3 years ago I started participating in the Grow Beyond Earth contest.  It’s a collaboration between NASA and the Fairchild Botanical Gardens in Florida.  The goal is to create a device that will grow food on the International Space Station.  That sounded like fun to me!  Year one focused on designing the growing area to take advantage of the 0G environment and fit in a 50cm cube.   I was fortunate enough to be a finalist and walked away with some prize money.  I was not able to participate in the 2nd year but I am back in for year 3. 

This year the focus is on creating a robotic harvesting and planting.  If you want to read all about it you can do so at the Make:Projects link below.  This has been a fun project and I learned so much.

https://makeprojects.com/project/0g-garden—year-3-professional-entry

Ever get excited after seeing an YouTube video?  It happens to me all the time.  When I was Thomas Sanladerer‘s video on using an MSLA printer to make PCB’s I knew I had to try it.  In fact I have worked it into February’s Model Monday project.  This month we will be designing an Addressable LED strip control box electronics and all.  You might not know that Fusion 360 can do electronics design but after a few classes you’ll be up to speed and ready to design.

I have been looking for an excuse to learn more about the electronics design work space in Fusion 360 and I had a member request it as a project.  It’s great to be able to have electronics parts and cad design all in the same software.  This is going to be a fun one with lots of new things to learn for all of us.  Join us Mondays @7pm live or watch the recordings on YouTube at your convenience.

Are you a boat or home owner?  Do you wish paying your bills was more fun?  Do you have stacks of cash sitting around just taking up space?  Well this is the project for you!  Over the next month we will be designing version 2 of the Rain Maker.  It’s a tool that you load with cash and then launch at about the speed most of my project eat cash lately.  Version 2 you ask?  That’s right most of the longer projects we model in class take me several attempts to get right.  Here is a link so you can see it in action. 

https://www.instagram.com/p/CYP6pMlIizE/

The first draft lets me work out the ideas and see if I can get a working prototype.   In this case I knew I wanted to try over molding like our favorite tool company here in Milwaukee and I was not sure if my cash accelerator device would work.  About a hundred hours of printing later I can tell you it does and I learned a lot of do’s and don’t when over molding on 3d printed parts.  I do really like the feel of the urathane rubber in my hand and it is so much fun to see money shooting our the front of the tool.  This is going to be a fun one so join us Mondays @ 7pm or watch the series on YouTube.

Over the past few months I have been playing with 3D fractals to create slip cast pottery.  I found a free program called Mandelbulber 3D and you know me, If it’s free I’ll take 3.  It’s shocking to me the availability of free software like this.  Right now I am just scraping the surface on what the software can do but I have a few examples of shapes made in the software posted on Thingiverse.

https://www.thingiverse.com/thing:5138435

Creating the fractals with the Mandelbulber is fairly straight forward.  Just experiment with varying a few values and click render.  The hard part is getting the shape to be cast-able with out having to make a 27 part mold.  A few weeks ago I pulled the first cast from my first successful mold.  This is part fractal and part Fusion.  The foot of the cup is part of the fractal pattern and the body of the cup is a shape designed in Fusion 360.  Although the final product warped in the kiln I think it was a good proof of concept.

After the shape is created digitally you have to make it physical.  My go to method is usually my 3D printer.  The constraints that make a part easy to 3d print without supports are similar to the  constraints that make a part easy to remove from a mold.  To make the slip cast mold I don’t print the cup but a plastic mold of the cup, there are two reasons for this.  First if you are going to make lots of slip casts you are going to need more than one mold.  Because of the time it takes to cast each cup you will need to pour several mold each day.  Second with a hard plastic mold you can make a soft silicone part.  This saves me from making a large silicone Mother Mold of my 3D printed mold.  My Mother Mold is half of the 3D printed mold with the full silicone cast part inside.  It’s worth noting that there is 15-18 percent of shrinkage from pour to final firing so you will need to scale up your prints to an almost comical size. 

(photo coming soon)…

On a side note I did some experimenting is soaking silicone parts in IPA to expand them.  This is a fun exercise if you have never done it.  To expand a part just place it in a container of IPA for several hours.  I let one part sit over night and go about the amount of growth I was looking for to but the part shrinks down slowly when removed from the IPA and the growth amount is not very predictable.  Below you can see an example of how much larger the part grew and the final fired piece from this process.

I am in the process of printing my molds right now so tonight at the open meeting I might have printed molds to show.  I also have other shapes to pass around.

I built my first RepRap 3D Printer in 2011/2012 after using a MakerBot CupCake CNC at the Makerspace a few years earlier. It worked well until it broke, then I fixed it, and it broke again, and over and over and eventually I bought a new 3D Printer, and my old RepRap sat mostly unused because it wasn’t a very good machine. So earlier this year I decided to disassemble it and start over, but this time I wanted to follow a few methods that Mark used for Son of MegaMax and for Ultra MegaMax Dominator. Also, he has a lot of 40mm extrusion on hand. ;)

I started by designing things in OpenSCAD and then started building once I got enough pieces in place. It’s actually starting to look like a RepRap. Since I’ve only built printers from kits or instructions someone else created, this is the first 3D Printer I’ve actually designed. There are a lot of challenges, but I find it enjoyable. I hope to have things moving within the next few months. (I’m in no big hurry, as I have twelve other projects I’m working on simultaneously!)

If you want to follow along, I occasionally post in-progress photos on Instagram, and you can check out the reprap category on my blog.

CP Terrarium

My first project was an attempt to learn some programming, some 3D printing, some sensor design, and combine them with a longtime hobby of growing carnivorous plants.

A Raspberry Pi 3B+ is the main control device.

1) It controls turning the lights on and off to match sunrise and sunset anywhere. Mine is set up to match the photo-period of their natural habitat.

2) It monitors the temperature and humidity and displays them on a remote dashboard that can manually override the automatic control.

3) Water level is controlled with a homebrew designed/built sensor. The sensor’s plastic element was drawn on Fusion-360. It was 3D printed at Milwaukee Makerspace. Water level status is also displayed on the dashboard and can be remotely run.

4) Coding is done with Node-Red, a graphical programming tool.

Node-Red Code

The actual terrarium is an uncovered 10 gallon tank. It has two species of Drosera  ( Sundews, a sticky leafed plant) and a Cephalotus. (Albany Pitcher Plant) Lighting is provide by a small LED fixture. Humidity and Temperature monitored with a DHT22 sensor. Water level measured with a CMOS Schmitt Trigger voltage division sensor. Remote viewing and control is done with VNC.

Real world progress is coming along. Code has been finished (until I get a better idea and redo it again) and checked. Temp/Humidity sensor is in place. Right now it’s only monitoring and displaying. Adding a heater and cooling fan is in the future plans. 3D printed sensor has been fabbed. Assembly, electronic circuit building, and testing will be the next phase I approach. Following that will be the addition of a water pump or solenoid to automatically replenish the water level when it drops.

TLDR version: Raspberry Pi monitors or controls a CP Terrarium’s lights, temperature, humidity, and water.

Node-Red Dashboard

3D printed sensor

The original design used to have a printed ABS top roller and I just pushed the roller against the flanges and finger-tightened the nut.  The problem was people kept taking it apart, so I added rubber bands to pull the roller down, and a nylock nut to prevent tool-free disassembly.  Then the rubber bands kept disappearing, and Tom came up with the idea of making a heavy top roller so the rubber bands wouldn’t be needed.  He cut a new, steel top roller on the lathe and it works great!  The bolt is just loose enough to let the roller slide up and down in the slot in the frame.  The roller is heavy enough that it just falls into position on the spool flanges.

Tangle-free filament spool holder

We had a visit from ShopWare during our open night on Tuesday, January 29th, 2019. They thought we might be interested in seeing a Markforged 3D printer capable of printing with nylon, Kevlar, and carbon fiber. And they were right, we were interested!

They showed a few videos that featured the capabilities of very strong 3D printed parts, and then answered questions, and had a number of samples to pass around and show off. They also brought a Mark Two for us to take a look at.

One of the weird things about how the Mark Two functioned was that it homed the x and y after every layer it printed. It also lowered the z just a bit while it homed the x and y, then raised the z back up to meet the extruder (which was dripping a small bit of filament) before then starting a new layer. (None of us could figure out why it was doing that, or what benefit it offered, though we had some guesses.)

These appear to be some sort of brake lever, maybe for a bicycle or motor cycle. They were very strong. There was no flex at all when trying to bend them by hand. Typically parts printed with PLA or ABS feel pretty “breakable” but these seemed like you’d need some tools to break them. (I really wanted to crush one in the hydraulic press when no one was looking!)

Printed threads are no problem, and again, appeared to be very strong, and the ball joint moved pretty good.

The metal part was not printed on the Mark Two, but another Markforged printer. The part gets processed after it’s printed, so it shrinks a bit, but the software deals with sizing up your model before printing so it comes out the correct size when done. We’re pretty sure this part was “finished” a bit after printing as well, perhaps on a lathe, which would explain why the rounded part is polished while the flat hexagonal part is not.

While the extreme cold weather kept some members away, we had a pretty good turnout to welcome ShopWare, and for those who were there, got to see some cool technology we home to someday have a the space.

Remember when we got the Prusa i3 Mk3? Well, even if you don’t remember, you might be excited to learn we just got the Multi Material 2.0 upgrade kit, and it’s been installed, and we can now print in multiple colors. Neat!