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Topic: Arduino, and Mechanical Movement of Objects - a Newbie Question (Read 3 times) previous topic - next topic

Retroplayer

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

This type of transmission would be perfect, since it would always be in sync and would would not require any sort of lever at all, but it's construction would be more difficult which is why I didn't show it last night. Basically you would have the run in one direction on half the gear and the run in the other direction on the other, inner half. When it reached the end of the spool, it would just reverse the direction on its own.

Dave_Burrows

I've never seen a gear like this one before, and it's an interesting idea. The down side to using it is that, whether I was splitting a 4 ply into (2) x 2 ply yarns, a 6 ply into (3) x 2 ply yarns, or an 8 ply into (4) x 2 ply yarns, the yarns would always occupy the same real estate on the drum. I'd want to spread the yarns over almost all of the drum however many new plies the splitter makes. So, if I were making  (2) x 2 ply yarns, each of the 2 plies would be distributed over almost half of the drum, and so on.

I'm happy to keep posting here; it's a friendly, well informed place. But as I lean away from using any Arduino hardware, or software, I'm wondering if I might be veering off topic too much? I'm guessing that there must be a forum that's better suited for amateur mechanical engineering topics such as this one is becoming.

jabbado

For a purely mechanical option, couldn't you use something similar to the level-winders on overhead and baitcasting fishing reels? I couldn't find a decent image to show you how it works. But the shaft is cut like this:

http://www.youtube.com/watch?v=v68WRtSdFGc

I'm sure you could use some adjustable (and removable) stops on the shaft to set the end-points for when the hooks need to change direction. And also add/remove them depending how many drums you're filling.

Retroplayer

ahh, yes, another great idea. Basically a spiral "screw" that your yarn would follow along with the groove. Pretty much a rotating "slide." I can see it working in one direction, trying to picture how it reverse, though. A double-helix perhaps?

As far as whether this discussion belongs here if you go purely mechanical, I am not sure. I am an old-school engineer that doesn't believe that a microcontroller is always the answer. You will find me suggesting mechanical methods all over, but not because I am anti-micro. I just think people way over-use stuff like the arduino to do things that really don't need it and tend to overcomplicate things.

I try to adhere to the KISS principles. You already have a crank providing driven rotation. You do not intend to motorize that. Adding a motor that needs to be synchronized to that crank requires sensors, limit switches, and other stuff as well as having to build mechanisms anyway....

Retroplayer

Speaking of screws by the way... your hooks could be connected to bolts that fit on a threaded rod. As you rotate the rod, it will travel the nut up and down the length of the shaft. The mechanism I showed you would still handle the reversing of this threaded rod. To eliminate what they call 'backlash" which in your case would mostly happen when switching directions, the "nut" usually consists of inner ball bearings which roll inside the groves. Your pitch and rotation speed will determine how fast the movement moves up and down your roll. This application would not require a fine pitch.

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