Stringatron string accelerator

[jam8280]

Behold, the Stringatron -- the world's first high-energy LEGO string accelerator for both loops and open-ended strands...

The Stringatron is all LEGO except for the string (1.5 mm twine and 3.0 mm paracord). String transport is done with a pair of pinch rollers. The lower roller is driven by a single RC Race Buggy motor (5292) powered by an old 9V train transformer. A twine loop 1.5 m in circumference running at full power exits the rollers at ~6.6 m/s (24 kph, or 0.000002% the speed of light). The string guides were the tricky part.

v  The linear actuator dials in launch angles between ~0° and ~85°. (The range can easily be shifted up or down as needed by moving the actuator attachments.)

More photos and detailed write-up on MOCpages at http://www.moc-pages.com/moc.php/441459.

[Davidz90]

Awesome! Such a creative idea :D Good thing the string is quite thick - at 6m/s, a thin one might be a serious hazard to the fingers 

[jam8280]

Just now, Davidz90 said:

Awesome! Such a creative idea :D Good thing the string is quite thick - at 6m/s, a thin one might be a serious hazard to the fingers 

Thanks! Still have all 10 fingers so far.

[ColletArrow]

An interesting and unusual idea, and a silly name to match!

What would happen if you ran it off the edge of the table, such that the return limb could hang in mid-air too? Would it be able to function, or just the weight of the return limb pull down on the outbound one? You might get some more interesting shapes out of it.

[jam8280]

1 hour ago, ColletArrow said:

An interesting and unusual idea, and a silly name to match!

What would happen if you ran it off the edge of the table, such that the return limb could hang in mid-air too? Would it be able to function, or just the weight of the return limb pull down on the outbound one? You might get some more interesting shapes out of it.

Thanks! Yes, silly names are half the fun.

At 5:11 in the 2nd video down, a breeze blows the loop over the edge of the table at 90° from the direction the Stringatron is pointed, and it just keeps on going. The outbound and return limbs are both at the same level at that point but manage not to get tangled. I've seen the same thing when the Stringatron is pointed directly over the edge of a table.

[MattL600]

Nice! I know I would have gotten frustrated as I hate working with string and lego ;)

[teflon]

Congrats. This is very unique idea and also seems like a lot of fun. I also like the rope figures you create, it seems like a small art project on its own. And it's first time I noticed jazz for music background of Lego videos.

If you would upscale the machine, you could get the machine for toilet papering things. Can you imagine toilet paper minigun:-)

[BusterHaus]

This is great!  It's relaxing to watch and the tests with the upper and lower limbs were very interesting.  The tires are looking a bit worn in the screen capture of the second video.

[Aventador2004]

Awesome!

[Boulderer]

Brilliant creation!  I'm seriously trying to work out how to get one of these built this evening 

[jam8280]

15 hours ago, MattL600 said:

Nice! I know I would have gotten frustrated as I hate working with string and lego ;)

String is evil, no doubt about it! No one's more surprised than I am at how rarely the Stringatron jams. When it does, it's nearly always because I was messing with the outbound limb of the loop -- never with the return limb or turnaround. And no jams of open-ended strands at all with the current strand guide. 

14 hours ago, teflon said:

Congrats. This is very unique idea and also seems like a lot of fun. I also like the rope figures you create, it seems like a small art project on its own. And it's first time I noticed jazz for music background of Lego videos.

If you would upscale the machine, you could get the machine for toilet papering things. Can you imagine toilet paper minigun:-)

Very kind, Teflon! Not a lot of jazz behind YouTube videos, period.

A LEGO toilet paper minigun, eh? I love it! You know, a single-shot toilet-papering machine is not entirely outside the realm of possibility with LEGO. The wheels are turning...

14 hours ago, BusterHaus said:

This is great!  It's relaxing to watch and the tests with the upper and lower limbs were very interesting.  The tires are looking a bit worn in the screen capture of the second video.

Thanks! Now that you mention it, the tires are showing a little wear. But I guess that shouldn't be too surprising, as they'd already put in 8-10 high-speed kilometers by then.

14 hours ago, Aventador2004 said:

Awesome!

Thanks!

[jam8280]

13 hours ago, Boulderer said:

Brilliant creation!  I'm seriously trying to work out how to get one of these built this evening 

Very kind! Lots of photos and written info on the design at http://www.moc-pages.com/moc.php/441459 . Coming up with reliable string guides was the hard part.