Making a sheet swallower. Any reference?

That’s it. I want to make a machine that moves sheets from a place to another and I haven’t find any other project to use as a reference.

The idea is to built somethink similar to a printer without actually printing anything. I’ve been working on a prototype without a controller for a long time, but no success. Now I’m planning to use an arduino and the code won’t be hard to make, it’s the hardware what is driving me mad.
Thank you in advance!

You could use a hand.

Bedsheets or sheets of plywood?

Paper sheets. It's meant to complement a stamp machine.

As anyone who has fought with printers over the years knows, reliably moving sheets of paper from one place to another is an unsolved problem.

But a printer would be one place to start.

I agree with @jremington. Moving sheets of paper is quite difficult. Get a job running a printing press and You will know. Get some more easy objects to move.

The systems I’ve seen (in commercial print shops), use a field of rubber vacuum cups on a moveable gantry to pick, move and place sheets of any size.

That sounds like good stuff. Know that the percentage of humidity in the Place where the paper sheets are stored is of greate interest especially at high paper speed.
Now we can talk Arduino, You probably need a vacuum Control device and one or more position sensors telling when to apply the vacuum and when to release it.

A vacuum pick and place setup for paper should be easy to mock up and test. I made a little vacuum table to test vacuum forming things using the thin plastic disposable picnic plates. It would be similar but flipped upside down so ti would pick up the paper and hold it until released.

Many thanks for all your responses.

When moving the paper sheet at the top, only static friction must be overcome by the machine, so using some sort of blower or a fan to spread the sheets could help. That way only some rubber bands moved by a dc motor may work.

What do you think?

Jarogue:
The idea is to built somethink similar to a printer without actually printing anything.

I agree with the others that this is a very difficult task - my hand is not even good at it.

However Epson (and other printer manufacturers) seem to have figured it out so why not use the paper handling mechanism from a printer?

...R

Picking one and only one sheet of paper from the stack is indeed a major problem. My cheap Epson XP245 printer (about a year old) is getting it right about 99% of the time, which is definitely way better than I can do by hand, especially at that speed. Sometimes a second sheet gets pulled in, usually no big deal, they just come out together as well. High end laser printers are close to 100% but the slightest wrinkle in the paper can still cause a jam there. Shaking the stack before placing it in the machine of course also helps a lot getting it right.

Anyway, I agree: a cheap printer is probably the way to go. For that matter I'm thinking of a small portable printer, as long as it has a function that allows you to feed a piece of paper without printing anything on it. Use an RPi to control the thing - it has the USB port you need to send the command to the printer to have it spit out a single empty sheet, after which your mechanism may take over.

I wouldn't try to physically modify the printer. The mechanisms are highly integrated, and the printers themselves also contain a microcontroller to actually operate the mechanisms properly. It's most likely easiest to keep that as much as possible intact.

Robin2:
I agree with the others that this is a very difficult task - my hand is not even good at it.

However Epson (and other printer manufacturers) seem to have figured it out so why not use the paper handling mechanism from a printer?

...R

An advice I got, okey "some time ago", was that Hewlett Packard seldomly jamed up the paper. They definatly don't use vacuum.

I have a small printer and it has a rotating rubber cam that rotates against the top sheet of paper and slides it into the rotating feed rollers.

Humidity was already mentioned.
The things you have to accommodate are friction, static attraction, and weight of the individual sheets.
Only you know what the paper path involves. That’s important.
One or more of the suggestions above will help address your requirement.

zoomkat:
I have a small printer and it has a rotating rubber cam that rotates against the top sheet of paper and slides it into the rotating feed rollers.

And that works until the rubber gets hard, which is when you dispose of the printer. :grinning:

On the old HP-5L/ 6L - note, Hewlett-Packard - it was the counter-pad against which the rubber cam works, that hardened and failed to separate the sheets requiring you to single-feed every sheet. There was a curious kit you bought (but I never did) which had a jig that you rammed into the paper feed which apparently inserted a second, newer rubber pad to stick in the right position. :roll_eyes:

I used them for some 15 years until the closing tabs on the casing became brittle and they literally fell apart. The vertical design was superb, took up an absolute minimum of desk space. It’s a pity they or no other manufacturer has reprised the sensible design.

"And that works until the rubber gets hard, which is when you dispose of the printer. :grinning:"

Sorry you had to toss your printer. When the rubber cam in mine got hard and would not feed, I scuffed the cam with a little sand paper and then put a light film of the tacky finger stuff on it and it went back to working again. I don't use the printer much, so didn't really want to buy a new one. YMMV

"tacky finger stuff"? :roll_eyes:

Paul__B:
"tacky finger stuff"? :roll_eyes: