Hi! I'm still working on learning the VP system. I am trying to place simple parts (for example a tantalum capacitor of size 2312), but here's what I find:
- When a part has a rotation of 0 or 360 degrees, the part is placed on my PCB in about the correct location.
- When a part has any other rotation value, the part gets picked up, brought to the camera, rotated, and then taken to the upper right-hand corner (NE corner) of the machine and dropped there instead of being placed.

I have tried using version 2.022 and I am now using version 2.027, but I have the same problem.
I am running the machine at low speed. I have tried different Local Speed values and it doesn't help. I have tried different brightness and contrast.
Can someone look at my .smt file and tell me what I might be doing wrong? Here is a link to the file as a GoogleDoc: https://drive.google.com/file/d/0BwL67S1...iew?usp=sharing
Thank you!
Dave

Update: In version 2.027, if I check the box labeled "Run Align" within the "Feed Edit" dialog, the parts no longer get discarded. However, they get rotated to the wrong angle while moving to the camera and they get placed on the board at an incorrect angle. It seems that my settings either cause the parts to be rotated while under the camera and then discarded OR the parts do not get rotated and then placed on the board at a strange angle. What am I doing wrong?

MtnMan,

Test head connector (Attached picture).
I have had problems with this connector, because it leaves its site and causes a similar failure to that described.

Regards,
Ricardo

Hi Ricardo and Michael,
Thank you both for your rapid replies. Here are my additional questions:
1. Ricardo, I am pretty sure that the connector is okay because I can see the parts getting rotated by the machine. If the connector was disconnected, I think I would see no rotation.
2. Michael, I am sure that rotation by 0, 45, and 90 work as you said. However, I am unsure about why my parts are getting rotated and discarded, instead of rotated and then placed on the board.
3. When I check the box "Run Align" it looks like the part does not get rotated while it is above Camera1. Is this what we should expect? Does checking this box mean that the machine does not look at the part while aligning it?
4. When I do not check the box "Run Align", but I only check the box "Visual Align", the part gets rotated while it is under the camera, but it gets discarded if the rotation is set to 180. If the rotation is set to 0, it does not get discarded. What would cause this?

I am attaching a screenshot of my Feed Edit dialog. You can also see the camera images. It looks to me like the part is getting recognized well, but perhaps I am wrong? I have tried lots of different brightness and contrast settings. I must be doing something wrong, and I would be happy to have your additional help.
Thanks,
Dave

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The detection box is too small, start with large detection box and reduce after.
The detection box need to be square, is not follow the rotation.
Do not use 360 degree, some time software discard without any reason, use alway 0 degree when you have 360 in your list.

Hi Luc and Sunny,
Thank you very much for your reply. Yesterday the rotation box was bigger, but today I made it smaller, so after I got your message I made it bigger again. I understand your point about not using 360. I currently do not have 360 in my parts list, only 0 and 180. 0 works but 180 always gets discarded. Sunny asked me for a video, which I made. Here is a link: https://youtu.be/DUHD_S1Ps44

Please let me know what suggestions you have!
Dave

The part suppose to be in right position when head are over camera, in this video is not i see.
Use bigger nozzle, i have some experience with part slip or rotate on nozzle when machine move (vibration), not all part have perfect flat surface.
Check the vacuum with part and when you put your finger on nozzle.
I use 30 to 45 on vacuum with perfect close nozzle, too much vaccum and small part lift to early when head pickup.
Ajuste in part field the vacuum limit lower, i put half to 3/4 value of normal vacuum pickup part.
The head turn too slowly, put 4 start and 10 run on rotation speed.
I also in my case ajust in camera setup, high number on precision XY and A, is reduce precision of camera alignement but between .1 and .5 degree... i not see difference on pcb and i have less reject!!!

Hi Luc,
Thank you so much for your suggestions. Where do I find the "vacuum limit lower" in the "part field"? I haven't found that control yet.

I followed your suggestions about the camera setup and I am now able to place rotated parts without rejection for the first time! Thank you! I changed the "Correction Times" variable from 10 to 20 (the max value) and I changed the "Precision XY" variable from 4 to 2 (improving the XY precision from 0.11mm to 0.055mm). I did not change "Precision A" from its default value of 2 (0.45 degrees). Just changing the two variables fixed my rejection problem. I will figure out which of the two is responsible for fixing my problem.

I now have a problem in which the parts sometimes get rotated to 0 or 90 instead of 180. Can someone take a look at the attached pictures from my system and tell me whether it is better to have the "Figure 1" settings or "Figure 2" settings for brightness and contrast (based on the part recognition)? I really appreciate everyone's help!

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In Feeder properties
In box Vacuum Test Settings
Change Vacuum test value for aprox 1/2 to 3/4 of max value you see on front panel when the part are pick by nozzle.

Hi Luc,
Well, you're very smart, but I'm still confused! I fixed my problem, but I don't understand why it worked! I am making a list of my actions and results below, and I'd like someone to explain why this worked:

1. Picking a SSOP28 package from vibration feeder with CN220 in head 1 from nozzle position 5 failed to align every time.
2. I moved the CN220 to nozzle position 4 (by hand -- I just swapped nozzles 4 and 5) and I changed the feed settings for the SSOP28 to pick with nozzle 4. Alignment works every time.
3. Under the "Nozzle List" > "Nozzle Edit", I changed vacuum for nozzle 5 from 75 to 25. I manually moved the CN220 back to nozzle position 5 and repeated step 1. Alignment works every time.

Working on placing an 0805 resistor, I found a similar situation:
4. Picking 0805 resistor from grid with CN040 in head 1 from nozzle position 2 failed to align every time.
5. I moved the CN040 to nozzle position 3 (manually swapped nozzles 2 and 3) and told the machine to pick using nozzle 3. Alignment works every time.
6. I changed vacuum for nozzle 2 from 45 to 25. and put the CN040 back in position 2. Repeat step 4. Alignment works every time.

I'm very happy that I fixed my rejection problem, but here's what I'd like to understand: When I have too high a pressure, why is it that the machine doesn't even try to align the part? In other words, when I have the wrong pressure, the machine takes the part over to the camera, but I never see the visual alignment box change to the correct size (the alignment box continues to be a tiny square instead of the large square that I specified), and the part gets rejected instantly. Why is there a correlation between vacuum pressure and whether the machine attempts visual alignment?

Thank you all for your help!

Okay, I've answered my own question: When the machine's vacuum pressure is set lower (using the mechanical knob) than the "Vacuum Test Value" that you set for a given nozzle, the machine knows that it cannot reach the desired vacuum, and it does not try to visually align the part. I am assuming that the program realizes that it is not able to hold onto the part as strongly as you want, and so it knows that the part may rotate on the nozzle. Further, I am assuming that the machine concludes that it is not worth it to try to visually align the part under these circumstances.

I turned up the vacuum pressure on the machine (the factory setting was 2 bar, and I moved it to 4 bar per the manual). When I did this, the machine successfully visually aligns the parts with vacuum values greater than 30 kPa (for example 40 kPa). What I realize now is that the "Vacuum Test Value" is simply a threshold that the machine's vacuum must meet in order for it to believe that it has successfully picked up a part. I originally thought that this value would set the actual vacuum pressure that each nozzle uses to pick up parts, but it looks like I cannot independently control the pressure used with each nozzle. Is this correct? I thought that since I have parts with different weights, I should be able to control how much vacuum is used on each part, but now I don't see a way to do that. Can someone help me with this?

Thank you so much!