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Re: Tape Strip Holders

Posted: Sun Jul 09, 2017 7:48 pm
by dmwahl
Perhaps the feeder itself could detect the pressure from the nozzle and advance the tape after a delay. That would be relatively simple to implement with a micro controller and and requires no software changes.

Re: Tape Strip Holders

Posted: Sun Jul 09, 2017 8:25 pm
by JuKu
Or with some other sensor, like strategically placed micro switch. Properly set the nozzle doesn't press down to the feeder tape, only touching ever so slightly to make the vacuum connection.

Re: Tape Strip Holders

Posted: Tue Jul 11, 2017 6:00 am
by Michael_N
Hi Juku,
Oh, I was not aware of that. So now you just gave me another project:)

Re: Tape Strip Holders

Posted: Tue Jul 11, 2017 1:31 pm
by JuKu
The bottom side of many tapes is not very strong, the full weight of the pickup tube can easily push a resistor through it. With feeders or strip holders you want to set it so, that the tip only touches, not pressing.

Re: Tape Strip Holders

Posted: Tue Jul 11, 2017 5:46 pm
by robjevans
Hi all after lots of work I have modified my Liteplacer to accept feeders from a TYCO machine. The feeders use an optical sensor that sees the nozzle and breaks the beam to the detector and then advances when the nozzle lifts up, easy to add an led and detector and no mechanical issues.....

Re: Tape Strip Holders

Posted: Tue Jul 11, 2017 6:11 pm
by JuKu
Nice! Show us, please!

Re: Tape Strip Holders

Posted: Tue Jul 11, 2017 7:54 pm
by robjevans
Overview of the modified machine showing the higher rails and feeders on the right
Overview of the modified machine showing the higher rails and feeders on the right
IMG_1376.JPG (93.62 KiB) Viewed 31613 times
Close up of feeder showing the sensor in red
Close up of feeder showing the sensor in red
IMG_1380.JPG (87.75 KiB) Viewed 31613 times

Re: Tape Strip Holders

Posted: Wed Jul 12, 2017 9:11 am
by mawa
JuKu wrote:The bottom side of many tapes is not very strong, the full weight of the pickup tube can easily push a resistor through it. With feeders or strip holders you want to set it so, that the tip only touches, not pressing.
I can only confirm Juhas words and add that many of the 5050 LEDs (monochrome and RGB) have a pressure sensitive transparent silicon-gel filling.
This filling is not just a thin windows but fills the full cavity thereby enclosing the thin bonding wires inside.
In one of the latest ws2813 data sheets this fact is documented. See precaution remarks on page 9 of http://www.szledcolor.com/download/WS2813%20LED.pdf.

This silicon-gel is also sensitive to humidity and heat and having placed almost 1000 WS2812 approx. 4 to 5 of these LEDs showed missing colors which appear after some minutes of active time and go on and off when you put manual pressure on the filling while powered.

Therefore I recommend NOT to use the probing option for pickup and placement heights but carefully manually measure the heights and use strip holders with a groove just deep enough for the tape pockets.

Re: Tape Strip Holders

Posted: Fri Sep 15, 2017 7:11 pm
by mike58
Hello,

I am in process of getting my design from paper to life.
On paper it looks promising - it a twin feeder - 1 servo moving two tapes https://www.youtube.com/watch?v=gsFAogGOqYo
https://www.youtube.com/watch?v=XDDw6E2iNwI
Forward movement is 4mm and can be adjusted by moving of servo or angle of servo arm. Reverse movement is by the spring.
The problems I see only in fabrication accuracy of actual as build parts....
The removing of top tape could be done in a way as in this video:
https://www.youtube.com/watch?v=9qJp1j-rdVU

Mike