... Now, if you made a disc that extended from on side of the open book to the other, then yes, you would need roughly 180 degree turn per page. However, if you make a disc that is much smaller (for example sake let's say 8"), and you position the disc 6" behind the book, and 1" to the right or left, you know have just a portion of the disc in front of the books center fold. ...
This was what I was sort of think about, but I couldn't see how to make it work. If you had rods extending out the sides of the disc that is turning, it could catch something at the bottom of the page to make it turn over. The cover would need the shortest rod, then the longest rod for the last page. But that won't work at the end since the longer rods will probably bump up on the cover or first pages. So then I thought that in the z-direction, the catches on the pages could stick down towards the ground lower and lower, so that the long rod at the back would slip under everything. But then how do you reset it..... It seems like the solution is close, but there is a little more working out that has to be done.Not necessarily... Consider the book design as follows... A sturdy solid spine, each page is attached to the spine with some type of small hinge. (if you've ever been to a tattoo shop then picture the way they typically display a wall of hinged frames with tattoo art). I'm also going to assume that the book is positioned leaning back at some angle around 45 degrees.
At this point the pages should flip manually with little effort and not bind due to the fact that top and bottom of the page is hinged. Now, if you made a disc that extended from on side of the open book to the other, then yes, you would need roughly 180 degree turn per page. However, if you make a disc that is much smaller (for example sake let's say 8"), and you position the disc 6" behind the book, and 1" to the right or left, you know have just a portion of the disc in front of the books center fold. At the center of the book, just inches away from the spine, the amount of travel needed is extremely small, and given the angle of the book you really only need to travel half that distance as the page is going to naturally fall on its own once flipped past the half way point.
Setting the center of the disc slightly to the right or left of the spine would cause the tab on the disc to clear the same tab as the disc continued to rotate for the other pages.
A separate set of tabs would probably be needed on the opposite side of disc that were correctly positioned to close the pages.
I haven't done any calculations on this yet but I'd be willing to bet you could achieve all page turns with a half rotation and a full reverse rotation to close, which should leave you right back at the starting position.
I would probably suggest a stepper motor in this case in order to get precise start and stop locations.
So, have I thoroughly confused everyone?
I haven't done any calculations but I'd be willing
In the last sketch the tabs are no longer used. The arm simply drops it's long edge over the frame (or top edge) of the page. There's no backside to arm and the arm sits slightly higher then the edge, so as it turns, the page will eventually fall back on its own. I had originally drew a contact type sensor for the arm to know when the next page had locked it, but it now makes more since that both sensors would be IR sensors. The second IR will let you know when the page has dropped backward... Or if the page doesn't have enough tilt to drop out the second IR will also let you know you have reached the previous page
If making a book, perhaps use of barrel hinges for each page, slid onto a long rod to act as a connector? Each set of hinges would be offset from each other and would support each page.
An extension arm would be attached to each page and extend thru the barrel "below" the book. A servo could then act as a traveler (or perhaps a worm gear with a traveler), and on the traveler is a 2nd servo that would engage each extension.
The extension would have a "slot" into which the 2nd servo would insert a pin. For "close enough" work the slot would be wide enough for mechanical slop in engagement.
Steps would be to move traveler to start position, rotate the 2nd servo to engage position, then move traveler to 1st position. The 2nd servo would thus be engaged on the page extension slot and then would rotate (thus the causing the page flip). Next the traveler would reverse direction slightly to disengage from the extension slot, rotate 2nd servo to engage position, then move traveler to next position. Repeat for each page.
The mechanics would be completely below the book and not visible. Also no sensors needed.
Thoughts?
Sorry for my late response, I was gone for Christmas and forgot all about this email. On my long drive home, I was thinking about this project and came up with a similar idea to what you were saying. I was imagining that my pages would have a rod that extends above/below the book and fits into drilled-out holes in a piece of wood. The pages could be ~ 0.5" apart in this hinge (is this sort of what you were thinking?). I was then going to have a second rod (i'll call it a catch) that extended down below the pages a couple of inches (and would be a couple of inches away from the "spine" (the further the easier to turn).
Then I Would have a stepper/servo that could turn a rod into position, extend a linear-actuator (or something else, still trying to work out something cheap/easy to use here) long enough to hit the catch and turn the page. I would need to know the position for the different catches so I can grab them one at a time, and I would need a way to close the book (maybe an addition thing sticking out from the servo that is long (wouldn't need to extend/retract any), that could hit all the catches and return them to the starting position.
Is this roughly what you were thinking?
I think roughly so, just a different approach. If I understand your thoughts, each page would be affixed to its own rod?
My approach would be a common rod with each page having it's own pair of connectors that are similar in thought to barrels that actually slip over the common rod. My approach would not allow the pages to lie completely flat and would only be able to rotate the page roughly 150deg, then rely on the weight of the page to open completely. I think your approach would not have that restriction.
I'm thinking that very thin brass sheets (like used for modeling) could be formed into the berrel hinge and then the flat be used as connector to the pages and the opposite side is used for the engagement. Advantage of brass is corrosion resistance.
An interesting thought is to use small amounts of extremely thin shim weights on the edge of each page. Then as the page is turned there might be a more natural look to the page movement. As the page rotates the edge weight causes the outside of the page to hold back, then as more and more rotation occurs the page will "flip" somewhat quickly.