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Yet another ropewalk. KNEX anyone?

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Some time ago I read up on making a ropewalk. The important part is that the three or four threads making up the rope have to be spun independently. It required three sets of gears.

Along comes my grandson and his KNEX ‘tool box’. This toy is great for youngsters who have some interest in building things. It is a modern version of the ‘erecto set’ I used to have. I scratched my head and decided to use the various gears and shafts to build my ropewalk.  

The pictures below probably explain the details better than I can in words.post-246-0-45023400-1364842485.jpg



post-246-0-03496600-1364842449.jpg  post-246-0-68799500-1364842469.jpg
The end to the left is the sled which has to be able to slide in the track. A string with the grey pulley has some weights hanging down to keep an even tension. Notice a little crank at one end. That was quickly replaced with an electric hand drill. Likewise another hand drill spun the other end.

This worked fine and I made lots of rope.


The problem was, however, that I have to be able to turn both ends as I am making rope. I would give one end a few spins, stop and go to the other end. One reason they call this a ‘rope walk’, I guess. Sometimes my admiral would help me, but she is not always available. So back to the KNEX tool box.


post-246-0-84809000-1364843440.jpg  post-246-0-22366000-1364843450.jpg
I jury rigged one end with a large and smaller gear driven by a variable speed hand drill. Notice the twister tie on the trigger. Now I can ‘control’ the speed, use a switch at the other end to operate the drill while I was holding a hand drill at the far end.

Still not good enough. KNIEX has several types of electric motors. I mounted one on top of the moving sled, hooked it up with another set of gears.

post-246-0-77986200-1364842515.jpg  post-246-0-56469900-1364842496.jpg




Now I stand back and watch the action without touching anything except the switches. Besides, the results are much better with a more uniform twist all along the eight foot length of rope.

Edited by Modeler12
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Very Nice Jay.

Yes Knex and Lego are great ways to build stuff. I am curious about the twisting at the rope forming end. Why does it need to be twisted. My own experience has the rope twist as a natural effect of the three lengths twisting up. I am not suggesting anything just curious about the method.



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Guest midnight

Nice set up Jay . Isn't it amazing the amount of things that we have around the house that help us in our hobby .

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Micheal, I found that with very thin threads, they became quite tight and a couple times broke if I did not help them along. Thicker thread no problem, but with the setup I have now, it works very well by rotating both ends. However, said that, i must add that the rope end rotates much slower than the three gear end.

I think one reason for the 'problem' above is that the tension I use maybe a bit too much. Also the friction of the sled sliding in the track is a bit high. I could wax that but have not bothered.

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  • 2 weeks later...

K'nex are my favorite medium for building mechanical devices because they are so simple. I made this rope walk several years ago and liked it so much that I never disassembled it. although I never made a official tail stock yet I just trow something together when I use it.




post-1993-0-68182500-1366058649_thumb.jpgThe yellow rod in the center is for attaching a K'nex motor to power it.

Edited by qwerty2008
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After the previous post I decided to make a rope with the ropewalk. First I made a crank because all my K'nex motors were dead and I didn't have any batteries then I made the tailstock and track. The finished rope is 12 strands (72 feet in total) of contractors twine and about 3 feet long.






Edited by qwerty2008
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