Re: [time-nuts] pick and place problems/design (was: OT stuffing boards)
I'm not a fan of tweezers either. I use a sticky toothpick. Post-it note glue. Tweezers tend to make parts fly off into space. As for parts moving around, that is what vision is for, to find the part that needs to be picked up. On Sat, Jun 25, 2016 at 7:52 AM, Bob Camp wrote: > Hi > > Even on a “real design” desktop pick and place, vibration is an issue for > parts moving around. The same > is true of parts “squirming” on a pick head as it does it’s thing. Part’s > aren’t as flat as you might think they > are and you can only get just so much vacuum. > > Lots of grubby design details. > > > > One thing that has not been covered so far is (at least to me) the best > way to do manual pick and place. > A lot of people try to do it with tweezers. I find that to be a massive > pain. A vacuum pickup with a foot > switch goes *much* faster for me. It also is a much better way to keep > your hands out of the solder paste. > You can get some nice long pickups. A setup is not very expensive, even > with an illuminated magnifier to help see > what you are doing. > > As an added bonus, some systems will let you reverse the pump and use it > to dispense solder paste. The > net result is that you have an effective way to both put down solder and > place the parts. I prefer stencils for the > solder side of things, but that is very much a mater of debate. > > Bob > > > > On Jun 25, 2016, at 9:16 AM, bownes wrote: > > > > And try to tell transistor A from transistor B from diode C when they > are all upside down. > > > > A moving head design can be made to pick up parts off of reels on all > four sides. But it takes more table space. Which is money. > > > > As someone else said, you need Z rotation, which isn't as easy as it > sounds when using pneumatics to pick up the part. > > > > Moving table design sounds like a recipe for shaking the parts off the > solder pads. I've not had good luck with solder paste staying tacky for > long. In which case you are dispensing paste then sticking part. Not a deal > breaker but slow. > > > >> On Jun 25, 2016, at 04:12, Adrian Godwin wrote: > >> > >> Many parts can't be recognised visually. Capacitors are the obvious > example. > >> > >> On Sat, Jun 25, 2016 at 6:11 AM, Chris Albertson < > albertson.ch...@gmail.com> > >> wrote: > >> > >>> The ideal hobby use pick and place machine would be very different > >>> from a commercial machine. Lets say I want one board made. What I > >>> want to minimize is my time. With a conventional machine by FAR most > >>> of my time is spent setting the machine up. In fact setup is so slow > >>> that for smaller PCBs I could do it with tweezers in a fifth of the > >>> time needed to set up the machine. > >>> > >>> So a hobby machine must be designed such that you could get it going > >>> in nearly zero time. In the ideal case you drop the parts all mixed > >>> up, (but right side up) in a small tray. They are mixed and in random > >>> orientation. then you give the machine your PCB design file (not a > >>> special pick and place file) and then a vision system IDs the parts. > >>> Today vision is dirt cheap. > >>> > >>> But the 3D printer needs one more degree of freedom. It must be able > >>> to rotate the part (or the PCB) as it is unlikely the part on the tape > >>> or tray only needs translation to the PCB, likely ration is required > >>> in almost all cases. > >>> > >>> I think a hobby machine would only be successful if it could reduce > >>> the setup time to nearly zero and for that it would need a really good > >>> vision system that could hunt down randomly placed parts. It would > >>> have to work pretty much like you or I would do the job manually. But > >>> we have software like openCV and good "board cams" with M7 > >>> interchangeable lenses for $35. A vision system actually saves a ton > >>> of money because the machine need not be so precise as vision closes a > >>> feedback loop. > >>> > >>> Also how many hobbyists are going to have reels of parts? I might buy > >>> some parts by the dozen but most no more than about 4 or 6 at a time. > >>> I don't want a large machine. It should have a working surface, a > >>> white melamine table about 12 inches square and I place the PCB to be > >>> stuffed and all the parts on the same foot square table at any random > >>> location then press the "go" button. The camera scans the table. > >>> This kind of machine would be horrible for production work but a one > >>> foot cube machine that required zero setup is what most of us want. > >>> > >>> Going a little farther. I'd like this SAME machine to actually make > >>> the PCB too. A 3D printer could route the copper and drill holes and > >>> print the solder resist plastic too. > >>> > On Fri, Jun 24, 2016 at 8:56 PM, Attila Kinali > wrote: > On Fri, 24 Jun 2016 13:59:58 -0500 > "Graham / KE9H" wrote: > > > Lots of problems to be solved... > > Most of these problems are easy: >
Re: [time-nuts] pick and place problems/design (was: OT stuffing boards)
Hi > On Jun 25, 2016, at 12:56 PM, Chris Albertson > wrote: > > At home I have a parts bin and I find I need to stock about two dozen > resister values. Ok, chip resistors run about ten for a penny. Buy 1,000 of each for a buck a value. So far you have spent $24 and maybe tossed 10 resistors on each batch to come up with a good leader. Put the 10 pieces in a tray and use them for rework. > I can buy a pack of 1,200 resistors for about $12 and > there are all 24 values in the package. With the chips you now have 20X as many resistors for 2X the cost. > If I had to spend $20 per value > I'd have to spend $480 and some how find space to store 24 reels. If you spend $20 per value, you have 20,000 resistors per value. >Yes, > one project is not going to need all 24 values but over time they all get > used. The same might be true of 20,000 but it might not be in a couple of lifetimes :) > > The problem is worse with ICs. I'm likely to only need one of a certain > part ever. Run them from a tray unless they are a common part > Yes there are some common parts like an op amp but mostly each > project is unique. So it seem silly to program a machine to pick on one > single part and place it on one PCB. Unless the machine already knows where the tray is and you simply tell it “tray 3 or Reel 6”. > I can do that quicker with tweezers. Try a vacuum pickup … lots easier. > For the machine to be use any use to me it needs to be "zero setup time”. Well, your manual place process is not zero setup time so it is not clear that this is a reasonable goal. > > I think the ideal hobby sized machine is one that does not need parts on > tape or reels. Again, not a reasonable goal since there is no practical way to do that. Bob > It would be much slower per PCB stuffed but much faster to > get the first PCB finished. That is pretty much why I do hand work. > > > > On Fri, Jun 24, 2016 at 11:27 PM, Hal Murray > wrote: > >>> Also how many hobbyists are going to have reels of parts? >> >> Reels of small resistors or caps are ballpark of $20. I'd be happy to buy >> one for any part that is likely to get use multiple times on a board and >> again on the next board. >> >> >> >> -- >> These are my opinions. I hate spam. >> >> >> >> ___ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> > > > > -- > > Chris Albertson > Redondo Beach, California > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] pick and place problems/design (was: OT stuffing boards)
At home I have a parts bin and I find I need to stock about two dozen resister values. I can buy a pack of 1,200 resistors for about $12 and there are all 24 values in the package. If I had to spend $20 per value I'd have to spend $480 and some how find space to store 24 reels.Yes, one project is not going to need all 24 values but over time they all get used. The problem is worse with ICs. I'm likely to only need one of a certain part ever. Yes there are some common parts like an op amp but mostly each project is unique. So it seem silly to program a machine to pick on one single part and place it on one PCB. I can do that quicker with tweezers. For the machine to be use any use to me it needs to be "zero setup time". I think the ideal hobby sized machine is one that does not need parts on tape or reels. It would be much slower per PCB stuffed but much faster to get the first PCB finished. That is pretty much why I do hand work. On Fri, Jun 24, 2016 at 11:27 PM, Hal Murray wrote: > > Also how many hobbyists are going to have reels of parts? > > Reels of small resistors or caps are ballpark of $20. I'd be happy to buy > one for any part that is likely to get use multiple times on a board and > again on the next board. > > > > -- > These are my opinions. I hate spam. > > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] pick and place problems/design (was: OT stuffing boards)
Hi Even on a “real design” desktop pick and place, vibration is an issue for parts moving around. The same is true of parts “squirming” on a pick head as it does it’s thing. Part’s aren’t as flat as you might think they are and you can only get just so much vacuum. Lots of grubby design details. One thing that has not been covered so far is (at least to me) the best way to do manual pick and place. A lot of people try to do it with tweezers. I find that to be a massive pain. A vacuum pickup with a foot switch goes *much* faster for me. It also is a much better way to keep your hands out of the solder paste. You can get some nice long pickups. A setup is not very expensive, even with an illuminated magnifier to help see what you are doing. As an added bonus, some systems will let you reverse the pump and use it to dispense solder paste. The net result is that you have an effective way to both put down solder and place the parts. I prefer stencils for the solder side of things, but that is very much a mater of debate. Bob > On Jun 25, 2016, at 9:16 AM, bownes wrote: > > And try to tell transistor A from transistor B from diode C when they are all > upside down. > > A moving head design can be made to pick up parts off of reels on all four > sides. But it takes more table space. Which is money. > > As someone else said, you need Z rotation, which isn't as easy as it sounds > when using pneumatics to pick up the part. > > Moving table design sounds like a recipe for shaking the parts off the solder > pads. I've not had good luck with solder paste staying tacky for long. In > which case you are dispensing paste then sticking part. Not a deal breaker > but slow. > >> On Jun 25, 2016, at 04:12, Adrian Godwin wrote: >> >> Many parts can't be recognised visually. Capacitors are the obvious example. >> >> On Sat, Jun 25, 2016 at 6:11 AM, Chris Albertson >> wrote: >> >>> The ideal hobby use pick and place machine would be very different >>> from a commercial machine. Lets say I want one board made. What I >>> want to minimize is my time. With a conventional machine by FAR most >>> of my time is spent setting the machine up. In fact setup is so slow >>> that for smaller PCBs I could do it with tweezers in a fifth of the >>> time needed to set up the machine. >>> >>> So a hobby machine must be designed such that you could get it going >>> in nearly zero time. In the ideal case you drop the parts all mixed >>> up, (but right side up) in a small tray. They are mixed and in random >>> orientation. then you give the machine your PCB design file (not a >>> special pick and place file) and then a vision system IDs the parts. >>> Today vision is dirt cheap. >>> >>> But the 3D printer needs one more degree of freedom. It must be able >>> to rotate the part (or the PCB) as it is unlikely the part on the tape >>> or tray only needs translation to the PCB, likely ration is required >>> in almost all cases. >>> >>> I think a hobby machine would only be successful if it could reduce >>> the setup time to nearly zero and for that it would need a really good >>> vision system that could hunt down randomly placed parts. It would >>> have to work pretty much like you or I would do the job manually. But >>> we have software like openCV and good "board cams" with M7 >>> interchangeable lenses for $35. A vision system actually saves a ton >>> of money because the machine need not be so precise as vision closes a >>> feedback loop. >>> >>> Also how many hobbyists are going to have reels of parts? I might buy >>> some parts by the dozen but most no more than about 4 or 6 at a time. >>> I don't want a large machine. It should have a working surface, a >>> white melamine table about 12 inches square and I place the PCB to be >>> stuffed and all the parts on the same foot square table at any random >>> location then press the "go" button. The camera scans the table. >>> This kind of machine would be horrible for production work but a one >>> foot cube machine that required zero setup is what most of us want. >>> >>> Going a little farther. I'd like this SAME machine to actually make >>> the PCB too. A 3D printer could route the copper and drill holes and >>> print the solder resist plastic too. >>> On Fri, Jun 24, 2016 at 8:56 PM, Attila Kinali wrote: On Fri, 24 Jun 2016 13:59:58 -0500 "Graham / KE9H" wrote: > Lots of problems to be solved... Most of these problems are easy: > How do you take loose parts or cut tape or tape reels You don't. No loose parts with any kind of pick&place machine. As for cut tape, these can be taped on an empty reel to make them compatible. Everything has to be in a tray, reel or similar. > and get the right > part out, and into the chuck, oriented in the right direction? Orientation is defined by the reel/tray the parts come in. This is also do
Re: [time-nuts] pick and place problems/design (was: OT stuffing boards)
Hi If you are doing the sort of boards that started this discussion (100+ parts per board / 5 to 10 boards) a reel of bypass caps will get used up pretty fast. Shame on you if your designs don’t standardize on a bypass cap or three and about five resistors. Resistors reels of 10,000 are ~$10 so that’s $50 for your “most used” resistors. Caps in full reels of 4,000 at $16 a reel are not all that hard to find. If two of your three bypass caps are covered that way, you are up to $82 for inventory. Your third cap is likely a tantalum and it will be a bit more. Buy it in a "short reel" of some sort. Net result (at least for the bulk of your passives) is a startup inventory cost of < $100. Compared to all the other stuff you are buying. That’s not a big deal. Bob > On Jun 25, 2016, at 2:27 AM, Hal Murray wrote: > >> Also how many hobbyists are going to have reels of parts? > > Reels of small resistors or caps are ballpark of $20. I'd be happy to buy > one for any part that is likely to get use multiple times on a board and > again on the next board. > > > > -- > These are my opinions. I hate spam. > > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] pick and place problems/design (was: OT stuffing boards)
And try to tell transistor A from transistor B from diode C when they are all upside down. A moving head design can be made to pick up parts off of reels on all four sides. But it takes more table space. Which is money. As someone else said, you need Z rotation, which isn't as easy as it sounds when using pneumatics to pick up the part. Moving table design sounds like a recipe for shaking the parts off the solder pads. I've not had good luck with solder paste staying tacky for long. In which case you are dispensing paste then sticking part. Not a deal breaker but slow. > On Jun 25, 2016, at 04:12, Adrian Godwin wrote: > > Many parts can't be recognised visually. Capacitors are the obvious example. > > On Sat, Jun 25, 2016 at 6:11 AM, Chris Albertson > wrote: > >> The ideal hobby use pick and place machine would be very different >> from a commercial machine. Lets say I want one board made. What I >> want to minimize is my time. With a conventional machine by FAR most >> of my time is spent setting the machine up. In fact setup is so slow >> that for smaller PCBs I could do it with tweezers in a fifth of the >> time needed to set up the machine. >> >> So a hobby machine must be designed such that you could get it going >> in nearly zero time. In the ideal case you drop the parts all mixed >> up, (but right side up) in a small tray. They are mixed and in random >> orientation. then you give the machine your PCB design file (not a >> special pick and place file) and then a vision system IDs the parts. >> Today vision is dirt cheap. >> >> But the 3D printer needs one more degree of freedom. It must be able >> to rotate the part (or the PCB) as it is unlikely the part on the tape >> or tray only needs translation to the PCB, likely ration is required >> in almost all cases. >> >> I think a hobby machine would only be successful if it could reduce >> the setup time to nearly zero and for that it would need a really good >> vision system that could hunt down randomly placed parts. It would >> have to work pretty much like you or I would do the job manually. But >> we have software like openCV and good "board cams" with M7 >> interchangeable lenses for $35. A vision system actually saves a ton >> of money because the machine need not be so precise as vision closes a >> feedback loop. >> >> Also how many hobbyists are going to have reels of parts? I might buy >> some parts by the dozen but most no more than about 4 or 6 at a time. >> I don't want a large machine. It should have a working surface, a >> white melamine table about 12 inches square and I place the PCB to be >> stuffed and all the parts on the same foot square table at any random >> location then press the "go" button. The camera scans the table. >> This kind of machine would be horrible for production work but a one >> foot cube machine that required zero setup is what most of us want. >> >> Going a little farther. I'd like this SAME machine to actually make >> the PCB too. A 3D printer could route the copper and drill holes and >> print the solder resist plastic too. >> >>> On Fri, Jun 24, 2016 at 8:56 PM, Attila Kinali wrote: >>> On Fri, 24 Jun 2016 13:59:58 -0500 >>> "Graham / KE9H" wrote: >>> Lots of problems to be solved... >>> >>> Most of these problems are easy: >>> How do you take loose parts or cut tape or tape reels >>> >>> You don't. No loose parts with any kind of pick&place machine. >>> As for cut tape, these can be taped on an empty reel to make >>> them compatible. Everything has to be in a tray, reel or similar. >>> and get the right part out, and into the chuck, oriented in the right direction? >>> >>> Orientation is defined by the reel/tray the parts come in. >>> This is also documented in the datasheet, usually. >>> How many different kinds of parts, sizes, shapes, pin counts, IC footprints, can you handle at once? >>> >>> As many as there is space around the machine :-) >>> How do you know it is the correct part? >>> >>> You put it manually in the right feeder and double check that it >>> fits the programming. >>> How do you know where the "+" end, or "pin 1" is? >>> >>> This comes with the orientation of the part in the reel/tray. >>> How do you know that there actually is a part in the chuck? >>> >>> Your trays are guaranteed to be non-empty by manually loading them. >>> How do you know the part in the chuck is oriented the way you expected >> it? >>> >>> The manufacturer guarantees that the reels/trays are loaded correctly. >>> How do you know where the footprint on the circuit board is located? >> (to a few thousandths.) >>> >>> This is provided by the pick&place file. Usually its 3-5 digits after the >>> decimal point, when using mm. But as I wrote before, you don't have to >>> place part hyper exact. Being within 0.1-0.3 of the pitch of the part >>> is usually enough. Surface tension does the rest. >>> >>>
Re: [time-nuts] pick and place problems/design (was: OT stuffing boards)
Many parts can't be recognised visually. Capacitors are the obvious example. On Sat, Jun 25, 2016 at 6:11 AM, Chris Albertson wrote: > The ideal hobby use pick and place machine would be very different > from a commercial machine. Lets say I want one board made. What I > want to minimize is my time. With a conventional machine by FAR most > of my time is spent setting the machine up. In fact setup is so slow > that for smaller PCBs I could do it with tweezers in a fifth of the > time needed to set up the machine. > > So a hobby machine must be designed such that you could get it going > in nearly zero time. In the ideal case you drop the parts all mixed > up, (but right side up) in a small tray. They are mixed and in random > orientation. then you give the machine your PCB design file (not a > special pick and place file) and then a vision system IDs the parts. > Today vision is dirt cheap. > > But the 3D printer needs one more degree of freedom. It must be able > to rotate the part (or the PCB) as it is unlikely the part on the tape > or tray only needs translation to the PCB, likely ration is required > in almost all cases. > > I think a hobby machine would only be successful if it could reduce > the setup time to nearly zero and for that it would need a really good > vision system that could hunt down randomly placed parts. It would > have to work pretty much like you or I would do the job manually. But > we have software like openCV and good "board cams" with M7 > interchangeable lenses for $35. A vision system actually saves a ton > of money because the machine need not be so precise as vision closes a > feedback loop. > > Also how many hobbyists are going to have reels of parts? I might buy > some parts by the dozen but most no more than about 4 or 6 at a time. > I don't want a large machine. It should have a working surface, a > white melamine table about 12 inches square and I place the PCB to be > stuffed and all the parts on the same foot square table at any random > location then press the "go" button. The camera scans the table. > This kind of machine would be horrible for production work but a one > foot cube machine that required zero setup is what most of us want. > > Going a little farther. I'd like this SAME machine to actually make > the PCB too. A 3D printer could route the copper and drill holes and > print the solder resist plastic too. > > On Fri, Jun 24, 2016 at 8:56 PM, Attila Kinali wrote: > > On Fri, 24 Jun 2016 13:59:58 -0500 > > "Graham / KE9H" wrote: > > > >> Lots of problems to be solved... > > > > Most of these problems are easy: > > > >> How do you take loose parts or cut tape or tape reels > > > > You don't. No loose parts with any kind of pick&place machine. > > As for cut tape, these can be taped on an empty reel to make > > them compatible. Everything has to be in a tray, reel or similar. > > > >> and get the right > >> part out, and into the chuck, oriented in the right direction? > > > > Orientation is defined by the reel/tray the parts come in. > > This is also documented in the datasheet, usually. > > > >> How many different kinds of parts, sizes, shapes, pin counts, IC > >> footprints, can you handle at once? > > > > As many as there is space around the machine :-) > > > >> How do you know it is the correct part? > > > > You put it manually in the right feeder and double check that it > > fits the programming. > > > >> How do you know where the "+" end, or "pin 1" is? > > > > This comes with the orientation of the part in the reel/tray. > > > >> How do you know that there actually is a part in the chuck? > > > > Your trays are guaranteed to be non-empty by manually loading them. > > > >> How do you know the part in the chuck is oriented the way you expected > it? > > > > The manufacturer guarantees that the reels/trays are loaded correctly. > > > >> How do you know where the footprint on the circuit board is located? > (to a > >> few thousandths.) > > > > This is provided by the pick&place file. Usually its 3-5 digits after the > > decimal point, when using mm. But as I wrote before, you don't have to > > place part hyper exact. Being within 0.1-0.3 of the pitch of the part > > is usually enough. Surface tension does the rest. > > > >> How do you know the part left the chuck and ended up where you intended > it > >> to be? > > > > You dont :-) > > > > The way how this is checked is either a pre-solder and/or post-solder > visual > > inspection. This is either done manualy or using a camera system where > > computer compares the PCB to the picture of a known-good PCB. > > As this is ment for a small volume and hobbyist system, doing the visual > > inspection manualy is good enough and more than fast enough. > > > > Attila Kinali > > -- > > Malek's Law: > > Any simple idea will be worded in the most complicated way. > > ___ > > time-nuts mailing list -- time-nuts@febo.c
Re: [time-nuts] pick and place problems/design (was: OT stuffing boards)
Hi > On Jun 24, 2016, at 11:56 PM, Attila Kinali wrote: > > On Fri, 24 Jun 2016 13:59:58 -0500 > "Graham / KE9H" wrote: > >> Lots of problems to be solved... > > Most of these problems are easy: > >> How do you take loose parts or cut tape or tape reels > > You don't. No loose parts with any kind of pick&place machine. > As for cut tape, these can be taped on an empty reel to make > them compatible. Everything has to be in a tray, reel or similar. > >> and get the right >> part out, and into the chuck, oriented in the right direction? > > Orientation is defined by the reel/tray the parts come in. > This is also documented in the datasheet, usually. If the part is oriented top-bottom and you have it on the board both top-bottom and left-right .. you need to be able to re-orient it after you have picked the part. If it is a diode or semiconductor , you have four obvious orientations for the part. Doing four reels for every diode or semi just isn’t the way it is done. You buy one reel and let the machine deal with it. If you add in things that are oriented at a 30, 45, or 60 degree angle, you simply can not have a reel for all the orientations. The Z axis needs to rotate. > >> How many different kinds of parts, sizes, shapes, pin counts, IC >> footprints, can you handle at once? > > As many as there is space around the machine :-) If it is a moving table design (as many if not most are) that really does not count. You can’t get the head there. Bob > >> How do you know it is the correct part? > > You put it manually in the right feeder and double check that it > fits the programming. > >> How do you know where the "+" end, or "pin 1" is? > > This comes with the orientation of the part in the reel/tray. > >> How do you know that there actually is a part in the chuck? > > Your trays are guaranteed to be non-empty by manually loading them. > >> How do you know the part in the chuck is oriented the way you expected it? > > The manufacturer guarantees that the reels/trays are loaded correctly. > >> How do you know where the footprint on the circuit board is located? (to a >> few thousandths.) > > This is provided by the pick&place file. Usually its 3-5 digits after the > decimal point, when using mm. But as I wrote before, you don't have to > place part hyper exact. Being within 0.1-0.3 of the pitch of the part > is usually enough. Surface tension does the rest. > >> How do you know the part left the chuck and ended up where you intended it >> to be? > > You dont :-) > > The way how this is checked is either a pre-solder and/or post-solder visual > inspection. This is either done manualy or using a camera system where > computer compares the PCB to the picture of a known-good PCB. > As this is ment for a small volume and hobbyist system, doing the visual > inspection manualy is good enough and more than fast enough. > > Attila Kinali > -- > Malek's Law: >Any simple idea will be worded in the most complicated way. > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] pick and place problems/design (was: OT stuffing boards)
> Also how many hobbyists are going to have reels of parts? Reels of small resistors or caps are ballpark of $20. I'd be happy to buy one for any part that is likely to get use multiple times on a board and again on the next board. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] pick and place problems/design (was: OT stuffing boards)
The ideal hobby use pick and place machine would be very different from a commercial machine. Lets say I want one board made. What I want to minimize is my time. With a conventional machine by FAR most of my time is spent setting the machine up. In fact setup is so slow that for smaller PCBs I could do it with tweezers in a fifth of the time needed to set up the machine. So a hobby machine must be designed such that you could get it going in nearly zero time. In the ideal case you drop the parts all mixed up, (but right side up) in a small tray. They are mixed and in random orientation. then you give the machine your PCB design file (not a special pick and place file) and then a vision system IDs the parts. Today vision is dirt cheap. But the 3D printer needs one more degree of freedom. It must be able to rotate the part (or the PCB) as it is unlikely the part on the tape or tray only needs translation to the PCB, likely ration is required in almost all cases. I think a hobby machine would only be successful if it could reduce the setup time to nearly zero and for that it would need a really good vision system that could hunt down randomly placed parts. It would have to work pretty much like you or I would do the job manually. But we have software like openCV and good "board cams" with M7 interchangeable lenses for $35. A vision system actually saves a ton of money because the machine need not be so precise as vision closes a feedback loop. Also how many hobbyists are going to have reels of parts? I might buy some parts by the dozen but most no more than about 4 or 6 at a time. I don't want a large machine. It should have a working surface, a white melamine table about 12 inches square and I place the PCB to be stuffed and all the parts on the same foot square table at any random location then press the "go" button. The camera scans the table. This kind of machine would be horrible for production work but a one foot cube machine that required zero setup is what most of us want. Going a little farther. I'd like this SAME machine to actually make the PCB too. A 3D printer could route the copper and drill holes and print the solder resist plastic too. On Fri, Jun 24, 2016 at 8:56 PM, Attila Kinali wrote: > On Fri, 24 Jun 2016 13:59:58 -0500 > "Graham / KE9H" wrote: > >> Lots of problems to be solved... > > Most of these problems are easy: > >> How do you take loose parts or cut tape or tape reels > > You don't. No loose parts with any kind of pick&place machine. > As for cut tape, these can be taped on an empty reel to make > them compatible. Everything has to be in a tray, reel or similar. > >> and get the right >> part out, and into the chuck, oriented in the right direction? > > Orientation is defined by the reel/tray the parts come in. > This is also documented in the datasheet, usually. > >> How many different kinds of parts, sizes, shapes, pin counts, IC >> footprints, can you handle at once? > > As many as there is space around the machine :-) > >> How do you know it is the correct part? > > You put it manually in the right feeder and double check that it > fits the programming. > >> How do you know where the "+" end, or "pin 1" is? > > This comes with the orientation of the part in the reel/tray. > >> How do you know that there actually is a part in the chuck? > > Your trays are guaranteed to be non-empty by manually loading them. > >> How do you know the part in the chuck is oriented the way you expected it? > > The manufacturer guarantees that the reels/trays are loaded correctly. > >> How do you know where the footprint on the circuit board is located? (to a >> few thousandths.) > > This is provided by the pick&place file. Usually its 3-5 digits after the > decimal point, when using mm. But as I wrote before, you don't have to > place part hyper exact. Being within 0.1-0.3 of the pitch of the part > is usually enough. Surface tension does the rest. > >> How do you know the part left the chuck and ended up where you intended it >> to be? > > You dont :-) > > The way how this is checked is either a pre-solder and/or post-solder visual > inspection. This is either done manualy or using a camera system where > computer compares the PCB to the picture of a known-good PCB. > As this is ment for a small volume and hobbyist system, doing the visual > inspection manualy is good enough and more than fast enough. > > Attila Kinali > -- > Malek's Law: > Any simple idea will be worded in the most complicated way. > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow th
