Rapid Feeder - A new type of feeder

7,868 views
Skip to first unread message

Shai

unread,
Jan 17, 2020, 12:24:38 PM1/17/20
to OpenPnP
In continuation of my last post here on I2C feeder design, which allows the flexibility to move feeders along an axis without the need for mechanically indexing them, here is a picture of my first working prototype without a sprocket. I hooked it up to a breadboard setup to test. My next plan is to get CNC'd PCBs. These PCBs are expensive at low volume and my hope is that others here may also be interested in this to help out in developing it. In doing so, I am wondering how many would like to join in on the first round of prototypes? I have most of the pieces already, just need to buy more motors to match the volume of PCBs and 3D print the cover of each feeder from PLA (which is a non critical part for dimensional accuracy). The sprocket will also be made out of 1mm thick PCB. This would include the motherboard to plug the feeders into as well. All the feeders will be SMT assembled, but ship mechanically un-assembled (to save space in shipping box). The feeder is designed to work with all tape types shown on this guide: http://www.vishay.com/docs/60034/tapereel.pdf This includes proper min bend radius of wider tapes. This first batch will only be for 8mm wide tapes, but the feeder is designed to be expandable to wider tapes by swapping the standoffs and dowels to longer ones. The entire setup runs on Arduino code and uses two optical sensors. What still needs to be figured out is the mounting of the feeders to the motherboard. Currently there are two holes on top and under the 5 pin spring connector as you can see, but these don't work well. The idea was to have it clip onto two rods, but PCBs don't flex well enough to make it work. Any suggestions appreciated.

How many people here would be interested in getting these feeders in classic green color and what is a price point that works for you so I can calculate the volume required to meet that price point? Please also let me know quantity you would be interested in. My hope is to get enough people interested so we can lower the price point with a group buy. Note that these have only been mechanically tested, but the code is ready and compiles.


2019-12-23.jpeg


IMG_7308.JPG



screenshot_166.png



Mike Harrison

unread,
Jan 17, 2020, 12:30:17 PM1/17/20
to ope...@googlegroups.com
On Fri, 17 Jan 2020 09:24:38 -0800 (PST), you wrote:

>In continuation of my last post here on I2C feeder design

No! No! No! - I2C is absolutely the wrong for this type of application for so many reasons.

RS232 or RS485. CAN if you must, but that's more expensive.

Even 5V TTL UART would be better than I2C



Marek T.

unread,
Jan 17, 2020, 12:37:32 PM1/17/20
to OpenPnP
Hi Shai,

Is there not any shuter?
Do you have some photos with the feeder fully assembled? With the reel and tape, showing how this is advanced and how the covering tape is taken off?

Shai

unread,
Jan 17, 2020, 12:44:56 PM1/17/20
to OpenPnP
@Mike, I don't see why this wouldn't work with I2C? It's capable of hosting 128 devices on one motherboard.

@Marek, see attached picture of how cover tape gets pulled. When it is loose, the optical sensor is clear and knows to cut off power to motor to stop pulling tape. I think by shutter you mean something cover the components after the tape is pulled? There is none. I designed it so the part is picked right where the tape is pulled off. The motors are not super fast and *shouldn't* make the parts bounce. 

screenshot_168.png


Shai

unread,
Jan 17, 2020, 12:51:45 PM1/17/20
to OpenPnP
Here is another view from the top. The opening dimensions change with the width of the tape. Wider the tape = bigger opening. So the plan is to have slight variations between different feeder widths. 

IMG_7956.JPG


Jon Raymond

unread,
Jan 17, 2020, 12:54:58 PM1/17/20
to OpenPnP
It's been explained to you before why I2C shouldn't be use. It's a noise issue. Do you have a working feeder(s) to showcase on a machine?

Jason von Nieda

unread,
Jan 17, 2020, 1:10:26 PM1/17/20
to ope...@googlegroups.com
Hi Shai,

Nice work - looks like it's really come a long way!

For mounting, how about something like this?

IMG_3400.JPG

Forgive the rough drawing. Basic idea is that the mounting point is a piece of t-slot extrusion (perhaps 20x20 or 40x40). The feeder has a fixed hook on the top that catches in one of the t-slots, and the feeder has a spring loaded lever on the bottom that catches in the bottom t-slot. Your slider PCB could mount to the "front" of the extrusion using a third t-slot.

Loading the feeder on would mean angling it a bit to get the top hook caught and then lower it until the spring loaded lever rolls over the bottom slot and catches. Pull on the lever to remove.

I feel like maybe you looked at something like this previously, but I didn't see the email. Forgive me if you've already considered and discarded this idea.

Jason


--
You received this message because you are subscribed to the Google Groups "OpenPnP" group.
To unsubscribe from this group and stop receiving emails from it, send an email to openpnp+u...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/openpnp/77b7477f-6c35-43c9-836b-a6a13274430c%40googlegroups.com.

Shai

unread,
Jan 17, 2020, 1:10:45 PM1/17/20
to OpenPnP
On Friday, January 17, 2020 at 12:54:58 PM UTC-5, Jon Raymond wrote:
It's been explained to you before why I2C shouldn't be use. It's a noise issue. Do you have a working feeder(s) to showcase on a machine?

One has to consider other constraints here. There are a very limited number of spring contacts on the market and the pin count maxes out at 5 pins I believe from the research I did. In addition to that, the spring connector would have to have a high cycle count. The spring contacts I am using have 5,000 cycle counts, ensuring the feeder lasts for a long time. I2C can be improved using a filter of sorts. The feeders are 10mm width, so you can fit quite a bit, over a short distance. As mentioned, I don't have working feeder yet with the PCB because they have to be CNC'd, which is expensive and why I was hoping to do a group buy for others who may be interested to experiment.
 

Shai

unread,
Jan 17, 2020, 1:15:15 PM1/17/20
to OpenPnP
Thanks Jason! It's been months in the works testing multiple prototypes before committing to CNC'd PCBs. I have thought extensively about mounting to extrusions, but there's a few issues. 

1. Requires to grow the PCB footprint significantly, which adds cost.
2. Are you suggesting a lever for each feeder? This brings back mechanical indexing (assuming the lever is on the machine side).
To unsubscribe from this group and stop receiving emails from it, send an email to ope...@googlegroups.com.

Shai

unread,
Jan 17, 2020, 1:17:06 PM1/17/20
to OpenPnP
I was hoping I can find some sort of metal or plastic clip off the shelf that can be sandwiched between the PCBs. Of course you can 3D print it... but that's a lot of printing :) It would also have to grow in width with wider tapes.

Jason von Nieda

unread,
Jan 17, 2020, 1:18:21 PM1/17/20
to ope...@googlegroups.com
No, the lever is part of the feeder. No indexing required. I would imagine the top is a 3D printed piece that goes between the two PCBs and the bottom is 3D printed or maybe CNCd if more strength is needed.

If it's not clear still, let me know and I'll try to do a better drawing :)

Jason


To unsubscribe from this group and stop receiving emails from it, send an email to openpnp+u...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/openpnp/84821fcc-7243-4606-b70e-ed2612d9398f%40googlegroups.com.

Shai

unread,
Jan 17, 2020, 1:23:59 PM1/17/20
to OpenPnP
Hmm CNC = much higher cost. Here is what I was thinking of 3D printing for a "clip" design that gets sandwiched between both PCBs.

screenshot_169.png


Jason von Nieda

unread,
Jan 17, 2020, 1:34:19 PM1/17/20
to ope...@googlegroups.com
I think you are going to find that if you use metal rods they are going to flex significantly when you are adding/removing/moving feeders, throwing off all your feed locations every time you touch one.

Here's a better drawing:

IMG_4363.JPG

I think the lever / catch can easily be 3D printed. It will be at least 6mm thick or so, and should be plenty strong.

Jason



On Fri, Jan 17, 2020 at 12:24 PM Shai <shai...@gmail.com> wrote:
Hmm CNC = much higher cost. Here is what I was thinking of 3D printing for a "clip" design that gets sandwiched between both PCBs.

screenshot_169.png


--
You received this message because you are subscribed to the Google Groups "OpenPnP" group.
To unsubscribe from this group and stop receiving emails from it, send an email to openpnp+u...@googlegroups.com.

Shai

unread,
Jan 17, 2020, 1:42:23 PM1/17/20
to OpenPnP
I agree that it can flex. That was my concern too. However, this also depends on the linear rod material and diameter. I have some samples here that are about 250mm long and don't flex. It may vibrate a bit when adding/removing feeders, but should return to position once untouched. The issue I see right away other than cost with your design is it would require increasing the feeder size significantly as there's no more room left.

Jason von Nieda

unread,
Jan 17, 2020, 1:45:49 PM1/17/20
to ope...@googlegroups.com
Fair enough. I think you are going to find that when you hang a bunch of leveraged weight off those rods they are going to flex quite a bit, unless you are talking like 20mm+ diameter, but I guess the only way to know for sure is to try :)

Jason


On Fri, Jan 17, 2020 at 12:42 PM Shai <shai...@gmail.com> wrote:
I agree that it can flex. That was my concern too. However, this also depends on the linear rod material and diameter. I have some samples here that are about 250mm long and don't flex. It may vibrate a bit when adding/removing feeders, but should return to position once untouched. The issue I see right away other than cost with your design is it would require increasing the feeder size significantly as there's no more room left.

--
You received this message because you are subscribed to the Google Groups "OpenPnP" group.
To unsubscribe from this group and stop receiving emails from it, send an email to openpnp+u...@googlegroups.com.

Dave McGuire

unread,
Jan 17, 2020, 2:02:51 PM1/17/20
to OpenPnP
On 1/17/20 12:54 PM, Jon Raymond wrote:
> It's been explained to you before why I2C shouldn't be use. It's a noise
> issue. Do you have a working feeder(s) to showcase on a machine?

RS485 would be ideal for this.

I'm not at all throwing stones at what looks like a really nice feeder
design, but I'd be awfully nervous about signal integrity there. I2C
was not designed for this. Yes, it may be able to be made to work, but
there are protocols that were specifically designed for applications
like this one, and they're easy and cheap to implement.

-Dave

--
Dave McGuire
McGuire Scientific Services, LLC
New Kensington, PA

Shai

unread,
Jan 17, 2020, 2:14:41 PM1/17/20
to OpenPnP
I'm all up for implementing RS485. I'm not familiar with it, so if someone here is interested in offering a helping hand, I'll be happy to implement it. Seems like MAX485 chips are cheap on aliexpress, so perhaps its fine to implement it unless there's additional ICs needed? Note I'm currently using Attiny84 on feeders and Atmega328P on motherboard. So if there's not enough pins, it would require to upgrade to a bigger IC. Again, I'm not familiar with RS485, so if someone wants to help modify it to that, I'm happy to do so.

Marek T.

unread,
Jan 17, 2020, 2:19:17 PM1/17/20
to OpenPnP
Shai shatter is not matter of rapidity of the feederb only. In case where the ventouri is used, when there is no suction the nozzle is blowing. And then small parts are blowed away from the tape pockets. The shutter must be opened straightly before the tip touches to the part, moreless in the half of the distance. So in this case, my case, the feeder without the shutter is useless for parts <= 0805. Pity because it looks really cool.

Dave McGuire

unread,
Jan 17, 2020, 2:20:38 PM1/17/20
to OpenPnP
I'd be happy to assist you with the RS485 aspects of the design.

Shai

unread,
Jan 17, 2020, 2:23:37 PM1/17/20
to OpenPnP
Understood. I designed these feeders with my setup in mind (PNP I am still working on) which does not blow air when vacuum is off. I gathered that most OpenPNP machines that are built do not have air blowing, so I did not consider a shutter. A shutter would also not be easy to implement in this design.

Dave McGuire

unread,
Jan 17, 2020, 2:35:58 PM1/17/20
to ope...@googlegroups.com
Actually, and I don't know why I hadn't thought of this before, CANbus may be an even better option for THIS, especially if you're already doing I2C-ish things like multiple slave communications. I'm in the middle of a CANbus design now, and could also assist with that, if needed.

Marek T.

unread,
Jan 17, 2020, 2:40:04 PM1/17/20
to OpenPnP
You're right, probably most of people use vacuum pumps not compressors+ventouri. But if you'd implement it the product could be fully universal and really good!
I can turn off the blowing, it's adjusted with the screw, and then it works like machine with vacuum pump. But from my experience, with the blowing the small parts are placed better. Also when I turn off the the blowing, when do the discard the small parts like 0603 gets off the tip in some 3sec or more, 0402/0201 don't get off at all but remain on the tip - don't know why but it is.

I need some 30 good feeders. Now I have some feeders but they are not precise enough for 0402. I think about pneumatic yamaha but it's complex plate and not cheap, electrical yamaha - simple plate but expensive feeders...

Do you live in around of EU or US?

Shai

unread,
Jan 17, 2020, 2:42:30 PM1/17/20
to OpenPnP
Located in US and understood about the blowing reasoning. I think that is for another future feeder design ;)

James Carter

unread,
Jan 17, 2020, 4:23:04 PM1/17/20
to OpenPnP
People are being quite harsh here. You've come up with a good design and if it works for you that's great.

Push forward with it and see if the design works for you and if you have any issues with I2C you can always modify the design.

Good on you for getting a decent design that works in a small footprint.

James Carter

unread,
Jan 17, 2020, 4:26:17 PM1/17/20
to OpenPnP
P.S. I have a CNC I can lend some time on to help you prove this design out. Smallest endmill I generally use is 2mm.

If you want to send me something to make I'll run it for you.

ja...@loveelectronics.co.uk

Michael Anton

unread,
Jan 17, 2020, 5:05:40 PM1/17/20
to OpenPnP
You probably have far more gearing on that design than you actually need, especially since you are using a worm gear, and a gear head motor. I think at the very least, you could drop out the middle gear.  If you find out later that you need more gearing, you can always move to one of the other N20 motors with a higher gear ratio.

Shai

unread,
Jan 17, 2020, 5:10:11 PM1/17/20
to OpenPnP
To reply to Michael Anton's email that got sent to the emailing list instead of here:

"You probably have far more gearing on that design than you actually need, especially since you are using a worm gear, and a gear head motor. I think at the very least, you could drop out the middle gear.  If you find out later that you need more gearing, you can always move to one of the other N20 motors with a higher gear ratio."

Adding that gear was necessary because I am using off the shelf gears. You can't 3D print these gears either for many reasons. And there's no off the shelf worm gear that can attach directly to the sprocket or even the middle gear. This was literally the only combination of gears/worms that are possible with off the shelf parts that are cheap.

I should probably re-iterate to everyone that the goal of this feeder is to make a feeder that is cheaper than any other out there. Of course reliability is important, otherwise it's useless. But, if the cost goes up too high, you may as well get a metal stamped feeder off Ebay or Aliexpress.

Marek T.

unread,
Jan 17, 2020, 5:18:45 PM1/17/20
to OpenPnP
Not harsh but honest.

The group is to exchange the thoughts, not to agree with everything.

For me the feeder looks very very cool. Except the shutter lack and i2c ;). But it's still far from good working... Some 1-2 years ago, here was a man named Darren with Assisi very promising project of the feeder. I remember "he had a dream" but it looks he woke up and forgot about it ;). Let's wait so...

Marek T.

unread,
Jan 17, 2020, 5:20:59 PM1/17/20
to OpenPnP
Assisi = also...
Damned keypad auto-corrector...

Mike M.

unread,
Jan 17, 2020, 6:10:42 PM1/17/20
to OpenPnP
Shai
You can make sch for bouth options like this:
and place under the chip two resistor pads - than you are ready for bouth options !?

Mike

Shai

unread,
Jan 17, 2020, 6:13:17 PM1/17/20
to OpenPnP
Mike,

The Attiny84 I am using on the feeder doesn't have RX/TX pins. I would need a different IC. Just how much better is RS485 than I2C? And is anyone willing to code the Arduino?

John Plocher

unread,
Jan 17, 2020, 7:32:22 PM1/17/20
to ope...@googlegroups.com
On Fri, Jan 17, 2020 at 3:13 PM Shai <shai...@gmail.com> wrote:
The Attiny84 I am using on the feeder doesn't have RX/TX pins. I would need a different IC. Just how much better is RS485 than I2C? And is anyone willing to code the Arduino?


RS422/485 is "just like" RS232, but with different electrical details that make it a good fit for this use case - the bus is differential, and so can be robust in the case of noise and differing ground floors on either end.
It exists in both a 2-wire and 4-wire versions; in your case, the 2-wire half duplex version should be sufficient...

The 'Tiny should be able to serial on the pins you would have used for I2C; if you are banging something up with the Arduino IDE, you can use the SoftwareSerial library:

#include "SoftwareSerial.h"
const int Rx = SDA; // change as needed
const int Tx = SCL; // to match your circuit

SoftwareSerial rs485Serial(Rx, Tx);

void setup(){
pinMode(Rx, INPUT);
pinMode(Tx, OUTPUT);
rs485Serial.begin(9600);
}

byte resp[...size...];
void loop() {
rs485Serial.write(... some command...);
resp = rs485Serial.read(); ...
}

RS485 is a multi-drop half duplex protocol that can easily support many feeder clients, the protocols used on top of it tend to be half duplex so that you don't have to worry about devices talking over each other at the same time.
This implies that each feeder/device/slave will need some sort of fixed ID, so you can say things like "feeder 42, do _this_" and have just the feeder with ID 42 respond - not really different from giving each feeder its own unique I2C address.  From a protocol design perspective, think in terms of initially iterating through an ID range to enumerate the installed feeders and then a loop of "read, modify, write" to get things done.

  -John
 

John Plocher

unread,
Jan 17, 2020, 10:00:07 PM1/17/20
to ope...@googlegroups.com
also

... depending on the bus driver chips you choose (1-unit load or 1/4 unit load), at a slow baud rate (19,200, not 256,000) and short bus (3', not 5,000'), you should be able to handle up to 32 - 64 nodes on a single bus.

  -John

Jan Juranek

unread,
Jan 18, 2020, 4:44:02 AM1/18/20
to OpenPnP
Hey Shai,

perfect design!! Will you make this design open source?  We still don't have our machine built, but we can help you with coding as we are doing this for living :)

Let me know.
Honza

Dne pátek 17. ledna 2020 18:24:38 UTC+1 Shai napsal(a):
In continuation of my last post here on I2C feeder design, which allows the flexibility to move feeders along an axis without the need for mechanically indexing them, here is a picture of my first working prototype without a sprocket. I hooked it up to a breadboard setup to test. My next plan is to get CNC'd PCBs. These PCBs are expensive at low volume and my hope is that others here may also be interested in this to help out in developing it. In doing so, I am wondering how many would like to join in on the first round of prototypes? I have most of the pieces already, just need to buy more motors to match the volume of PCBs and 3D print the cover of each feeder from PLA (which is a non critical part for dimensional accuracy). The sprocket will also be made out of 1mm thick PCB. This would include the motherboard to plug the feeders into as well. All the feeders will be SMT assembled, but ship mechanically un-assembled (to save space in shipping box). The feeder is designed to work with all tape types shown on this guide: http://www.vishay.com/docs/60034/tapereel.pdf This includes proper min bend radius of wider tapes. This first batch will only be for 8mm wide tapes, but the feeder is designed to be expandable to wider tapes by swapping the standoffs and dowels to longer ones. The entire setup runs on Arduino code and uses two optical sensors. What still needs to be figured out is the mounting of the feeders to the motherboard. Currently there are two holes on top and under the 5 pin spring connector as you can see, but these don't work well. The idea was to have it clip onto two rods, but PCBs don't flex well enough to make it work. Any suggestions appreciated.

How many people here would be interested in getting these feeders in classic green color and what is a price point that works for you so I can calculate the volume required to meet that price point? Please also let me know quantity you would be interested in. My hope is to get enough people interested so we can lower the price point with a group buy. Note that these have only been mechanically tested, but the code is ready and compiles.

Michael Anton

unread,
Jan 18, 2020, 6:25:43 PM1/18/20
to OpenPnP
I think that you can drive your larger gear directly with the worm, or at least that's what I was doing in the design I worked on, and it looks like it should work ok, even if it isn't ideal.  It's not like there is a huge load to get it to turn.  Like you, I was using easy to get off the shelf gears.  I've attached a 3D pdf of the version I was working on, which may give you some ideas.

At the very least, you should be able to drive the small gear with your worm, and skip the larger gear next to it, since it has the same modulus as the final gear.
Feeder Assembly.pdf

Shai

unread,
Jan 18, 2020, 6:48:51 PM1/18/20
to OpenPnP
Hi Michael,

I see how you did it. If I do it like that, I have to make the feeder wider. Currently my feeder is 10mm thick, which is very skinny and allows more feeders to be mounted.

Brynn Rogers

unread,
Jan 18, 2020, 9:28:09 PM1/18/20
to OpenPnP

The Tiny102 and tiny104 have a UART.      I looked and the ATtiny's have like 64 byte of ram and some smallamout of code space (1k to 8k).
I have gone all ARM,   for almost the same price you can get an arm M0 that has 1Kram minimum, and like 8k code minimum, Way nicer to use...
NXP  MKL02 or something   0.50 each for some variations...

And please do not use I2C.   

Brynn

Shai

unread,
Jan 19, 2020, 10:44:30 AM1/19/20
to OpenPnP
One option is to use a fuse holder such as this: https://www.digikey.com/product-detail/en/keystone-electronics/3622/36-3622-ND/2745822 so the feeder clips onto 5mm diameter linear rods. However, this means downsizing from the original 6mm rods I thought of using, which seem strong. Not sure how strong 5mm linear rods are, but of course you can probably add 3D printed supports along the path to strengthen it, although not ideal since you lose feeder space. But these are the only fuse holders that fit inside an 8mm tape feeder. The next size up is 6.35mm fuse holder and those are too wide to fit into an 8mm feeder.

Shai

unread,
Jan 19, 2020, 1:50:52 PM1/19/20
to OpenPnP
I've gone ahead and modified the feeder design to include these fuse clips. My main concern is the solder would break after multiple uses, so I cut 5mm slots into the PCB to guide the feeder perpendicular to the linear rails. There's a hole in the center of this fuse so that solder can protrude through for better bonding, perhaps that would help. There's also no cycle count on these fuses, but considering it's made out of a strong material, I think it will last long. See attached pictures. Thoughts? Very "tacky" but it should work and it's simplest/inexpensive design I can think of... still open to ideas :)


screenshot_171.png  screenshot_170.png



Shai

unread,
Jan 19, 2020, 2:17:20 PM1/19/20
to OpenPnP
Here's a better design actually to ensure the linear rods don't get pushed too far into the fuse holder and are guided more straight into the fuse holder. Another concern I realized would be to ensure the feeder isn't too heavy and the fuse holders can grab onto the linear rods well enough.

Only way to find out is to test :) If all else fails... I guess the best option is to just make a through hole and slide these feeders onto the rails and then mount it...

screenshot_172.png


Jason von Nieda

unread,
Jan 19, 2020, 2:23:42 PM1/19/20
to ope...@googlegroups.com
Hi Shai,

Are you intending to have the reels hang off the feeders, or will you have a separate reel holder? If the former, there is no way those fuse holders will bear the weight of most reels.

How about something like this instead:

IMG_7479.JPG

Sort of like a keyslot. You set the top entry point on the rod, so the weight is borne by by the stronger PCB or plastic, and then you use the fuse holder at the bottom simply to hold it in place.

Jason


--
You received this message because you are subscribed to the Google Groups "OpenPnP" group.
To unsubscribe from this group and stop receiving emails from it, send an email to openpnp+u...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/openpnp/3b44de30-c7f8-4953-98e7-0c4ba1edaf39%40googlegroups.com.

Shai

unread,
Jan 19, 2020, 3:12:04 PM1/19/20
to OpenPnP
Hmm, good point. I completely missed the opportunity to do that! I currently don't plan to hang the reels on the feeders themselves, but perhaps in a future version. I will try to modify the design to do it how you suggested.

Shai

unread,
Jan 19, 2020, 3:58:00 PM1/19/20
to OpenPnP
Much better :)

screenshot_173.png


Marek T.

unread,
Jan 19, 2020, 4:09:48 PM1/19/20
to OpenPnP
Much better because keeps a bit better the feeder against loosing the x location.
However I'm not sure if this lower (on you picture) holder will hold it strongly enough.

Maple_Dude

unread,
Jan 19, 2020, 8:17:37 PM1/19/20
to OpenPnP
Looks interesting

Michael Anton

unread,
Jan 19, 2020, 9:09:25 PM1/19/20
to OpenPnP
Currently, mine is at 10mm as well, though in truth I was only trying to get 12mm, so I may have planned on having a thicker base to mount it on initially.  I was planning to use an aluminum PCB for the base of the feeder, but I don't require any routing which at least makes them fairly inexpensive.

Since I use a spring clamp to hold down the tape, I don't need to trap the tape on both sides, and the adjacent feeder forms the second side, so the feeder is narrower than it appears.  The large plastic part that supports all the assembly is only 8.4mm thick, which leaves 1.6mm of PCB to get 10mm in width.  

I planned to clip my design onto 20mm T-Slot extrusions, using a clip similar to what Jason proposed, but from the side rather than the bottom.  So, the front clip catches the front of the extrusion, and then the rear clip locks it into place.

Given that the tape can be up to 8.3mm wide when you include tolerances, that means that the skin on each side of your tape is under 1mm?

Shai

unread,
Jan 20, 2020, 10:59:18 AM1/20/20
to OpenPnP
Michael,

So I plan to cut a depth of 1.1mm. The manufacturer told me their tolerance is 0.15mm for each direction. Is it actually that? Who knows, this is a factory in china and I doubt their sales people even know their specs too well (from experience). So the total width for a tape, I planned to be at 8.2mm give or take. If you were to buy some old tape from aliexpress, yea it might be too thick or wide or low quality and may not work. I've tried a few and some are a bit harder to push on a 3D printed resin sample, but then again my 3D printed resin sample wasn't firmly flat like a PCB would be. I think the only way of knowing if this will work is trying prototypes, but prototyping a milled PCB is very expensive when you don't have a CNC to do it in house and need to send it out :)

Shai

unread,
Jan 20, 2020, 11:03:44 AM1/20/20
to OpenPnP
Hi James, just sent you an email!

SebG3D

unread,
Jan 20, 2020, 3:37:23 PM1/20/20
to OpenPnP

One question that might have been answered, but I could not find it:

 

Why would you use a pcb for the sprocket.

Lasercut steel would be really precise and cost very little in high quantity.


While working on my version of a feeder (which is on pause right now) I planned on having the sprocet lasercut with holes for a IR encoder.
And I also struggeled with finding the right cheap gears for the job.
Apperently you have succeeded.

Good luck with this project.

Thomas Langås

unread,
Jan 20, 2020, 3:58:21 PM1/20/20
to ope...@googlegroups.com
https://blog.exploratory.engineering/post/feeder/

Here's our sprocket, laser cut steel with two rows of holes for IR photo diodes.  These holes are the smallest you can make with that laser (0.2mm) . It's basically just a burn through.

This sprocket was pretty cheap, even in low qty.


Mvh / Best regards,
Thomas Langås
(+47) 95731546

--
You received this message because you are subscribed to the Google Groups "OpenPnP" group.
To unsubscribe from this group and stop receiving emails from it, send an email to openpnp+u...@googlegroups.com.

Shai

unread,
Jan 20, 2020, 4:30:47 PM1/20/20
to OpenPnP
Where exactly did you get your sprockets made Thomas and how much did they cost? 

@SebG3D,

I tested with a smaller sprocket and it seemed to work well for a PCB sprocket. I had to make some design tweaks to the teeth, so we'll see how the next one works. The reason being is that I couldn't find anyone who would do it for cheaper than a PCB. As mentioned before, I'm trying to keep all of this low cost because otherwise you may as well buy a professionally made feeder.

Shai

unread,
Jan 20, 2020, 4:34:04 PM1/20/20
to OpenPnP
I've submitted the design to the manufacturer and hope to have them start making samples after Chinese New Year, which would be start of February. I'll be testing these with I2C to at least know that the mechanics work.

Jason von Nieda

unread,
Jan 20, 2020, 4:37:49 PM1/20/20
to ope...@googlegroups.com
Hey Shai,

For what it's worth, I think there is value in what you are doing above it being cheap. In my opinion, an open source, reliable, hackable feeder at the same price point of a commercial feeder is still more valuable than the commercial feeder. So, I guess my point is that even if the price has to come up a bit for it to be reliable or sustainable, that's probably okay.

Jason


On Mon, Jan 20, 2020 at 3:34 PM Shai <shai...@gmail.com> wrote:
I've submitted the design to the manufacturer and hope to have them start making samples after Chinese New Year, which would be start of February. I'll be testing these with I2C to at least know that the mechanics work.

--
You received this message because you are subscribed to the Google Groups "OpenPnP" group.
To unsubscribe from this group and stop receiving emails from it, send an email to openpnp+u...@googlegroups.com.

Thomas Langås

unread,
Jan 20, 2020, 5:13:27 PM1/20/20
to ope...@googlegroups.com
We used a local company, here in Trondheim, Norway.  Usually this kind of work is more expensive here than in other parts of the world.

I don't remember exactly, but I think we payed about 1.5 euro pr piece in small numbers, and we got a quote for around 0.25 euro in larger numbers.


Mvh / Best regards,
Thomas Langås
(+47) 95731546

--
You received this message because you are subscribed to the Google Groups "OpenPnP" group.
To unsubscribe from this group and stop receiving emails from it, send an email to openpnp+u...@googlegroups.com.

Michael Anton

unread,
Jan 20, 2020, 6:38:44 PM1/20/20
to OpenPnP
I had a couple of stainless steel sprockets made by lasergist.com, but I'm not sure they still exist.  I think I paid under $15 USD including shipping for the pair, though that was a special deal at the time.  In quantity, I'd imagine that you could find some place that would be able to do it for less than that.

The old EIA taping specs, say the tolerance on all tape widths is a max of +0.3mm up to widths of 24mm, and wider widths are +-0.3mm.  I'd tend to trust that over just measuring a bunch of random samples.  Tape thickness for punched tapes (paper or another material) can be up to 1.6mm according to the same specs.

Shai

unread,
Jan 20, 2020, 11:56:26 PM1/20/20
to OpenPnP
Thomas, thanks for that info. I will explore it a bit more to see if I can get a similar price. That ends up being around the same or cheaper than PCBs at $0.25. I'm sure the shipping is expensive at a high quantity since it's metal and heavy.

Jason, I agree and will do my best :) 

Shai

unread,
Jan 21, 2020, 12:10:31 AM1/21/20
to OpenPnP
Perhaps it's worth asking before these go into production - what features should a feeder like this have? Currently the options are as follows:

  1. Set X encoder clicks = Y mm travel
  2. Manual entry of each feeder's address in code before uploading to feeder (wasn't possible to do physical jumpers with the code.. or at least I don't know how :) ) This needs to coincide with QR sticker on feeder.
  3. Forward Feeder# FeedLength
  4. Backward Feeder# FeedLength
  5. Tape puller is independent of ICs (closed circuit) and only gets activated if feeder's cover is in position. Disabled when opened so it doesn't stay on endlessly.
  6. I was thinking a feature to detect when tape is about to run out so PNP can pause... not sure if necessary since PNP can detect vacuum? (if a user has it).
  7. Anything else worth implementing info the feeder/motherboard?

Michael Anton

unread,
Jan 21, 2020, 1:01:22 AM1/21/20
to OpenPnP
I planned to put a little 7 segment LED display, and a couple of buttons on mine, for setting the index feed distance, and the feeder address.  I never worked out how this would be done exactly, but you can do a lot with a couple of buttons and a simple display.  It is similar to how some of the commercial feeders operate.  Probably a combination of long presses, to cycle between different modes, with short presses advancing the feeder in each direction.  This way, the feeder is set for the appropriate index, and the software doesn't have to worry about it at all, and just sends a feed command, though you could make a feed command take an optional parameter so it could be set in software.

I would recommend applying some sort of current limit to the motors, in case something jambs.  It might be a case of only energizing the motor for a limited period of time, if no movement is seen by the optical sensors.  There is a lot that can go wrong with feeders over time.

I wouldn't worry about #6.  This has to be dealt with by the PnP anyhow, as pickup misses can happen for reasons other than running out of parts.

SebG3D

unread,
Jan 21, 2020, 2:17:47 AM1/21/20
to OpenPnP
Instead of adding cost to every feeder (and complexety) I would rather have some sort of programming adapter board and a software tool or a display + button combination.
A crappy setup with combination of pressing long and short wont feel like a solution to me.
Its also less easy to implement in firmware especialy if you later add/change the ui.

Shai

unread,
Mar 13, 2020, 11:15:26 AM3/13/20
to OpenPnP
Happy to share that first round of samples is finally being shipped over. These are pictures sent by the manufacturer. Due to the virus going on, it was delayed over a month. Will post some pictures once I have it assembled and running! Getting close :)

screenshot_184.png


Jason von Nieda

unread,
Mar 13, 2020, 11:50:20 AM3/13/20
to ope...@googlegroups.com
Looking good Shai! I can't wait to see one working!

Is the tape path a milled slot that isn't quite milled all the way through? How thick are the PCBs?

Jason


On Fri, Mar 13, 2020 at 10:15 AM Shai <shai...@gmail.com> wrote:
Happy to share that first round of samples is finally being shipped over. These are pictures sent by the manufacturer. Due to the virus going on, it was delayed over a month. Will post some pictures once I have it assembled and running! Getting close :)

screenshot_184.png


--
You received this message because you are subscribed to the Google Groups "OpenPnP" group.
To unsubscribe from this group and stop receiving emails from it, send an email to openpnp+u...@googlegroups.com.

Shai

unread,
Mar 13, 2020, 6:28:12 PM3/13/20
to OpenPnP
@Jason,

Yes that is correct. The PCBs are 2mm thick and the slot is milled not all the way. Tolerance of tapes is accounted for.

Maple_Dude

unread,
Mar 13, 2020, 7:16:17 PM3/13/20
to OpenPnP
I didn't know that you could get PCB's with variable depth slotting!?

Shai

unread,
Mar 13, 2020, 7:23:10 PM3/13/20
to OpenPnP
Yes, it's called depth milling. It's essentially a custom order and because the demand is low for this as well, the price is generally high. It only makes sense for either a large order or a specialized PCB.

Mike M.

unread,
Mar 15, 2020, 7:05:05 AM3/15/20
to OpenPnP
On Saturday, 14 March 2020 00:23:10 UTC+1, Shai wrote:
> Yes, it's called depth milling. It's essentially a custom order and because the demand is low for this as well, the price is generally high. It only makes sense for either a large order or a specialized PCB.

I did a test sprocket out of StainlesSteel - laser cut 1.1mm plate in UK
The issue is that the holes for sensor can not be cutt very nice - some debries from Laser cutting remain
See picture enclosed
Mike

B57557BF-9B33-4ED0-90E0-46AE2C43CD1A.jpeg

Marek T.

unread,
Mar 15, 2020, 8:37:28 AM3/15/20
to OpenPnP
This is the problem of 1mm thickness I think. I made here some laser cut wheels made with 0.5mm steel sheet in company where I do the stencils for soldering paste - and an effect is really great. If you want to try and 0.5 (this is max thickness that their laser can cut) is ok for you - I can manage it for you and send by some post.

Mike M.

unread,
Mar 15, 2020, 9:11:38 AM3/15/20
to OpenPnP
Sprocket shall be 1 to 1.2mm thickness or your tape will not be guided properly in the slot....
0.5 mm would mean you need to join them and than you have more problems...
the best Option might be purchase already made ones from Alliexpres or xy....

Marek T.

unread,
Mar 15, 2020, 9:18:49 AM3/15/20
to OpenPnP
In my Philips feeder there is originally 1mm. I need new wheels for 2mm advancement, and these 0.5mm instead of 1mm works well.
But agree it's not good idea to connect wheels off you need 1mm necessary.

Michael Anton

unread,
Mar 15, 2020, 4:36:45 PM3/15/20
to OpenPnP
Why don't you try to pick up the teeth with an optical sensor, instead of using the holes?  If you put in two sensors with the right spacing (like half the pitch), you can double the resolution as well.  This is what I planned to do on my feeder, since I was aware that laser cutting small holes is problematic.

Shai

unread,
Mar 15, 2020, 4:43:07 PM3/15/20
to OpenPnP
Yeah, you can offset sensors instead of the holes on the sprocket, but intuition tells me that considering the entire industry does it this way (I think?) then there's probably a reason. Also take into account that reflowing these sensors precisely is probably another issue, but that affects both methods of course.

TheCunningFellow

unread,
Mar 15, 2020, 5:13:52 PM3/15/20
to OpenPnP
I guess the industry does it this way because they CAN make the wheels therefore can utilize cheap standard quatrature detectors for counting.

If you can't cut the slots then it might be easier for you to put multiple discreet tooth sensors spaced around the wheel to achieve same effect.

As Hedwig says you have to work with what you've got.

Jason von Nieda

unread,
Mar 15, 2020, 5:18:30 PM3/15/20
to ope...@googlegroups.com
FWIW, the NeoDen 4 feeder sensors the teeth with a single sensor: https://imgur.com/XVQudSA

Jason


--
You received this message because you are subscribed to the Google Groups "OpenPnP" group.
To unsubscribe from this group and stop receiving emails from it, send an email to openpnp+u...@googlegroups.com.

Shai

unread,
Mar 15, 2020, 5:36:12 PM3/15/20
to OpenPnP
What sensor do they use? Seems like they're counting the spur gear teeth rather than sprocket?

Jason von Nieda

unread,
Mar 15, 2020, 5:41:25 PM3/15/20
to ope...@googlegroups.com
I'll tear it apart again later on and check what the sensor is, but I do know it's sensing the sprocket teeth. It's hard to see in the image but if you zoom in you can tell. It's a basic opto-interrupter type and the sprocket teeth run between its two sides.

Here's the full teardown: https://imgur.com/a/osEGC

Jason


On Sun, Mar 15, 2020 at 4:36 PM Shai <shai...@gmail.com> wrote:
What sensor do they use? Seems like they're counting the spur gear teeth rather than sprocket?

--
You received this message because you are subscribed to the Google Groups "OpenPnP" group.
To unsubscribe from this group and stop receiving emails from it, send an email to openpnp+u...@googlegroups.com.

Shai

unread,
Mar 15, 2020, 5:47:38 PM3/15/20
to OpenPnP
Sounds good Jason! I think if they are just measuring the sprocket, those are some pretty big angles... not sure how they keep it precise?

On another note, I'm considering possibly opening up a tool to injection mold custom sprockets with gears. What are some things to consider for the design and anything missing? Trying to figure out what's the best way to design this so it works well for everyone once (if) produced.

screenshot_185.png


TheCunningFellow

unread,
Mar 15, 2020, 5:56:29 PM3/15/20
to OpenPnP
The gear reduction from the motor to the tape sprocket is about 500:1

I'd guess they could just use the opto to detect start of tooth and interpolate.

Jim

unread,
Mar 15, 2020, 6:02:12 PM3/15/20
to OpenPnP
Hi Shai,

On my chineese copies of fuji nxp feeders there is the main stepper motor geared down 24:1 to a sprocket wheel with 38mm diameter and 30 pins.
There is a optical sensor for 30 pulses for one rotation of sprocket wheel and a magnetical sensor for index.
So for a 2mm movement the stepper makes exactly 160 fullsteps.
A second smaller stepper motor helps to peel the tape and holds with an optical sensor the tension of the cover tape.

With a stepper motor you can make precise movements forward and backward.
How do want to make precise movements with a simple dc motor especially for 0402 and smaller where pickup position is essential?

Jim

Jason von Nieda

unread,
Mar 15, 2020, 6:55:21 PM3/15/20
to ope...@googlegroups.com
More images added to the bottom of the album, showing the sensor and it's placement: https://imgur.com/a/osEGC

Unfortunately there doesn't appear to be any markings on it. It looks quite a lot like this one: https://www.digikey.com/product-detail/en/rohm-semiconductor/RPI-352/511-1351-ND/638549

Jason


--
You received this message because you are subscribed to the Google Groups "OpenPnP" group.
To unsubscribe from this group and stop receiving emails from it, send an email to openpnp+u...@googlegroups.com.

Bill Ruckman

unread,
Mar 15, 2020, 7:03:00 PM3/15/20
to ope...@googlegroups.com
It seems to be sensing the slot between the teeth, which appear to be 2mm wide.  So it can move 2mm (1 edge) or 4mm (2 edges).


Mike M.

unread,
Mar 16, 2020, 7:54:48 AM3/16/20
to OpenPnP
Hi,
Tested similar version as well - but 2mm feeding is here a problem -4mm could work...
Mike

On Sunday, 15 March 2020 23:55:21 UTC+1, Jason von Nieda wrote:
More images added to the bottom of the album, showing the sensor and it's placement: https://imgur.com/a/osEGC

Unfortunately there doesn't appear to be any markings on it. It looks quite a lot like this one: https://www.digikey.com/product-detail/en/rohm-semiconductor/RPI-352/511-1351-ND/638549

Jason


On Sun, Mar 15, 2020 at 4:47 PM Shai <shai...@gmail.com> wrote:
Sounds good Jason! I think if they are just measuring the sprocket, those are some pretty big angles... not sure how they keep it precise?

On another note, I'm considering possibly opening up a tool to injection mold custom sprockets with gears. What are some things to consider for the design and anything missing? Trying to figure out what's the best way to design this so it works well for everyone once (if) produced.

screenshot_185.png


--
You received this message because you are subscribed to the Google Groups "OpenPnP" group.
To unsubscribe from this group and stop receiving emails from it, send an email to ope...@googlegroups.com.
Feeder_Sprocket test.jpg

Shai

unread,
Mar 16, 2020, 10:06:53 AM3/16/20
to OpenPnP
Hi Jason, how does your Neoden feeder do 2mm feeding since there's only one sensor?

Shai

unread,
Mar 16, 2020, 10:07:38 AM3/16/20
to OpenPnP
Mike, what sensor did you use?

Mike M.

unread,
Mar 16, 2020, 10:11:09 AM3/16/20
to OpenPnP
I used Omron EE-SX1103 OPTO SENSOR
Using two might be solution but have not tested it...
Mike

Shai

unread,
Mar 16, 2020, 10:12:28 AM3/16/20
to OpenPnP
Sorry for triple post... here's another idea I had if I were to go the injection molded route. I currently use the VCNT2020 sensor, but it has to be on top of the sprocket using a 2nd PCB that is elevated above the sprocket using a specific mezzanine connector to ensure the sensor is 0.5mm away from the sprocket. The new idea pictured below would have the VCNT2020 sensor under the sprocket and the light would be reflected off the extruded slots. Only issue I currently see is the "slots" are grouped tightly together because it's inside the gear (only way to do it). The best way is to have the sensing done as close as possible to the outer diameter so it's more precise. So not sure how precise this would be as I can't make them thinner than 1mm due to injection molding.

screenshot_186.png


Jason von Nieda

unread,
Mar 16, 2020, 10:26:42 AM3/16/20
to ope...@googlegroups.com
I don't know if it does or not - I've never been able to use it. But, as Bill mentioned, it could sense the start or end of the slot to do it, probably.

Jason


On Mon, Mar 16, 2020 at 9:06 AM Shai <shai...@gmail.com> wrote:
Hi Jason, how does your Neoden feeder do 2mm feeding since there's only one sensor?

--
You received this message because you are subscribed to the Google Groups "OpenPnP" group.
To unsubscribe from this group and stop receiving emails from it, send an email to openpnp+u...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/openpnp/28a6641c-5895-46f4-b37c-5bb03498f342%40googlegroups.com.

Marek T.

unread,
Mar 16, 2020, 12:35:39 PM3/16/20
to OpenPnP
Hi Jim,
Can you place some link to this Chinese Nxp feeder that you have, pls? I thought they clone the yamaha only.

Jim

unread,
Mar 16, 2020, 1:42:51 PM3/16/20
to OpenPnP
On Monday, March 16, 2020 at 5:35:39 PM UTC+1, Marek T. wrote:
Hi Jim,
Can you place some link to this Chinese Nxp feeder that you have, pls? I thought they clone the yamaha only.

Hi Marek,

Yamaha never had such a feeder. The original design is from fuji for their nxt-ii machines.
The clones have nearly same mechanical system but the case has been designed to be compatible for yamaha cl busbars. Even the stepper motors were cloned.

I wouldn't dare compare it to an original japanese or german branded product, but I don't regret buying this expensive chinese stuff.

Biggest disadvantage is that there is only 8,12 and 16mm available and pocket depth is insufficient for higher parts.
But, in one year i assembled around 600k parts without any significant problems.

Jim

Marek T.

unread,
Mar 16, 2020, 1:59:56 PM3/16/20
to OpenPnP
Ah, so I undesrtand now, I didn't know about their origin.
I know these feeders and even asked my Chinese friend to find possible cheap source for them. But the prices he found starts from US$150 for clones.
So looking on price not on electric feeders advantage (that they no need a source of air and many valves) and comparing it to pneumatic Yamaha - it is at least x3.

As I know Mike is trying to make an upgrade of pneumatic Yamaha into electric, replacing a pneumat actuator. It could be nice solution if work.
I also have ordered some parts to try to do this. I should get them soon so we'll see.

Shai

unread,
Mar 19, 2020, 7:26:40 PM3/19/20
to OpenPnP
Excited to share that great progress is being made! Samples were received today and did a dry fit before soldering any components. All components fit perfectly and tape slides smoothly through! See pics below.

IMG_8814.JPG

IMG_1005.JPG

IMG_0211.jpg




Jan Juranek

unread,
Mar 19, 2020, 8:05:06 PM3/19/20
to OpenPnP
Hey Shai,

this looks amazing! Will you open source this design or not? :)

Thank you,
Jan

Dne pátek 20. března 2020 0:26:40 UTC+1 Shai napsal(a):

Jason von Nieda

unread,
Mar 19, 2020, 9:27:53 PM3/19/20
to ope...@googlegroups.com
Great work Shai! I'm really enjoying seeing your iteration and progress on this design! Looks like it's getting very close now!

Jason


--
You received this message because you are subscribed to the Google Groups "OpenPnP" group.
To unsubscribe from this group and stop receiving emails from it, send an email to openpnp+u...@googlegroups.com.

Shai

unread,
Mar 19, 2020, 9:30:22 PM3/19/20
to OpenPnP
Thanks Jason! I'm honestly surprised the mechanical stuff fit so well, I was expecting something to not quite fit as the tolerances are really tight. Only had one plastic tape not move through very smoothly, but that's an easy fix - just increase routing depth a bit.

Now to test the electronics and firmware... here's to hoping I got that part right ;)

John deGlavina

unread,
Mar 20, 2020, 12:55:05 PM3/20/20
to OpenPnP
wow, very nice! Was the countersink for the screws on the PCB a custom thing too? I've never seen that before. 

Shai

unread,
Mar 20, 2020, 2:15:54 PM3/20/20
to OpenPnP
Countersinks is possible on PCBs but there are none in this design. Using flat screw heads that are very thin. Took advantage of everything possible to save cost :)

John deGlavina

unread,
Mar 20, 2020, 3:00:21 PM3/20/20
to ope...@googlegroups.com
ohh okay, thanks for explaining. Seems like they aren't easy to find in the size that I need.

On Fri, Mar 20, 2020 at 2:15 PM Shai <shai...@gmail.com> wrote:
Countersinks is possible on PCBs but there are none in this design. Using flat screw heads that are very thin. Took advantage of everything possible to save cost :)

--
You received this message because you are subscribed to a topic in the Google Groups "OpenPnP" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/openpnp/tHkY0duicdI/unsubscribe.
To unsubscribe from this group and all its topics, send an email to openpnp+u...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/openpnp/08e04342-6277-43d0-aadc-0b9091982e30%40googlegroups.com.

Duncan Ellison

unread,
Mar 20, 2020, 3:29:31 PM3/20/20
to OpenPnP
@John - If you find a source of 2.5mm flat heads in the UK, let me know.  We both need these :-)


On Friday, 20 March 2020 19:00:21 UTC, John deGlavina wrote:
ohh okay, thanks for explaining. Seems like they aren't easy to find in the size that I need.

On Fri, Mar 20, 2020 at 2:15 PM Shai <shai...@gmail.com> wrote:
Countersinks is possible on PCBs but there are none in this design. Using flat screw heads that are very thin. Took advantage of everything possible to save cost :)

--
You received this message because you are subscribed to a topic in the Google Groups "OpenPnP" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/openpnp/tHkY0duicdI/unsubscribe.
To unsubscribe from this group and all its topics, send an email to ope...@googlegroups.com.

John deGlavina

unread,
Mar 20, 2020, 3:51:41 PM3/20/20
to ope...@googlegroups.com
I actually found some in a laptop repair kit on amazon.com, but I'm in the US. Not sure if theres something similar on .co.uk. The longer ones needed for the peeler gears I found on another site.

To unsubscribe from this group and all its topics, send an email to openpnp+u...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/openpnp/d92e14be-4579-4489-8e4e-bafb8cf6007d%40googlegroups.com.

Shai

unread,
Mar 21, 2020, 12:27:02 PM3/21/20
to OpenPnP
As I continue to improve this design, what features do people recommend adding to the feeder? I have just added  forward/reverse buttons for when loading/unloading the feeder, which I intend to have them move in 2mm increments (or move until released). What other features would you like to see added?

Jason von Nieda

unread,
Mar 21, 2020, 12:38:12 PM3/21/20
to ope...@googlegroups.com
Hi Shai,

Here are a few random thoughts from things I see on the production line:

1. It's not clear to me from your images how a person would get ahold of one of the feeders to remove / replace it when there are feeders on both sides of it. Is there going to be a handle that sticks out or anything?
2. Does the feeder have an auto tensioner for the cover film? If so, consider a button that performs that action. One commercial feeder I've seen has three buttons: forward, backward, home / reset. Home / reset pulls the film until it's at the proper tension.
3. LEDs to show status: Film tension correct, feed error, in use. I've found that on a machine with a lot of feeders, being able to quickly look and see which ones are being used in the job is very helpful. This will require an OpenPnP modification, but not a big one.
4. Think about how reels will be mounted, and make this extremely flexible. Often, reels will be in a large separate tray under the machine but it's also common to hang small ones right on the feeder from a hook. It doesn't have to be fancy, and the less constricting it is the better.

Jason

On Sat, Mar 21, 2020 at 11:27 AM Shai <shai...@gmail.com> wrote:
As I continue to improve this design, what features do people recommend adding to the feeder? I have just added  forward/reverse buttons for when loading/unloading the feeder, which I intend to have them move in 2mm increments (or move until released). What other features would you like to see added?

--
You received this message because you are subscribed to the Google Groups "OpenPnP" group.
To unsubscribe from this group and stop receiving emails from it, send an email to openpnp+u...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/openpnp/48f6b599-1ba3-4fa2-8ac8-e04f5b62b947%40googlegroups.com.

Shai

unread,
Mar 21, 2020, 12:50:16 PM3/21/20
to OpenPnP
Thanks Jason, great suggestions and some are already implemented -

1. I've thought about a handle but it adds some complexity. You can take the feeder out simply by lifting it up with a finger so the bottom fuse holder pops out of the linear rail and then the feeder protrudes from the rest to be easily pulled out.
2. Yes, there's an auto tensioner using the optical sensor on top and it also checks to make sure the cover is closed before tensioning. 
3. Used feeder, sure I can probably implement that. I guess it would just be a high/low pin to turn on an LED. Not sure how to check "film tension correct". Only thing I can do is turn on an LED when the tension motor is done working? I think this is a redundant feature perhaps because if the cover somehow gets tangled, no way to detect that.
4. I thought about adding some sort of reel holder onto the feeder, but that makes the PCB bigger and expensive. Plus reels vary in size/thickness. I'd rather have people come up with a separate reel holder design.

What's home/reset you speak of?
It is loading more messages.
0 new messages