PCB Engraver, 3D Printer, P&P Machine - Page 1
Forum section: electronics / projects

author: Indodude
author_rank: Newbie
timestamp: July 20, 2012, 04:03:03 am
content: Parts~Stepper Motors : $60~Stepper Motor Drivers : $30-40~Wooden Frame : $20-30~Tracks, Gears, Misc. : $20-50~Micro Controller : ??(Up for discussion)~Air pump : $20-30~Drill : $30-40~Extruder : $20-30~???Explanation~For now this is an idea that i hope will become a reality so everyone could have the benefits of these machinery without the high costs.~Please do not bash this idea just because you don't want to accept that it could be done or don't see how it will.~This is a thread meant to fine tune everything to actually get a working design/model which i will design after everything has been worked out.~This will be open source so anyone could build it at home. Mass production possible.How it works~The way it would work is that it would use the same frame and motors but different software controlling the motors for the 3 different uses.~The extruder/drill/P&P nozzle will be interchangeable to allow for different uses but probably will not be designed to be used all at once.~All it is is combining the different machines into one compact 1 meter cubed area to fit on a basic lab table or so.~I don't expect anyone to understand how it will work until i draw a basic representation of what it will look like and how these goals will be implemented.~I am 15 years old but don't take me as any other 15 year old as you should never underestimate me or others.~All the parts i listed above i estimated to cost $300 at most but i am leaving it to $500 just in case if i may be wrong or if any parts are added.~This most likely will NOT be a CNC mill as the gear system would get too complicated (Larger motors cost more so a gear system might be required) and it is best to keep things simple so there would be less room for error.~I would probably name the open source project the IndoLab or Indroid but that would be left for discussion.

author: David_AVD
author_rank: Super Contributor
timestamp: July 20, 2012, 04:20:23 am
content: 3 metres cubed is pretty big (3m x 3m x 3m). Did you mean 3 cubic metres by chance?I think you have grossly underestimated the "tracks and gears" pricing unless you are only wanting very rough (and not repeatable) results. Likewise with the "drill" part.

author: Indodude
author_rank: Newbie
timestamp: July 20, 2012, 04:24:17 am
content: Yeah i was just estimating because who knows, it might be possible to find something relatively inexpensive that works great.

author: free_electron
author_rank: Super Contributor
timestamp: July 20, 2012, 04:34:07 am
content: I think your prices are grossly underestimated ...3 meter cube. you will need some big steppers to handle such a large platform.I don't see a power supply for this beast in the price ...Wooden frame ... that's going to get wobbly for such a large machine. Or you have to use thick wood and then you will need heavy steppers.You could do multiplex but you need to go the laser cut route. not everyone has a precision wood workshop. The frame parts need to be available ready make like the guys from makerbot did.I would love a pick and place robot style makerbot , but i am only interested if i can buy the mechanical stuff all ready cut to correct size. I don't have metalworking or woodworking tools nor the skill to cut two pieces of wood to exact size. Any dimensions discrepancy and the whole things goes to stink. Assembling a kit like the makerbot is no problem. making all the parts IS a problem ! for a lot of people !So the design should be available as either a DXF file or a 1:1 scale vector file ( illustrator or coreldraw compatible. you could use SVG using free tools like inkscape for example) so it can be read by popular lasercutters such as the Epilog. Then people can have this cut by one of many services like pololu or techshop in either wood or an acrylic material.Extruder i am not going to comment on. I consider plastic extruders crap. The output quality is coarse, brittle and overall poor. Rapid 3D prototyping should be done using laser sintering or liquid polymer. Those create excellent results.Pick and place... you forgot a bunch of stuff :- tape feeders .. you will need a mechanism to feed the tape and advance it every time a part is picked. you'll need one motor per feeder... or you could go with electromagnet and lever advancer... but prepare to blow the budget out of the water ... a commercial pick and place machine will eat an equal or larger amount of money in feeders for the machine than the base cost of the machine ...- stick feeders ...- tray feeder ... for multitrays ..Now comes the hard part :- you need a detection for a mis-pick- you need a way to detect the orientation of what you picked from the tape- you need a way to rotate the part along its axis before placing...- you need a way to detect correct rotation- you need a way to correct x-y and theta offset of the board positioning..In other words. You need a vision system... there goes the 300 pricetag....A good start would be the makerbot platform and modify that. All mechanical drawings for all parts are available.Just make the extruder part removable and have a pick and place head go in place...The design of that head and part rotation / alignment alone will be a serious job.Second key problem : control softwareA pick and place is useless without good control software. That means you need to be able to read coordinate system , scale it and angle offset it .PAP files give you part center location X and Y , a rotation angle, top and bottom and part description. The operator simply tells 'all parts with this description are on feeder x. The machine does the rest ! if you flip the board over the machine needs to do coordinate translation...Anything more complicated than that is unacceptable.Just my two cents. I'm not bashing the project. I'm just feeding you the reality.

author: Indodude
author_rank: Newbie
timestamp: July 20, 2012, 04:56:56 am
content: ~First of all it is 1 meter cubed~What you are trying to do is hold this up to 20-30k P&P standards to mass produce boards which makes you ignorant in my eyes. When all you need is predefined locations.~The price tag i stated was 500, the material estimate was 300-500.~I was already thinking of getting an open source company to take on the production to sell kits for it etc.~The extruder is necessary because it is the cleanest way of producing 3D models with relatively precise accuracy and is cheap.~If you need to imagine something imagine a maker bot 1 meter cubed but with all the uses i described.~The size of the motors would be close to that of the maker bot as well.~Plus as i stated, this is an idea and is open to change. I just needed a support for the design so i described what was required for it to do.

author: Monkeh
author_rank: Super Contributor
timestamp: July 20, 2012, 04:59:01 am
content: Quote from: Indodude on July 20, 2012, 04:56:56 amHow is a pick and place machine going to pick and place when it has no way to feed the parts, locate the parts, locate the target for the parts, or orient the parts?

author: Indodude
author_rank: Newbie
timestamp: July 20, 2012, 05:03:00 am
content: Predefined locations, plus you could use a very small motor to push the reels forwards if a part is picked from a specific reel. I know it may seem a little unreliable but you can't expect to have every problem solved right away that is why i opened this thread so you guys can help me elaborate the designs.

author: Monkeh
author_rank: Super Contributor
timestamp: July 20, 2012, 05:08:20 am
content: Quote from: Indodude on July 20, 2012, 05:03:00 amPredefined and located how? What method do you use to ensure the machine knows precisely where the board and the reels are in three dimensions and can check this on the fly?Please bear in mind that youdoneed high precision or the entire idea is pointless. You get it wrong by so much as .5mm and you've missed. Game over, pins on the wrong pads.

author: free_electron
author_rank: Super Contributor
timestamp: July 20, 2012, 05:15:16 am
content: Quote from: Indodude on July 20, 2012, 04:56:56 amFine, that's a great way to start when i want to help you to get this on track. I explicitly said i am not blasting you i am only telling you what is required for the BARE MINIMUM pick and place.even the simplest homebrew pick and place needs :- a location to put multiple reels with parts and feed one reel one step forward at a time. so this is either one motor per feeder or one electromagnet + ejector mechanism per feeder- you got the x-y gantry to pick a part.- but now comes the problem you need to be able to rotate the part and verify it's position as it sits on the pickup head.- second problem : how does the board sit on the table.- third problem figure out where you really need to be base don infor from problem 1 and two and the pick and place data ... you need the end x , y and theta.if you cannot solve the above 3 problems you have no pick and place machine. it's a simple as that.moving the pickup head to the feeder at a fixed position is easy , picking the part too.But figuring out how to get it where it needs to be , compensating for all offsets and rotation s is the hard part.. the maths is easy , it's obtaining the measurement that is hard !I deliberately left out the 20K$ machine features like upward looking camera's, teach in camera's , fiducial recognition , missing pin detection , glue dispensing and other fancy bits.I only gave you the bare minimum for a pick and place to do its work : pick a part : figure out how it is holding it right now and figure out what it needs to do to get it in its target spot under the right angle.If you fail to see that then you are the ignoramus. and that's all i am going to say about this. good luck with your project.

author: Indodude
author_rank: Newbie
timestamp: July 20, 2012, 05:33:31 am
content: I am sorry i was just mad because everyone else bashed the idea when i proposed it in the chatbox. :/ But yes i will review everyone post and see if i can incorporate them into the final design. everyone please send a list of everything i need and need to make sure of and i will try to buffer the finished design to the best of everyone's specifications. Please make them numbered etc so i can make a list of everyone's list easily. I am open to everyone else because i really do want to make an inexpensive all in one sort of machine. First i will draw out the dimensions then i will try to make a 3D model of it in some software for ubuntu.

author: free_electron
author_rank: Super Contributor
timestamp: July 20, 2012, 05:55:37 am
content: get on youtube there's a bunch of people already made such a thing with various idea's and successrates.picking off the good parts of each build should get you a workable machine.here is a couple of things you can not escape and will make your build easire :try to find a stepper motor with a hollow axis that goes all the way throught the motor ( so the axle sticks out both sides. ) they do exist.get a rotary vacuum coupler. put the pickup nozzle on the other side. that way that mechanical conundrum is solved.Do't bother making your own pickup nozzle. it's precison engineering and they are cheapyou can buy them here :http://www.madelltech.com/m2-2_parts.htmla couple of good video's that should give you idea's :camera :nozzle changing and holding :feed mechanism :Good bas idea but i would alter the feed mechnism and not use the nozzle ( they use stupid piece of plastic.. not good ) to advance the tape. try to come up with a peeling mechanism to strip off the foil of the tape as well. have a separate 'advance - pin ' that you can extend and retract simple electromagnet with a spring would do the trick. something like a car-relay has enough lift to do this kind of stuff.gantry system :especially watch the dual head in this machine : one extends a pin to move tape forward , other one has the pickup nozzle.anothe rpickup head construction :looks like a stepper motor with worm drive from floppy disk or cd rom lens transport. he's got some optical indexer in there as well to find zero spot of that motor.he is using commercial feeders though.this is a very advanced homebrew :he is using usb cameras and does vision recognition on the pc ... dirt cheap as a usb webcam is 20$ ... he has a smart 'centering method. he adjusts only the angle and measures the size ( length and widht using the camera), then moves the head inside a small box in a fixed pattern. this pushes the part aroudn so it becomes centerd on the nozzle.some more idea's :check out SMTmax and madell machines. there's plenty of video's and pictures to 'steal' idea's from.it can be done. plenty of machines on youtube that were homebuilt.

author: Indodude
author_rank: Newbie
timestamp: July 20, 2012, 06:08:43 am
content: Thankyou. By the way, i think you may like the way i set up the interchangeable holder for the different uses of the machine. I will make a drawing soon and post it.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: July 20, 2012, 07:43:55 am
content: As others have mentioned the biggest problem in making a cheap P&P is feeders. Without reliable and cheap tape feeders, any other effort is a total waste of time.Anyone can put a pickup head on an X/Y gantry, although getting sufficient accuracy and reliability whilst moving fast enough to be worthwhile is generally expensive.Speed is also not something that can be ignored - if it takes 10 seconds to place one part it is not a useful machine or any real work.For the accuracy problem, I think the only answer that could ever be cheap and scalable would be to throw cheap computing power at it, i.e. use clever vision/sensing methods to provide closed loop position control of lower-cost mechanical parts.It is also possible that computing power could solve the feeder problem. Imagine a row of dishes, with vibrator motors on them and cameras looking down. It would in principle be possible to recognise and pick loose parts.

author: Indodude
author_rank: Newbie
timestamp: July 20, 2012, 07:49:15 am
content: Everyone will know what my mind is capable of soon enough. I will design a very cheap way of doing this whether people think it is impossible or not. In fact i already thought of a way of doing it with a laser mouseBut it might not work i have to see a reel of smd components in person first.

author: Galenbo
author_rank: Super Contributor
timestamp: July 20, 2012, 01:21:04 pm
content: Quote from: Indodude on July 20, 2012, 07:49:15 amPromises, promises. Much chicken croaking. Instead, simply show us the eggs.Wether your 15 or 72 years old, I will not on purpose under/overestimate your skills.What new software you found, what platform you'll use for some software painting, I don't care.What user advantages it will have, are for the marketing development later on, to print on the box.Simply build a wooden/other structure to lift 5 kg, or drill a hole with 1mm accuracy 50cm away.And make a list of real tech specs (s.m.a.r.t. can be your guide, read it) andbuildsomething.Then you'll see, then you'll learn, expierience, get some other unexpected expierience.I've been 15 also, but that didn't make me capable build such things for under 3000 euro.Maybe start with a single motor, 1 driver and 1 slider. This will make you learn about spindles, greasing, clearance, resistance, backlash, temperature, bearings specs, xyz and angular load,...If you haven't gone throug this, you're like someone who says he'll climb the 2 highest mountains in the world, on the same day."everybody bashes my idea"

author: Wilkins
author_rank: Contributor
timestamp: July 20, 2012, 01:43:06 pm
content: Quote from: Indodude on July 20, 2012, 07:49:15 amAnyone who knows basic manners would be thanking Free_electron, Mikeselectricstuff, David_AVD and Monkeh for helping them instead of talking themselves up.A little bit of humility will serve you much better, anyone who tells you they are brilliant and better than anyone else is a dickhead, that is the wrong attitude for this field, there is always something new to learn no matter how experienced/capable you are.

author: free_electron
author_rank: Super Contributor
timestamp: July 20, 2012, 01:53:15 pm
content: Quote from: Indodude on July 20, 2012, 07:49:15 amNow i am getting scared and sceptical... Up till now i was neutral and interested.So, You have not seen a reel of parts... Yet.. But you have a full blown idea on how to make a machine that handles them.... Which leads me to the following question : have you ever seen a real P&P ? Have you ever seen several different mechanisms for a P&P ? Linear motors ? A 'spider' ? A vinbrafeed ? A turret based macbine ? A dual gantry machine ?Do yourself a favor : go look at an assembly plant where they have a couple of machines like Siplace or Juki or Quad or Panasert. Especially the siplace is impressive. Rotating head with 32 nozzles. Two gantries. One is loading while the other shoots parts. It's like a friggin gatling gun....

author: Monkeh
author_rank: Super Contributor
timestamp: July 20, 2012, 01:54:57 pm
content: Quote from: free_electron on July 20, 2012, 01:53:15 pmHe was talking about making this thing a CNC mill too, earlier. Because the real things don't start at $20,000 for a reason, that's just what they want to charge.

author: David_AVD
author_rank: Super Contributor
timestamp: July 20, 2012, 10:31:18 pm
content: We're part way through building a small (approx 800mm x 500mm x 150mm travel) CNC mill at work.So far it's cost about $3000 in basic parts alone (steppers, drive boards, PSU, base frame, acme threads, bearings, etc).We haven't even gotten any of the gantry Y/Z metalwork made or bought the spindle motor yet!

author: LEECH666
author_rank: Frequent Contributor
timestamp: July 26, 2012, 10:10:06 am
content: This thread gets my vote for thread of the year.?Genius or a mild form of thishttp://en.wikipedia.org/wiki/Dunning–Kruger_effect?

author: David_AVD
author_rank: Super Contributor
timestamp: July 26, 2012, 10:29:01 am
content: Quote from: LEECH666 on July 26, 2012, 10:10:06 amLMFAO !!!

author: EEMarc
author_rank: Regular Contributor
timestamp: July 27, 2012, 02:50:02 am
content: I never thought I'd learn something from a Leech.I've seen that effect a lot. Now I have a name for it.

author: Wilkins
author_rank: Contributor
timestamp: July 27, 2012, 08:23:23 am
content: Quote from: LEECH666 on July 26, 2012, 10:10:06 amI love it, reminds me of a a technician i have to work with.

author: LEECH666
author_rank: Frequent Contributor
timestamp: July 27, 2012, 11:39:12 am
content: Quote from: EEMarc on July 27, 2012, 02:50:02 amOh that's just a nickname. I can assure you that I am a human being.