Hello everyone,
I made yet another video of a problem that I'm having. The problem is that the placement stops permanently in the middle of a run. The stopping (halting) always happens at the same component, and it happens when the part is about to get picked up. In my case, the problem happens after an 0805 resistor is successfully picked by head 1 (using nozzle 2, CN040), and the machine stops right before picking up a 1206 capacitor array using head 2 (nozzle 3, CN065). You can see this at 3 minutes, 10 seconds in the video below. The vacuum trip point of both nozzles is the same (both set to 25kPa in the Nozzle menu and both set to 0kPa in the feeder menu). I get no interesting messages in the white message box. A similar failure happens after the video ends (I ran out of memory on my SD card), and this time the failure happens when we try to pick a Land Grid Array (LGA) part from a grid. I can always halt the run by pressing STOP, pick up where I left off and the run will continue just fine. When the run fails, the machine thinks the run is still going (the STOP button must be pressed before I can do anything else).

Here are some of the things that I have tried (yes, I tried them carefully and one at a time -- I undo each change before I make the next one!). I made the changes to the problem feed (the 1206 cap) and the part before (the 0805 resistor). None of these changes fixed the problem:
1. Reducing the vacuum pressure from 5bar to 3.5bar using the knob on the side of the machine.
2. Setting the vacuum threshold to 25kPa in the feeder editor for both parts.
3. Different suctionDelay and putDelay values (original values: 200ms and 700ms. new values: 20ms and 70ms. I had high values to start with because this really helped to prevent parts from rotating as they get pushed off the heads.)
4. Un-check (i.e. turn off) the "Local Speed" option for both the feeds. My original value was "Local Speed" checked, and "Small Parts Speed" selected for both parts.
5. Turn off AlignXYA for both parts
6.

If anyone has seen this sort of problem, please let me know! I'd love to make a simple change to my settings to fix this issue.

Here's my video (sorry for the low quality this time!): https://youtu.be/UJfP1l0oEDE

Here is a picture of my feed settings for the part just before the halt (the last part to successfully get picked up):


Here is a picture of my feed settings for the part that the machine fails to pick up:


Thanks,
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I thought it also might be helpful for you to see my Placement Strategy settings (see picture below). I have tried "Nozzle Number", "Part Number", and "Part Packing" and I always get the same halting (with all three strategies the two parts happen to stay next to each other in the list, so it's easy to see that the failure keeps happening).
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Hi Michael,
Thank you for your reply. No, there is no message in the white message box. I made sure to look for that. In fact, I hooked up a bigger screen to my laptop just so that I could see the white message box.

About the delays: I was using short delays like you suggest, but the parts were moving (rotating) when the parts get pushed of the heads. I am sure that I don't need 200ms and 700ms, but I found that I needed more delay than I started with. Here is my plan: I want to get everything working well (nice alignment, all parts placed) with long delays for Suction and Put (because I get better results with the longer delays) and then I will reduce my delays and make sure that I still get good alignment. Does this seem like a reasonable plan to you?

Yes, in 1 head mode all of the parts get placed. Of course, I need to get 2 head mode working so that I can speed up the run and get the nice performance that I know your machine is capable of. What other experiments should I try to figure out why the halting problem is happening in dual head mode? What other information would you like me to send you?

Thank you so much!
MtnMan
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Hi Michael,
In my last post, I attached a picture of my Placement Strategy. It shows 2 Nozzle Different mode. I want to assure you that I have also tried 1 Head mode (I did that this morning) and 1 head mode does work. I just didn't want you to be confused by my attached picture.
Thank you!
MtnMan

Zitat

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That will happen if Pick up height setting is wrong.
Move the nozzle tip down to the part surface and take over the Z position using Z button and setup part height = measured part height - 0.1mm.

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I will try your suggestion.

Zitat

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Maybe PCB height setting critical too!

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I have been very careful with PCB height -- I measured it by putting a nozzle down on the PCB, just like you suggest for the part height.

Zitat

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Don't want to change everything in the first step get the single head mode working first!

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Single head mode is working. I am able to load the board with single head mode. Now I would like to load the board using dual head mode, but I can't because of the halting problem. Let's work together to figure out why dual head mode is not working! Please give me additional suggestions. Thank you!

Yes, I did, and then I used my calipers to carefully measure the PCB thickness, which is 1.6mm.

Zitat

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Move the nozzle tip down to the part surface and take over the Z position using Z button and setup part height = measured part height - 0.1mm

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Hi Michael,
Which Z button are you referring to? I obviously don't want to use the Z button in the feeder dialog, because that sets the Z of the part when it is in the feeder. I've included a picture of the feeder dialog in this post, and I don't see any other Z buttons there. I do know that there are Z buttons in the nozzle dialog, but I certainly don't want those buttons for part height measurement. I don't see any Z measurements in the camera section or the controls section (the areas on the left side of the software). So, which Z button should I use?

Thank you very much!
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