3D Printing Adventures - The Quest to Lift Marbles (and how Failure is part of Learning)

Wednesday, July 1st, 2020

Today it's me vs. gravity in the ultimate engineering showdown in one of the oldest challenges in the book. My goal is to lift a marble approximately 32cm off the ground. (for those who prefer it in inches, that's 12.5 inches). This is a goal that should be easy, but as is everything in life, it was easier said than done.

First, a Note about Sadness

It's never fun to be sad. But as a reminder to future me (and of course, all of you), if you're ever feeling sad, go outside and do something. I started writing this after getting home from a ride inspired by me just not feeling right, but a little vitamin D cleared my head right up. Turns out demons can't run very fast, and I easily out-ran them! (out-biked? I don't know).

Design Happens in Iterations

This is probably going to be my first blog post covering more than one iteration of a design. And I thought I would go into a little bit about how I design things and why I follow the process that I do. I'll even explain what causes me to abandon a project, and hopefully inspire you to keep working even if you run into points of failure.

I had an initial design for my marble lifter, which was going to require a lot of CAD and 3D printing knowledge that I didn't yet have. And with the motor that I purchased, I was going to not only have to build a lifter, but also something to bring the speed of my motor down to power that lifter. (you can read about my gearbox adventures here).

So I did some research, jumped into CAD, and after several hours and design failures later, I had version four of the first version of my marble lifting device.

Assembled Drive Train of Version 4

This was something that I knew was going to require tweaking, and I honestly doubted that it was even going to work when I started printing it out. Well, many hours and many grams of 3D printing material later, I had brought the design to life.

My next step was to add the steel wires that would guide the marbles and form the support structure. This is where I started to run into issues, like glue not working and how to solder without messing up the gears. The tension on the marbles started to be a bit too much, and the whole thing was just flimsy and could easily fall apart. It was around then that I finally reached a point that I've reached with many other projects before this one.

Every Experience is a Learning Experience

As you start building things, especially for the first time, the experience is mainly there to teach you what doesn't work. This is some advice I've learned over my however many years of building things, and some advice I would love to share with you.

That advice is that every experience is a learning experience. Back when I was just getting started with 3D printing, I was also into a computer game called No Man's Sky. All jokes aside, I loved wandering the depths of space while jamming out to chill music for hours on end. One of the things in the game is called a Multi-Tool, basically your mining-laser, grenade-launcher, and bolt-blaster all in one. What made it cool was that multi-tools were generated differently depending on what star system you were in, so I knew that the chances of coming across someone with my same multi-tool were very, very slim.

One day, maker-me and gamer-me put two and two together. I had to build one of my own in real life. Not an actual mining laser and blaster, but at least a replica of one.

So I started modeling. At the time, it was my most complex CAD model I'd ever built. I spent hours modeling this thing, starting with a real drawing of it and working from there. This thing was going to have all of the bells and whistles, with full RGB LEDs, on/off switches, and a threaded battery compartment (at the time this was amazing to me). I was eager to get printing.

Finished 3D Model

As I printed and assembled the pieces one by one, I started to come across mistake's I'd made during the design and build process. I didn't account for tolerating, which caused some of the pieces to misalign. I hadn't exactly designed it to be strong, which I knew was going to be a problem. And at one final moment when I accidentally forgot to put a resistor between my smaller LEDs and the power supply and fried them all in a brilliant pop, I realized I was way in deep with this project, not knowing if I was going to make it out successfully.

But what I could do, and what I ended up doing, was taking everything that I'd learned over the course of the project and carry it forward, leaving the project itself behind. Because the most important things, more important than any build or physical model, is the lessons learned and the experience gained along the way. To illustrate this point, I'll rely on a quote from one of my family's favorite animated films of all time (see if you can guess which one).

Fun Fact: I blame Meet the Robinsons for making me into an engineer as well

I know many of you will disapprove, since I've admittedly done this on several occasions. A 3D printed wolf head with LED matrix, or this marble lifter that I've made. But I feel that sometimes you get too far into a project, to the point where trying to dig yourself out of a hole of mistakes becomes more of a burden than starting anew with the new knowledge you've gained. I know now to better plan for disassembly, and how to properly tolerance a 3D model. The end result of my adventures might not be beautiful enough to carry around a convention or show off in a public space, but I can look back at them and know that I learned quite a bit putting them together.

By no means am I saying you should quit whenever you encounter a bump. Situations will arise where you make a mistake and should identify what happened and then try to overcome it. In this case, the marble lifting device is simply a piece of a larger project, and making the wrong kind of lifter is a simple bump. But rather than give up on this whole project all together, I've taken a step back, let the ideas ruminate, and sat down and built a better model. I identified what didn't work, why it didn't work, and how I was going to change the design to rectify it. I took the lessons I learned from my failed attempt at a marble lifter and applied them to this design. And while I'm probably going to end up getting rid of most of the other lifter's parts, I'll emerge with a design that works better.

So remember. Sometimes you 3D print tons of stuff and realize that there is no way in heck that you're going to make this align and look good short of printing it again. Identify what didn't work, figure out why it didn't work, and figure out how to make something that does. You'll likely end up with several versions, but it doesn't matter, because experimentation and iteration is just part of being a maker!

Marble Lift Revision 2

So clearly trying to build a lifter combining steel wire and 3D printing in a precise configuration wasn't going to work, at least not with my current set of skills and experience. So I got back to the drawing board, watched some more videos on the subject, and even scoured for designs that had already been made. What I eventually came up with is something I'm actually pretty happy with, and am confident it will have a high rate of success.

Marble Lifter V2

This design works by putting the marbles in a groove on the corner of the build, then lifting it up using a rotating shaft with a helical groove built into it. The marbles are then pushed off the top of the lifter and onto a set of wire tracks, put into the build by the small holes at the top. I plan to have this particular design be hand-cranked instead of motor powered, since I'm not sure I have the right motor or the right skills to make the motor work just yet.

(Yes, this means that sadly, the gearbox isn't going to be the thing driving this project like I had originally intended it to. Oh well, I'm sure it will find use someday).

Marble Lift Revision 3

So after some testing I realized that this clunky frame surrounding the marbles was going to cost me a lot in material and print time, and was overall unnecessary for what I was doing. (Very important, since I'm running low on material and MatterHackers doesn't restock until the end of July). So I opted to design a third iteration, and this time, I knew it was going to work.

Mounting Disc for bottom of lift

This design replaces the marble frame with a disc and some steel wire to create the lifting groove. The helix is also further optimized for 3D printing, since the last one had an overhang that was still too shallow for the printer to print cleanly.

Partially Assembled Lift Screw

I also finally gave in and ordered a 9v power supply, on/off toggle switch, and a motor which spins at 11 RPM. I then modeled a hole in the bottom of the lowest screw segment that fit nicely around the motor shaft and allowed it to spin around as needed.

The final result is assembled using 14 and 16 gauge steel wire onto a frame I'll be discussing more in detail on my post about Marble Machine 2.0. This will also be the main lifting mechanism for that machine, and I have a quick sneak peak of the work in progress!

The final working lift

Thanks for reading, and keep making things!
-Will

Marble Machines Part 1 - First Attempt

Sunday, July 5th, 2020

Hello again everyone! today I'm going to cover the build process for my first attempt at a rolling ball sculpture. Then, I'm going to critique my own build, figure out what worked and what didn't work, and plan a little for my next sculpture and what I hope to improve upon.

Inspiration for the Build

When I was younger, yet another one of my fascinations was with these wire rolling ball sculptures. They had one at my local planetarium and children's museum, and I would spend hours just watching the balls make their ways down the various paths built into the sculpture.

Now, this was a time when YouTube was just starting to take off. There were many videos on the internet of different ball sculptures that I would spend lots of time watching, and I always dreamed of having one of my own someday. Though, at the time, I was unfamiliar with where you could go to buy a rolling ball sculpture and didn't yet understand the concept of having to commission someone to build one for you.

So I shelved the idea. It's always been in the back of my head, but I haven't ever made an actual attempt to try to get one.

Fast forward to the year 2020. There's this global pandemic going on, and I finally realized that keeping myself informed wasn't doing wonders for my mental health. So I started to take on more and more projects, hoping that by working on lots of things at once I could distract myself from the fact that society is on fire. It was then I finally came across a fantastic YouTube video with complete instructions on how to build a marble machine with steel wire.

That video is here for those curious. It's a fantastic guide, one that I didn't follow step by step but used for general guidance.

I knew how to solder, and I knew how to bend wire. Maybe the marble machine of my dreams wasn't too far out of reach...

Getting Started and Constructing the Sculpture

After saving up money DoorDashing, I purchased some steel wire. I opted to go for both 16 and 14 gauge wire, intending to use one for the main structure of the machine and the other for the track itself. So I soldered together a mesh grid for the base and added a few support struts before trying to put some track together.

After two or three days of work, I had a very, very simple track. Nothing fancy, but to me it was a good start.

Initial track on the machine

I moved my workspace into the garage, and the next time I sat down to work, I began on trying to build a track switching mechanism. This took me all of two or three hours to solder, because I was more familiar with soldering electronics and not structural wire. The result wasn't the best switcher to ever exist, but I knew it would work well enough.

Marble Divider in Action

I spent the next week or two constructing the rest of the track while I brainstormed how to build a lifting mechanism. As the machine came together, it became less flimsy and more fleshed out, and I was actually pretty happy with how the build was turning out. However, I was running into an issue with the lifting mechanism, and ultimately the problems started stacking up as they usually do. Eventually, I had a sculpture that was 80% done, though there was a conversation between me and my mom that made me realize something.

She asked when it would be done, saying she wanted to display a marble machine around our house somewhere that could run off a motor automatically. Given my previous adventures with gearboxes and lifting mechanisms, I realized that adding a motorized lifter to this sculpture was going to be difficult.

That wasn't my biggest concern though. This thing wasn't enjoyable to look at in the slightest. What I envisioned was a beautiful sculpture with balls and a lifter that would be the centerpiece of a room or make a good talking point in conversation. What I had produced looked like a half-hearted final project for a high school shop class. I wasn't going to proudly display this on my desk in my dorm room, I was probably going to shelf this in my closet with my other experimental projects.

And so I realized this was probably the end for this particular sculpture. But even if I'm not going to display it proudly in a public space, I did learn an awful lot about how to build one, and I feel that with a little bit better planning, I'll be able to create a sculpture 10x better and more fun to look at.

Almost Finished Build on Workbench

Lessons Learned

There's a few things I learned during the build process that I would've loved to know beforehand. I'll be documenting those here just in case you'd like to build your own and don't want to have to learn these things on your own.

1.  Soldering vs. Welding

"Professional" marble sculptures are built using TIG welding, which is probably the most precise of welding processes. This ensures strong connections between wires, and I'm fairly sure steel wire plays better with welded joints rather than soldered connections.

The reason I'm not using TIG welding is because I don't currently have access to the equipment needed. However, I learned that soldering steel wire can cause the wire to heat up and screw up nearby solder joints, which isn't something that occurs with welding. If I build larger sculptures or end up using larger marbles in the future, I'll likely start to use a welder to put the sculpture together. However, for now, soldering should be just fine for what I'm building.

2. Planning is Essential

The biggest lesson I probably learned was about planning. The only planning I did was building a steel mesh to base the sculpture off of, and that was it. This left me a lot of room for experimentation, which is good, but I didn't know what I wanted the end result to look like. It's like knowing your destination is North but not having a map to follow, and in this case, I wasn't really satisfied with the look of the end result.

I've already started planning how I'm going to build my next sculpture, and let me tell you, I think it's going to turn out great. I've given myself dimensional limits, and I've put in space for the lifting mechanism before instead of after, so I know I will be able to fit it.

3. Helping Hands are Excellent

If you intend to do any sort of work on a smaller scale, I recommend you get a set of helping hands. Not a friend or family member, but a small jig that will help hold parts. These can be awesome when it's hard to reach a particular spot, hard to hold still, or if the part you need to hold will burn you if you touch it. I will probably even be getting a second set since they were so helpful on this project.

A Sneak Peak into Future Sculptures

Now that I've learned from my first time building a marble sculpture, I've set a few goals for my next marble machine:

- Machine must be nice to look at
- Machine must be motorized, and powered by wall power
- Machine must have an on/off switch
- Machine must be constrained within a predefined space
- Machine must use a combination of wireworking and 3D printing

The last goal is a stylistic choice. As I've researched different marble machine makers, I'm starting to realize that just like many different kinds of art, each maker has their own unique style. And I've decided that I want to pioneer the combination of 3D printing and wireworking into one marble sculpture. I think this will bring a lot of life and color into the sculpture itself, which should make it look all that much better.

So the next step is to get some new 3D printing filament, and to wait for my low-rpm motor and power supply to show up. Until then, I suppose I can work on some of the 3D models, but you never really know how things are going to turn out until you're holding a physical prototype in your hands. Having this project under my belt, I have high hopes for the next sculpture!

Thank you again for reading, and as always, keep making things!
- Will