My 3rd Generation Scanner Build Thread

[jradi]

Well, it's a beautiful design. I hope you get it working!

[you1]

I know the frustration of an idea not panning out.

Here is one possible solution in an effort to make the rails rise up (if it works) ...

Connect a rigid handle directly to the rails, rather than connecting it to the platen

[daniel_reetz]

Very interesting, thanks!

I had a few other ideas today, including one based on the hingeallelogram. I can see your suggestion working well if the thing was braced along the length of the drawer slide, something like this:

rigid-handle_2.jpg (82.16 KiB) Viewed 2581 times

I'll post pictures tonight or tomorrow... lots of new ideas happened today, some simple, some not. I think your general idea of returning to simplicity is so right... the more complex this gets the uglier the solutions get. However, I *really* want to make a suitcase scanner, so I'll keep working on this for a bit.

[tsttm]

i guess depending how heavy your platen is, i was thinking instead than fixing the platen to the 'outside' side of the drawer slide supports, you fix them to the inside side. Then on the outside, you screw a board to it that's slightly taller- then you may be able to attach springs from the inside/platen side to the outside board (two springs on each side of the platen) pulling upwards...so you get this natural tendency for the platen to rise. That might facilitate raising & lowering the platen. maybe?

where are you planning to put the cameras? i was thinking you could even attach the cameras to the outside slide drawer board as well if the viewing angles all work out.

[daniel_reetz]

Great thoughts.

I had a similar idea involving a camera support shaped like an upside-down "U", which would sit over the drawer slide. At each corner of the "U" there would be a rubber band that would attach to the platen. The top of the inverted "U" would hold the camera. But that's a lot of complexity and it would limit the speed with which I could set up and tear down the scanner.

I haven't been able to spend time on the scanner the last night or so as I'd planned -- too much going on, and working my ass off trying to pay for some dental work (had an infection in my jaw that could very well have killed me). I have two new ideas that don't involve drawer slides -- I hope to try them out by the weekend.

[daniel_reetz]

Here's another non-portable idea I found on my desktop.

Yet_Another_Design.jpg (124.62 KiB) Viewed 2570 times

[you1]

And yet another idea...

Move the rails from the side of the platen to the back (where the hing use to be). Keep the rails side ways (same orientation), because they are designed to handle the weight from the side of the rails (not from the front). That is, if you stand in front of your scanner, you will see the side of the rails (like you do now) rather than the front of the rails. I believe this should make for a smother lift.

You could probably get away with one rail, but I think if you use two, you'll get less side to side movement (i.e. single hinge vs two hinges).

[daniel_reetz]

Very interesting... that just might work! I noticed the side-loading nature of these rails earlier when I was looking at this rail for a 19" rackmount server:

rail_IMG_2030.jpg (145.55 KiB) Viewed 2567 times

I had the idea to look around in the mechanical engineering section of the library, and I found this mechanism book, which featured the Scott Russel linear motion mechanism, also interesting:

ingenious_mechanisms_IMG_2033.jpg (255.29 KiB) Viewed 2567 times

scott_russel_IMG_2034.jpg (163.3 KiB) Viewed 2567 times

[Karyudo]

On June 18, in the "Words of Wisdom" thread, I wrote:

"In my purely conceptual design thus far, I'd have a linearly-moving platen cantilevered with drawer slides from a central light-and-platen support at the back..."

So yeah, I can't see why nobody has put the drawer slides at the back already.

[daniel_reetz]

I just went back and re-readyour post, and I think you've got some great points that just got lost in the clamor without illustration. You've got an A590 and a pen and paper, right? I'd be particularly interested in your ideas about camera mounts.

I'll give this idea a try sometime this week or weekend, even though I have something else planned. It is certainly intriguing and would be cool if it worked.