How to Interface Automatic Slider mechanism with PI

[arr0nst0ne]

I need to make a Slider mechanism for my last year project.I need a ways to create the slider using Raspberry PI interfacing.

[techpaul]

Define slider as this has many meanings from from a sliding mechanism (linear mortoe and rack and worm gearing) to slider as in a linear potentiometer, and many more definitions like someone who skives off woirk early..

[arr0nst0ne]

Actually we are making a Semi automatic winding machine for this we need to slide a copper wire so as no to overlap . This sliding will be done on the basis of speed of main motor and also the slider should slide on both the side.

[techpaul]

Plenty of prior art as I believe the first use of such mechanisms was in the 18th century for rope winding machines.

Do a few web searches as most of the slider mechanism are worm gears and similar .

Lots of better descriptions and references out there, until we know what sensors and motor drives you are using it gets a bit difficult to guess.

Especially as cable winding is done on many sizes of 'reels' from approx 12mm dia to the cable winding for ocean cable laying ships (the width of a ship).

[PiGraham]

Search "leadscrew". Turn a threaded rod with a stepper motor, or DC motor + encoder, and it will control the position of a "nut" on the rod. You can literally use a length of studding (threaded metal rod) and a nut (as in nut and bolt) for a light-duty system. For something more serious you might use a "re-circulating ballscrew".

Another options is a tooth belt fixed to a carriage running on rails with linear bearings.

Take a look at printer or scanner mechanism. There are probably too lightweight for your use, but they illustrate the principles.

[Ravenous]

Also people out there on the internet have tried to make amateur pickup winding machines, for electric guitars. For pickups a nice even wind with the right tension might help to prevent the pickups being "microphonic", which means individual loose windings vibrate when played loud. It might be worth searching around to see if there are any useful ideas.

Just a specific idea you might want to try searching for.

[jamesh]

I'd go for a purely mechanical system! Driven off the drum motor you automatically get speed compensation. Worm gear plus cam would work.

Sewing machines use something like that for winding bobbins! My auto retracting air hose reel does similar internally- but never looked to see the exact arrangement.

[PiGraham]

That's sound advice James.

A cam or a crank are anothe ways to translate rotation into linear motion, so that would work for direct drive or stepper/servo drive.

I can't think of many functional reasons to use a motor driven system.

You could vary the cross-sectional profile of the coil (why?)
You could stop the spool and draw out the wire to one side prepare a tap in multi-tapped windings.
You could mix sparse and packed winding layers (don't know why you might want to)

[PiGraham]

If this is a teaching assignment it make sense. It's a simple two-axis CNC. Electronic cams are often use in place of mechanical cams (especially where elaborate or variable cam profiles are required).

[arr0nst0ne]

Its our last year Project. I am thinking of using a ac servomotor with proper drive and a worm gear mechanism to control the slide...What i need to know is that Should I be able to connect the controls of drives with the PI controller...both MAIN WINDING MOTOR and SERVO motor(servo motor start or stop depends on main motor speed precisely 1 slide per rotation of main motor) And also able to interface the LCD for displaying the main counter i.e total rotation.

[Burngate]

http://info.ee.surrey.ac.uk/Workshop/ad ... index.html

[arr0nst0ne]

Search "leadscrew". Turn a threaded rod with a stepper motor, or DC motor + encoder, and it will control the position of a "nut" on the rod. You can literally use a length of studding (threaded metal rod) and a nut (as in nut and bolt) for a light-duty system. For something more serious you might use a "re-circulating ballscrew".

Another options is a tooth belt fixed to a carriage running on rails with linear bearings.

Take a look at printer or scanner mechanism. There are probably too lightweight for your use, but they illustrate the principles.

Thnxx dude...!!!