Getting a vacuum pump manual pick-and-place - Page 1
Forum section: electronics / projects

author: zapta
author_rank: Super Contributor
timestamp: February 21, 2014, 07:16:37 pm
content: I am looking for an effective manual pick and place vacuums tool for small scale hobby use at home. I tried a simple Handi Vac tool by Virtual Industries but results were very poor, so I bumped up my requirements:A. Need to have continuous vacuum (that is, active pump, I don't have an existing vacuum source).B. Pick/Release operation should not be done by the picking hand (for stability). It can be foot operated, by the other hand (less desirable) or anything else that worksC. Total cost at most $200-300 (in the US).I would appreciate any feedback on the subject but also have a few specific question1. Any off the shelf system that falls into this price range (new or used)?2. I like the DYI approach shown in the video below except for the pick/release activation by the picking hand (vibrations). Any suggestion for a electro mechanical valve and foot pedal? Will a pneumatic pedal like the one below, in series between the pump and the picking point, work well (I can put the pump on the floor close to the pedal).http://www.ebay.com/itm/Pneumatic-Foot-Operated-Pedal-Valve-3-way-2-position-/250525883392?pt=Pneumatic_Hydraulic_Valves_Parts&hash=item3a54819c00

author: SeanB
author_rank: Super Contributor
timestamp: February 21, 2014, 07:41:47 pm
content: Pneumatic foot operated valves are darn expensive, ca $100 US each. I would use an electric valve rated for vacuum operation ( or a piloted one if you have air pressure to operate it) and a simple foot switch in a box. I use the foot valves at work, and they last about 2-3 years before they pack in, which is a lot less than any other valve, just from the off axis forces from the foot which wears them out.As well add a filter to the vacuum line before the filter, a cheap and easy to get one is a regular plastic fuel filter, just get the small universal one with 6-8mm inlets and outlets and a clear plastic body ($3), and place it in line with the tubing from the pickup tool. This will collect the most amazing amount of dust and keep it out of the vacuum pump and switching valve. Keep a spare one or two around for when they get clogged.

author: calzap
author_rank: Frequent Contributor
timestamp: February 21, 2014, 08:30:45 pm
content: Gast vacuum pumps are among the best and can often be found on eBay at reasonable prices. Their quality is high, and parts are readily available. Get an oil-less model so you don't have to mess with oil levels. An alternative to a pneumatic foot switch is an electric foot switch and solenoid valve; you would also need a needle valve to adjust flow. This won't work though if you need true proportional flow control.Mike in California

author: zapta
author_rank: Super Contributor
timestamp: February 21, 2014, 10:56:54 pm
content: Quote from: SeanB on February 21, 2014, 07:41:47 pmWhat does 'rated for vacuum' means? So it in several places when looking for valves. Is it about directionality? Seal quality?Should I care about it for my simple application?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: February 21, 2014, 11:12:31 pm
content: Quote from: zapta on February 21, 2014, 10:56:54 pmYes it's about directionality - some valves only work with positive or negative pressure.For a vac pickup it's very non-critical so pretty much anything can be used - e.g. surplus pneumatics parts from ebay, or something improvised with a solenoid, or maybe even a servo

author: SeanB
author_rank: Super Contributor
timestamp: February 22, 2014, 05:33:49 am
content: Vacuum rating means the valve will switch with any pressure in it's operation range, from a vacuum to the max, typically 10 bar. These are called direct acting valves, and are rated for lower flow rates and slower switching speeds, along with being mostly available with either 1/4 or 1/8 or M5 connections. This means there is no air operated spool to enable a fast switching or a large port, to get that you need a valve with a pilot air connection which then provides the operating power to change the valve over. You find a large number of modular ranges ( Festo, Numatics, SMC etc) have a provision on most of the units for a pilot connection, and offer a small kit mostly consisting of a few seals, a spacer plate with milled grooves and slots and a small M5 air connection to convert the valve to pilot operation for vacuum use. You do need an air supply with regular pressure ( 2-6bar, filtered and oil free or oiled) to connect to it though.

author: zapta
author_rank: Super Contributor
timestamp: February 22, 2014, 05:47:33 am
content: Quote from: mikeselectricstuff on February 21, 2014, 11:12:31 pmDoes this one looks good? (I presume that it has a return spring, no need to reverse polarity to toggle position)http://www.ebay.com/itm/1-8-Inch-Pneumatic-3-Way-Electric-Air-Solenoid-Valve-12V-DC-Zero-Pressure-Valve-/111240139537?pt=Pneumatic_Hydraulic_Valves_Parts&hash=item19e66dd311Something like this for the hose connectionshttp://www.ebay.com/itm/STAINLESS-STEEL-HOSE-BARB-3-16-hose-1-8-NPT-/251452915847?pt=LH_DefaultDomain_0&hash=item3a8bc30087And this pedalhttp://www.ebay.com/itm/Foot-Switch-Power-Pedal-FootSwitch-1NO-1NC-10A-CFS-01-/250843031063?pt=LH_DefaultDomain_0&hash=item3a6768e617

author: SeanB
author_rank: Super Contributor
timestamp: February 22, 2014, 06:14:12 am
content: Yes, just when connecting make sure that you connect the piping correctly. In that valve the side port is connected to the vacuum pump, and the port on the long side is connected to the tool via a small filter. That way the pump will not have a continuous flow of air into it and will generate a good vacuum. As well I would recommend the line from the tool to the pump to be as short as possible, and use a small filter as well to minimise lag. The piping to the pump should be a lot larger ( and will have to be a very rigid pipe as well as vacuum will collapse most piping with ease, typically you use a pipe with a steel spiral reinforcing in it) so that you have a large volume of low pressure to evacuate the tip quickly. Valve has a very limited flow rate with a 1mm port.

author: zapta
author_rank: Super Contributor
timestamp: February 22, 2014, 07:34:17 am
content: Quote from: SeanB on February 22, 2014, 06:14:12 amThanks Sean. I am looking at the diagram belowI am think connecting as follows1 vacuum pump2 tool3 open (exhaust)In the passive valve state the air will flow from the tool to the pump. In the active state, the air will flow from the exhaust to the tool (release) and the pump bill be blocked (?).Is this the correct way to connect?

author: SeanB
author_rank: Super Contributor
timestamp: February 22, 2014, 07:57:19 am
content: Correct but wrong thinking. In relaxed state the 1 is closed and 2 and 3 are connected to vent pressure to atmosphere ( 3 is on top of the coil). In operate 1 and 2 are connected and 3 is closed. You connect the vacuum pump to 1 and the tool via the filter to 2. Filter is very important as these valves block up easily and then either leak or do not open at all.

author: zapta
author_rank: Super Contributor
timestamp: February 22, 2014, 08:10:16 am
content: Quote from: SeanB on February 22, 2014, 07:57:19 amI see, reversing the polarity such that pressing the pedal picks the part rather than releasing it. My thinking was not to block the pump in the rest state. I will also make sure to have a filter. Thanks Sean.

author: SeanB
author_rank: Super Contributor
timestamp: February 22, 2014, 08:21:20 am
content: You want the pump to operate to a vacuum at all times when not in use. This ensures that an oiled pump pumps oil, and an oil less unit does the least work. You can also have a vacuum accumulator and a pressure switch to stop the pump when you have not used the pick for a while, and this saves energy by not running the pump all the time. An old disposable refrigerant or gas container of about 15l will hold enough to operate quite a few hold down operations with little energy used. These are easy enough to get empty, a little work on them and they make a nice vacuum reservoir.

author: SeanB
author_rank: Super Contributor
timestamp: February 23, 2014, 11:06:36 am
content: That would work, but there probably is the same item available cheaper unbranded on fleabay. Looks like the bead crafts and SMD have similar problems with small things.

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: February 23, 2014, 01:18:36 pm
content: I did roughly what MikesElectricStuff did in his video and it worked pretty well. Very useful videoie. Fleabay vacuum pickup with the manual vacuum removed and an electric footswitch controlling the vacuum.I also added one of the chinese liquid dispensors from AliExpress, to the same pump. So I could do solder paste dispensing too.Got some plastic tubing from the chemist shop and some plastic tube T connectors and end stops from AliExpress.One parcel of endstops cost me two dollars for twenty, of which I used 3, but it was free postage. AliExpress is great for some things.I just change the tubing in two placing to swap from dispense to pickup. Also I used an old scotch bottle as an air chamber. Dont the technical term but like a capacitor is in electronics.I still need two foot switches though, it would be nicer with one.

author: mjkuwp
author_rank: Unknown
timestamp: February 23, 2014, 03:15:42 pm
content: I went down this same road of research (considered a pneumatic valve, foot pedal, etc). I found in reality there is a very simple solution. I have used this simple setup for my last 4 builds.My hot air rework station which cost in the region of 150 USD has a vacuum output on it. The air flow is adjustable on the unit and the feedback is that metal ball floating in the tube.I hold the hose with my left hand and pinch to drop the part. Hold the tool in my right hand, sometimes with my finger over the bleed hole (for big parts) and other times I leave the bleed hole open and this helps the parts drop nicely.I also have a tool with a mechanical pushbutton on the want but of course pushing that button will tend to shift the part. A foot pedal might work... but the existing solution is so simple.

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: February 23, 2014, 03:36:55 pm
content: Hi,I have build one exactly like the system described in the video.The Tetra Whisper 40 air pump is very easy to convert to Vacuum, by rotating the valve assembly 180 degrees.I used a 3mL syringe, manufactured by BD.I used the rubber seal from the syringe and some 5 minute epoxy to attach the tubing to the syringe.It works great!!I may make a custom hand piece to replace the syringe, just to make it more comfortable to use. I found it was about 3 - 4 time faster than using tweezers.Jay_Diddy_B

author: zapta
author_rank: Super Contributor
timestamp: February 23, 2014, 04:15:30 pm
content: Quote from: wilfred on February 23, 2014, 10:40:02 amLooks very interesting, compact, adjustable, and has an on/off switch. I just ordered one.The video explains why the adjustment knob is important. I saw a youtube review of an Aoyue 932 where the reviewer complained about the the parts not releasing due to excess suction, an adjustment knob would solve it.BTW, got yesterday a Tetra 40 from a local pet store and did the direction swapping mod but suction was not strong enough IMO.

author: zapta
author_rank: Super Contributor
timestamp: February 23, 2014, 05:14:35 pm
content: Anybody worries about the ESD safety of their picking tools?

author: JuKu
author_rank: Frequent Contributor
timestamp: February 24, 2014, 11:58:03 am
content: Quote from: zapta on February 23, 2014, 04:15:30 pmI have an Aoyue 932, and indeed, it sucks. Well, it is supposed to, but it sucks way too much. My solution was a relay operated valve and a footswitch, and the tool is rather good now. A tip: aquarium owners need to switch air on and off; your local aquarium shop likely has a reasonably priced valve.

author: zapta
author_rank: Super Contributor
timestamp: February 27, 2014, 05:11:53 am
content: Quote from: wilfred on February 23, 2014, 10:40:02 amThe Pick It Up arrived today and looks very nice. Its a better pump than the Tetra 40, better suction and adjustable. Not sure yet if I will add to it a foot activated value, will see. Below are a few close ups:The flow control. It's a potentiometer with a small circuit that is connected in series with the pump and the 110VAC power.The pump. It is made of a AC solenoid and two permanent magnets that vibrate on a pivots and operate the diaphragms. The Tetra 40 is similar but has only one magnet and diaphragm.The bottom have 4 pointy rubber feets to reduce vibration and filter. Since this is an exhaust filter I am not sure what it is for.The pump comes with a long wire with a switch, very nice. The tetra 40 does not have a switch.The adjustment knob. Could be made easier to turn but not too bad.The pickup handle. I would prefer it would be thicker. Also, the hole should be closer to the pickup end, it's awkward as is. I plan to close it and drill a hole closer to the end. The handle is made of metal which (I think) neutralize static that is generated along the rubber tube.The hose that came with the pump is not bad but packaging was terrible which caused it to have kinks in few places. I replaced it with a nice aquiarim silicon air hose from a local pet store.The unit does not have standard label with UL logo, power specification,etc, just this one. Must be a cheap Chinese source. However, since it is well isolated I am not concerned about getting electrocuted.

author: VK5RC
author_rank: Unknown
timestamp: March 09, 2014, 03:17:25 am
content: For interest, in Australia the "Tetra APS 150" is exactly the same as the Tetra Whsiper 40 used in the OP linked video, from Pet shops can be bought for ~$30.

author: zapta
author_rank: Super Contributor
timestamp: March 16, 2014, 05:58:32 pm
content: I added to my vacuum pump a foot pedal and a solenoid and it works very well. I select a 12VDC solenoid to avoid high voltages, the valve is 3 way NC, with 2 NPT 1/4 ports and one exhaust port (I am using fitting adapters to connect the hose). Still not sure if I want lift on release on pedal press, but can switch easily between the two with a wire change.Using this pedalhttp://amzn.com/B005GRCJ5Q(it has a COMMON/NC/NO switch, and comes in different colors), and this valvehttp://www.ebay.com/itm/301021177728?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649(NC, 12VDC, 100ma, 110AC and NO versions also available).The cons of my configuration are that in in normally-lift mode the solenoid is normally activates and in normally-release mode, the vacuum pump is normally blocked (more load on the pump?).However, the placement accuracy is much better. No more last minute movement when moving the finger to open the bypass hole.

author: SeanB
author_rank: Super Contributor
timestamp: March 17, 2014, 08:15:45 pm
content: Most vacuum pumps are very happy running into a vacuum. Running with air flowing through leads to excess wear on the valving inside. I would recommend adding an inline filter to the suction side, a cheap small plastic fuel filter works well there. Place it before the vacuum valve as well.

author: M. András
author_rank: Super Contributor
timestamp: March 17, 2014, 10:07:54 pm
content: Quote from: zapta on February 23, 2014, 05:14:35 pmmetal end with grounding wire?otherwise where to get esd safe tubing for a fair price