Introduction: Erection - a K'nex Ball Machine

About: I love building. A mechanical engineering student, most of my instructables involve modeling projects, K'nex ball machines, and Lego creations. I am also a model railroader, and I enjoy science (astronomy is m…

Hello everyone! I'm proud to present my fifth ball machine on this site, a construction-themed machine named Erection. It is, in essence, my old K'nex Tower Crane modified into a ball machine. Erection has four lifts, five paths, and at least five new elements, in addition to some modified older elements. Standing six feet tall at its highest point (that's a little under two meters for all you metric users), and three feet wide, this ball machine towers over my previous ball contraptions. The most unique characteristic of this machine is the crane boom, which rotates a full 360o and acts as a massive path separator.
     This is my first large ball machine, as well as the first that I've been able to motorize. I hope you enjoy the might of the heavy-lifting ball-crane...Erection!

*Music in video was composed by Frederic Chopin and played by Vladimir Ashkenazy:
     -Polonaise for piano No.  3 in A major ('Les favorites 3' - 'Military') Op. 40-1, B. 120
     -Etude for piano No. 23 in A minor ('Winter Wind') Op. 25-11, B. 83

Step 1: The Lift Network

     Choosing my lifts was a key step in this machine. In order to retain the "tower crane" impression, all the lifts had to fit inside a tall shaft, which was still rather thin for holding four lifts even after thickening the old tower frame. Of necessity, then, all my lifts were of the more vertical type. They are, from bottom to top, as follows:
     -Shadowman39's Shifting Arm Lift
     -A wheel lift I designed. I believe I saw a similar one once, in The Prize by nschmal1 on YouTube, but I "re-invented the wheel" (no pun intended) in any case because I didn't look at the video when designing this machine.
     -Shadowman39's Inverted Double Helix Lift (runs on same motor as the wheel lift)
     -Kariah's Mill Lift (I added a new modification to this lift by adding a "jog", or sidestep, as it went up. The lift needed to be centered to go straight up into the center of the crane arm housing if I was to have free rotation. It started to the side, though, and so...)

     All four lifts together move the ball about eleven red rods high.

Step 2: Path Separators

     For Erection, it is difficult to fit all the path separators into a single step, because they are placed at different points in the machine, and some paths are not selected as often as others. (Specifically, Path 1 is used four times as often as the other paths.) Several elements are used jointly before some paths truly split. In addition, each of the four path separators on Erection is different. One is totally new, and two are modified. The four are as follows:
     -Rotating Crane Arm Path Separator. This is the most impressive feature of Erection. The top of my tower crane had to receive a new mounting in order for the lifts to bring the balls up to the Crane level without getting in the way. The entire crane arm can be lifted right off of the ball machine; the arm rotates on K'nex wheels around a ring of tubing which circles the top of the tower. As the crane rotates, it alternately allows balls down the front and back spans, making it a path separator. The front span leads down a chain drop to Path 1. The back span has a short length of pathing which empties into a ball arm, depositing the balls on a ramp attached to the tower's side. This ramp leads to the rest of the paths.
     -Sathothy's Ball Arm Separator. I used this two-ball arm as a path separator; a nice advantage of this separator is that while one ball drops down a bit, the other ball actually gains some height. I had to modify this element to fit my tower by reducing its length. The separator's top path goes to paths 2 and 3, while the lower path leads to paths 4 and 5.
     -Horizontal Path Separator. My own version of this older type, I used a square panel as the floor and rods slid through the holes to guide the ball through the path separator to paths 2 and 3.
     -Vertical Rocker. Oldest design in the book. Splits to paths 4 and 5.

Step 3: Path 1

     This is the most frequently used path, and arguably the most impressive. This is mainly because it begins with the "chain drop", creating the appearance of the crane actually raising or lowering a load. After falling off the chain drop into a basket I designed, the ball falls through a hole onto sandroknexmaster's spiral stairs. The stairs give way to a short section of flexible path I (as far as I know) invented, and used again in this ball machine. Leaving the flexible path, the ball rolls onto martb95's zig-zag stairs. At the bottom of these, the ball rolls on two red rods through my "Secret Panel" element. In essence, a vertical white floor section is placed into the tower side, and the ball bursts through the seemingly seamless panel unexpectedly. It would probably be more exciting as an element when used in a larger wall section, where it would blend into the background more.
     After rolling through the Secret Panel, the ball goes onto 8chillpill's version of the Fall-through. At the bottom of this, the ball returns to the lifts.

Step 4: Path 2

     All the paths besides Path 1 use the back of the crane, the tower ramp, and the ball arm path separator. Path 2 begins at the higher exit of this path separator, following a section of nschmal1's panel stairs to my new element, the Flexi-rod Funnel. Really more of a path used as an element, I found the flex-rod ratio for making perfect half turns on the normal high-velocity pathing. This spiral ends at the horizontal path separator. The path then leads onto a series of three flippers, dropping the ball onto another new element: the Chain Ramps. The ball moves back and forth over the chain pathing while dropping through a hole in each end. The ball leaves these to land on martb95's half-pipe (also known as Shadowman39's inverted Cataclysm tunnel), and onto the return track.

Step 5: Path 3

     Path 3 takes the other side of the horizontal path separator, falling directly through my version of Vertical Clickers, which I simplified to work well with few pieces. The ball arcs out of this element while retaining its speed, soaring around a sharp curve in the towers inner structure. The ball then descends a flight of Knextreme's stairs, down a piece of makeshift pathing, rides two ball arms, and lands on a piece of high-velocity pathing. This short section empties out into a longer curve of this path, ending in 8chillpill's Fall-through. On this curve the ball passes under a little pendulum, which apparently hangs from a load that one of my Knexmen is trying desperately to save from falling!

Step 6: Path 4

     Path 4 begins at the lower exit of the Ball Arm Separator. The ball follows a ramp system a brief way to the Vertical Path Separator. Path 4 consists of a Panel Spiral I designed, based loosely on Knextreme's Panel Stairs. This twisty slope feeds into Knextreme's Vertical Panel Zig-Zag (although mine is minus the Zig-Zag, since mine all face the same direction and are one big slope). The ball swings around a curve at the bottom of this and slams into a rubber-band which I placed because the balls would previously get stuck from bouncing back into the panel slope. The path at this point feeds into Path 3.

Step 7: Path 5

     Path 5 is the last of Erection. The path starts on the other side of the Vertical Path Separator, and drops onto a new pathing I designed: K'nex Cap Pathing. I never have been able to find a good practical use for all those K'nexmen caps I have extra. Stick two on either end of a white rod and connect the rods with orange connectors, and Voila! A simple and thin, yet cool looking path type. I even did a corner with it...
     The ball next drops off of that path down a Corkscrew Canyon Tube (any freefall design that fits in a blue rod tower should work if you don't have one). At the bottom, a tubing path carries the ball at high speed around a double box loop like the one found in the ball machine Automation. The ball then speeds up a ramp at the end, which empties into my Green Flex Path, curves around, and falls through Knextreme's Tire Stairs. These flow into the return track.

Step 8: In Conclusion...

     Well, there you have it...Erection! Thank you for looking; now it's time for me to go out and make an even better ball machine! Maybe you'll even build your own. Until next time...

Toy Rods and Connectors Contest

Runner Up in the
Toy Rods and Connectors Contest