# CNC Beer Part 1 – Overview and Theory

## Overview

A bit over a year ago, I began a project to build a computer-controlled beer brewing system that Beer Church (Pumping Station: One’s homebrew club) could use to brew all-grain beer. I had no idea when I started this project that it would lead to visiting people from multiple countries, two synchrotron radiation sources, and a nuclear research reactor, or that control systems engineers from international labs would provide assistance. While it still isn’t ready to brew beer yet, I’ve recently reached a milestone in integration testing, and I’m rapidly approaching the point where the first test batch will be possible. Unfortunately, I haven’t been blogging about it, so a lot of catching up is needed….

So, why would someone want to make what could be called a CNC machine for beer? First, it’s not about eliminating humans. The goal isn’t automation to the level of “push button, get beer.” Humans will still need to load the ingredients and monitor the process. We don’t want a hose breaking, resulting in 12 gallons of beer wort on the floor and a propane burner melting the bottom of the resulting empty stainless steel keg. Rather, the primary reasons are:

1. Repeatability. I want to eliminate human error. Repeatability often is the domain of commercial brewers, but for hobbyists, repeatability still is critical. Transitioning from good beer to great beer means experimentation. And that requires having good control over all the variables. How do I know if that different yeast I used made my beer taste better, or if it could be explained by sloppy temperature control in the mash process?
2. Predictability. Shareware and free beer design software exists that acts like CAD for beer. You can design your grain bill based on a library of ingredients, enter a mash and hop schedule, yeast, fermentation temperature, etc. and it will simulate the process, telling you what you can expect in terms of initial and final specific gravity, percent alcohol, color, bitterness, etc. You can tune the model based on the efficiency of your brewing system. But prediction works only as well as the repeatability of your process.
3. Capacity. Right now, we are limited to 5 gallon batch sizes. While we certainly can buy larger hardware, it makes sense to upgrade to automation at the same time. With a system based on 15.5 gallon beer kegs, we can produce 10 gallon batches at a time.

And, well, there are plenty of secondary reasons that can best be described as “Because hackerspace!” I’ve wanted to learn more about industrial control electronics and the EPICS software environment. It was a great excuse to learn to weld. I had acquired authentic cold war indicator lights from actual nuclear missile systems that needed to be put to an awesome new use. And I could do all that while brewing beer!

To describe the CNC beer system, I first need to explain all-grain brewing and the issues inherent with our current brewing method. To be clear, these issues affect repeatability, not quality. We are already making really good beer. Nothing is wrong with what we’re doing. This new system likely will improve beer clarity (and that is important in homebrewing competitions) but otherwise it won’t do much on its own to make the beer better. Start with a bad recipe and you’ll end up with bad beer; the new hardware just makes it repeatably bad! Rather, it will provide state of the art tools to anyone who wants to experiment, and this could be very useful to brewers wishing to be competitive in homebrewing contests.

# X,Y,Z Finder for the ShopBot

The PS:One ShopBot is a great CNC machine that has the benefit, among other things, of being huge, allowing for a lot of cuts on large pieces of material. One of the difficulties working with the machine, however, is getting the bit at exactly 0,0,0 in the X, Y, and Z axis so that if you need something cut at exactly six inches from the edge of the material, it will be exactly six inches. There is already a built-in method for setting the Z axis, using a metal plate and clip and running a specific program on the ShopBot, but there is no such program for setting the X and Y, requiring the user to manually position the bit. This can lead to inaccuracies and wasted work.

To help everyone with accurate setting of the the X, Y, and Z axis, I made a thing:

This is an aluminum plate that is milled to be as precise as I could make it (read: probably a lot of room for improvement) where it sits on the lower left hand corner of the piece to be cut, with the corner of the work sitting directly in the middle of the circle.

With the piece placed on the work, the cable is plugged into the back (I had originally drilled two holes on the front left and bottom of the plate, forgetting that is where the bit has to touch so as to not push the plate off the work, so I drilled a new hold on the back and wrote “Do not use this hole” on the other two) and attached via the alligator clips (ToDo: make a better cable) to the Z plate.

The user should position the bit somewhere over the top part of the plate, where doesn’t matter. The user loads xyz-zero-finder.sbp (the code is available at this GitHub repository) into the ShopBot software and runs it. Assuming the bit is somewhere over the top, it will then slowly move the bit down until it touches the top, at which point it will move to the side (visually this appears to be moving towards the front of the machine, but in reality the side of the machine with the power switch is technically the bottom, or X axis). The program will move the bit inside the circle at what it believes is exactly 0,0,0 and, after displaying a message, will move the bit up two inches to allow the user to remove the plate and put it away.

The plate is in the drawer under the ShopBot in the Arduino box (ToDo: Make a real box for the plate). Feel free to use it and report back how it worked for you, so that we can make it better.

I want to thank Dean, Everett and Todd for giving me valuable advice about how to mill the plate on the Bridgeport; it was tricky because both sides of the plate are milled and getting it to sit properly in the vice was very worrying to me. I also want to thank Eric for suggesting the project in the first place.

# Our New Quiet(er) Planer!

Hey All!

Last Tuesday, we received the planer that we decided to purchase in that vote informal action from a month or two ago.  It can plane a board up to 16 inches wide, and thanks to the skewed cutting angle provided by the helical cutter head, it is far quieter than our previous planer.  Last Friday and Saturday, I planned and built out the dust collection, figured out the power layout for the shop, and researched how to run a 220V line.  After much reading, I decided I wasn’t competent to hack our 220V electrical system and started hunting for an electrician.  On Tuesday night, after showing Eric B. what I had planned, I learned that I had already done the hard parts.  Eric’s knowledge helped carry me over the finish line, and I’m happy to report that the planer is up and running!  The first authorizations will be coming soon, as soon as your Wood Shop team can craft a training checklist for the machine.  Here are some pictures!

Can you feel the excitement?  Andrew can!

# Make anything a Drone: a first person video camera rig.

Radio control flying is traditionally done “line of sight.”  That is, you stand in one place, and watch your toy fly around.  Modern electronics means we can get little cameras, that hobby size aircraft can easily lift.  For example, that little camera package you see there, is 17.5 grams.

My previous camera package fried when I hooked the wrong power supply up to it a few weeks ago.  For the record, putting 12.6v from a LiPo battery pack, doesn’t do good things for the health of a 3.3v video transmitter.

Here were my ingredients.  Not quite mise en place but definitely close enough for hackerspace work.

We have some protoboard, my new transmitter, my old transmitter, the video camera, some pin headers, a JST style battery connector, a set of dip switches, and most importantly, a voltage regulator.  That last bit is to stop me from frying the camera or transmitter on accident again.

When doing protoboard assemblies, it’s always a good idea to dry fit everything.

In a fit of bad practice, I have no decoupling (capacitors) to support my voltage regulator.  As with many things in electronics.. sometimes it works even if you do it a bit wrong.  If the video signal ends up being poor, I can always add more power filtering later.

When I first fried the video transmitter, I thought it had shorted out against my quadcopters chassis.  It’s not a good idea to leave power rails exposed, so there’s a good bit of hot glue on the bottom of the board.
Once that was done, I powered it up, and made sure I could change channels using the DIP switches, and that the video was clear in my goggles.

Antennas are a funny thing.  Most people doing FPV use circularly polarized antennas.  I didn’t have any small coax handy when I built this the first time, so I just reused my conventional antenna.  That little black wire, is a full wave antenna at 5.8ghz!

Other than being twice the weight of the previous camera rig I was running, I’m quite happy with how this turned out.

Keep making stuff!

PS: If you’d like more detail on the build: http://realtinker.blogspot.com/2015/07/building-better-fpv-video-rig.html

# Woodshop @ Pumping Station: One

When I took over the Pumping Station: One wood shop (a little more than 2 years ago), I started making cutting boards as my metric on how functional the shop is. I reasoned that it’s an excellent entry level project, and most of the users of the shop would be people with no woodworking experience. The first boards I made at the space were pretty good, but every step was a chore. The jointer could never stay sharp for more than a month, the planer required weekly maintenance, dust collection was a hassle, and it took 10 minutes of setup to do jobs that should take only seconds. Well, little by little, training, equipment upgrades and accumulation, shop days, and community has made the shop much easier and safer to use. My most recent cutting board demonstrates what the shop is capable of.

Last year, one of my favorite coworkers invited me to her wedding, and I decided that I’d make her something special. After discovering the color scheme in her kitchen, I chose padauk, purpleheart, and cherry and made a design in a free cutting board design program.

To prevent the wood from warping while in service, I milled the wood square (rectangular, really, but it’s woodworking jargon) and let it dry for two weeks in the shop.

As expected, the boards warped again as they dried. I milled them again and two weeks later, they were still square, so they were ready to glue up. After the initial glue up, I had a board that looked like the top board in the design program. I planed down one side of the glued-up board with handplanes and then ran it through the planer the board was flat. At that point, I set up the tablesaw sled to cut the board into $1 \frac{5}{16}$ inch wide strips. I created the pattern by flipping every other strip.

After cutting the edge-joined board into strips, I glued up those strips and gave my board to a friend who ran the board through his 40 inch drum sander, to flatten down the glued up strips. My target thickness was $1 \frac{1}{4}$ inches, so I was thrilled with the $1.227$ inches that I achieved. At that point, I used a handplane to clean up the edges, and took an obligatory picture of my handplane with the produced shavings.

After getting the board milled to the desired dimensions, I set up the router table to cut handholds. After the handholds were cut, it was time to sand. And sand. And sand. And then sand a little bit more. After about 10 hours of sanding, I decided that I was going to get an angle grinder style rotary sander and handle that work in maybe an hour for all future boards. When I was content with the smoothness of the board, I soaked the board in mineral oil overnight, to seal the board against water. At the end of the soak, I wiped away as much mineral oil as I could, although the board kept bleeding mineral oil for about a day. At that point, I used a mixture of mineral oil and beeswax to seal the board and create the beautiful finish that I achieved. I applied the mixture, waited for it to haze (I waited about 90 minutes), and then wiped as much away as I could. Then I sanded using waterproof 1000 grit paper, which buffed the finish and filled in any potential gaps. Then I used a polisher to polish the board until I achieved a glassy finish. Project complete.

# Chicago Northside Mini Makerfaire 2015

Thanks to everyone who helped make this year’s Northside Mini Makerfaire a success! Our awesome volunteers helped everyone from little kids to adults build 100 noisemaker kits. Thanks also to the donors who helped pay for the kits. Yay awesomeness!

Vinyl cut signage:

Dalek checking out the crappy robot contest:

Noisemaker:

Noisemakers and volunteers:

Ray’s chairs and tables:

Crappy robots:

If you’d like to see more photos, please check out Drew Fustini’s G+ link on the mailing list. Also of note is that we are going to the Detroit Makerfaire, July 25-26th. Announcements will come soon, but email jenny@pumpingstationone.org if you are interested in volunteering for the Detroit Makerfaire.

# Mother’s Day approaching!

I just got back from taking my kids to spend a week with my mom, but before I did I snuck into the woodshop for an evening to jumpstart an early Mother’s Day present for her: replacement drawers for her kitchen. She’s been managing with one functioning drawer in there for ages due to broken boxes, busted rails, broken face frames – the kitchen is an early 1970s relic, really. A few hours of work and \$20 worth of plywood scrap later, I had them ready to haul to Iowa:

Drawers are a quick build, and a great refresher on some of the woodshop tools.

Over the course of the week we spent at her place, I fixed up her frames, added sturdier drawer supports, installed the new rails and boxes, and put on her old hardware – from the outside you can’t tell anything is different on the ones I finished. I also cut out a sagging cabinet shelf and installed a new one. I left two drawers unfinished, because one of her fronts was missing – I brought the matching front home to bring into the shop and try my hand at copying it. Even with the installation only half done, though, she’s gained a lot of function.

Mother’s Day is just about two weeks away. If your mom has a house full of projects (I suspect this is very common), pop in and use the tools to cross something off her list!

# Knit a Working Loudspeaker

I’ve been working on an embedded speaker design off and on for the last few years, and finally got around to posting an Instructable for it.

I created knitted and non-knitted versions, and am quite happy with how it turned out. The secret is using dipolar magnets and hard drive magnets are a cheap way to do this. (Plus, a really big amp.)

Props to Sache for lending her glue and paper expertise!

# CNC Build Club – 2/5/2015 7:00pm

This month’s CNC Build Club meeting will be a demo night.  Bring something to show.  It can be a project you finished, something you made, a work in process or something we might think is cool.

I will be bringing several things I have recently completed.

The bipolar ORD Bot: This is a CNC machine I built for 2015 ORD Camp.  It is a super simple drawing machine with some fun math behind the motion.

The DC Power Supply Interface: This is something I did for Inventables that we will be selling soon.   It really cleans up the wiring when you use a DC power supply on a CNC machine.

The TB6600 Stepper Driver Shield:  This is another Inventables project.  The TB6600 can do a ton of cool CNC stuff.  Now you can interface it to the free grbl CNC controller.

The CNC Club is a monthly meeting of Chicago area people passionate about learning, building and using digital fabrication equipment.  It is held at the Pumping Station One Hackerspace.  It is open to non members.  We also have a Google Group called CNC Build Club.

Each meeting we talk about, build, train on and use CNC machines.  We have 3D printers, laser cutters, CNC routers and vinyl cutters.  Come out and join the fun.

Please RSVP on Meetup.  I will have a CNC or Inventables related door prize to a random person who RSVPs and is present at the meeting.