Does anyone have a suggestions how to pick up small pieces of paper (and move them)? I was thinking of replacing the arm with some sort of small suction device that would engage to pick up and disengage when I want the paper to be dropped.
Thank you in advance.
Get a little aquarium pump, and use it to create a small vacuum? Check into pick-and-place robotic chip manipulators, they often move parts this way. Surplus?
Paper movers are often a tube with slots/holes, and a weak vacuum.
Alan KM6VV
Also if it’s like a business card these might work ok.
Here’s where to get them.
anver.com/document/company/v … uction-cup
![hitechcp_large[1].jpg](http://community.robotshop.com/forum/uploads/default/original/3X/7/7/7704fec10a6bdaf335262bedb4be895500613270.jpeg)
If the pieces of paper are really small, you might want to consider utilizing a brief “puff” of air to release the paper. Here at my work we have chip placement machines that provide a moment of positive pressure so that those small 0603’s components will remain in the solder paste rather than stuck to the nozzle. If you program the trimming just right, it will stay right where you place it. 
Maybe a small fan motor would work OK here?
I posted a reply on the thread about a vacuum picker-upper about maybe using a small fan to create suction, and it was pointed out to me (thanx, Fallentine!) that it would be way too weak to pick up anything substantial.
But here! it might work well. as in that post, I noted that as soon as the fan is turned off, suction drops to nothing. This should release the paper, no? Not a positive puff to release, but it does have the advantage of extreme simplicity.
And I love simple.
I’d sugest trying something like a 5v USB keyboard vacuum. I should be able to pick up things like playing cards and such. If that is too weak, move up to a dust buster.
Robotdude released this.
lynxmotion.com/p-788-vacuum-gripper-kit.aspx
For something small like a playing card, theres a 50% chance a 30-40mm DC computer fan might work. And it can be turned on and off with a simple transistor relay.
For the fan to work. you need to use the fan AS the suction head, IE you place the fan against the small paper/playing card.
If the paper or card is rigid enough it should hold. but if the paper is bigger than 5"x5" i wouldn’t count on it, as the paper will lose it’s suction should a side start to sag.
a servo and syringe would still be the best bet. I’ll test the fan idea in a bit and get back to you.
Edit:
Just gave it a try with 2x 60mm fans.
Only when stacked did the fans create enough suction. It was noisy and bulky, and quite frankly didn’t work. But it was worth a shot.
Also tried a keyboard vacuum, same effects. The problem with the keyboard vacuum, as soon as i put a hose on it, half it’s suction power was lost, and it had almost none to start with.
The negative PSI just isn’t there with active fans vacuums of this size. And i’m affraid the power needed would just be overkill.
I’m not the biggest fan of how the servo-syringe is setup, as it adds a bit of bulk, but it seems to be the only thing so far able to create the necessary vacuum pressure. And if you use soft silicone/latex suckers, it should be able to pick up anything within it’s weight limit. From a piece of paper, to a small apple.
I’ll think it over, see if i can come up with anything else.
Fallentine, it is great that you are able to test some of these ideas so quickly. I am righteously jealous of your time, and test area. I have to make do with getting everything out and set up before I can begin to work. I seem to have more ideas than time and materials to test them out.
OK, even the ideas ain’t too great sometimes 
but my meat-based processor is overworked and underpowered.
Keep shooting down the unworkable ones, you have no idea how much time and frustration you save me! And sooner or later I’ll have an idea or two that does do something!*
*Based on the ‘enough typing monkeys’ principle.
I had the fans an the keyboard vac readily available in a drawer. It was only a matter of connecting a decent battery to it.
I’m always full of ideas, though my budget usually holds me back. That and i don’t think many here take me seriously, probably because of the construction methods i use in my contraptions.
I don’t have stuff like SES brackets or anything, so i can’t do to much on my end.
I tested some other fans, and another small keyboard vac, but the results were the same.
They can lift glossy paper, but it’s unstable and the paper will move a little from the vibrations, So it’s not at all accurate.
i dug up an old damaged syringe thing from a while back to see if it would work. sadly the syringe is in such poor shape i cant even pull the plunger out without separating it from the rubber plug thing.
I’m still looking for other alternatives. What size papers are you planning on picking up? maybe if i knew the general sizes i can look for something more specific to that.
It occurred to me that you may be trying to pick up the paper from a smooth solid surface, such as a table top. 
The problem with this is the surface tension is too great to overcome with a vacuum on the top side. If you were to place the card or small piece of paper on top of a grid of tooth picks, was going to recommend a honeycomb, but that’s not usually a household item. lol
So anyway you need to let the air flow under the object you want to lift… 
For a test see if the vacuum can hold the card, not lift it, just hold it. If it can hold it then it should be able to lift it with the right setup.
Already considered that. When testing with the fans, i held the fans up, then lifted the paper under it and then checked to see how well it can hold onto it. I know all about various forms of surface tension and it’s cousin, static attraction.
well, nevermind… lol
A syringe setup is not tolerant of any air leakage. Any air leakage will eventually result in the object being dropped. A continous vacuum system is leak tolerant. If the object can be picked up, then there is a reasonable expectation that the object won’t be dropped unless leakage is increased by mechanical means.
Already thought about that too.
viewtopic.php?f=6&t=6562&p=67270#p67270
Since paper isn’t perfectly smooth unless it’s gloss paper, theres bound to be leakage. A continuous pumping syringe setup would work fine. Possibly even too well.
A dual syringe setup. with additional check valves would also work.
This might work.
dealextreme.com/details.dx/sku.46930
But with all dealextreme stuff, shipping could take a week or a month. And it’s worse around holidays.
You can get an inexpensive aquarium airline check valve at walmart in the aquarium dept so you can test your theory. I think you will find it won’t work as you expect.
It should work the same way as the intake of an air compressor. Though i may need a pressure reservoir to help maintain a negative pressure.
1 way valves are cheap, but you need the right kind.
I’ve seen some online for <$2 each, but i have other priorities right now.
PS i checked out the baby oral syringes at walmart. Wouldn’t work, they wouldn’t be able to handle any type of pressure.
I’m working with someone to get some project funding my way. And the whole syringe ideas are on my list of projects.
Albeit on the bottom of that list.
