Pick and place vacuum pickup - Page 1
Forum section: electronics / projects

author: Rachie5272
author_rank: Regular Contributor
timestamp: April 15, 2019, 02:16:24 am
content: I'm building a robot based on pick-and-place machines, hoping to reuse as much of the common technology as possible. I have the movement and control system figured out (it's nowhere near as capable as a true pick-and-place, but good enough for me), but I'm not sure what to do for the vacuum pickup.How exactly do commercial pick-and-place machines generate and manipulate vacuums? Ideally I would just buy a few of these parts off the shelf, but I have no idea what to even look for. Is there specific terminology I'm missing? I want something which can hold on to a part, and release it precisely.Thanks!

author: jmelson
author_rank: Super Contributor
timestamp: April 15, 2019, 03:44:44 am
content: My machine has a vacuum venturi that creates vacuum from compressed air. Very inefficient, but it works. It has 3 nozzles, so needs 3 separate venturis. It has a valve for each that allows it to switch between vacuum and a very slight air pressure, to separate the component from the nozzle.Jon

author: MagicSmoker
author_rank: Super Contributor
timestamp: April 15, 2019, 09:42:28 am
content: Small DC motor powered air and vacuum pumps are fairly common. See, for example:https://smile.amazon.com/Uniquers-Vacuum-Diaphragm-Compressor-Silicone/dp/B071GL3XXQ/ref=sr_1_4?keywords=dc+vacuum+pump&qid=1555321265&s=gateway&sr=8-4Some aquarium air pumps can be used for vacuum, but it's hard to tell until you open it up.

author: Kjelt
author_rank: Super Contributor
timestamp: April 15, 2019, 02:09:19 pm
content: Quote from: Rachie5272 on April 15, 2019, 02:16:24 amThe pro machines have dedicated vacuumpumps from companies as Busch and Edwards which costs 4 to 5 figures.Sometimes you can pick them up cheap at auctions.If you buy the low end vacuumpumps (<$100) make sure they go as low as 50kPa (500mbar) (0 being absolute vacuum and 100kPa or 1000mbar being normal environmental pressure)which is IMO what you at least need for handling heavier packages.For only resistors , caps etc you can get away with less vacuum.If you have a cheap pump it normally doesnot have a high flow rate, meaning it takes forever till your vacuum level is reached.You can use a small iron pressure vessel (old scuba tank that is out of date can be get for $20 for instance) that you use as a buffer.It kinda acts like a capacitor for voltageThen you can run the pump for an hour before working and have a nice buffer.

author: Rachie5272
author_rank: Regular Contributor
timestamp: April 15, 2019, 04:51:35 pm
content: The good news is I have a ready supply of compressed air, so a venturi is probably the way to go for me. I'm only picking up small objects (tiny ball bearings), so I'm not as concerned about vacuum pressure right now.Will any old solenoid valve do for switching the vacuum line? Do I need positive pressure as well? Open PNP uses a single normally closed solenoid valve to open the vacuum line to ambient air, and doesn't use positive pressure at all. Does it make more sense to switch the line before or after the venturi?If anyone can post pictures of their machines' pneumatic systems, that would be very helpful.

author: Kjelt
author_rank: Super Contributor
timestamp: April 15, 2019, 05:32:23 pm
content: Normal valves will do for low vacuum, make sure they activate and deactivate on the coil.I had an expensive Festo vacuum valve and it needed pilot air to open, the coil was 50mA and opened the small pilot air valve. So make sure you got something about 2W or so and which does not need pilot air.If you are going to use a venturi you don't need a vacuum valve just a normal pressure valve ofcourse in front of the venturi element.You only want that thing to create vacuum when you need it, so just before the nozzle has to clamp.You have to experiment with the times, it will take some time before the vacuum is high enough, but that will show itself.If the time to release the vacuum takes too long you can add a blowvalve after the venturi. You open it after closing thefirst valve to quickly release the vacuum, which saves time in P&P cimponents per hour.

author: Skashkash
author_rank: Regular Contributor
timestamp: April 15, 2019, 05:42:34 pm
content: You may want to nose around on this site for some ideas.https://www.robotdigg.com/category/47/SEMI-SuppliesShould be able to find some off the shelf nozzles and additional parts that may be of use.

author: GreggD
author_rank: Regular Contributor
timestamp: April 15, 2019, 05:52:35 pm
content: I made my vacuum pump from a Walmart Aquarium Air Pump $10, and a foot operated electric air valve.Works great for hand P&P.https://www.instructables.com/id/Electric-Vacuum-Pen-From-Aquarium-Air-Pump/