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 81  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. []

Christmas robot shopping

I went to the hardware store after work today to pick up the items on my shopping list.  Walking to their register I fell victim to their bargain basement aisle.  In the process I dropped the $3 superglue I had found and picked up four times as much for $2.  Sure, its a no-name house brand…  but as long as its reasonably sticky there shouldn’t be any problems.

I also picked up some 3-in-1 oil for the various rods.  I installed the Z-axis rods without cleaning them properly (too enthusiastic to get building).  I also bought a large flexible magnet in sheet form (the kind used for fridge magnets – only in an 8.5″ x 11″ size), work gloves, and another utility knife.

Adding the circuit boards

Once I had the opto-endstops all soldered up, I really wanted to keep going.  I made the Y-endstop cables, bolted the opto-endstops on, and bolted the motherboard and stepper motor boards to the MakerBot.  Clipped in the cables and it looks like a robot after all!  I’m going to need to organize those cables, but that will have to wait until all the other parts are in place.

An interesting side note – as I was moving the various axes someone noticed that little lights started flashing on the stepper motor boards!  Cool!  I presume moving the platform caused the motors to act like generators and pushing power to the boards, lighting up the LED’s.

Once the opto-endstops were done, I couldn’t resist bolting them on.  Once I started doing that, I wanted to make the Y-endstop cables, then the ribbon cables, and wire it all up.

If nothing else, it looks like a robot now!

Things I learned while soldering opto-endstops

The opto-endstops marked the very first parts I had to solder for this MakerBot.  Not having soldering anything more complicated than two wires together, this was an adventure and learning experience.  Here’s what I learned today:

  • The 3-pin connectors used for two of the opto-endstops (on the Y-axis stage) are in the Generation 3 MakerBot Electronics Kit (Mostly Assembled) with some of the other connector bits.  I was a little confused about this for a while.
  • It helps to lay out all the little bits in an organized fashion beforehand.
  • Keep a long thin rigid stick handy for bending delicate leads into the circuit board holes.
  • Although I read the RepRap electronics fabrication guide and found it helpful, I still felt a little lost.  I found the most effective way to solder the parts in was to:
    • Get the soldering iron good and hot
    • Put the leads through the holes
    • Bend the leads a little so that they stayed in place
    • Flipped the board over so the leads were sticking up
    • Touched the solder to where I wanted the joint
    • Gently stroked the solder with the soldering iron tip towards the joint
    • This process seemed to create a pretty good joint
  • You’re going to burn a finger at some point, accept it.1
  • This almost goes without saying, but go slowly.
  • Check and double check the orientation and placements.
  • I found it helpful to take a large sheet of aluminum foil and shape it into a tray.  This helped contain the parts I was working on and was a good way to catch the flying leads that I clipped off.
  1. I burned two. []

Shopping list

I’ll need a few extra things to get going:

  • Superglue for the idler pulley and bearing
  • 3-in-1 oil for the rods (I need to clean the threaded rods).  It will be a little bit of a pain to pull them out of the MakerBot, but I want to make sure I’ve done everything I can to make the robot work properly.
  • Popsicle sticks
  • Daft Punk

Things I learned while assembling my MakerBot

I’ve assembled quite a lot of my MakerBot today.  This entailed assembling and putting together the X axis stage, Y axis stage, pulleys, putting gears on stepper motors, mounting gears, putting in the slider rods, Z axis threaded rods, bolting on the motors, and assembling the two “dinos.”

  • If you’ve got a Batch 9 MakerBot, definitely install the Z-axis after assembling the body of the MakerBot.
  • Put off adding the Z-stage/extruder-stage for as long as you can.  It will just be in the way.
  • Keep that sandpaper handy – you may need to sand down some tabs or widen slots or holes to make things fit, especially if you painted your MakerBot.
  • If the smooth slider rods are just a smidge too short, they will slide back and forth causing a little extra noise as your MakerBot operates.  I haven’t gotten mine running yet, but I have read this is the case.  I noticed that one of the slider rods for the X axis on my Batch 9 MakerBot was about 1mm too short.  When I put the caps on, I noticed that it still had some wiggle room.  I took a scrap of paper towel, folded it up so that it would push up against the end of the rod, and clamped it down.  There’s no wiggle room now, so hopefully that’s it.
  • Make sure the top bearing is just under the top edge of the top panel.  This is in the directions, but it’s really important to make sure everything spins freely.
  • Putting gears on the stepper motors is tough!  Even when you back the tightening screws on the gears out as much as you can, the fit is incredibly snug.  I eventually sanded the inside of the gear slightly, put the motor on cardboard, and then pushing downwards slowly and forcefully.
  • When you’re installing the geared belts, get them as level as you can manage.
    • For the top stage this will involve adding/subtracting washers/nuts from the printed pulleys as well as adjusting the gear’s placement on the stepper motor.
    • For the X and Y stages, the height would essentially be dictated by the height of the belt on the clamps.  The height of the belt on the clamp is essentially set, so the pulleys and gear on the stepper need to be matched to that.
  • When assembling the carriages with the plastic sliders, the instructions suggest you may need to sand the circular hole they fit into.  Just make a point of sanding them, if they’re tight they could affect the looseness of the stage on the rods.
  • Inspect your Y-stage pulley (this is the smallest printed pulley) to make sure the top is level and there are no protuberances.  Even a little bit of a nub will prevent it from rotating properly.
  • The easiest way to remove the itty-bitty sticky-paper protective acrylic cover is to use a razor blade or exacto-knife to pop them off.  You probably don’t need to, but it’s an aesthetic thing.

Additional parts and tools required for Deluxe kit

Although I have the CupCake CNC Deluxe kit, there are still some parts and tools required.  If you’re getting ready to build your own MakerBot, here’s what else you’d need to build everything in one go:

  • Primer, paint, masks, cardboard, duct tape, and pen – if you’re painting.  While the other stuff is obvious, I found the pen handy for labeling the cardboard next to the parts that had to be painted differently from other nearby parts.
  • Sandpaper for sanding down punch-out-nubs and leveling off plastic parts so they’ll fit.  Based upon my enormous background in robot building, I’d recommend a super fine sandpaper for the nubby bits wooden bits and a medium course sandpaper for sanding down plastic parts.  You won’t need much, so there’s no need to buy a whole pack.  You may also need the course sandpaper for widening the openings for the plastic sliders on the X and Y axis platforms and/or to make some of the tabs fit better if you’ve painted.
  • 3-in-1 oil is needed for the various slides/rods and as part of the cleaning of the Z-axis threaded rods.
  • Paper towels are just a good thing to have around.  Damp they’ll help you wipe down a little bit of the fine ash left by the lasercutter.
  • Electrical tape and an electric drill along with paper towels and 3-in-1 oil are used for the recommended method for cleaning the threaded rods.
  • Zip ties for organizing cables.  But, seriously, you should just have these necessities anyhow.  They’re good for everything.  If you’re going out for zip ties, I’d highly recommend picking up (1) an assortment of colors/sizes in a large pack (2) a pack of uniformly colored small zip ties and (3) a pack of uniformly colored large zip ties.
  • Hot glue gun, hot glue sticks are needed for affixing the plastic sliders on the X and Y axis stages.  Like zip ties, if you have these around you’re going to find they’re a good solution for a lot of problems.  It’s like Windex that way.
  • Popsicle sticks and black paint are needed for completing and installing the opto-endstops.
  • An exacto-knife or razor blade will come in very handy for removing the very very tiny bits of protective cover on the acrylic lasercut parts.
  • Super glue is needed for affixing a pulley to the idler pulley and for laminating some parts of the two “dinos.”