ebay auto feeder- feasible?

lfkeyboards
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ebay auto feeder- feasible?

Post by lfkeyboards »

I realize that the liteplacer is designed assuming you'll never need/want an autofeeder, but...

I'm assembling PCBs that have 25 diodes per board, more than half of the total part count. Since I'd only need one, the ~$150 for a commercial feeder isn't a problem, but I'm not sure if they could be made to work.

Anyone have any experience in this area?
JuKu
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Re: ebay auto feeder- feasible?

Post by JuKu »

You can make the software to pick up always from a same spot. The issue is how to advance the feeder.
ivars211
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Re: ebay auto feeder- feasible?

Post by ivars211 »

Found these semi-auto 3d-printable feeders. Does not require additional electronics for most part, any chance for support (moving the head to latch the next part)?
https://github.com/alexavr2/alexfeeder

I believe these are perfect for what this PnP is for. Costs close to nothing to make (if 3D printer available)
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dampfboot
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Re: ebay auto feeder- feasible?

Post by dampfboot »

Hello World,

I - and maybe most of us - have the issue to place per PCB 8x 0,1 µF, 4x LED or 9x 1 k Ohm - that is no fun and you cry for a feeder.

To determine which feeder has to be re-feeded is so easy! Just hook an Arduino on the RX line of the tiny G Serial and listen to the traffic. Identify sequences like this
{"gc":"G0 X100.537 Y100.895"}
and compare the coordinates with your feeder positions - allow +/- 3 mm because of homing differences. If you identify a feeder position give the appropriate signals to your feeders - I will try to do this before the pickup to ensure an empty tray when removing the feeder - but if my feeders are to slow, I will look for the rising nozzle G-Code and feed the part afterwards...

Maybe this easy hint will help you to build your feeder dreams.

I got some old mechanical feeders and managed to move it by an ordinary RC-Servo. Will build the rest of the setup this weekend and show more of it later.

Rainer from Hannover, Germany
PS: If you want some mechanical feeders just send a PM

JuKu
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Re: ebay auto feeder- feasible?

Post by JuKu »

> realize that the liteplacer is designed assuming you'll never need/want an autofeeder,

Actually, I haven't found a reliable source for a feeder that fits the LitePlacer price-wise.

> To determine which feeder has to be re-feeded is so easy! Just hook an Arduino on the RX line of the tiny G Serial and listen to the traffic. Identify sequences like this
{"gc":"G0 X100.537 Y100.895"}

Maybe this could be even easier. Making the application scriptable is the true solution, but not easy. What would be easy is to add to the system a source code file "feeders.cs" and put there your code that you need to use feeders. There would be calls that the system does before picking up a component or after, start of a job etc. In normal use, the functions are empty; if you have your own feeder solution, add the code. Adding some empty calls in right places of the software is not a big task.

Another way to make this more easy to use would be using g-code comments (but that can be done with the above, too). The software knows which component it starts to pick up, when it was picked up, when the head is away from the pickup area and so on. It even knows what component comes after the current one, so you can advance the feeder for the next part after pickup of the current part.

But as said, I still don't have feeders that I can sell, so I haven't put in support for any. (If/when I do, I'll do it the way I described above, so I don't lock away people that use other feeder solutions). But I'm willing to start supporting feeders, as I hope to have feeders in my store some day. So, what software features would you like to see to support feeders?
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dampfboot
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Re: ebay auto feeder- feasible?

Post by dampfboot »

Hello Juku,

today I have assembled my 4 test feeder. The operation by 4 RC-Servos works fine. In general you tend to place the high count parts close to the PCB to shorten the travel time. Meanwhile this travel time is so short that I barely get the parts feed into the pick up position by my actual strategy.

My first wish for a good feeder signal would be to get it earlier - maybe after placing the last part and before moving the nozzle up. That should be enough time for most feeder designs? With this you would avoid any problems/spilled parts if the placing of the previous part would go wrong and stop the machine. The code could be any individual character sequence send to the Tiny-G serial which identifies the feeder by coordinate or even by name - it would be luxury to get the part value also for displaying it on an additional display.

Next wish would be a signal which indicates, that the part was picked up for sure - with this you could also avoid spilled parts - if something went wrong and the part was not picked, you do not have to feed a new one at the next attempt - but I could generate this from today's G-Code already.

A major change would be to use an additional serial port for sending out the feeder signals. This would not generate that much traffic - but an extra USB port. I assume, that most feeder will need an extra MCU for its management. By this nobody has to solder a serial wire to the "holy" tiny-G ;-)

Have to assemble 15 PCBs tomorrow. Will do so with the new feeder and send a video.

Rainer from Hannover, Germany
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dampfboot
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Re: ebay auto feeder- feasible?

Post by dampfboot »

4 feeder ready set up for tomorrows p&p job...
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dampfboot
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Re: ebay auto feeder- feasible?

Post by dampfboot »

It is running - have produced the first 25 PCBs with
8x 0,1 µF = 200 parts
4x 1 k = 100 parts
3x LED = 75 parts
2x 10 µF = 50 parts

No major problems - I am happy not to feed the flat bad feeders with this amount of parts - 75 more PCBs are waiting for this p&p job already. Time to install more feeders

I had to change the pick strategy a little. To keep the parts nicely in place I had to open the little lid first - let the machine pick the part - and feed the next not before the lid was closed to keep the part in its compartment while it was transported with the belt. Therefore i needed two signals from the LitePlacer software.
1) open the lid when the picker is mowing towards the feeder.
2) close the lid and feed after the part was picked. I just used the {"gc":"G0 Z0"} command and gave the closing signal 0.4 sec later.
This might be different with other feeder designs...

Rainer

Have a look here:
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dampfboot
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Re: ebay auto feeder- feasible?

Post by dampfboot »

Because I am waiting for more RC-Servos to operate more feeder I have build feeder holders to hold some of my feeder in a cabinet right over my p&p maschine. To keep 45x 8mm 12x 12 mm and 2x 16 mm on stock should be enough for my little PCBs. If someone is interested in such mechnical non motorized feeder please ask.
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lfkeyboards
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Re: ebay auto feeder- feasible?

Post by lfkeyboards »

Dampfboot - I missed your replies somehow, but this is _exactly_ what I'm looking for!

What kind of feeders did you use and where did you get them?
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