Twin direction worm gear?

[graduate_owner]

My wife wants me to make a machine that will wind wool onto a cone or bobbin. She wants it bigger than the little plastic ones that sell for £10 on ebay. It also needs to be electrically driven.
Mounting a cone and turning it is easy enough, but I want to have a sort of moving arm which travels the length of the cone and back, and so the wool gets more evenly wound.

OK so there is a device which is a rod threaded in both directions. As the thread rotates a nut travels along one way, then when it reaches the end of the thread it reverses to travel to the other end, then the whole precedure repeats. This would provide a solution for me, but DOES ANYONE KNOW WHAT IT IS CALLED?

K

 

[Dee J]

I can understand what you mean... but I can't see it would be a very simple or cheap mechanism. Wouldn't a simple cam or crank be more straightforward?

 

[Johnboy]

Spring loaded arm with a cam to move it would be fairly simple.

John

 

[novocaine]

a neat solution to a surprisingly complex problem.

https://www.youtube.com/watch?v=3aobPgGzB-U

they did it better than I could.

if it's electrically driven, the most simple solution is an arduino, limit switch and motor driver (you could hard wire it and do away with the arduino if you don't like programming, but you are missing out on a chance to learn something), stick a switch at either end, an or gate between it and away you go. if switch 1 is the most recently pressed move one way if switch 2 is most recently pressed, move the other way. would me another small motor.

 

[donwatson]

How about this ?

https://www.youtube.com/watch?v=zae2ZePQTwQ

take care
Don W

 

[novocaine]

thats the one I was looking for. well found Don.

 

[bugbear]

thats the one I was looking for. well found Don.

It's a reciprocating rack, not the spiral you asked for.

The closest I can find is this:

BugBear

 

[bugbear]

This ones even better (but no more useful)

http://www.diytrade.com/china/pd/133352 ... anter.html

BugBear

 

[beech1948]

Heres one in wood and plastic

https://www.youtube.com/watch?v=zae2ZePQTwQ

 

[bugbear]

This animation calls it a "barrel cam"

https://www.youtube.com/watch?v=LLIwVdaRViM

BugBear

 

[graduate_owner]

Plenty of food for thought. Thanks guys.

K

 

[xy mosian]

I wonder if a Spiralux screwdriver shaft could be pressed into service.

xy

 

[graduate_owner]

I have a spiralux that has not been used since cordless drills became affordable. That is an interesting idea, very interesting.

K

 

[beech1948]

Just for sh*ts and grins here are some much older methods....The Whitworth Quick Return Mechanism.

https://www.youtube.com/watch?v=CVVwkbvhecg

[urlhttps://www.youtube.com/watch?v=Jx5nOn0tf_k][/url]

 

[xy mosian]

Thinking about the Spiralux, or similar, again. How about a forked lever, one arm either side of the shaft, with a suitably angled groove follower. At one end of the shaft, swing the forked lever so that the other angled follower engages the other shaft groove?

xy

 

[Robbo3]

These are commonly used to lay line across a drum on multiplier fishing reels.
Probably not large enough for your purpose but it gives you another avenue to search.

 

[xy mosian]

Sorry, earlier I suggested a forked device. I don't now think it could work.
xy