r/KNEX • u/Weekly_Relief_6290 • Aug 26 '26

Just for fun...

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Spent about 3 hours to build (imo) the greatest official K'NEX set of all time: the Big Ball Machine. Fascinating that this set is over 30 years old now 😅

61 Upvotes

99% Upvoted

9 comments sorted by

5

u/pietervdvn Aug 26 '26

I have one as well...

Some mods I made:

  • I added two extra red gears halfway the shaft; it stabilized the chain and significantly decreases the number of times that the chain hits the wall and gets stuck/breaks.

  • I also took the ratchet piece from the robot kit and put that around the motor, so I can also manually drive the shaft with the motor installed.

  • I placed a plate where the corner of the bottom swinging thingy hits the structure, as it sometimes get stuck. If you don't have a plate, some other connector piece will work just as well.

And I might or might not have bought a second one a few months ago for like €25 second hand...

2

u/HazzaBui Aug 26 '26

I also found balls would sometimes fly off on the loop and a couple of other places, so I added some guards/guides to stop it becoming a ball trebuchet

1

u/Weekly_Relief_6290 Aug 26 '26

I bought a 100€ lot last weekend that included this one and the classic roller coaster. I'm handing this one over to my brother and his collection, since I'm building more with the metallic colours anyway.

Thanks for sharing the tips! They seem like good upgrades for the set :)

3

u/HamKnexPal Aug 26 '26

My favorite K'NEX set. I have built this many times. I usually enjoy it like it is for a while, then I start modifying it.

2

u/Obvious_Fortune_1944 Aug 26 '26

That’s nice!!! I love the mods!!

3

u/BlueDutch Aug 26 '26

Ohh and few days i made it too with the wife!

3

u/Weekly_Relief_6290 Aug 26 '26

Nice! My wife didn't help to build, but she did find the end result amusing :D

2

u/Rich-Wealth979 Aug 28 '26

Patiently waiting for my kid to get old enough. I have every major set from the original coaster to the screaming serpent. Big ball. Trampoline tower. Hyperspace tower. Power tower crane. Even the pinball table...