Can you suggest common material for 600 students? (ShapeOKO 3)

Good Day, folks

On Monday I’ll purchase the ShapeOKO 3 for my Engineering and Technology classroom (6-8th grades).

I also have two (soon three) 3D printers.

My course is nine weeks. During that time students learn a bit of theory and history (drafting, design model, inventors, business, fabricating, and more). It’s a short course, but I want it to be as hands-on as possible.

Here’s essentially how I do the hands-on portion:

  1. Students learn how to make a (for their age) formal multi-view drawing, including an isometric view (of a rectangular puzzle piece).

  2. I also teach them how to make a 2D scale model of the classroom, including movable furniture (they make a map of the room’s walls, doors, permanent fixtures on graph paper, followed by scale furniture on index cards). They have to account for walkways, etc., and everything is to scale.

  3. Thirdly, I make them scale down, draw, and build a piece of furniture using hand tools and soft woods.

  4. Next is CAD. They start with TinkerCad and can move up at their own pace to 123D Design, Sketchup, and a couple others.

Once they are comfortable with 3D design on a basic level, I allow them to begin making projects. They are horrible in general with the concept of originality, invention and innovation, but that’s something I need to work on from my end (teaching them how to think).

And now to my question: I have a $1,000 budget for consumable supplies (materials). The money cannot be used for tools unless it’s small replacement parts (bits, extruders, etc.).

I want to get the most for that money. I’ll use about $200 on filament for the 3D printers, but I don’t know what to purchase for the ShapeOKO3 in order to give every student an opportunity to design and build a model.

I generally want each kid to have a piece of soft material that is about 2-3 inches thick, about 4-6 inches wide, and about 6-8 inches long. It seems that perhaps poplar or pine would be a good choice.

I’d love to get a lot of machinable wax, but I don’t know if my budget can handle that for the number of students I teach.

Any thoughts on a common, soft material that can be purchased in large amounts?


HDPE panels are quite affordable and able to make a wide variety of objects.

Some other things are listed there.

If you have reasonable dust removal, a number of the composites are inexpensive, machinable, and structurally pretty good. I have stacked and glued MDF and plywood to make thick stock, and both machine well. MDF needs dust extraction. You might look for microlam material, as well. I have used offcuts (nice having friends in the trade, no?) for a variety of things, and it cuts and machines well, with about the same chip and dust mix as dense plywood.

Another option is foamed materials. They are inexpensive, light weight, glue-able, and can be had in several thicknesses and types. The styrenes are recyclable in some areas, if the chips are reasonably clean, but I don’t know if the urethanes are. They are not in my area.

The tough parts with going to dimensional stock include that it is usually pretty far from flat and often has internal flaws that can lead to the heartbreak of psoriasis^h^h^h^h^h^h^h^h^hbreakage of smaller features on the finished part.

HDPE (milk jug material) is available in sheets to about 1", machines well, is recyclable, but doesn’t glue. It pretty much needs to be heat molded. Clean cuttings are recyclable in house. A search will provide a lot of sites with instructions for recycling and casting hdpe. Might even be a nice tie in: the kids cast their own blocks from to machine, and learn a bit about the recycling process. Could even lead to grant money, if you want to do the legwork.

If you want to go with woods, you might talk to local construction types for reasonable size offcuts in the larger materials, and put the budget to smaller/thinner stock.

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Wow, two amazing replies in just a couple hours. Thank you.

Next year I’ll have a larger budget for materials, and I have the benefit (sort of) this year to make my dollar stretch because I’m already a third of the way through the school year. By the time I get set up I’ll only have about 300 remaining students for the year (I get 150 at a time, separated into six classes for a nine week period).

If I am fortunate enough to have a few years in this position (this is my first year), I will really be able to develop a good program. My focus is engineering with technology, so printers and CNC go right along with that. I’ll also get into casting of resins and such, but that won’t be this year unless I put in my own money (or, actually, MORE of my money. I’ve already spent a lot of my own).

The application part of the class (other than the machinery and tools) will be inventions and innovations on a small, practical level. This is the part I’ll struggle with (am struggling with). I want kids to invent gadgets and make them. For now they are of the mind that they want to make what has already been invented and they think downloading an STL file and adding their initials is innovation.

I want their minds to think like engineers and solve problems. And, yes, I want them to make fun gadgets, but only if they have a practical purpose.

When students want to make something, my first question is “What does it do?” If they can’t answer that, then the project isn’t for my class. I tell them, “I love art, but this isn’t an art class.” They have a difficult time with that concept and want to make Nike logos and such.

I’m on a journey. Hopefully I can make a big difference.

Background: 21 years of teaching elementary school (all subjects), first year teaching middle school engineering and technology. My job feels like a dream come true. I’m so happy to have this opportunity.

Years ago (about 20), for an innovation and design class I was teaching (high school level… yup the name was something like that back then, Then it became introduction to design, and is probably going to become something trendy again) I had a similar problem. What I did then varied from class to class, but things included: design your own animal made by folding paper and gluing tabs. Got some cool ones, including an elephant head that year. It had to fit a B-size (US) sheet of card stock. Another year was a vehicle. Only permitted materials were card stock, elastic bands, and wood pencils. A lot of what one would expect, but a few really creative, awesome designs (one used the lead for the axles for low friction. Small, very cool)

These types of projects require guidance for the kids. The hard part is not guiding too much.

I might have the kids look at mechanisms such as screws, sliders and four-bar linkages, etc. For the class I teach these days, I bring tools (pliers, small bolt cutters, compound crimpers, drill chucks), cutaways and disassembled things like valves, and so on for them to see. Window cam locks, ratchet lock for a display case, small vise, ball and socket examples (like speaker wall mounts and a miti-mite magnetic holder), a dovetail slide rescued from an old mini lathe, A large bolt (1-1/4" diameter?) sliced in half, a damaged Starrett micrometer frame, sliced into about half a dozen sections, and whatever else I think of goes into my cabinet of mysteries. I also generally have the students bring something of their own to analyze and dissect. The things have ranged from tools to toys to the lock from the students front door at home.

Along with the samples goes measuring tools. I buy second hand calipers and other tools at yard sales whenever I see them. The schools invariably purchase the cheapest, least accurate garbage they can in this line-- I spec a $30 decent import caliper that is accurate to 0.04mm and graduated to 0.02mm, they pay $20 for a stamped sheet metal tool-shaped ornament that is accurate to, at best, 0.5mm. No money saving there, since it isn;t usable. I pop maybe $20 or $30 a year replacing and fixing measuring tools, take it off on taxes, and save more than that in aggravation. The tools I end up with are not crap. I do any repair and adjustment needed to make them meet original spec, calibrate with certified gauge blocks (my only splurge, and I use them when I wear my engineering hat), and maintain them to spec. The students use the tools to measure the samples. Only way to really understand is to measure it, draw it, pull it apart and put it back together, etc. It isn’t possible to design real things if you don’t handle and work with real things. The model in the CAD system can look as good as you want, but if the motion doesn’t work out in the final device, it is useless.

You might require that a plan include one or more standard named mechanism. Examples with a sliding joint would be a box with a sliding lid, fit to hold a specific item. A four bar linkage with slider might be used similarly for a bos with a hinged lid to hold it open or stop it overtravelling. Both of these can be made from thinner sheet material, as the bulk comes from the stack of top and bottom. Think making boxes to hold tools.

Ideas off the top of my head to use as examples:
Maybe an automatic door stop (pinned joint and gravity so that the door opens, but the stop must be lifted to close it)
An adjustable cell phone holder with a place to wind headphones
A doorbell with pull cord (four bar linkage, spring or elastic, string, and a metal rod coiled into a planer spiral as a gong, as in many older mechanical clocks.)
Circuit board vise (see the stickvise on Hackaday) It is essentially a mod of the classic easel mechanism.

If the kids work the mechanism out first using paper and pins (paper fasteners? paper rivets? the little things with two legs and a head to hold paper together…) really, really cool things can be done

Ok. This is longer than I planned. I am avoiding grading a set of multivariable calc exams. I hope this sparks you a bit. Ask away for other ideas anytime. Where are you located that you can get machines in the middle school?

I’m in Fayette County, Georgia. Booth Middle School. I just started the job in August.
Essentially, a friend of mine had the job first, and took on a lot of roles. He not only taught Engineering and technology to 150 kids a day, but also ran the robotics team, the STEM program, and much more. He is an inspiration to me.

He was stretched pretty thin, so he asked if his job might be split into two jobs. That’s where I come in. I’ve been a tinkerer/maker my entire life, worked in industry before college, and always have some kind of mechanical project (or three…or four) going on at one time.

So my friend got approval to split the job. He teaches STEM for half the day (students have to apply, and the curriculum is rigorous, competitive, etc.), and the second half of the day he spends as our building tech guy (technology infrastructure).

I took over the elective courses (engineering and technology). I teach six classes, two from each grade (6-8).

I’m very much still finding my footing. The first nine-week period was hectic. I had very little to work with and bought some basic tools and inexpensive wood. I taught the basic theory and we drew. But I didn’t guide them well enough, and it was quite chaotic. Nevertheless, I loved it.

This current nine-week period is much better organized, but is still bumpy. Plus, I still need more gear (especially more hand tools, which I will get in the next week or two).

The 3D printers are new, and I’m already learning that kids just want to print toys. So on Monday I’m putting the brakes on that notion and will make them fill out a planning sheet that describes what their design can DO.

We’re also still in the middle of building miniature furniture from scaled-down models. I’m surprised that they know very little about scale models.

Thanks for all the suggestions. I’m soaking it up.

similar post here i think
Inexpensive practice material??

My suggestion would be to have the kids bring in a used plastic / HDPE cutting board if they have any to spare from home.

Alternately, see if you can find a local building goods shop which has inexpensive 4’x8’ panels — envy the Midwest having:

Apollo just posted a design for cutting up an aluminum can on a Nomad: Recycling with CNC: Soda POP Robots — have the kids design something on a similar size / scale to cut out of a can?

Safer, but equally accessible would be large plastic lids from food containers such as coffee.

I’ve got a back burner project of taking my caliper design: gets cut out of a broken CD case — those should be easy to source (an even cooler, but different idea is to make a CD case into a sextant). Another option are used / discarded CD and CD-Rs:

(though that’s back to toys)