Hybrid SMT Feeder working well

[Blowtorch]

I thought it appropriate to provide some feedback on the Hybrid SMT Feeder that has been discussed here a bit.  

I think is great - the concept appealed to me from the start.  To use common off the shelf factory components made from steel, together with a 3D printed frame is just brilliant.  I started working on this quite a while back, and my version differs from the version that Mike published on Grabcad, simply because I do not have easy access to some of the parts he is using (springs, small bearings).  I also attach it to my machine in a different manner.  

Here is a short video on it's first test run, linked here First run

This was supposed to be a test run, but it all worked so I ended up pushing 12 panels through - they small and simple, with low part count.  

Sidenote - also very happy with the latest fiducial checking code...that looks at the panel fiducial from an angle. Works great.  

Next steps are to dial in the firmware better - probably end up writing my own version of it. 

[Blowtorch]

I built a simple machine to test the feeders, and also to dial in the 2 PWM based positions (retract & advance).  While I was at it, I measured and logged timing, so that I would better be able to tune and integrate into OpenPnP.  Total ms is the total time for a feed, including tensioning the cover tape and includes 100ms delay waiting for the tension micro-switch to settle.  The feed ms is how long it takes after telling the servo to advance the tape, until the microswitch is activated by lowered tape tension.  tape ms is how long it takes to tension the tape, including a 100ms "settle" time.

This was for a 300rpm N20 motor.

 

[tianl...@gmail.com]

In fact, the spacing between the feeders in the SMT factory is larger, otherwise you cannot easily replace them.  

They also do not use Bluetooth, nor do they use the 485 bus, nor do they use automatic recognition. Because that would make the engineers on the production line feel troublesome.

---Original---

From: "Blowtorch"<jorg...@gmail.com>

Date: Wed, Nov 1, 2023 00:20 AM

To: "OpenPnP"<ope...@googlegroups.com>;

Subject: [OpenPnP] Re: Hybrid SMT Feeder working well

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[tianl...@gmail.com]

If you change the modulus of the worm and gear to 0.7（They can all  be   printed  by   3D   printer）, you can use a 60 RPM N20 motor, which is fast enough.

[Mr covert]

I would love more details on where and what parts you purchased to make this happen. I'm looking at making feeders myself now.

To view this discussion on the web visit https://groups.google.com/d/msgid/openpnp/6541f033.050a0220.1c51a.1e6e%40mx.google.com.

[Mike Menci]

You will find all the details here: 

https://grabcad.com/library/hybrid-smt-feeder-stl-parts-abs-material-or-better-1 

Hybrid SMT Feeder - known as well as Poor Man Feeder
8x2mm+8x4mm Tape, 3D print parts
12mm Tape, 3D print parts
16mm Tape, 3D print parts

Feeder Metal Parts sets available from:
Get the PM-feeder accessories here
https://www.microsmt.com.cn/products/...
Get the PM-feeder Open source documentation here
https://github.com/microsmt/Microsmt-...
Get the 0816 feeder Open source documentation here
https://docs.mgrl.de
See assembly video bellow - YouTube

[Blowtorch]

Bing has the parts as pointed to by Mike above at microsmt.com.cn  Also on his aliexpress store.

Re Bing's comment on spacing, I settled on 20mm spacing to get some space between them, to make it easier to handle component changes, or feeder changes.  But, I have a feeling I am not going to be changing the feeders themselves, except for maintenance.  It is so easy to load with new components, with the feeder staying in place.

However, my feeders are super easy to fit and remove.  To fit, I position it above and a bit behind, then I drop it onto the rail, and move it a bit forward, the rear locks in place.  A single 3mm screw secures it (screw inserted in feeder in top pic, lhs.).  Even with feeders on either side, it is easy enough.  In the pic, the feeder on top had a lock that I glued in place when setting everything up, but final version has an extended tape chute with locking key built in (bottom feeder in the pic).  

The 150rpm N20 motors are perfect with the standard nylon worm gear.  I did not like all the old designs of the tape peeler, where the worm gear is unsupported on top.  Most of the load on the worm is vertical, driving the gear, but there is some lateral loading, just over half way up, so I designed my own tape puller with a drop in support axle for the top.  No bearings, its just acting as a bush, but I got some 3mm bronze welding rod so friction and wear is hopefully ok.  Obviously bearings are better, if I could have got the small bearings Mike used, then I would have used the design that he has in the grabcad files linked above.

The other 2 gears are PETG also running on 3mm bronze axles.  To make sure everything was OK, I used an old school analog ammeter to check the current used by the motor, under different conditions:

1. free running, no top axle or gears

2. free running, with top axle but no gears

3. free running, with top axle and gears

4. actually pulling tape, with different tensions and thicknesses        

I also fed +- 1000 0603 resistors through a feeder continuously using my little machine I alluded to above, all good, I monitored servo and N20 temperatures very scientifically with my fingertips, they got a bit warm, but not majorly so.  This test drove the feeder much harder than OpenPnp ever would, with no delays between feeding.