Pick and Place machine brainstorm - Page 1
Forum section: electronics / general

author: Chris Mr
author_rank: Regular Contributor
timestamp: September 13, 2016, 10:51:06 am
content: Hi All,I've been thinking for ages that a really low cost pick and place machine would be great but up until recently couldn't come up with something that breaks the stepper motor barrier. I say barrier because a) they aint cheap, b) they need drivers which aint cheap and c) programs to drive them.So here's the idea for overcoming the stepper motor barrier. What I realised, which potentially removes the steppers, was that for a pick and place machine you don't need to know where the business end (picker / placer) is until it's at the target position - once at the target position you need to know it's arrived but that is all.Ages ago I made a capacitive sensor that measures distance. You can put the capacitor in an oscillator and measure the frequency really easily. So if you make a long capacitor (out of PCB say) and have a 'U' shaped secondary plate* that moves with the axis you get to know where the axis is; rather than stepping to a 'feed forward' position using steppers. Then all you need is a signal generator (read DDS) and output that to a phase detector that's looking at the oscillator whose frequency is dependent on the position of the axis. Once 'locked' you are ready to pick or place (or whatever else).The thing is, for this idea you can just use belts and simple DC servo motors, with audio amplifiers driving the servo motors. In turn that also means that the weight of the whole thing can be small allowing it to move really quickly. DC servos have more torque than steppers so there's room for some real funInstead of being code driven (to make steps) it would be analogue using PID loops to move the axes. A processor would send tell a DDS what frequencies to generate and then wait for the 'locked' signals to arrive.Anyone interested in discussing it further, to come up with something to actually build?I have built CNC milling machines in the past but not pick and place. I bet there are much more challenging things to consider than just the movement of the business end.* three parallel strips, two side strips are grounded with a tapered centre strip. The U shaped piece couples the ground to the tapered piece so the whole assembly is corrected for slight deviations from centre and shielded. Centre tapered strip is the oscillator capacitor to ground.

author: ataradov
author_rank: Super Contributor
timestamp: September 13, 2016, 04:03:06 pm
content: Stepper motors are probably the cheapest things in PnP machines. What you are inventing called servo motors already, so using servo motors and capacitive feedback is a bit redundant.And making this work reliably is not an easy task. Start from estimating accuracy of that capacitive position meter. You will get better luck with inductive meters, like all digital calipers do, but it is still reasonably hard to do.

author: macboy
author_rank: Super Contributor
timestamp: September 13, 2016, 04:11:55 pm
content: Reading your brainstorm I can't help but to imagine the FirePick Delta.https://www.youtube.com/playlist?list=PLc9sTVFTHAE7oFt5UNO2h9-KCpKGqn8bkIt uses 3 arms to position the head in 3-dimensional space.

author: ebclr
author_rank: Super Contributor
timestamp: September 13, 2016, 04:18:39 pm
content: Stepper motor's really are extreme cheap, step driver are also extremely cheap, you can have a driver / motor system for less than 10 USD, definitely price ins't the problem here. Your idea is a kind of DC servo motor who will be fair more complicated, the only advantage will be a better dynamic torque and speed and accuracy due to the close loop nature, besides those point's will be a easy loser for stepper system that are extremely simple and easy to work with.

author: daqq
author_rank: Super Contributor
timestamp: September 13, 2016, 04:26:59 pm
content: Quotea) Define cheap. You can get reasonable stepper motors for less than 15 EUR/pc.b) Define cheap. You can get drivers very cheaply.c) At the end of the day everything needs some software - you need to convert the placement positions to some kind of signal anyway. Unless you want to go full analog, which is a somewhat 1950s approach and you could gain nothing by it.QuoteThere is no stepper motor barrier, unless you are aiming for a sub-50 EUR BOM for the whole machine.

author: wraper
author_rank: Unknown
timestamp: September 13, 2016, 04:50:27 pm
content: Steppers may cause vibration which can cause parts moving when held by the nozzle.

author: Chris Mr
author_rank: Regular Contributor
timestamp: September 13, 2016, 05:31:28 pm
content: QuoteBlimey, you have 50 Euros to spend on oneI come from Yorkshire where if you find a fly in your beer you grab it, hold it over the edge of the glass, and say "now spit it out".A toy motor can be had for a Euro or two and an audio amplifier can just be an opamp and two transistors. If everything is light, and small, then the motors can be small too.Another idea is to use a rotary table as one axis, and the other moves across the rotary table - picking up and putting down, so the components would be arranged in a circle around the outer edge. That would mean that the PCB would be on the table so it would move - not sure if that's ok but it's another idea.I wasn't suggesting that it would be the fastest in the world, just light and accurate. Say the PCB area were for a 200mm square as a starting point. The sort of thing a school could build for fun and kids could make things - you know, to get them interested and excited

author: ataradov
author_rank: Super Contributor
timestamp: September 13, 2016, 05:38:33 pm
content: Quote from: Chris Mr on September 13, 2016, 05:31:28 pmToy motors barely have torque to turn themselves.Quote from: Chris Mr on September 13, 2016, 05:31:28 pmWhat are you winning by doing this?Quote from: Chris Mr on September 13, 2016, 05:31:28 pmYes, operating flaky PnP machine is super exiting. I doubt there is a school project that can't be build by hand way faster than you can teach the PnP machine. Especially if you are building only one board.

author: Chris Mr
author_rank: Regular Contributor
timestamp: September 13, 2016, 05:49:33 pm
content: QuoteRubbish - that's like saying toys don't workQuoteIt reduces the plan area and number of linear bearings. A single central bearing with a platter with the PCB on it would be light. The PCB would be mounted in the centre. Same capacitor idea, this time the two plates are half circles.<edit>I forgot to mention that the rotary table idea means that the business end can then be mounted directly to the base plate meaning that there aren't so many of those expensive moveable cable management bits<edit\>The capacitor idea has another neat feature in that it can have an abrupt change to its normal direction - so you can find two reference points without needing limit switches.

author: C
author_rank: Super Contributor
timestamp: September 13, 2016, 05:57:10 pm
content: Blind leading the blind.With steppers or a servo with attached optical encoder you are doingmotor positionnotpick head position. To try to make motor position work the costs of the axis increases and you still have error or limits.If you know pick head position then axis costs can decrease.Here I read the main part of idea as a capacitive sensor with direct connection between the axis part that moves and the fixed part. A cheaper axis that has backlash and other errors would have less effect the capacitive sensor.In addition It would not have to be linear, You just need a function that returns the frequency for position X.The direct sensing is what is important to lower costs and also allow even more accuracy when positioning of the pick head.

author: ataradov
author_rank: Super Contributor
timestamp: September 13, 2016, 05:57:38 pm
content: Quote from: Chris Mr on September 13, 2016, 05:49:33 pmNo, it is not. Toys do work, but that's basically all those motors can do.Quote from: Chris Mr on September 13, 2016, 05:49:33 pmYes, but you will need really high angular resolution. There is no way you are achieving that cheaply.Your are thinking in ideal terms, once you include all imperfections and backlash issues, your design cost will go though the roof. There is a reason why everyone is using classical Cartesian system.I mean, you can keep on dreaming, it is a good exercise, but I doubt you will find any serious supporters on this.

author: Chris Mr
author_rank: Regular Contributor
timestamp: September 13, 2016, 06:05:28 pm
content: QuoteOn what basis are you making that comment? By the way, vernier calipers are capacitive, not inductive as you stated earlier.https://blog.adafruit.com/2010/11/08/digital-calipers-tear-down/and that accuracy (+/-0.001") is with tiny platesYou are underestimating what I am suggesting

author: Koen
author_rank: Frequent Contributor
timestamp: September 13, 2016, 06:18:41 pm
content: You could team up withbootstrap : New Pick and Place design ideasandeneuro : Cheap recognition & pick & place & reflow oven solder machine for tiny PCBs.

author: Chris Mr
author_rank: Regular Contributor
timestamp: September 13, 2016, 06:57:47 pm
content: Koen, thank you for the suggestion - I'll read those threads through.There is another way I have up my sleeve too. In 1997 I was involved in making an ultrasonic positioning system which has a patent that runs out soon.https://worldwide.espacenet.com/publicationDetails/biblio?DB=EPODOC&II=1&ND=3&adjacent=true&locale=en_EP&FT=D&date=20020611&CC=US&NR=6404703B1&KC=B1That's for a single point to point system but you can use them in parallel, occupying different ultrasonic frequencies, to get more dimensions.The 3D version (which I have in a box) could resolve 0.001" over >40 Metres! It has two receivers on each side of a pair of glasses that can work out orientation (polar) as well as X,Y and Z. That thing updated at 1,000 times per second which at the time was quite something - probably still is!In 1996, when I started that one, doing square roots in a little processor was not possible (for real time work as it took too long) so I had to work out how to do the position calculations without square roots from the lengths and known fix station positions. How things have changed. All that can be done in the blink of an eye using nothing more than an arm processor these days with very little analogue.

author: C
author_rank: Super Contributor
timestamp: September 13, 2016, 07:28:08 pm
content: Chris Mrin addition to the linear cap, you might think of a second cap that has a repeating triangle pattern to assist main cap.See it serving two functions.The Max frequency change would let you compute the plate hight.The frequency change between the two limits should let you add more resolution.Calibration could be just moving at a almost constant speed and recording the results.Edit:A sheet medal shop should be able the cut some linear tapers to test with.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 13, 2016, 07:51:33 pm
content: X/Y motion is way down the list of problems. Steppers are cheap and work just fine, assuming you're not aiming to place 01005's on a 1 metre board.Pick & Place is not one big problem.It's lots and lots and lots of little ones, any one of which, if not done right, can reduce yield enough to make the machine basically useless.The biggest problem that nobody has yet found a cheap yet reliable answer to is tape feeders.

author: Chris Mr
author_rank: Regular Contributor
timestamp: September 13, 2016, 08:23:50 pm
content: C: (Is that how to pronounce your username or do you prefer just C)If the capacitor plate is constructed like a sawtooth, but only one long tooth and then two bits at either end, the abrupt change, which is in the wrong direction, is easy to spot and gives you two fixed points of reference. Moving towards the thin end increases frequency so a sudden drop is odd etc. The plates don't have to be wedge shaped either, they can be long thin rectangles and just positioned so that one part is out of view of the two ground plates. If you need more accuracy then just increase the angle of the taper.Glad mike mentioned the feeder issue; and it'd be good to hear more things to be aware of.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 13, 2016, 10:46:32 pm
content: Quote from: Chris Mr on September 13, 2016, 08:23:50 pmUnless you've actually used, or tried to build a pick & place you can barely begin to know all the issues involved. Most of them aren't to do with x/y positioning - that's a well-solved problem.

author: Chris Mr
author_rank: Regular Contributor
timestamp: September 14, 2016, 07:36:38 am
content: QuoteAh, I see. So the answer is to build something, re-iterate, re-design, re-iterate and so on. Everything done in a closed room where no-one else can see or offer their input?The thread does have "brainstorming" in the title - rather than "bashing"

author: daqq
author_rank: Super Contributor
timestamp: September 14, 2016, 08:13:30 am
content: Actually Mikes comments are reasonable - an XY table doing the positioning is the least of your worries here. XYZ movers of various shapes and sizes are becoming dirt cheap thanks to the onslaught of dirt cheap 3D printers. I just checked ebay, the cheapest 3D printer I saw at first glance was ~200 USD/pcs. This included various bits that are not required for a pick and place machine. See:http://www.ebay.com/itm/2016-Upgraded-Full-Quality-High-Precision-Reprap-Prusa-i3-DIY-3d-Printer-/281960334092?hash=item41a625430c:g:XugAAOSwtJZXXrqr&autorefresh=trueMaybe knowing your actual target budget would help.Yes, you can use DC motors for precise positioning, but you will pay with pricey feedback.If you want to go really dirt cheap, the cheapest, simplest (in terms of hardware) feedback system is to have no direct feedback from the motors, but rather from a camera that would look at the nozzle and determine the position of the nozzle based on what it sees - first the board could be scanned, compared with the image provided from the gerbers and a positioning "map" be made. Then it should be possible to determine the position of the nozzle based on which part of the board the camera is looking at. This would be obscenely impractical, computationally expensive, but probably reasonably precise I suppose.

author: Kjelt
author_rank: Super Contributor
timestamp: September 14, 2016, 08:29:55 am
content: P&P target markets are discussed numerous times, the result was that there are at least three markets: high end manufacturing, small time pro manufacturing and very small hobbieist market.You are targeting the ultra cheap hobbieist nothing to spent market, since the other two markets don't care what it costs as long as it is fast and reliable with the emphasis on the latter.The problem with this cheap target group is indeed as Mike mentions how to reliably and relatively fast sort the components that need to be placed without using feeders.Now if you find a solution to that problem that would be of great value to the community.A different cheaper XY placement HW is quite uninteresting since there are already a couple on the internet priced between $500 and $1000 and at least 100 persons have done and thought about this before you. Just my two cents.

author: Chris Mr
author_rank: Regular Contributor
timestamp: September 14, 2016, 08:54:50 am
content: Hi daqq,QuoteNot sure it would - any sound solution could be scaled.I have worked in R&D virtually all my life and the essence has always been to limit the scope at the end - to keep as much as possible in flux until you have had time to test, try, find failure points and so on. Only when you are happy with your "birds nest" do you commit it to finished hardware.QuoteOr several cameras, mounted at different heights, one high up to feedback where the PCB is etc. Computers are getting more and more powerful so vision systems will get more and more useful. Might even be able to do it on a smartphone (recycle old ones!). The great thing about cameras being that you can log the error conditions visually - look at them after the event rather than sitting around waiting for the event to happen and hope to see it.Storage space is also getting cheaper. I think we are already at the point where the cost of deciding to delete something is more than the cost of the storage, so having a complete log of operations would be a great idea - enter those little pill cameras.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 14, 2016, 12:15:03 pm
content: Quote from: Chris Mr on September 14, 2016, 07:36:38 amI've spent way too much time explaining to people who think they have "solved" pick/place why they are wrong. Plenty of threads here to look though.If you can find a cheap, accurate, consistent way of deternmining the position of the head in X/Y to around 0.05mm across the whole bed than maybe that would allow cheaper mechanics.Picking is at least as hard as placing, more so as parts get smaller.And don't even start with the idea that you can vision the board to get the placement position - it's covered in solder paste.

author: Chris Mr
author_rank: Regular Contributor
timestamp: September 14, 2016, 01:09:55 pm
content: Quote from: mikeselectricstuffand the reason you haven't done something about it?To put it another way, why take (way too much) time to explain when you could take time to solve given that you have the information in the first place?Quote from: mikeselectricstuffI wasn't, what I was thinking was that a camera above the placement head could see the position of the head; that's all, like a ballpark view. It can also see where the outline of the board is. That was all due to not being fussed about where the head is in-between fixed points.If your experience tells you that things go wrong then they need analysing and improving to get some new experience until they don't go wrong anymore. That's what brainstorming is all about..."What about the situation when the jack box spring deflects more than expected due to friction in the scrunion pully" etc. Ever tried teflon on the scrunion pully bearing?What is experience worth if you never use it

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 14, 2016, 01:32:28 pm
content: Quote from: Chris Mr on September 14, 2016, 01:09:55 pmI don't have the answers, just trying to save wasted time on hopeless approaches

author: ebclr
author_rank: Super Contributor
timestamp: September 14, 2016, 01:50:57 pm
content: If you really want's to go to on the closed loop dc motor approach here a IC that will make your live easierhttp://www.ti.com/product/fdc2212-q1But will never surpass stepper motor open loop in simplicity and cost

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 14, 2016, 02:10:39 pm
content: Quote from: Chris Mr on September 14, 2016, 01:09:55 pmWhat use is that - you need an accurate posiiton. Ballpart isn;t usefulQuoteHow is that useful ? You need the fiducial positions.

author: Brumby
author_rank: Unknown
timestamp: September 14, 2016, 02:52:13 pm
content: This discussion seems to have two rather distinct views on the subject.One comes from the conceptual perspective, floating a 'new' idea, backed up by a few techniques that have shown qualitative value.The other comes from the practical experience of actually making a real-world mechanism perform.The chasm, nay ABYSS, between these two is nothing short of galactic!Just because you have an idea for motion and another for measurement, does not mean you will be able to produce a mechanism that can perform in the real world. It doesn't mean you won't, either.The big difference comes from all that stuff that comes under the heading of "product development" - something which is completely absent from the "concept view" camp. It's in this part of the process that issues like backlash, torque, overshoot, acceleration and a hundred other parameters are thrashed out ... and where limits of components are discovered and alternatives are examined. If an existing technology cannot achieve the necessary objectives, then the success will rest on the development of new technology that can - if that is at all possible.This is where the "practical experience" camp has weighed in. There are some practical issues that the "concept view" camp have not even raised, but will have to address and resolve. Ones that, in many cases, members of the "practical experience" camp have already been burned and learned.Until the "concept view" camp have actually ventured down the path of a practical implementation, opinion between the two camps will not converge.The "concept view" camp has the optimism - and the "practical experience" camp has reservations, if not doubt. Who will win out will never be settled until the new idea has been put through the development wringer. The big question is ...will that happen?

author: Chris Mr
author_rank: Regular Contributor
timestamp: September 14, 2016, 04:30:36 pm
content: ebclr, thank you for the suggestion, unfortunately that device is limited to under 14k samples per second. I was thinking of using a cascode (great isolation) oscillator where the capacitor is in a tank (with an inductor) - oscillating say a few MHz to give very fast update rate. That would go into a psd (4046) whose other input is the DDS (which are normally 32bits, 28 bit resolution go to 0.05Hz) to a PID and then audio amplifier.Suppose you go for 1/2 octave change from 7.5-10MHz, even with a 28 bit DDS, you get 2,500,000 / 0.05 = 50,000,000 gradations of 200mm would be 4 nano meters - well into detecting the imperfections of the edge of the tapered capacitor. Clearly the range has to be more than 200mm (that's just the size of the board) but the figures tell you that it's well within reason.For a turntable type axis you only need half the distance as the business end only needs to go (precisely) through the middle. You can turn the turntable to get to the other side.QuoteIt is if you want 'belt and braces' - "My position system is no-where near where my visual feed back says it should be - yipes! now would be a good time to stop" - before it impales itself into the opposite wallQuoteIf someone removes the board, or something lands on it, or someone moves their arm nearby - belt, braces & safety pin(s)I agree Brumby,Maybe one issue is lack of information about my character. I am not Meredith Perry, I don't go blindly into things and think I can do it just because I think I can. I am more cautious than that. I am confident about the position measurement because I have used it many times. One version was used at Leeds university to measure the amount piezoelectric devices move when stimulated - that could resolve well under a 100nM.I have built CNC machines that are rigid - none of this gantry stuff, real "built in a box" devices. I am fully aware of backlash which is why a servo system offers so many advantages.Somehow text doesn't convey the necessary information - but I am trying (very trying)

author: TheSteve
author_rank: Unknown
timestamp: September 14, 2016, 07:15:21 pm
content: I would suggest using/operating a few different pick and place machines before trying to design one. It's all the little things that end up being a pain.Like it or not everything Mike has said is bang on.

author: C
author_rank: Super Contributor
timestamp: September 14, 2016, 07:49:14 pm
content: Quote from: mikeselectricstuff on September 14, 2016, 12:15:03 pmQuote from: mikeselectricstuff on September 14, 2016, 02:10:39 pmUsing a image of board with solder paste and a image of bare board it should not be too hard to get a mask of solder paste locations.This results in two outputs that could be used separately or together.1. Does image of board less masked area have enough information remaining to place parts?2. Does the solder paste have enough information to place parts?So you know for a fact that #2 above can not be used as extra fiducial positions in an optical positioning system?This is a huge change from old school to using machine learning to do the job..I see cheap light weight optics as a foundation to other changes.These optics could make a huge difference in the feeder area.

author: Chris Mr
author_rank: Regular Contributor
timestamp: September 15, 2016, 08:07:22 am
content: Quote from: CCouldn't agree more.Seeing the deepmind agent play space invaders & finding the solution to breakout got me going - and it only took a few hundred attempts to get super human.Imagine giving the machine a few different pick tools to try on different components - it would very soon work out which was the best for any given component. That would lead to making better pick tools and so on.You would imagine pick and place machine learning being for one machine but what if you network many machines that are attempting the same task !

author: Koen
author_rank: Frequent Contributor
timestamp: September 15, 2016, 08:20:01 am
content: So, what's your plan ? What are you going to work on first ?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 15, 2016, 08:46:17 am
content: Quote from: Chris Mr on September 15, 2016, 08:07:22 am

author: Chris Mr
author_rank: Regular Contributor
timestamp: September 15, 2016, 09:08:14 am
content: Hi Koen,I'm still wondering what the best layout is for it getting access to components and board. I really like the idea of a ring around the outside of the board area that can rotate 360 degrees with a gantry fixed to it (or even two orthoganal grantries) that goes through the centre of rotation (so it can reach any position on the central area).But there are many possibilities..

author: Chris Mr
author_rank: Regular Contributor
timestamp: September 15, 2016, 09:14:23 am
content: Good to see mike is having a good old think about it. Let's all join in

author: Kjelt
author_rank: Super Contributor
timestamp: September 15, 2016, 09:15:44 am
content: If you even had half the P&P experience Mike has you would be very

author: Chris Mr
author_rank: Regular Contributor
timestamp: September 15, 2016, 09:29:21 am
content: Hi Kjelt,In machine learning terms what you are talking about is "grandmothered" - lots of experience that only allows one way thinking.This is what new generations are for. They don't look at the problem the same way as they don't have the experience - so they come up with different solutions; or they make a mess of it; either.But they do something

author: Kjelt
author_rank: Super Contributor
timestamp: September 15, 2016, 10:15:34 am
content: They are designing these kind of machines for over 40 years, it is as with cars, the biggest innovation of the last decade is change the petrol engine for an electric engine, but there are still 4 wheels and the elementary principle has not changed since the t-ford.If you want to innovate a P&P you will probably have to change other "standards" that are fixed and blocking in the industry such as the packaging of the components, or the reflow process it self.So yes there are a lot of SciFi innovations possible such as floating transport carriages that place the individual components and then weld it to the pcb and hundreds working simultaneously, but given the XY placing problem and camera usage therefore I doubt there is a more optimal solution, still surprise us but patent it first

author: Chris Mr
author_rank: Regular Contributor
timestamp: September 15, 2016, 10:36:16 am
content: Hi Kjelt,The subject of patents is probably another 10 threads (underestimate). I have had lots of experience of them so am probably grandmothered!It would seem, from my experience, that patents are a tool used by large companies against either small companies or other large companies. It isn't the cost of getting them that's the barrier (even though that is considerable) it's the cost of testing the patent in court - hence why it is used by large companies. Owning a patent doesn't really have much value; once you've been to court, and won, it has a lot of value.Large companies tend to be slower to change - so you can counter getting a patent by changing quickly. Put another way, if by the time someone copies what you have done you are in front of them, you win

author: Kjelt
author_rank: Super Contributor
timestamp: September 15, 2016, 11:16:09 am
content: Yes lets not go into patents indeed.

author: Koen
author_rank: Frequent Contributor
timestamp: September 15, 2016, 11:29:30 am
content: Guys, I have a brilliant idea. Hear me out. Floor space is expensive. Vertical space is cheap. Industry needs more space-efficiency. Let's reinvent the reel. Instead of a small center hole, let's make the hole a meter wide. In this space, let's have a pick and place : a gantry surrounded by a 2 meters stack of horizontal reels. The gantry rotates, its base moves up and down. The PCB is introduced on top. All the components of reel 1 are placed. The base plate lowers itself one level. All components of reel 2 are placed, boom it goes down to reel 12. After all useful reels are done, the PCB continues a few steps lower into a warm bed of vapour and reflows. Then it shoots back to the top to be packed. It naturally warms going down to activate the flux and naturally cools when going up, brilliant. I've assembled a quick proof of concept :

author: Chris Mr
author_rank: Regular Contributor
timestamp: September 15, 2016, 12:05:18 pm
content: proper brainstorming material thereBy removing the vapour phase stage and make it separate, you could then process a board at every level - in parallel, think of the throughput of that lot. Obviously you would have to have components like 100n on more than one level, else it would be down to how fast you process them, but so what!A ring of reflow ovens pointing out from the centre to take the boards away.It is interesting to think that whilst components are delivered on reels, with nicely spaced holes etc, ready to go on machines, there is no reason why they couldn't go onto "bespoke processing jigs" (AKA reel with Meter wide hole in it or whatever) first. Of course this is what a feeder is - a bespoke processing jig - but it could be completely different.I remember doing brainstorming training. We were tasked with designing something that's impossible to make. After about 20 minutes of heated discussion, and one member of the team saying nothing, we came up with a box with 3 dials and one button. One dial was "where you want to be", another was "when you want to be there" and the last was "how big you would be when you got there" - the button was to make it happen.We were all pretty pleased that it would indeed be impossible to make.Then the guy who had remained quiet said "and it all has to run from a PP3 battery for a year"

author: macboy
author_rank: Super Contributor
timestamp: September 16, 2016, 01:03:41 pm
content: Consider that a hard drive head is positioned using a linear (non stepping) motor, to a precision orders of magnitude higher than necessary for a P&P, and it hits that mark within single-digit milliseconds.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 16, 2016, 01:30:24 pm
content: Quote from: macboy on September 16, 2016, 01:03:41 pmBut it uses closed-loop servo feeedback from data on the disk platter, and operates over a much smaller distance.

author: Chris Mr
author_rank: Regular Contributor
timestamp: September 16, 2016, 03:54:34 pm
content: Quote from: Koen on September 15, 2016, 11:29:30 amHas Koen hit the nail on the head - just point the hammer at a different nail?Time taken from getting the business end from picking up the component to placing it will always be affected by the distance traveled, the further the distance the longer it takes. The plan area of the board can't be changed (apart from by redesign) but the way the components are presented can.Ridiculous as it sounds, can the components be removed from the reels / waffles etc and then stacked vertically - the expensive floor space (that takes time for the business end to traverse) could be reduced by many times if the parts are right up to the edge of the board?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 16, 2016, 06:31:21 pm
content: Quote from: Chris Mr on September 16, 2016, 03:54:34 pmMost boards have a fairly uneven mix of parts, so you get close to this by simply putting the most-used parts in the closest feeders.For boards with a very large number of a particular part, e.g. LED strips, mounting a feeder on the head would make some sense - I've seen a video of what AFAIR is a homebrew machine that does this - can't immediately find it.De-taping parts ahead of placement isn't very sensible for a number of reasons, including that you don't necessarily know exactly how many will be used, due to mis-picks/vision fails etc.Also handling of loose parts would be difficult - getting hard ceramic parts of varying sizes with sharp edges to move reliably is going to be even harder than making tape feeders.I have occasionally wondered about something that resembles a PEZ dispenser for chip parts....Here's one impressive system using non-taped parts

author: Koen
author_rank: Frequent Contributor
timestamp: September 16, 2016, 08:14:06 pm
content: This might be the video you were looking for Mike :

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 16, 2016, 08:25:07 pm
content: Quote from: Koen on September 16, 2016, 08:14:06 pmYes that's the one.

author: rx8pilot
author_rank: Super Contributor
timestamp: September 16, 2016, 08:39:12 pm
content: Quote from: Brumby on September 14, 2016, 02:52:13 pmYes.My first adventure in precision motion control was for an advanced stereo 3D camera system. I designed it conceptually without any real experience. It did not work. Not even close. By the time I dealt with all the real world issues, it was vastly more complicated and expensive and the capability was about half of what was originally dreamed.My view of P&P before I got one was very Utopian and simplified. One I purchased one and started making PCB's, the practical reality smacked me like a 10-ton truck. Designing a P&P machine with no previous experience will lead you toward a very expensive and time consuming learning curve. The most important thing to remember is that P&P exists to solve a business problem - not a hobby problem. if you need to assemble 3 PCB's, you get a microscope and a vacuum pickup. If you are making 100's of PCB's - they are probably not just for fun. In the context of business, a P&P needs to be very solid and reliable to have any value. Speed and many other whiz bang marketing features are useless if the machine mis-picks just one part on every cycle.The established methods have been established after massive amounts of experimenting and practical every-day lessons. At the end of the day, it is a fools errand to make a cheap P&P. The 'cheapness' gets VERY expensive when it does not get the job done. The goal of P&P should be to deliver properly assembled PCB's every time at a tolerably fast speed. Making the first requirement of a new design -'CHEAP' ensures failure. When that requirement is combined with a design group that has never used or designed anything like it - makes a successful outcome not likely.I would look at existing successful designs - big-small-expensive-cheap. You really cannot simulate experience, so you need to listen very closely to those that do this all the time. Some make PCB's 24hrs/day while some (like me) only make a handful of PCB's per month. Some make the same board over and over while some are constantly changing the setup.The time and cost of P&P is NOT the motion control system. It is the feeders, the operator, software, change-over speed, reliability, and other things. A novel way of moving and detecting position will not be much of an added value in the context of a full assembly system.

author: Kjelt
author_rank: Super Contributor
timestamp: September 16, 2016, 09:07:32 pm
content: This is pretty good, 8 and 16 gattling heads they can interchange, they even can load the new reel when the old tape is still processed and the feeder automatically concatenates the new one, did not know that was possible , but then I am not into this business.

author: rx8pilot
author_rank: Super Contributor
timestamp: September 16, 2016, 09:14:37 pm
content: I think that after hiring Industrial Light and Magic to produce that video - they spent the cost equivalent of 1,000 Neoden4 machines for a promo piece. That is big biz to justify that effort. Huge effort.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 16, 2016, 10:18:26 pm
content: Quote from: rx8pilot on September 16, 2016, 09:14:37 pmYes but just one of those machines with feeders is going to be many hundreds of thousand $, and they're aiming at people investing in multiple lines, so the cost of the video is small change.

author: rx8pilot
author_rank: Super Contributor
timestamp: September 16, 2016, 10:21:13 pm
content: Agreed.... it is indeed big business that very much demands super slick marketing. If I was spending $millions, I would certainly expect an amazing presentation.Sent from my horrible mobile....

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 16, 2016, 10:23:10 pm
content: Quote from: Kjelt on September 16, 2016, 09:07:32 pmNot at all clear how it handles the cover tape though... looked a little suspect to me.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 16, 2016, 10:24:38 pm
content: Quote from: rx8pilot on September 16, 2016, 10:21:13 pmAnd if you're only spending $thousands, this is what you can expect...

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 16, 2016, 10:33:05 pm
content: Nice example of a highly specialised pick/place setup :

author: Chris Mr
author_rank: Regular Contributor
timestamp: September 17, 2016, 06:39:59 am
content: Quote from: mikeselectricstuff on September 16, 2016, 06:31:21 pma simple plate, just slightly thinner than the component, arrangement with a hole in it (fancy shapes allowed) sliding perpendicular to a tube of parts would be one way - a rubber bung (which is only for example, rubber has too much stiction) in the bottom of the tube and low pressure air keeping everything under slight compression would effectively "feed" the parts upwards. Friction from one part to the next allows the (fancy shaped) hole to guarantee that one edge (possibly two if everything is at 45 degrees) are in a known position. A lid over the top of the tube stops them all flying upwards so just a slot either side of the lid allows the plate to move in and out.and it might be that there's a way of picking them straight out of the top of the tube - or rather feeding them upwards so there is always one at the top once one has been pickedSuppose you started 'tubing up' with resistors. If the tape were laid upside down on a table and arranged to go into a tunnel so that you can use the cover tape as a means to unwind the reel, you could arrange the (slightly bigger profile than the component) tube under a hole in the table so that when a component is in place a simple punch pushes the part down. Here, gravity is your friend and there is no where else for the component to go. With a rubber bung (again, rubber for example) in the tube first, the punch only has to overcome the resistance of the rubber bung so it wouldn't be a punch, more of a push. The punch doesn't even need to be the same size as the part; perhaps something more 'spikey' or 'knifey' so there are no paper / cardboard shavings clogging things up.You could put as many components in the tube as you like. 0805 is about 0.5mm thick so a complete reel of 3,000 would be 1.5M long (too long) but 1/2 a reel would be ok at 750mm (goes under a table anyway).It ought to be possible to do that really quickly - 10 per second? (de-bandoleers are that order so I would guess faster) That would be 36000 per hour so it's getting there.The point being that one 0805 resistor 'jig' could replace many 'feeders' and lower the floor plan of the pick and place machine.An 0603 could be the same 'jig' with a different hole in the table - move everything over a bit or just a different die.SOT23s are arranged with the legs pointing away from the direction of travel so they could be done similarly as one would slide onto the top of the previous one.I can see TQFPs would be a challenge unless they can be picked right out of the top of the tube - and I can see that teeny parts (like 01005) would require a more specialised dooings but they are really special cases anyway. Gaussian theory - 80:20To put it another way, reels of components have poor packing density when it comes to how many are on a board vs the machine floor plan they take up (as the video mike added shows).

author: Chris Mr
author_rank: Regular Contributor
timestamp: September 17, 2016, 09:12:00 am
content: Supposing the tube were 0.5mm wall thickness (which is an exaggeration) then a complete series of 0805 E96 (1%) series would measure a little over 25mm square.Now, I don't know about anyone else, but as an amateur wanting to build a few boards, having a little box 25mm square by say 100mm long (with a lid of course!) that has the whole E96 series in it and 200 of each would be good for me.If you did that with 0603 resistors, 0805 resistors, 0805 capacitors, 0603 capacitors diodes and so on, in an area no bigger than A4 that would be really useful.The caveat being that one would need a way to push them up that stays where it is - which I'm thinking about. Maybe an x,y over something that can move up one, like a screw thread; winds down to the bottom, you move the box over the screw thread, as you pick the part the screw thread winds up until the next component comes flush with the top (camera?). Just a few thoughts, nothing fixed yet.Actually, you could close the lid on the box and pressurise the underneath - everything would go to the top again.Endless possibilities(Turn the box over and pressurise it to put it into 'filling mode')

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 17, 2016, 09:17:19 am
content: I don't think floor footprint is a really major issue for anyone in the overall scheme of things - if you really wanted it to be compact you could move reels partially underneath, or maybe overheadI think it would be really difficult in practice to handle loose parts - because they're hard ceramic they bounce like crazy. As you get to smaller sizes you start getting some electrostatic effects. Thicknesses vary, especially for capacitors, so any system would need to be adjustable for thickness.There might be some very specialist cases where it would make sense to unload parts from tape into a loose-part PEZ stacker ( e.g. the LED example - transfer a stack from a tape feeder to to the head to reduce moves), but it's not going to be generally useful.Multiple heads are the most obvious way to save move time, and has the advantage of scalability - most other solutions are going to be very niche and only worthwhile in a small market segment.A lower-end approach to the Siplace bulk feeder would seem to be very viable, and especially applicable to low-end machines that will be used for smaller runs and prototyping.Vision is cheap, so a system can be envisioned where you manually fill trays with loose parts, which are then located with vision, and the tray tapped/vibrated as required to shuffle them around, and the pick location signalled to the pick/place system.

author: tooki
author_rank: Super Contributor
timestamp: March 30, 2017, 07:10:15 pm
content: Quote from: mikeselectricstuff on September 16, 2016, 10:24:38 pmI assume you mean MX$thousands?