January 2013

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At our last 3D Printer Club meeting, the kids on the team started cutting threaded rods. We were clamping the rods to a table with a standard bar clamp to keep them in place. The problem was that they were slipping a lot. One of the adults had to sit on the end of the rod to keep it still. That didn’t seem very safe to me, and so I figured there must a better and safer way to hold them still while they’re being cut. The classroom doesn’t have an appropriate vise to use, so this seemed like a great project for a custom 3d printed object!

I used OpenSCAD, which is a free and open source CAD software tool, to design a simple attachment. The attachment has a v-groove on the bottom to hold a rod in place. (The v-groove is useful because it allows us to use it for different diameters of rods.) It also has a lip around the top to hold it in place on the clamp jaw.

This clamping attachment is going to need to take a lot of pressure, so I printed it with ABS plastic, three perimeters, three top and bottom layers, and 25% honeycomb infill. You can find it on thingiverse here: http://www.thingiverse.com/thing:44588

Bar Clamp Rod Adapter


To help prepare the kids for the next meeting, I sent this email to all of the club members. The robots I’m referring to are a handful of little Maker Faire Robots (http://www.thingiverse.com/thing:40212) that I printed to give away at the previous meeting.

Hello fellow makers! (This email is for the kids, but advisers can read it, too)

Our next meeting is this Friday, and we should be able to make more progress on the build. Based on the responses I saw from [build team member] email last week, it looks like we’ll have a couple more hacksaws to work with, and I’ll try to bring some more clamps — and those little printed robots I forgot to bring last time. (I’m printing more of them as we speak, and I’ve attached a picture!

I’ve seen emails from several of you regarding things like hacksaws, meeting frequency, and parts that we still need to locate, and I really appreciate the hard work that’s been going on between our meetings. Without this effort, our progress will slow down considerably, so thank you!

[Build team member] on the build team had the idea of increasing the frequency of our meetings to weekly, and although I think what would definitely help us move along faster, I think at least for the time being I’d like to keep meeting every other week. My hope is that we’ll be able to get more legwork done between meetings so that we can focus more on the build during the meetings. There’s always an option for smaller groups to meet in the off week, too.

Some of you may have met [hackerspace member] last time. He’s a member of the local maker space (or hackerspace) and was helping out last time with the makers. He and I were talking about some neat project ideas we can work on in the future. Thank you, [hackerspace member], for your time!

I was very happy to send out our first thank-you card that accounting team put together and had everyone sign. It also looks like the BOM team has been hard at work finding a few remaining parts that we need.

I believe the blog team is working on a website update, but I think they would consider posting information from other team members as well. For example, I plan to write a couple of paragraphs about the promotional video you’ve all seen and ask them to post it. So if you have any ideas, please feel free to share them!

I was very happy to see the membership team working on the sign-ins at the last meeting. They may need a little extra help in the coming weeks, so if you’re interested in membership-related duties, please feel free to contact them to offer your support.

I look forward to seeing you again this Friday! Remember to bring your science notebooks or an extra hacksaw if you have them or are able to!


P.S. Remember the email addresses you can use to contact your team or other teams: [email list addresses]


Here’s another email from the build team explaining the schedule slip. It’s funny to see kids use words like “aggressive” used to describe the schedule, but there’s a good reason for it: I used that word and explained it to the build team members after the last meeting when we realized that they weren’t going to finish what they hoped to finish.

This email also illustrates another mistake I allowed them to make — the one about rescheduling the Z axis before the X. Soon I plan to help them realize that they might be able to use the resources available to do more than one thing at a time.

Hi everyone,

Our last meeting seemed great to me, and I’m looking forward to the next meeting. I have three things I want to let you know.

The build schedule changed. The next thing we are going to build is the Z axis, not the X. We can’t build the X if we don’t have the Z to put it on! This means that the BOM team has a little more time to get the parts for the X axis, and we need the Z axis parts a lot sooner. Nothing will really affect the other teams.

I wanted to let you all know that our schedule has slid. The cutting and all that stuff took longer than I thought so we are going to keep building the frame next meeting. I think the reason the schedule slid in the first place was that we need more hack saws and that my schedule was too aggressive.

I have a few suggestions to help this problem. We can meet every Friday instead of every other Friday. We would have to get permission to do this. What do you think about it?

Another way to help solve this problem is we could get more hack saws. Does anybody have a hack saw they would be willing to let us borrow? We could use another one. We could also buy another hack saw if we have enough money.

Does anybody have any other suggestions? If so you can just email me.


This is one of several emails that I sent out to team advisers in order to clear up concerns about expectations and direction.

Hi [accounting team advisers],

As you know, my emails are usually directed toward the kids, but this one is for you. With the start of the new quarter upon us, I wanted to share with you a bit more of my vision for the accounting team to get your input and hopefully help make their goals and purpose a little more cohesive.

My goal for the accounting team has been twofold: First I wanted to give the kids with number sense or a particular interest in math a very meaningful role in the club — one that they could learn from, take responsibility for, and feel proud of. Second, I wanted give all the other club members a sense of finance and budgeting by integrating the accounting role into what they’re doing.

To meet this first goal, my hope has been that the kids on the accounting team (with guidance form the adult advisers) develop a method of keeping track of the overall budget, and from the last meeting, it looked like they were on their way to accomplishing that. They’ve been asked to keep track of a few things so far, but moving forward they’ll be getting even more data to manage. Hopefully this will help them hone their system. I don’t think the work they do has to necessarily be slick and professional (it might as well be managed on paper in their notebooks) and I think little mistakes along the way are probably a good thing, though we should try to guide them away from making big ones.

To meet the second goal, I’ve been emphasizing budget and cost when working with the other teams, and asking them to interact with the accounting team where appropriate. For example, I’ve been telling the maker team, “If we can find something we can use, we won’t have to pay for it.” And, at the last meeting, I asked the BOM team to submit their list of hardware parts to accounting for approval. I’d also like the accounting team to ask everyone to help raise funds by asking around (not from their parents, but maybe their parents’ offices, or in the neighborhood, or at special events).

These are the types of questions and requests I see them getting moving forward:

  • “How much money do we have available?” This is basically the uncommitted funds available, and can be managed just like a checkbook ledger.
  • “Can we afford (or will you approve) [some specific] expense?” This is where their rough budget categories come into play. As they’re getting set up and familiar with their responsibilities, I’m sure this will be pretty chaotic and feel pretty blind, but right now I’m doing all the actual buying, and I’m not going to let them get burned. Eventually I’d like them to be able to confidently answer these questions, though — including saying “no” when appropriate. For example, if approving a hardware expense would put us over the hardware budget, then the answer should be “no” until they’ve addressed the budget problem. They can address a budget problem by shifting funds from another budget category, by raising funds and increasing the budget, or by encouraging the member making the request to find a alternative or ask for a discount.
  • “Here’s a donation for you to track.” I hope we’ll get more discounts or donations, and we’ll need to manage those appropriately. Each person or company that makes a donation should receive a handmade thank-you card in return, and I’d like them to be creative with it. If they include the amount donated, it can probably even be used as a tax receipt.
  • “Please reimburse me.” For this one, they’ll need request and track an expense reimbursement from the school. Of course, it needs to be an expected expense!
I hope this helps out going forward. As always, please don’t hesitate to contact me if you have any questions or concerns!

So far I’ve been doing all of the purchasing for the club — partly because I don’t want the kids to be overwhelmed, and I don’t want to burden the kids’ parents with the extra expenses that won’t be reimbursable until after the accounting team learns about reimbursements. This also allows me to protect the kids from expensive mistakes because I’m able to order exactly what’s needed even if the projects that the BOM team sources aren’t quite right.

Here’s an email I send out to the accounting team that lists what I’ve purchased so far. They have most of it already on their general ledger, but this puts most everything in one place for them to double-check.

Hi there, accountants! (Parents, this one is for the kids again.)

As I mentioned in my Accounting Team Update email earlier this week, I wanted to get you a list of the things we’ve acquired for the club so far, along with their costs and categories. I believe you’ve already recorded some of these expenses, and I know others will be new. I’ll wait until we’re a little further along with the build before I submit a request for reimbursement.

  • J-head hot end (2, with extras): Donated by Reifsnyder Precision Work! ($110 value)
  • Hardware (7 three-ft threaded rods): $1 each + 7% tax, no shipping, from Lowes
  • Hardware (smooth rod and most screws, washers, and nuts): $45.98 + $3.42 shipping, from McMaster-Carr
  • Electronics (circuit board and components): $33.25, free shipping, from ebay
  • Electronics (4 stepper motor drivers): $9.95 each + $2.13 shipping (total), from Pololu electronics
  • Stepper Motors (5): $8.50 each, no shipping, from ebay
  • Frame vertex with feet (4): printed by me, so no real cost here
  • Frame vertex without feet (2): printed by me, so no cost here, either
  • Bar clamp (8): printed by me — free!
See you on Friday! (Remember to have a brief team update prepared — and don’t worry if you don’t have time to include all this before the meeting.)

In an effort to trim down the team to only the most interested and motivated students and parents, I sent out this email to only the parents.

With the new quarter starting up, this is probably a good time to talk to your kids about their involvement in the 3D printer club. As the build actually starts, we’re going to be relying on each team member more and more to take responsibility for his or her role and the work that goes along with it — not only during the scheduled club meeting times, but outside of those times as well. We won’t be able to complete this project without this concerted effort (there are simply not enough scheduled meeting hours left), but if the kids follow through between meetings and come prepared, then we should still be on track.

So please take a moment and talk to your kids about the club. Is this something they’re still committed to seeing through? Are they still willing to work hard toward a long-term goal? Are they willing to come prepared for the club meetings, work hard at them, and follow up between them?

I also want to express my sincere gratitude to the parent and teacher volunteers who are helping to see this project through. The talent and dedication they bring to the table is incredibly valuable — directing a project of this scope with a team this size would be impossible without them. Thank you!

Finally, I want tell you a bit about some of the hard and dedicated work I’ve seen from the kids so far. After every meeting, I’ve had a new story to tell about a student stepping up to a challenge, coming up with a creative idea, or discovering something new. I’ve received emails from them about things like club branding and sourcing parts. I’ve seen kids feverishly running numbers and tweaking budgets, interviewing teammates, taking pictures, researching parts, taking notes, organizing lists, asking questions, proposing solutions, coming up with creative new ideas, and a whole lot more. The enthusiasm and curiosity I’ve seen from them has been positively inspiring.

See you Friday!



I’ve been attending open meetings at Splat Space, our local hackerspace, for over a year now. They’re familiar with our school build project, but I wanted to remind them that I wanted to bring in some outside help and presenters as well.

At the open meeting, I got up and explained the project again, and asked members to come talk to me if they had any interest in helping, or if they were willing to make a short presentation to the kids on something interesting that they’re making. I got a couple of people to take me up on the offer, and I arranged for each of them to visit the club during a meeting.  


One of the build team leads send out a lengthy email to the whole team. (He’s young, so it was mostly dictated.)

I recognized during the previous meeting as they were developing the build schedule, that it was very aggressive. At this point the build team is planning to have all the rods cut and the frame completely assembled during the next meeting! This is a mistake I’m willing to let them make and learn from, though. Personally, my hope is that we can at least start cutting.

Hi everyone!

This is [build team lead]. I hope you had a good break. I’m looking forward to the next meeting on the 11th. Make sure you remember your notebook, if you have one.

[Other build team lead] and I made a build schedule, and according to the build schedule, it looks like we should be cutting the threaded rods for the frame the next time we meet! According to my research, in order to build the frame we need threaded rods, 5/16” nuts and washers, and 6 plastic frame vertices. We already had the threaded rods, we ordered the nuts and washers, and we printed the frame vertices, so we have everything we need to start building the 3D printer!

We’ve been getting some crucial parts to build the 3D printer.

The other day we got the motherboard (or the circuit board) with all the components that go along with it. My dad found a really good deal on ebay, and he just ordered it because there were only two left in stock. We still need to solder the motherboard all together before we can use it. We also need to program its “brain.” The “brain” is a computer chip. He also found good deals on motors and motor controllers so we have those now, too. According to my schedule, we should be putting the electronics together at a later meeting.

We got two hot ends. Hot ends are the things that heat up the plastic and squirt it out. We got these before the last meeting as you probably know. We will only need one of the two for the 3D printer.

We got the threaded rods before the last meeting, too. The threaded rods are for the frame mostly and also for the Z axis. We still need to cut the threaded rods to size and put them together. We’re going to cut them with a hacksaw. We are probably going to do that at the next meeting. We might need some help with that, and it would probably be a good job for some of the makers.

We got a bunch of hardware from McMaster-Carr. McMaster-Carr is this online hardware store. I congratulate the BOM team for finding those products on McMaster-Carr. We got nuts, screws, bolts, and all that kind of stuff. We also got the smooth rods from McMaster-Carr. The smooth rods are for the Z, Y and X axes. They allow the axes to move back and forth, up and down, or side to side. We need to cut them, too. According to my schedule, we should be doing that at a later meeting also.

We got some high-temperature wire from McMaster-Carr also. High temperature wire is wire that doesn’t melt in high temperature. We need that because we need some wire to give the power to heat up the hot end without melting.

I’m looking forward to getting started building!


With the new year rolling around, I wanted to express my sincere thanks to all the teachers and other adult advisers that are helping to make this club a success — and provide a little vision as well.

Hi, everyone. Most of my emails are directed toward the kids, but this email is for the adults who are helping with the 3D printer club.
  • First, thank you all so much for all your help with this project! I really appreciate it, and I think your help will be the key to this club’s success. The build plan that [build team leads] worked out has construction starting this week!
  • I love that everyone seems to be letting the kids do a lot of the work. (I’ll of course continue to include the advisers in team updates.) I think we’re helping the kids succeed and learn a lot by guiding them along as they figure out how to best do their work — even if they make some mistakes along the way. When I work with them, I try to help them think things through. I’ll let little mistakes happen, but I’ll try to help them catch the big ones — usually by asking lots of questions. (“Would somebody be able to go out and buy this part the way it’s described?” or “What else might the reader need to know?” for example.)
  • As you might already be aware, we’ve set up group emails to make it easier to communicate. You can email everyone in a specific team by sending a message to one of these addresses: [team email addresses]. The [adviser email] address is all of us — just the adult advisers listed below. (Thanks, [blog adviser] for all your effort in getting this blog and email service up and running!)
  • I’m not convinced that all of my lists are correct, but hopefully they’re close enough. In particular, though, I wanted to be sure I have the correct adult advisers matched with the correct teams. Please take a look at the list at the end of the email and let me know if you see any problems. (For example, I had [three advisers] all helping with membership, and I’m not sure that’s right.)
  • I realize that some of you might feel a little lost sometimes, but I think to some extent that’s okay, because it gives us a chance to sit down with the kids and say, “Let’s figure this out together.” But if you ever feel completely lost or feel like you don’t have enough information to help the kids on your team along in a meaningful way, then please just let me know so we can work it out.
  • I’m planning to send a message out that is directed to the *parents* this week, and I’d like to suggest to them that this might be a good time for them to talk to their kids about the club — just to make sure they’re really still interested in giving it their all. The club is still a lot bigger than I originally expected, and so we might need to get a little creative with things to do from time to time — particularly once the excitement of “taking stuff apart” wears off for the makers. Does anyone have any concerns about this?
This is how I have the advisers broken up. Any mistakes or omissions here?
Accounting: [accounting advisers]
Blogger/P.R.: [blog team advisers
BOM: [BOM team advisers]
Build: [build team advisers]
Makers: [maker team advisers]
Membership: [membership team advisers]

I didn’t want to leave the helpful advisers out of the updates, either. Over the break I’d heard a concern about expectations and overall direction, so I wanted to provide a little more information about these things just for the advisers of each team. With all these kids, the meetings can be a little chaotic and scattered, and because we’re asking the ids to do so much, we never really end up doing exactly what we planned.

My goal for the maker team advisers was to remind them of how I see the kids on their team fitting in moving forward.

As this next quarter starts up, I wanted to take a moment and share with you a bit of my vision for the maker team. The team is a bit different in size and scope than we had originally intended, but I hope that can work to our advantage. I think it could give us an opportunity to get creative with how they contribute in the future, and even if that contribution is only tangential at times, I think each member of the team can take away some valuable lessons.

During the first quarter, the team has been focused on taking stuff apart, and I had a few goals in mind for this. First, I wanted to try to help demystify mechanical devices by showing that they’re not just magic boxes — they contain a bunch of stuff that works together to do something useful. The goal for disassembling a machine is not to see how quickly or completely it can be done, but instead to try to figure out how it works: “What are these wires for?”, “What makes this part move?”, “How does it know when to stop?”, “Why is this shaped the way it is?”, etc.

Second, I wanted the kids to see subassemblies in place, and how they relate to the function of the machine as a whole. For example, in inkjet printers there is usually a print carriage that moves back and forth along smooth rods using a motor and belt, and that’s exactly what happens in a 3Dprinter as well. One motor moves the print carriage, and another motor moves the paper through. Each of these motors is attached to a circuit board that serves as the brain, and that circuit board is fed power from a power supply that’s connected to the wall.

Finally, I wanted them to be on the lookout for useful parts. To be sure, we won’t actually find a lot of parts we can use from these machines, but we will likely be able to use some for different projects in the future — things like motors and belts that are too small for a 3D printer might be just right for a robot that draws on eggs, for example, and I’d like them to think creatively about uses like these. (As an example, one of the kids found a belt last time and then came up with the idea of making mini 3D printers when we discovered that the belt would be too small for our project.) What we should be able to find, though, is a couple of power components like cords and cables, and maybe even things like a power supply, glass, switches, belts, and motors.

This quarter things will hopefully be a bit different. Soon I believe the maker team will be a little more involved with the actual build process, and hopefully some of the other processes, too. (I’ve been trying to encourage other teams to tap maker team resources when they need help.) With the build schedule in place, one of the first things we’ll need to do is prepare some parts for assembly, and I’m strongly suggesting that the build team use maker resources for this. But because you’re probably new to this process, too, I thought I’d give you a heads-up with some specifics.

We have several 3-foot rods (both smooth and threaded) that will need to be cut to size. This will involve some thinking ahead, including how to efficiently lay out the cuts to preserve stock, how to measure and mark the parts, how to cut the rods straight, how to secure the parts that need to be cut, and how to clean up the parts after the cut. You can guide them through this, but they’ll need to lay everything out first, then thread nuts onto them, clamp the parts down, saw them into pieces with a hacksaw, deburr the ends, and then unscrew the nuts to clean up the threads.

We also have several printed plastic pieces that will also need to be prepared for assembly. Because 3D printed parts aren’t absolutely accurate, we’ll need to carefully drill out the holes to the correct sizes so that they fit the hardware they’re supposed to fit. This is also something you can let them discover: Try to fit the plastic frame vertex over the threaded rod, and when it doesn’t fit, ask, “Okay… so what can we do to make this work?”

But here’s how I hope this will work: I’d like the kids on the build team to explain what specific parts are required for the scheduled work. I’d like the makers to ask questions if necessary and then work through how they’ll accomplish the task with the supplies they have. Allow them to make little mistakes, but save them from the big ones. For example, if they decide to try to cut without clamping the work, I’d let them try (supervised, of course), but then suggest that there’s probably an easier and safer solution if they give it a little more thought.

I’m going to try to bring several tools in this Friday, and my plan is to review them and some safety guidelines at the start of the meeting. Among the tools I plan to bring are a hacksaw, clamps, a cordless drill and drill bits, files, wrenches, tape measure, and calipers. I’m also going to bring a lot of hardware and begin to introduce it.

I hope this helps a bit going forward. I’ll see you on Friday!

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