Small 0402, 0201 parts on 8mm tapes that index 4mm?? - Page 1
Forum section: electronics / general

author: rx8pilot
author_rank: Super Contributor
timestamp: May 18, 2016, 01:18:28 am
content: I am hoping to figure out a solution to a P&P pickup problem. The issue is that my 8mm feeders index 4mm on each pickup but 0402 and smaller parts come on tape that have parts every 2mm. This means that the P&P machine will skip a part every pickup and the feeder will fill up with wasted parts.One person suggested the strategy of picking up a part behind the pickup senor (which prevents the feeder from advancing) and then the next pick is on the sensor so that it advances. That makes sense, but my machine does not support that kind of programming.At the moment, for all of my small parts, I am using a custom cut-tape feeder that is programmed like a matrix tray. It is a good work-around for small parts, but keeping it loaded is a pain in the but compared to having reels of parts. I have 8 precision feeders that are good enough for 0402, but not capable of 2mm indexing.I called DigiKey to see if anyone offers parts on tape where the pitch of the parts is 4mm either by design or by skipping every other pocket in the tape. Has anyone else figured this out. Seems like it would be a common problem, especially with older and/or lower cost machines.

author: electrolust
author_rank: Unknown
timestamp: May 18, 2016, 06:19:10 am
content: PPM is advertising a 2mm index feeder on their home page. Don't know if that helps you.

author: rx8pilot
author_rank: Super Contributor
timestamp: May 18, 2016, 06:32:43 am
content: Those gems have a list price of $1885 each - $1200 if they have used stock. I am hoping to avoid those. The feeders I have have good repeatability and replacing them with the 2mm versions will cost $10's of thousands.Sent from my horrible mobile....

author: l0wside
author_rank: Regular Contributor
timestamp: May 18, 2016, 08:37:33 am
content: With 0402 and 0201 resistors, it might be cheaper to throw away half of the parts than replacing the feeder. Too bad there is no market for bulk 0402 resistorsHave you considered modifying the feeders of your machine? I imagine this might be easier than adapting a different feeder to your Quad 4000C.Max

author: IconicPCB
author_rank: Super Contributor
timestamp: May 18, 2016, 12:25:13 pm
content: What other tape pitch do your feeders support?are they single tape feeders or blocks of tape feeders?how do they communicate with the controller ( when to advance and how far)?You mention a sensor. What kind of a sensor is it.. and how does it interact with feed gearing/motor driving the tape?

author: rx8pilot
author_rank: Super Contributor
timestamp: May 18, 2016, 05:57:18 pm
content: Quote from: l0wside on May 18, 2016, 08:37:33 amThrowing away the parts is not that big a deal when looking at the cost of the parts, the problem is that they create a mess inside the feeder and the feeder base requiring a cleanup effort. I have considered making a new optical encoder that tricks the feeder into indexing at half the normal distance. It is a software controlled device using relatively ancient tech so tricking the current software seems to be an option.Quote from: IconicPCB on May 18, 2016, 12:25:13 pmThey are all single feeders, no bank feeders.They do 4, 8, 12, 16, 24, 32mm indexing.They control is entirely inside each feeder. There is some optional communication to the machine that ID's the feeder/parts but I don't have that. The feeder has an optical trap that detects the nozzle picking up a part and advances by the programmed amount. If there is an issue with the feeder, the machine does not now about it until it tries to pickup a part and fails to verify vacuum or the part is not detected by the side scanning camera.There is a super low-tech open optical encoder on the motor - 4 pulses per revolution. I could, in theory, make my own encoder wheels with 8 pulses per rev and it would index 2mm when the control thinks it advanced 4mm.I was certainly hoping that there was an easy option of buying the smaller parts in tape that indexes at 4mm. Modifying or buying new feeders is slow and/or expensive. I guess I need to pay to move up.

author: electrolust
author_rank: Unknown
timestamp: May 18, 2016, 07:33:02 pm
content: Can you add a magnet and wiper so that when one part is picked, the previous (/next) is whisked away?

author: IconicPCB
author_rank: Super Contributor
timestamp: May 18, 2016, 10:15:22 pm
content: I guess the motor which drives the tape is a stepper motor drive. try slipping a divide by 2 flipflop into main drive line.. divide the number of step pulses by two and may be..

author: rx8pilot
author_rank: Super Contributor
timestamp: May 19, 2016, 05:52:55 am
content: Tom Nisbet from PPM saw a post I made (similar to this one) on SMTnet forum. He decided to call me to help get to the bottom of the challenge. AWESOME!We talked about all the various feeder options and how they got to be so expensive. The goo part is that he told me how to do a 'double pick' with my existing feeders that can only index 4mm. The software on my machine can be programmed to pick one part ahead of the normal pick point where the feeder will not know to advance. The next time the part is picked, it picks the normal location and the feeder advances two parts. It's a bit of a work around but it will allow me to use 2mm pitch tapes without have to immediately buy new feeders. What I have is probably good for 0402, but may be a problem with 0201.Going out to try it now. Fingers crossed.

author: IconicPCB
author_rank: Super Contributor
timestamp: May 19, 2016, 06:49:55 am
content: My Mechatronika m10V has block feeders capable of dispensing 2mm pitch components.You can pick up, from memory, a block of 18 feeders for about 3000 Euro new. They are also available second hand.

author: tomgroenland
author_rank: Newbie
timestamp: June 29, 2016, 10:03:19 pm
content: Quote from: l0wside on May 18, 2016, 08:37:33 amLooks like soon there could be.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: June 29, 2016, 10:38:40 pm
content: Another option is to find a way to tell the machine to offset the pick position by 2mm, and feed, every other pick.

author: rx8pilot
author_rank: Super Contributor
timestamp: June 30, 2016, 12:09:05 am
content: Quote from: mikeselectricstuff on June 29, 2016, 10:38:40 pmQuote from: rx8pilot on May 19, 2016, 05:52:55 amThis works! The software, of course, does not make this obvious by having a 'double pick for 2mm pitch' button. In the end - I know how to pickup a part with a 2mm offset without the feeder advancing followed by a normal pick that advances the feeder. VERY happy this works so well, now I can use the feeders I already have.

author: 48X24X48X
author_rank: Frequent Contributor
timestamp: June 30, 2016, 02:49:15 am
content: 1 thing I notice about the Yamaha CL feeder used by the Chinese machines (TVM920 & CHMT530P).For 8 mm, they have 2 version, one for the regular pitch and one for 0402 "special".

author: ez24
author_rank: Super Contributor
timestamp: June 30, 2016, 04:09:42 am
content: Quote from: tomgroenland on June 29, 2016, 10:03:19 pmHoly crap

author: rx8pilot
author_rank: Super Contributor
timestamp: June 30, 2016, 04:36:45 am
content: That is insane. Crazy insane and awesome.

author: mrpackethead
author_rank: Super Contributor
timestamp: July 01, 2016, 05:43:42 am
content: 2mm pitch is stanard. Not sure what feeders are you are using, but for Yamaha CL feeders, you buy one that advances 2mm. Most 0402's are 2mm pitch.

author: rx8pilot
author_rank: Super Contributor
timestamp: July 01, 2016, 03:04:21 pm
content: I've been using 0805 and 0603 that are 4mm. Hoping to transition to 0402 and 0201 to improve PCB density and performance. The feeders I have are the original Quad design that were only intended for 0603 and larger. The newer ones can do 0402 by precision, but are still 4mm pitch. The newest models are 2mm and designed for 01005 (super tiny).The cash outlay to get 30 of the newest models is no joke, so I have to make-do with what I have for now.Sent from my horrible mobile....

author: mrpackethead
author_rank: Super Contributor
timestamp: July 01, 2016, 08:31:44 pm
content: intresting about the cplace.. Jason at OpenPNP has been working on loose pick up in the last few weeks, and has been able to reliably pick and place loose parts out of a tray, from random orientations.. This tech is'nt too far way from the sub $100 market.

author: rx8pilot
author_rank: Super Contributor
timestamp: July 01, 2016, 11:50:10 pm
content: Quote from: mrpackethead on July 01, 2016, 08:31:44 pmThe approach allows your to avoid very complicated feeder mechanisms. Machine vision hardware and software are so mature and low cost - the fancy feeders may no longer make sense. OpenCV and modest quality camera system is enough to make it happen with minimal challenge.The crazy thing they pull off at Siplace is the remarkable pickup speed followed by remarkable placement speed. My machine maxed out is 8% of that speed if perfectly optimized and I still can't keep up with it (printing, oven, prep, etc.) It would be cool to have a carousel type setup with bins that rotate to a single pickup position. Kind of like some of the manual P&P systems use.Fun to think about.