Author Topic: My take on the DIY pnp smt feeder  (Read 1270869 times)

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Offline Spikee

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My take on the DIY pnp smt feeder
« on: August 29, 2015, 09:52:38 AM »
Been designing a pnp feeder for my liteplacer pick and place machine.

I have thought about using photo transistors , encoders , magnetic encoders , gears and solenoids.
But the stepper motor and tape pulling method seems the best for low cost and low part-count feeder.

The current test design is for 16mm tape. I have the trays ready for 8 and 12 mm but I need to do a few small adjustments to fit the top plate with the stepper.


Files (STL + solidworks (parts and assembly)):
https://www.youmagine.com/designs/16mm-pnp-tape-feeder-with-stepper-test-phase

stepper + driver board is 2$ on aliexpress / ebay:
http://www.aliexpress.com/item/Smart-Electronics-28BYJ-48-5V-4-Phase-DC-Gear-Stepper-Motor-With-ULN2003-Driver-Board-for/32314913056.html

The whole design can be 3d printed and it should function without issue. the tolerance on the 32mm tape roll (the thing on the stepper motor) has not been tested yet. I'm expecting my stepper to show up in a few days.
Some more details about development can be found here:
http://liteplacer.com/phpBB/viewtopic.php?f=11&t=7&start=30

Some more screenshots:




The holes in the side are 8mm and intended for a precision steel guide to go trough it. The tape tray has a 2.5 mm set screw to hold it in place on the guide bar.

looking for some very cheap parts on 16mm real so I can test the design.

Looking for feedback / testers :)


Edit:
Here is my high tech drawing:


Exploded view:


The tape goes over and back down. The idea is that this "promotes" the tape to go more in a forward motion instread of moving up/down a bit. And me trying to keep the slack out of the tape.
When the tape is off the top is closed so components hopefully don't fall out or whatever because of the tape pulling "stress".

One thing that may happen is that because of the tape rolling up the next part requires a very little amount more rotation than the previous.
This could add up large amount of parts are placed.

This can probably be fixed fixed in firmware by counting the parts and possibly implementing micro-stepping.

It is also possible to calibrate this once in a while via the lite-placer camera.

Btw Rx8pilot , I stole the tape cutout dimensions from your solid-works files :)

Free-electron I tried your "sketch designs" for this but it gets a bit complicated or wide when multiple tape sizes are used:
[8mm tape]

But it should work nice for manual pick and place work.

-----
The parts could be cnc machined but that is kinda overkill. 3D printing works fine with Ultimaker 2 on medium settings.
With a minor mod the whole top plate can be cnc machined or laser cutted. The bottom tray can be cnc machined if needed.
« Last Edit: August 29, 2015, 10:19:55 AM by Spikee »
Freelance electronics design service, Small batch assembly, Firmware / WEB / APP development. In Shenzhen China
 

Offline ConKbot

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Re: My take on the DIY pnp smt feeder
« Reply #1 on: August 29, 2015, 10:20:44 AM »
Personally I'm keen on Mydata's agilis feeders.


Only about 2 or 3" of leader needed, the blade lifts one edge of the cover tape, the part is exposed in the window, the machine grabs it out, and as it feeds forwards, the cover tape lowers.  Little pawl mechanism pushes the tape forwards. Not sure if it's a tiny solenoid in the feeder, or a lever or other mechanism in the magazine that actuates it. Easy to load, good with short strips of tape, good for short runs.

« Last Edit: August 29, 2015, 12:39:09 PM by ConKbot »
 

Offline Spikee

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Re: My take on the DIY pnp smt feeder
« Reply #2 on: August 29, 2015, 07:42:33 PM »
Only about 2 or 3" of leader needed, the blade lifts one edge of the cover tape, the part is exposed in the window, the machine grabs it out, and as it feeds forwards, the cover tape lowers.  Little pawl mechanism pushes the tape forwards. Not sure if it's a tiny solenoid in the feeder, or a lever or other mechanism in the magazine that actuates it. Easy to load, good with short strips of tape, good for short runs.

Something like that may be hard to replicate without lots of custom parts. More data would be needed which we probably can't find about the construction.
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Offline Spikee

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KISS
« Reply #3 on: October 27, 2015, 06:18:23 AM »
Keep It Simple Stupid!

This works great, there is no sideways or up/down play. paper tape fits snugly.Holes are still clearly visible and the blue provides great contrast for the hole detection.I plan to have reels on a bar And just slip the tape in these holders. When lets say 50 parts are gone i can just slide the tape forward and cut of the used part.

This is intended for my liteplacer pnp but works also fine for had assembly.

www.youmagine.com/designs/8mm-smt-smd-pnp-paper-tape-holder-with-holddown-no-play







Certain paper tapes are a bit thicker and need some persuasion to move. Just stick a screwdriver in there and pull. Or edit the solidworks file and change the 1mm size to 0.6 / 0.75 ;)
« Last Edit: October 27, 2015, 06:32:23 AM by Spikee »
Freelance electronics design service, Small batch assembly, Firmware / WEB / APP development. In Shenzhen China
 

Offline Spikee

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Re: My take on the DIY pnp smt feeder
« Reply #4 on: October 27, 2015, 10:47:12 PM »
Here are the new files:

https://www.youmagine.com/designs/8mm-smt-smd-pnp-paper-tape-holder-with-holddown-no-play-hole-not-coveredHoles
 fully visible , 0.3mm instead of 1mm "narrowing".Tape still sits fine in it. It is easier to slide the tape in the holder than the previous design.
Freelance electronics design service, Small batch assembly, Firmware / WEB / APP development. In Shenzhen China
 


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