Semi-automatic passive printable/castable feeder

[Oaklands]

How is the exact 4mm advancement controlled, using this approach?

(or how is the position of the next component fixed every time?)

I can see how the weight takes up the slack on the tape cover...

[wormball]

It is like this: https://github.com/alexavr2/alexfeeder

[Oaklands]

So I take it that to advance by 4mm, this is 'controlled' by the head pushing down on the lever, which I presume must be tuned for each feeder to avoid it getting out of sync over time.

(Based on the video, I am assuming you are not doing hole recognition for each pick??)

I also noticed that the bottom of the lever is circa 3mm width - so are you moving the tape by inserting the lever into an empty component slot (vs a hole)?

[wormball]

No!

[wormball]

Manual: https://github.com/dining-philosopher/litefeeder

[Oaklands]

A comprehensive & excellent write up...tnx:)

..will download the files to see how they print out !

[ds23man]

https://www.robotdigg.com/product/560/D ... ving-Wheel

[wormball]

Thank you! I accidentally found what i have been searching for about a year (i saw this site earlier but did not find it until this day). Cheap tape pulling rod! https://www.robotdigg.com/product/1641/ ... -48VA-48VB And not so cheap, but compatible tape holder. https://www.robotdigg.com/product/561/Desktop-PnP-Mat With this all cheap feeder designs (including mine) are rendered obsolete. However it is not for the liteplacer software which i use mostly cos i could not make liteplacer cameras work with openpnp.

[ds23man]

I posted these parts on this forum before! It would be nice if Yuha can write some code for it.

[Oaklands]

@wormball
I printed out your Litfeeder based on Github files linked above (3D printed using PLA) and after 6 iterations I finally have something that looks like it might work for me(tbc ?).

I am still waiting on the compression springs to arrive (Hopefully tomorrow), So I am just testing it manually without a spring for now.


The list of mods are as follows: (refer to the indexed image below/ numbers refer to location in image)

1. I made the shaft for rotation a bit smaller as movement wasn't easy at first.
2. Instead of the waiting for the flat metal spring to arrive in 2 months, I printed one in PLA (same dimensions), with a semi-circle piece on the end to assist tape roll-over (will need to smooth this a bit or cover with tape)
3. Increased the size of the cavity for the spring holder so that the PLA one would fit.
4. added a half-round piece here (coming out horizontally from the 'stop' block) to make sure the spring is held down & provide a roll-over guide for the removeable tape.
5. Added a narrow lip covering the tape holes only to keep the tape in place (does not cover the removeable tape part or pick up location) (doesn't cover the front screw hole either )
6. Added a full width lip @8mm to guide the tape at the rear. Inserted hole for access to rear screw.
7. Used a metal male header pin to drag the tape. Anything thinner just bent in use. I also added a very small 1mm hole in this which was almost invisible but made the insertion easier. Held the header pin with a pliers and heated it with a soldering iron - then inserted the hot pin thru the PLA with care. Then trimmed/bent the pin carefully.

So when manually operating this it seems to work well. The arm seems to hold up well, but could be a weak point long term(tbc?). I hope the spring will be strong enough to automatically advance the tape - will know in a couple of days.

3D Printing Details: (Your printing may differ)
- PLA
- Infill 100% (solid infill). Things broke easily on my first attempt with 20% infill
- All 3 parts can print together on their side.
- Initially used support(mainly for the compression spring holders) but have since printed without support, as it wasn't worth it.


Congrats again on an ingenious design.

Other Notes:
It may be possible to do away with the spring mechanism and replace with a friction piece at the front to hold the tape. (I wonder if static will become an issue. If so maybe use grounded metal/metal tape as the friction piece etc)