huge amount of force needed to overcome the spring. I looked at the head and realized I didn’t have *one* adjustment, I had *two*. The silver set screw that set where the button releases, and the black set screw that set the spring tension:

![undefined](setscrews_0_o.jpg)

I realized I’d have to calibrate the nozzle before I could run a printer calibration.

First, I loosened the silver screw until I heard the switch click, then I tightened it slowly until I heard it click again. I pressed the nozzle to prove the switch was actuating properly, because a couple times I just tightened it until I heard it click again but it didn’t reset with nozzle movement.

Second, I loosened the black set screw until the switch opened, then tightened it back up until I heard the switch close again.

After calibrating the print head, I was getting much better calibrations that didn’t shake the unit so badly.

Finally, to deal with the print head jamming itself into the print bed, I discovered a setting called Z-offset. I was able to change the z-offset from the unit faceplate.

First I went to the control menu:

 ![undefined](controlmenu_0_o.jpg)

Then the motion menu:

 ![undefined](motionmenu_0_o.jpg)

and Finally set the Z-offset:

![undefined](zoffsetmenu_0_o.jpg)

I figured out the z-offset by setting my height (I used the faceplate in the prepare menu, but you could easily use Repetier to do it from your computer) lower and lower, until I couldn’t slide a piece of paper under the nozzle anymore. I set the Z-offset to the number of mm.

The final improvement I made was to place a fan near the bed. The unit has a fan built onto the nozzle, but this didn’t seem like a bad idea.

I was finally able to consistently make successful prints. Early on, I designed and built these clips so we can screw our undercabinet lighting to the cabinets:

![undefined](lightclip_0_o.jpg)

And by the end of the day I had printed a spool holder I designed:

![undefined](latestprint_0_o.jpg)

I was really happy how this one turned out. Not so happy about how the picture turned out, mind you. No promises how it will hold up once I place a 1kg spool on it instead of the smaller provided spool.

A few things I’ve discovered in a day of printing:

Don’t waste time trying to save material. A 1kg spool of filament has about 330m of filament. All the designs I’ve been printing use less than 10m of filament.

You see a lot of prints that look like they’re really substantial, but they might not be. The prints might be completely hollow inside. The above print has a 5% infill, so very little inside.

Shell thickness is your friend. I printed a tube with a 0.5mm shell thickness, and it was a great demo, but very quickly broke. I printed with 1mm shell thickness, and everything was much more substantial and is holding up much better. Given the choice between infill and shell thickness, I’ll choose shell thickness every time.

I didn’t need a raft or anything once I had the printer well calibrated. Suddenly the bottoms of my print were good by themselves.

Even though professional designers using molded plastic might use voids to conserve material, that seems to be a really bad idea here. I created an earlier spool holder that used a thick column with voids, and it was a really complicated print — it was constantly retracting and spooling out and ended up being really messy.

Today’s prints pushed the limits of a 40mm radius print bed, so I spent some time doing some tests. I figure I can safely print to 70mm without the print head or arms contacting anything, so I increased the print radius to 70mm in the marlin source code and re-uploaded.

I had a calibration error I couldn’t figure out — my Y axis was off, but only my Y axis. A post on the marlin forums suggested moving to the latest, so I moved to the nightly and re-uploaded. That worked perfectly. After upgrading, the printer calibrated happily and I’m ready for more printing tomorrow.

Because I don’t want someone like me to have to deal with the annoyance that was my first day, I took the configuration headers and submitted them to the marlin project for entry into the examples file.