Better nozzle with auto change?

WayOutWest
Posts: 198
Joined: Thu Jul 16, 2015 12:18 am
Location: Washington State, USA

Re: Better nozzle with auto change?

Post by WayOutWest »

vonnieda wrote: The coils could probably be done on a tiny PCB that gets embedded into the nozzle holder.
Unfortunately that won't work... commodity PCB fabs have minimum board size requirements that are much, much larger than anything that could possibly fit inside the nozzle holder. Any PCB fab that can make a board that tiny will charge a major premium for it.

:(

This is basically the problem with the Juki Z-sensor. The space that you have to cram the sensor contact into is so tiny that it rules out all the ordinary solutions.
- Adam
WayOutWest
Posts: 198
Joined: Thu Jul 16, 2015 12:18 am
Location: Washington State, USA

Re: Better nozzle with auto change?

Post by WayOutWest »

WayOutWest wrote: Unfortunately that won't work... commodity PCB fabs have minimum board size requirements that are much, much larger than anything that could possibly fit inside the nozzle holder. Any PCB fab that can make a board that tiny will charge a major premium for it.
Hrm, now that I think about it, I wonder if it's possible to use internal cutouts for this. Like a panelized board with only one panel, where the panel is a tiny circular board that fits in the nozzle shaft. You'd snap the itty-bitty board out of its PCBfab-friendly-sized carrier and dremel off any tags.

Not sure if commodity PCB fabs would still barf all over it due to having such a tiny part with flimsy connections to the rest of the board during milling.

Anybody ever tried this? I have very little experience with trying to sweet-talk board houses into doing funky milling. How cranky will they get?
- Adam
mawa
Posts: 139
Joined: Wed Jun 10, 2015 1:23 pm
Location: Near Hamburg, Germany

Re: Better nozzle with auto change?

Post by mawa »

WayOutWest wrote:Anybody ever tried this? I have very little experience with trying to sweet-talk board houses into doing funky milling. How cranky will they get?
This little board has been made without any extra cost by my PCB manufacturer (http://www.pcb-pool.com/). They even corrected the rest ring size of the vias and put it on a panel with two of them.

If you are asking what that board is for - it contains a BME 280 pressure, humidity and temperature sensor and an APDS-9960 proximity, color and gesture sensor (used in samsung smartphones).
Attachments
Is this small enough?
Is this small enough?
IMG_1405.JPG (336.92 KiB) Viewed 20880 times
best regards
Manfred
WayOutWest
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Location: Washington State, USA

Re: Better nozzle with auto change?

Post by WayOutWest »

mawa wrote: This little board has been made without any extra cost by my PCB manufacturer
Unfortunately any board that fits into the nozzle shaft would have a maximum dimension of less than 1/3rd of the board you show.

I mean we're talking really, really, really tiny here.

I'll take exact measurements as soon as this run finishes (it's placing right now... bad time to disassemble the pickup head!).

Edit: okay, I put the digital calipers on it.

The majority of the shaft is a 5mm bore; if the contact is smaller than this then it needs to have some extra mechanism to prevent it from being sucked up the tube by the vacuum. So most likely it should measure more than 5.0mm in at least one direction.

The bottom portion of the holder is a cylindrical chamber 6.98mm (say 7) in diameter. The contact MUST be no larger than this in any X-Y plane direction. That's what I mean when I say tiny. The largest it could possibly be is a 7mm-diameter disc.

The chamber is approximately 10.3mm tall. I can't quite get the calipers in there, so this number came from measuring the nozzle head and some subtraction; not as exact as the others.

The part of the nozzle-tip that pushes up to make electrical contact is a tube, 3.19mm outside diameter and 2.06mm inside diameter. So the contact plate should have a 2mm drill in the center (to let air through) surrounded by a 0.565mm-wide ring of copper. The part that pushes up is contained in a 3.73mm-diameter housing which is supposed to be grounded, so that can't contact the copper ring on the contact plate -- this determines the maximum opening in the solder mask.

Here's a first sketch, and the gerbers, hastily thrown together just to see how much of a fit OSHPark throws over it... for five bucks shipped with ENIG gold finish... hey I can afford to be wrong here.
juki_nozzle_plate_10.png
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Well, their automated system accepted the order. Let's see how it turns out.
oshpark-paid.png
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juki_nozzle_plate_v10.zip
(161.84 KiB) Downloaded 749 times
- Adam
WayOutWest
Posts: 198
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Location: Washington State, USA

Re: Better nozzle with auto change?

Post by WayOutWest »

Well, they put in on a panel, which means it can't be obviously rejectable.

The fab still has final say (OSHpark is just an aggregator) but in practice they have a pretty low false-positive rate since one rejected board means delays for all the customers on that panel, which is no bueno.
panelized.png
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- Adam
Pixopax
Posts: 122
Joined: Tue Feb 02, 2016 4:16 pm

Re: Better nozzle with auto change?

Post by Pixopax »

I still fight with my placer, one of the most annoying things was the needle and the flipping needle axis, it made things worse.
So I decided to rebuild my Z-Axis a bit, and use the parts suggested by Malte. I found the axis of Misumi was exactly 8.00 mm, but the corresponding bearings were quite a bit larger :-( So the axis can still move a bit, which is now kept small by the "spring". Still crap, I will rebuild that again with fitting parts. But the misumi swivel greatly reduces the movement of the nozzle, that is a thing Juha should consider adding to the kit.

I also put a Samsung-NP40-Nozzle holder on the axis, and now, tada....I have no nozzle calibration needed anymore, I found that the nozzle has only 3-5µm position change in a 360 degree turn, that is good enough for me.
Lastly, I added a pressure sensor, which really makes placements better, thr rmod-release repeats 3x until it switches to the nex part on the tape. Helps a lot.
I still have the Juha-Made z-switch left, so the basic funcionality is still there. Auto-Nozzle-Change is not possible this way, it would trigger the Z-Switch. I look for a way to overcome that.

Now I will figure out how to cancel the needle calibration, as I do not need it, also, the Up-Cam is useless now.
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noz3.jpg
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noz2.jpg
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noz1.jpg
noz1.jpg (89.21 KiB) Viewed 20811 times
mrandt
Posts: 407
Joined: Mon Apr 27, 2015 10:56 am
Location: Stuttgart, Germany

Re: Better nozzle with auto change?

Post by mrandt »

Hi Louis,

looks nice :-)

You mentioned that Misumi shaft + bushings have significant play? That's weird - in my case they were a nice, snug fit...

Where did you buy the Samsung nozzle holder from and how did you fixt it to the shaft?

Cheers
Malte
Pixopax
Posts: 122
Joined: Tue Feb 02, 2016 4:16 pm

Re: Better nozzle with auto change?

Post by Pixopax »

There was .15mm air, far too much.

The nozzle holder is from Aliexpress, it has a M5 thread and fits perfect to the axis from misumi.
It is a Samsung CP40 nozzle holder. It has a fairly strong spring inside.
martin123
Posts: 19
Joined: Tue Feb 16, 2016 8:06 am

Re: Better nozzle with auto change?

Post by martin123 »

Pixopax wrote:There was .15mm air, far too much.

The nozzle holder is from Aliexpress, it has a M5 thread and fits perfect to the axis from misumi.
It is a Samsung CP40 nozzle holder. It has a fairly strong spring inside.
Do you have a link to the seller and did it come with the the nozzles?

Just about to order the shaft, bearing and coupling from Misumi.

For pressure sensing did you upgrade the firmware to this version? http://liteplacer.com/phpBB/viewtopic.p ... ensor#p483

Martin
Pixopax
Posts: 122
Joined: Tue Feb 02, 2016 4:16 pm

Re: Better nozzle with auto change?

Post by Pixopax »

http://www.aliexpress.com/snapshot/7390849509.html
and
http://www.aliexpress.com/snapshot/7390849507.html

They deliver in 5 days, worked this time.

And yes, that was the firmware i used.

Louis
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