Again, another feeder design

[Knas]

I've been working on a cheap but reliable feeder design that is entirely mechanical and does not require any extra movements from the machine, as to not slow down the process. I've come up with this:https://vimeo.com/144454867. It's all been done on my CNC machine and probably cost me ~$5 in materials at the most.

The feeder is actuated by the down-going movement of the head during the pickup process, a lever is being pushed down by the head that is part of an escapement gear setup that tries to do *exactly* 4mm of movement. in theory this works great (this is how clocks work!) but in practice my CNC machine (and probably many others) isn't exact enough to do a given radius sprocket without at least *some* error. And *some* cumulative error is a no-no in feeder design. So i added a little needle that goes down and physically halts the tape once it's come to it's perfect pickup position. This seems to fix the problem entirely.

The cover plastic is removed by some kind of tension, i tried using weights first but found it to be cumbersome and now i'm using a butchered $20 laminator (as can be seen in the video) that should be good for removing the covers of all the feeders i'll ever need and is waay cheaper than any "real" tensioners i've seen. The tension is also important for the feeders operation as it sometimes needs that extra "push"..

At the front of the feeder, just before the tape is removed, is a magnet that sits under the tape. The idea is that it slides the components left and back as they move forward over it, hence vision should not be necessary as the components should always be located in the lower left corner.

The current design also has a holder that you slide the feeder into when mounting it, the back attaches to a standard rail like those used in the LitePlacer.

The design is modular and should be able to do any tape width or hole spacing necessary. I've done some very alpha attempts with 12mm/16mm and 2/3 hole spacing (and any combo within) and it seems to work perfectly.

The current 8mm feeder has *no* visible error when working correctly, though with the last statement comes the fact that i have to test it more. I did a test where i placed >100 components, only had one missing.

My thinking is to do this open hardware with a "hi-you-can-use-it-but-don't-make-money-off-of-my-idea" type GNU contract (sorry i don't know which one that is, BSD?).

Any input on this much appreciated!

Karl

[mrandt]

Hey Karl,

this is impressive. Nice design and great job at making this!

The simplicity and beauty of this mechanical solution is striking. I was so preoccupied thiking about motorized feeders that I did not even think about something like this...

How do you hold down the tape to avoid small parts "jumping" from their pockets? Or is this achieved by the magnet, too? What about non magnetic parts?

Do you have CAD files of the individual parts of this feeder? I wonder if some (or all parts) could be 3D printed...

Thanks and keep up the great work!

Malte

P.S.: I also like your Juki nozzle and automatic changer

[dave]

Cool

So the gear is not driven. the motor on the lamination machine causes the forward motion?

The gear on the wheel seems to stop it advancing to much.

[JuKu]

Wow. Just wow. This is, by far, like by order of magnitude, better than any low cost feeder design I've ever seen. Far better than any of my sketches, too. I have thought the tension roller too, nice to see that it works. I don't have words to express how much I respect this. (the nozzle changer is great, too.)

[Knas]

The simplicity and beauty of this mechanical solution is striking. I was so preoccupied thiking about motorized feeders that I did not even think about something like this...

Thank you, i thought a lot about motorized feeders to but it seemed excessive to me as there *had* to be a mechanical solution i thought, it took me *many* months but i think the current idea is quite solid.

How do you hold down the tape to avoid small parts "jumping" from their pockets? Or is this achieved by the magnet, too? What about non magnetic parts?

The tape doesn't get pulled of of the component until just before pickup so i've had no issues with jumping, i will add some better pictures.

Do you have CAD files of the individual parts of this feeder? I wonder if some (or all parts) could be 3D printed...

Not yet, i want to verify it's 100% before i clean up the files and make them public. Most of the stuff should be 3d printable, the housing is made out of HDPE and the gears are made out of aluminium. It *might* be possible to make the gears out of plastic but i did that early in the development stage and had issues with them breaking down very quickly 9as the escapement for the 1 hole/part gear requires some very very fine detail), i also had some problems with the lever bending due to the elasticity of the plastic and the overall motion wasn't very fluent but was a little "sticky". For the 2 and 3 part / hole gears plastic seems to be fine though and it's possible that now, after having developed this further for a few months, plastic could work over all.

So the gear is not driven. the motor on the lamination machine causes the forward motion?

The gear on the wheel seems to stop it advancing to much.

The gear is only driven by the lever actuated by the pick and place head, this creates the forward motion. However it seems at times this force isn't enough hence the laminator helps. Either way an external source will be necessary to remove the tape coverings. The way escapement gears work is that the lever exerts a forward going motion of the gear in both push-down and push-up motion while also effective blocking the gear from moving further once it's reached it final up or down position.

Karl

[dave]

I am really impressed. I also have a CNC mill so I could try make your project when released. soon though I will have over 10 Fuji CP6 feeders and I think I can advance them the same way you have, with no software mods.

Also. Where did you get the bits to make the juki auto changer. the spring bit you have. I dont have a lathe. I be happy to pay for you to make that bit and a spare, I like spares.

Regards

Dave

[Knas]

I am really impressed. I also have a CNC mill so I could try make your project when released. soon though I will have over 10 Fuji CP6 feeders and I think I can advance them the same way you have, with no software mods.

Also. Where did you get the bits to make the juki auto changer. the spring bit you have. I dont have a lathe. I be happy to pay for you to make that bit and a spare, I like spares.

Cool! I bought the nozzle holder on ebay http://www.ebay.com/itm/Customized-SMT- ... SwAYtWOGI0. I cut my own pulley just with a regular CNC - I will post the exact mods i did to the head in a bit, feel free to ask though.

Karl

[dave]

WTF if you go on ebay.com you can start to find Juki parts. None of this shows on co.uk verson.

I am so glad you show me this. Not just your amazing machine, Amazing Nozzle changer, but your amazing eBay skills also.

[Knas]

WTF if you go on ebay.com you can start to find Juki parts. None of this shows on co.uk verson.

I am so glad you show me this. Not just your amazing machine, Amazing Nozzle changer, but your amazing eBay skills also.

Oh yeah and then don't forget about alibaba.com and aliexpress.com, amazing sources - alibaba literally have anything you want, i haven done the craziest searches and something always pops up.

[dave]

I am yet to venture outside of ebay when dealing with china. I do window shop on them other sites though but never took it all the way.

I already ordered the 9 Nozzles and Holder. I am keen to have my machine built in December. Got to get a little click happy on ebay or nothing will happen .