Category: Tips

Tips learned from experience building a MakerBot

3x2x1 Rubik’s Cube assembly pictures

The design should be pretty intuitive.  However, I went ahead and took some pictures of the assembly anyhow.

As I mentioned in an earlier post, I think this one came out really really well.  :)

Tyvek Sled Kite… from office supplies

Tyvek Office Supply Kite

The picture to the right is of a kite that I built several weeks ago and only got around to actually flying this weekend.  It’s basically made out of office supplies.  :)

Originally I just wanted to make the Tyvek sled kite from the Howtoons shown in Craft Magazine, Volume 8. 1  But then I wanted to see how much of the kite I could assemble just using things from the office.  The answer is, basically all of it.

The Howtoons calls for:

  1. A large sheet of Tyvek
  2. Tyvek tape
  3. A washer
  4. Ruler
  5. Scissors

Instead I used:

  1. Tyvek from Tyvek office envelopes, rather than a large sheet or roll of Tyvek house wrap.  My office is sent dozens of these things a day.  It didn’t take long to collect 30 plus.
  2. Clear packing tape.  I used this instead of Tyvek tape.  Tyvek tape would have worked a LOT better, but I have no complaints.
  3. Rather than use a washer, I used a spare keyring.  I had other various office supply bits hanging around in case this didn’t work out.  Paperclips, binder clips, etc.
  4. Yardstick.
  5. Scissors.

Since the envelopes are significantly smaller than the sheet of Tyvek rolls, I had to either make my kite smaller or stitch them together into a larger sheet.  I did both.  I scaled the plans down to about 2/3rds the size from the diagrams and then used packing tape to put them all together.  To get the most surface area out of each envelope, I burst all of the envelopes at the seams and then taped them up.  Once I had a 36″ tall sheet, I started cutting it into the pieces I needed, re-taped it back together as indicated by the diagram, and then set it aside for weeks while I didn’t fly it.  :)

On the day of the launch I made the tail out of strips of leftover envelopes taped together with the gluey bits from some of the envelope flap sealants and more packing tape.  I punched a hole in the three ribs using a pen, ran the line through each of the three ribs, reinforced it with more packing tape…  and launched.

The only non-office supply things used in the construction were:

  • Crayons for coloring the kite (hard to see)
  • The ruler – I don’t have a yardstick at work
  • The kite line, purchased from Amazon

It flew pretty well.

  1. I found a copy of all three pages after googling around a little.  Howtoons: Sled on a Thread pages 1 2, 3 [↩]

3x2x1 Rubik’s Cube – done!

I’m so happy with the way this has turned out.

I’ve made a bunch of changes since the last revision of this printable 3x2x1 Rubik’s Cube puzzle:

  • I’ve totally redesigned the center barbell connector.  I simplified the design, removed the five support struts for each end and replaced it with a single support strut and a flat hexagon in the center of the piece.  The purpose of the hexagon is to give the barbell more contact area with the raft.  One of the earlier drafts didn’t have as many supports or this flat hexagon, and it tore off the build platform partway through the build.
  • I increased the diameter of the tube between the barbells.  This enabled it to print easier, made it a little more sturdy, and decreased the wobbliness of the barbell when everything is assembled.
  • I also shortened the entire barbell by 1mm, so that the entire puzzle is held together more closely.
  • I made the flat semi-circular tabs slightly thinner so they rotate a little more freely.
  • I significantly redesigned, thickened and simplified the two brackets that the barbell snaps into.  It’s been able to easily withstand numerous couplings/decouplings as well as numerous rotations.  With a few rotations, all parts now rotate easily.
  • All of the parts fit together SO much better than my first draft held together with a nut and bolt.
  • There is a slight bit of sideways flex that can occur with the use of the barbell.  It is really minor and it actually seems to help the puzzle be more forgiving as you manipulate it.  I see this more as a benefit than a design flaw.

The was one design choice on which I waffled.  I considered making the center cubes non-identical, with one having half a barbell stick out and with the other having the internal connector you see now.  This would have removed much of the sideways flex – since the barbell would be stationary.  I did not go with this design choice because whether the puzzle used one barbell and two connectors or male/female center cubes, there would always be some flex caused by the use of a connector rather than a static pin.  And, to be honest, I much preferred the symmetry of having everything assembled out of just three unique parts.

I know I’ve mentioned this before, but I really like the idea of a MakerBot printable toy that can be printed in one go and then assembled without tools or any additional hardware.  I also think this would make a great MakerBot print demonstration.

I’ll post some pictures of the parts a little bit later.

New 3x2x1 Rubik’s cube design – totally printable!

X-Ray view of the 3x2x1 puzzle cube
X-Ray view of the 3x2x1 puzzle cube

This is easily my most intricate digital design for the MakerBot yet.  It’s a 3x2x1 variation on the Rubik’s cube puzzle I had posted earlier.

This version incorporates the prior improvements as well as designing a connector system inspired by R3bbeca‘s beco block connectors.

This has enabled a totally printable toy.  This just makes me happy. 1  The idea that I can crank out a set of these parts, clean them up a little, and just snap the toy together is just amazing.

TomZ‘s original 1x2x3 “friendlier” Rubik’s cube designs were also totally printable – but required a printed pin that was later glued in place.  I like the ideal of all printed parts – but strongly prefer a design that can later be disassembled easily.  And, as I mentioned above – the ability to hand assemble the toy is important to me.

I wasn’t able to recreate R3bbeca’s female connector designs2 so I made a simplified version that should suffice.

The simplified connection mechanism is essentially two plastic fingers that will (hopefully) pinch the barbell into place.  This was made by designing the outline of the gripping “fingers,” creating a horizontal cylindrical hole slightly larger than the intended end of the barbell, then creating a vertical cylindrical hole in the center for the barbell to be inserted through, then a bit of cleanup.

The biggest potential problem is that this design will require a carefully tuned ‘bot.  The center cube pieces have a lot of stuff packed in there – semi-circular slots for the semi-circular tabs, connectors for the barbell, and thin walls separating things.  With those thin walls and interior overhangs, this may be a difficult design to print.

I think Bender is up to the task, but we’ll see in a few hours.  :)  I can’t wait to print this!

For me, having a MakerBot is like waking up to Christmas every morning.

Oh, and before I forget, if you want one of these – leave a comment or send me an e-mail through the Contact page.  Make me an offer.

  1. Perhaps a little prematurely, since I haven’t actually printed this yet… [↩]
  2. I believe I’ve already sufficiently lamented my inability to understand women and their mysterious lady ways. [↩]

Improving on the 3x2x1 Rubik’s Cube

I’ve been fiddling with the designs for the 3x2x1 Rubik’s Cube incorporating some of the changes I had considered:

  • I’ve widened the holes for the nut and bolt.
  • I’ve made all of the cubes solid.  I think it will just work better with solid parts.  I had left the four end cubes mostly hollow to:
    • Improve printing time
    • Use less plastic
    • Possibly make an interesting hiding place for something very small
  • I’ve shortened the “stem” that connects the semi-circular tab to the end cube to allow for a more snug fit.
  • I’ve made the semi-circular groove in the center cubes narrower, to allow for a more snug fit.
  • Make these cubes solid so that they slide against each other easier.
  • I’ve noticed that the nut and bolt I installed into either side of the center cubes were pushed sufficiently well inside that they don’t want to come out or rotate.  This is a very good thing for this design!  It turns out that if you rotate it too much in one direction, you can just rotate it back a few times and it will be tightened back up!  It also makes for easy disassembly/reassembly – just rotate the puzzle until it comes apart and rotate it back together to reassemble.

Advice for MakerBot based businesses

Pete Hinzy left a comment asking:

I am also attempting to start up a small business with the focus on providing low cost, custom parts. I have one customer now but have struggled trying to “reach the masses”. Any thoughts?

Hi Pete!

Well, you asked for it!

  1. First and foremost, absolutely, positively, get a copy of Guy Kawasaki’s Reality Check.  At $20, it is the best investments you’re going to make in your business, hands down.  This book distills his advice from his several other books and insanely fantastic blog posts on starting a business, business development, etc.  He gives simple actual concrete advice on how to take yourself from someone with an idea to a person who has their own business.  I own two of his books and follow his blog and the ideas and suggestions in his book have been invaluable to me as a small businessperson and entrepreneur.  You’re going to read and re-read this book, refer back to it, pour over it’s index, write in the margins, and dogear pages.  It’s that good.
  2. Invest in your own domain name, installation of WordPress, and a new theme.  It’s cheap and seems more professional.  There are hundreds and thousands of free themes.  Once you get people to your website, you want them to stick around.
  3. Tell people about yourself!  Blog, tweet, and other stuff!  Talk about the things about your MakerBot you’re enthusiastic about.  Your enthusiasm will show through.  Don’t just re-post or post a link to someone else’s information.  Blogs are so much more than that.  Put your own spin on it.  They’re additive forms of communication, people keep building on things others have said or done and contribute to the conversation.  You’ve posted a link because you find it interesting – tell us why.
  4. Every week more and more people are searching for information about MakerBots and RepRap.  What is a MakerBot’s print resolution?  How hard is it to put a MakerBot together?  What do I need to build a RepRap?  Answer the questions your potential customers have and they will come to you.
  5. One of Kawaskai’s best bits of advice is, “Let a thousand flowers bloom.”  Basically, try anything, try everything, see what works, what doesn’t, learn and improve.  I’ve done some prototyping for people with my MakerBot and am now running a pseudo-auction for a 3x2x1 Rubik’s Cube.  I didn’t plan on selling this prototype – but it occurred to me that it was a fairly popular thing on Thingiverse, I won’t have need of this as I work on better designs, perhaps someone would like to own it?  Try out some new ideas.  You could focus on printing small-run custom parts – but what if there’s a better use or market for your MakerBot?  Perhaps you might find it more lucrative to print Mendel or Mini-Mendel parts.  Keep your eyes and ears open for new possibilities and new ideas and new markets.
  6. Use your existing customer.  Ask your current customer what they want, how they use things, how you can help them more, what other ideas they have.
  7. I recently posted the results from my MakerBot poll.  There’s a lot of good information in there about what people like about MakerBots and why they’re interested.  This would be a good resource if you wanted to create a business geared towards these people or just write more content you think they would enjoy.

Designing with a MakerBot

After playing with this puzzle for a few days I’m really happy with how it turned out and I think the above improvements will make the next version a little bit better.  This reminds me of Forrest Higgs’ recent commentary on engineering with a RepRap in the design cycle.  It’s so easy to test out a new design that I don’t hesitate to whip something up, print it off, SEE and FEEL how it works and any unintended nuances of that design, and then redesign with these revelations in mind.

Thing idea: Crayon mold

Crayon Mold v0
Crayon Mold v0

Problem: Broken crayons, useless crayon bits, or crayon shavings.  Crayola has their own crayon making system – a cross between an easy-bake-oven and little molds.  However, I don’t think it is quite versatile enough.  Plus, why pay $20 for what could be accomplished easily for $0.20 worth of plastic parts?

Solution: A printed crayon mold!

Description: Crayons melt at about 128 – 147 degrees Fahrenheit, or up to about 66 degrees Celsius.  ABS won’t melt until around 88-125 degrees Celsius, so there’s a wide margin for melting the paraffin wax crayons without distorting the mold.1

I would want at least three different molds – the normal crayon size, the fat crayon size, and then a triangular non-rolling crayon size.  I’m picturing a two part mold for each, with the seam of the two parts running along the crayon lengthwise and a half funnel for pouring.

In addition to the half-mold, I’d also design a snug fitting square block for fitting the assembled mold into.  That way you could stand it up and pour crayon wax into it.

Another potential use for this would be to place the pieces of crayon inside the mold, close it up, then heat.  This would allow you to mend a broken crayon.

Usage: I can think of several different ways to use this mold.  Frankly, I’m not sure which is easiest/most advisable/least advisable.  There are easily several considerations:

  1. Assembly:
    1. The mold could be assembled with crayon inside to be melted and repaired.
    2. Crayon pieces could be melted and then poured into the assembled mold.
    3. Crayon pieces could be placed in the funnel at the top of the mold, the entire system heated and crayon allowed to melt down into the mold.
  2. Melting:
    1. Crayon could be melted in a test tube or similar container in the oven, microwave, hot water bath (such as on the stove) or perhaps even open flame and poured into the mold.
    2. Crayon could be melted while inside the mold by placing the mold in a heat source (oven, microwave, hot water bath).
    3. Crayon could be placed in the funnel and allowed to melt down into the mold with the application of a heat source (oven, microwave, hot water bath, open flame?, or sunlight plus magnifying lens!)
  3. Cooling:
    1. Allowing to naturally cool to ambient room temperature.
    2. Placing in fridge.
    3. Placing in freezer.
    4. Placing in cold water bath.

I’m not sure which method of heating and cooling are optimal.  Though I’d suspect it is preferable to apply the least amount of heat over the shortest period possible.

Variations: It would be interesting to create these molds in different shapes besides cylinders.  You could top each one with a geometric shape, the head (or tail!) of some kind of animal or character, or something else entirely.  You could mold crayons into spheres, blocks, chips, or little figurines.  While not particularly sturdy, you could even mold them into building blocks or components of some larger device.  A clever person could use some left over nichrome wire to build a heated metallic funnel.

  1. That said, my extruder isn’t pumping out plastic until it hits 200 degrees Celsius at least. [↩]

How do upgrade your extruder firmware

Just as an FYI for anyone who’s having trouble upgrading your MakerBot Cupcake CNC plastruder firmware, the instructions built into ReplicatorG don’t tell you to unplug the TTL cable from the motherboard and plug it into the extruder board.

So, save yourself 5 minutes of frustration and googling for the answer…  and just plug the TTL cable into the extruder board.  :)