Jck57's Full Auto Scanner Scheme #6

[M@rtijn]

That's solid scanner engineering.

It would be an idea to use the rotating axle to transfer is to an other momentum that can drop the wedge.

Like extending the axis with another cylindrical cam...

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but by placing it under an angle with perhaps a universal joint / swing shaft so that the wedge is aligned to the book when it's dropped.

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[M@rtijn]

Or something along the lines of...

Extending the rotating axis with a universal joint / swing shaft and replacing the current square with one holding a Reuleaux polygon. The rotating axis then gets transferred to a small square motion.
With some extra tweaking and extending the axis construction, this square motion can be transferred over to a larger square path so is timed to drop and lift the wedge when a page gets turned.

wedge_drop.jpg

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[jck57]

Hey M@rtijn, great ideas. Maybe the square cam follower with the yellow parts could be linked to go coaxial with the camshaft by simply extending it over. What do you think? Thanks.

[M@rtijn]

Yes, or perhaps two axis can be driven with sprockets in between for being able to time the wedge drop.

[daniel_reetz]

I have a 3D printer now and will print any object you can send/spec/draw to speed you along, jck57!

[M@rtijn]

Polystyrene can be used to create different cylindrical cams for tryouts.

Dow Styrofoam extruded polystyrene (XPS) blue foam works great as a modelling foam.

Perhaps someone can draw the final cam in Google SketchUp and export it to a file needed for 3d printing.

[M@rtijn]

With cylindrical cams I meant to say rectangular cam...

[dbmoura]

I can help drawing 3D models. From any sketch, photo we can start. I already helped with past models here.

[jck57]

Thanks for the helpful ideas. Dan, thanks for the offer to make parts on your new 3D printer.

My latest idea is to go with a pivoted movement for the wedge. Let me know what you guys think. For simplicity, this drawing omits the page flipping parts which would drive directly off the end of the shaft.

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Cam 1 raises and lowers the whole assembly. Wedge spins free on shaft, is restrained in rotation by Wobble Drive and Cam Follower pushing on Cam 2. Gearmotor shaft is attached to Wobble Drive which turns Wedge. As the wedge rotates into position over the book, Cam 2 Follower pushes on the ramped area of Cam 2 making the wedge quickly flip into alignment with the book. In this way, the wedge speeds ahead of Wobble Drive and thus stays rotationally stationary as Gearmotor shaft continues to rotate. Just as Wedge slips into alignment over the book, Cam 1 lowers the assembly so Wedge contacts the book. Everything pauses while the camera takes the picture. As Gearmotor starts again, Cam 1 lifts Wedge off the book. As Wedge lifts, Cam 2 Follower continues to keep Wedge in alignment because Wobble Drive hasn't caught up yet. Right as Cam 1 fully raises the assembly, Wobble Drive catches up to Wedge and rotates it away from the book so the page flipping parts can get to work.

[dbmoura]

The first trial to translate the first idea.

master.skp

the 3d osf the parts

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Just a view