LEGO Sky Parade for MIT Mini Maker Faire

LEGO Sky Parade for MIT Mini Maker Faire

by kaschm lightnin scientiffic tmickel | updated February 09, 2015

Develop a drop in activity using LEGO for MIT Mini Maker Faire. Anyone can come to our table, build their own cable-car gondola and mini-fig, and send them on a journey through the skies.



We want to create a drop-in Maker experience for participants at MIT Maker Faire. There are several goals:

Evoke a Narrative

We want the Maker to feel a part of their creation, and to be able to imagine themselves riding it off into the distance. It should be able to go someplace that they themselves can't go - either into a tunnel, or up in the air.

Low Floor

The workshop should be easy for Maker Faire participants ages 5 and up to dive in and create something cool.  

Wide Walls

Even though it's simple to get started, it should be possible to make a variety of creative cable cars.

Participants will begin by making their own Mini-Fig, and then design their own LEGO cable-car gondola. Once they're ready, they'll put them on our string / wire, and watch them sail into the (tent ceiling? Sky?), past a video camera that they can tweet images from.

September 15, 2014 at 3:09 PM
Created by lightnin
Comments (2)
could you have the gondola going downhill instead of uphill? might help a bit with the traction issue.
over 2 years ago
This is an AWESOME proof of concept. Do you think you might be able to get it going up with with either string with more friction and/or a wheel with more friction, or perhaps increasing the tension of the string?
about 2 years ago

We want the gondolas to glide by a webcam that's high up in the air, perhaps with a nice view in the background. Creators will be able to watch their creation go by via webcam, and press a big (maKey maKey?) to snap a picture that will be tweeted out. They can then retweet the picture / do with it what they will.

Today Amos, Kasia, and Tim scouted out the space to think about where we might string the lines. Attached are a few photos. We're thinking we might hang the long line from a big red steel sculpture, and place the camera somewhere on it.


The webcam / tweet thing has some implementation details to be worked out. Some explorations appear in next steps.

September 17, 2014 at 9:37 AM
Created by lightnin
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One approach to tweeting the photos is to use a computer with a usb webcam on a long USB extension cable. The camera is placed up high, with the wire in the background. Its view is displayed on a large (20 x 30) screen driven by the laptop. There's a big red button, probably made with maKey maKey, that participants can hit to take a photo and tweet it out. 

Potential problems:

* USB cables can only go so far, and the layout of the wire is still to be determined. It migth be too far.

*Haven't found a free photobooth clone that will automatically tweet / allow for no delay from button press / take keyboard input for photo. Cheese looked promising, but doesn't tweet. Be nice if something could display the tweet (and twitter account it tweeted from) after tweeting it.

September 17, 2014 at 9:43 AM
Created by lightnin
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Here's a vine of Eric R and I exploring the design space around this idea.


Extra possibilities that emerged:

* Kinetic sculpture workshop. Really open ended and cool. But harder to describe the activity to participants in one sentence. May also be a little intimidating.

* Modifying the "course" in interesting ways, a la the carousel / gra the gold ring approach, or allowing participants to modify the course. This is cool, but may skew towards a competitive feel that I want to avoid.

* Eric also mentioned that folks at Exploratorium often create a small boundary - even if it's a knee high fence - around the work table for an activity. This means that people who are in are "in", and have expressed some level of comittment by crossing this small barrier to entry. They are therefore more likely to tinker to some level of completion. This is a great point, and affects the proposed design of our space.

After reviewing these possibilities with collaborators Kasia and Champika, we settled on sticking to the previous plan: Invite users to modify / hack / create a gondola and set it on a long wire. We did decide to have more test wires in the working space to better support iterative design, and that was inspired from this exploration.

September 17, 2014 at 9:56 AM
Created by lightnin
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I'm excited to be helping out with this project!  Today, lightnin and I ordered parts from Digikey.  We originally tried to order from Sparkfun, but not everything would be shipped at once, so we went with the electronics beast that is Digikey (even though their UI is much less friendly...)

We purchased:

A pro-tip from our colleague dmellis – ordering batteries from Digikey is much, much cheaper than buying them at your local drugstore!

I'll be working more on this next week, so stay tuned for updates then...

September 17, 2014 at 4:30 PM
Created by scientiffic
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Tim, LLK's new MEng student, made a test script using Tweepy that should tweet any photo added to a target folder by photobooth software (in Linux, that'll be the elegantly simple Cheese https://wiki.gnome.org/Apps/Cheese). So we now have a viable path for the Webcam / USB tweeting of images model.

The challenge depends on layout -- USB doesn't go very far (15 feet max according to the spec), so we might have to think of a way to get the display / button farther away from the camera than that.  

September 18, 2014 at 3:45 PM
Created by lightnin
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Here is where I create a design that ends up being unusable because the car requires an open design (to easily add it to the string, etc.)

The original idea behind it was to retain the string using some additional wheels (skeched).  But I'm still trying to incorporate this idea using an open-car design.

You can see from the video above, though, that there isn't enough traction between the plastic hub and the string for the car to go uphill.

September 22, 2014 at 4:55 PM
Created by scientiffic
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Lightnin and I went to a hardware store to check out what type of materials we could use to increase traction between the car and the string. We tried out some rubber o-rings, which I think could actually work decently well if we had the right sized hubs for them. We purchased some nylon string, and my plan going forward is to seek out some small rubber bands / o-rings and potentially 3d print some custom hubs to use instead of the stock LEGO parts. This would help ensure that we can fit whichever tread we end up using and that there's enough material around the tread to retain the string. More to come in the next few days!

September 23, 2014 at 12:52 AM
Created by scientiffic
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I made a stop at Pill's Hardware on my way to lab and found a bunch of rubber stoppers / rings / tubes in their toilet repair aisle.  Thinking they were about what we wanted (in terms of size and having a flat edge), I purchased 4 for testing.  I'm confident that we'll be able to purchase more too because the had two cups full of them.  They were $0.25 each.

September 23, 2014 at 11:48 AM
Created by scientiffic
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Inspired by his trip to the Tuft's LEGO Lab, Amos suggested using two rubber wheels side-by-side to carry the car up the string.  The nylon string we purchased was too wide for this design, as the wheels kept slipping off the wheel, so I added a small spacer.  This worked pretty well, but didn't work well when the car tried to go uphill.  I'm guessing this is because there isn't enough traction between the spacer and the string.

September 23, 2014 at 11:53 AM
Created by scientiffic
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In this step, I tried using one of the LEGO wheels with its corresponding tread.  The wheel is designed...well, to be a wheel, so the tread itself has little surface area.  While it worked going uphill, it didn't work particularly well because of the limited surface between the string and the tread.

Also, because of the diameter of the wheel, this car went really fast–a little too fast!

September 23, 2014 at 12:03 PM
Created by scientiffic
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In this final test, I wedged the toilet rubber ring in between two retaining gears.  This worked pretty well, but it worked even better when the ring was hot glued to the gears to ensure it didn't slip on the axle.  

We were able to get it to go up a 20 degree incline!

September 23, 2014 at 12:10 PM
Created by lightnin and scientiffic
Comments (1)
Oh wow!
Great to see you guys were able to work out the whole traction problem! It's looking awesome!
about 2 years ago

I spent some time today working on a design for the template gondola - the base gondolas we'll give out to participants who join the workshop. I realized as I went along that I had some basic design criteria:

  • Should be pretty bulletproof. For example, the battery mount should use technic pegs rather than clutch power, as it's harder for them to work themselves out. These are going to get dropped, more than a few times.
  • I wanted there to be a way to move the battery pack fore and aft so it can be used to trim the balance of the gondola. It shouldn't be necessary to worry about lateral balance.
  • The template design should be utilitarian and a little boring. It should invite the user to add their ideas, not suggest its own. 

That last point caused me a little pain - as one idea I realized I'd been attached to was to make the gondolas more "boat" like, to evoke a sense of voyage. In speaking with the colleague Carl about that tension, I ended up feeling that the need to be basic / boring outweighed the need to evoke a journey. Hence the design is square, and doesn't use the nice LEGO wings I'd been toying with. 

September 23, 2014 at 2:55 PM
Created by lightnin
Comments (2)
I wouldn't necessarily think of the basic template as "boring" - maybe it feels that way because all the pieces in the image above are grey. ( : if it's colorful and we have fun examples, it'll be evocative without being over constrained, I think.
about 2 years ago
I think having the "boring template" is fine!
As long as you give people some awesome examples they're sure to produce some awesome things! (that way you can still make your winged boat and have the template!)
about 2 years ago

We noticed that the axle tends to get detached from the motor, so I built a holder to try to prevent the axle from moving laterally.  I started off using axles but switched to a more robust design using some of the LEGO struts.  I'm still learning about the LEGO pieces that let you build at 90 degrees – I think the design right now might be a little overkill, so perhaps the next step is to simplify the design.  But it works!

September 24, 2014 at 12:05 PM
Created by scientiffic
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Aside from providing templates & materials, we also want to create a few "other" examples to spark peoples' creativity about how they can iterate on the concept. 

In the video, both examples use the same battery pack / motor setup.

One example uses two wheels and one gear-driven wheel that make contact with the string to provide additional stability. The final attached spinning "windmill" shows some possibilities with the design. 

The second example sports an "all-wheel drive" setup with dual gears driving the two wheels. 


September 25, 2014 at 11:37 AM
Created by kaschm
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After prototyping the drive system and car design, we decided to start creating all 20 templates to use for the Mini Maker Faire!

This involved constructing the LEGO base, soldering our LEGO connectors with our 3xAAA battery packs, and hot gluing our store-bought rubber disks with LEGO gears.  

It took four of us several hours to get this complete!  

September 25, 2014 at 4:33 PM
Created by scientiffic
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After testing our templates, we still had a few outstanding issues:

  1. The axle loosened from the motor over time.  To resolve this issue, we prototyped a few different options, including the "fence" design described in Securitng the Drive System.  Lightnin ended up finding that stuffing plastic (from a plastic bag) in between the axle and the motor would help secure the axle, and this seemed to resolve the problem!
  2. We also found that the LEGO piece holding the motor to the cart was not as secure as it could be.  This led us to slightly redesign its connection – thanks to Tim for working on this!

September 25, 2014 at 6:24 PM
Created by scientiffic
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The images shown above are two examples built to provide inspiration (and invite people to create their own drive systems too!)

The first is a design created by Carl, and the second was created by kaschm!

September 25, 2014 at 6:26 PM
Created by scientiffic
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Carl designed a beautiful poster for the "Sky Parade," and after savaging our lab area for materials, we settled on using a poster tube and cardboard backing to support the poster.  We plan to string a piece of string through the poster tube to hang it in our space!

October 3, 2014 at 6:41 PM
Created by scientiffic
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I showed up at the Maker Faire at around noon, after lightnin, kaschm, and champika had set up the course.  Luckily, we were able to do a table swap to get a corner of the tent.

A ton of children came and built all types of floats for the LEGO parade, many of which you can see using the hashtag #MITSkyParade on twitter.

​Interestingly, Twitter ended up capping the number of photos that we could post, so a second Twitter account needed to be created!

Perhaps the most challenging part of the activity was resetting templates after people finished their designs.  While we made about 18 starter floats for the start of the day, we basically had to remake them at least 2x over because of the amount of turnaround we got.  Eventually, lightnin began telling the participants to build off of the template without taking it apart, which made things a little bit easier.

I wasn't around for the cleanup, which was probably the most difficult part – imagine what the sorting will be like!

Overall, it was incredibly rewarding to see so many kids building their own original creations and testing them out.  Thanks to lightnin for getting me involved in this effort! ( :

October 5, 2014 at 1:30 AM
Created by scientiffic
Comments (2)
It looks like the event was a blast!
Haha yeah there was the same problem of quality when I helped out with a LEGO master build one time. My friend and I basically spend hours sitting in a side room taking apart and organizing LEGOs aha.
about 2 years ago
Yeah we've been talking about how LEGO needs to build a cheap LEGO sorter. Would be huge!
about 2 years ago

Here's the fancy video that Eric and I made documenting SkyParade! It was fun. :)

October 15, 2014 at 9:31 PM
Created by lightnin and scientiffic
Comments (1)
Haha I LOVE how you guys made a fancy video about the whole event, it looks very well put together, Well done!
about 2 years ago

Rough notes from the post event meeting, for consideration in future!

Skyparade Debrief

Green Light:
- Lots of people / it worked / interesting
- Most friendly of activities for people that we saw at Maker Faire
- Awesome that twitter photo thing worked.
- Good gender balance, although more dads than moms. + we attract stylish grandmas. Champ said we had best gender representation.
- Accessible for younger kids.
- Colored string a big plus, made it easy to navigate.
- Very few templates broke off the line, especially when they hit people's heads.
- Maybe shoot animated gifs and share to twitter on each button press?
- A lot of long time participation! Some for hours, some for dozens of minutes.
- Very family centered. 

Yellow Light:
- People used photo booth button too much. Needed more instruction.
- Need giant tweet button, with sound. Maybe delay?
- Hard to see the photo that was just taken. 
- Bigger sign showing twitter account that the tweeted photo is going to.
- Need more signage to direct users / resources.
- Maybe need a build area "from scratch" with motors and stuff / etc.  Tell them if you want to make your own from Scratch, use that (and don't destroy built template gondolas)
- Some strings kids couldn't reach. Maybe that's ok ... not sure. 
- Maybe the photobooth needs an attendant / explainer? They also get people to take 
- Need better pics of kids with their creations.
- Is there a way to encourage collaborative building? It was kind of a feeding frenzy. 
- Might be worth having small tables, so people build in small pairs / groups near eachother. Better for shy kids / less frenetic feeling.
- Maybe a border around the build area? Make sure that not too many people are in build area at once.

Red Light:
- People didn't know what the parts were / how to get it / buy it.
- People wanted to know how long the batteries lasted.
- Not clear how to get people into position on the table. Think about people flow from join to fly to leave.
- Twitter shut us down.
- Didn't get photo permissions. 
- Not enough templates! Had to rebuild too much.
- Duct taped laptop to top of monitor: youch! 
- Need sound feedback from the button: Sound, clearly showing that people took the picture.
- Damn camera cut out a lot of the frame! Many pics w/ out people and creation.

October 15, 2014 at 9:35 PM
Created by lightnin
Comments (9)
Daww Glad to see so many positives!

Do you think you guys will run this event again?
about 2 years ago
I hope so! It's not directly in line with any of our projects, so it will be a matter of waiting for the right opportunity. But it's a good fit for Maker Faires.
about 2 years ago
Hi - what an awesome project!! We would like to run a similar project at an upcoming community day. Do you have specific plans for the gondola design that worked well and you ended up using?
almost 2 years ago
Thanks! (: For the drive system, we used two LEGO gears sandwiching a pretty thick rubber gasket (as described in Test 3: Toilet Ring + Retaining Gears).

The final gondola design was pretty similar to what is shown in "Bullet-proof template," but we did tweak it even further after this design. In the end, we used regular LEGO bricks with holes (instead of the Technic linkages) to make it more sturdy. You can kind of see an image of it here: ../../buildinprogress.s3.amazonaws.com/image/image_path/12181/image.jpg?v=1423148069636

If you run a similar project, I'd love to see how it turns out!
almost 2 years ago
Thanks! I looked over the pictures again and I think I understand the design.
almost 2 years ago
How is the battery box connected to the gondola base? and did you just cut LEGO power functions extension wires in half to create the extension onto the battery box?
almost 2 years ago
We built a retainer for the battery box underneath the base of each gondola (which was built using axle pieces that ran across the front and back of the battery box). I don't think we actually got any images of this, sorry!

Yes, we cut the LEGO power cable and soldered it directly to the battery box. There are some pictures of it in this step: http://buildinprogress.media.mit.edu/projects/1919/steps?step=7051

lightnin might be able to recall more specifically which cables were connected - I do remember it was important to ensure the direction was the same for all the connectors to ensure that the gondolas all moved forward instead of backwards.
almost 2 years ago
Did you use the LEGO L-motor or the M-motor?
almost 2 years ago
Hiya! They / were M Motors. :) As it happens, I've moved to Denmark to work for LEGO, and spent part of last weekend figuring out how to make a SkyParade gondola using only parts from the LEGO Education simple and powered machines kit. http://education.lego.com/en-us/lego-education-product-database/machines-and-mechanisms/9686-simple-and-powered-machines-set
almost 2 years ago

So the previous design required a non-LEGO battery pack, some soldering, and a big rubber washer. Turns out you can make a nice gondola using all stock parts from the LEGO Education Simple and Powered machines kit. Two small crown gears sandwiched together make a fine drive wheel when using paracord for the string.  Here are a few examples. Note that the sailboat model uses a LEGO rechargeable battery pack that doesn't come with Simple and Powered machines, but which is really great for this activity since it's much lighter than the normal (6 AA) LEGO battery pack.



February 7, 2015 at 2:43 AM
Created by lightnin
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