My problems with limit switches - my assembly progress

[majsta]

No, all is in same height. But, what Z has to do with this problem?

[JuKu]

> But, what Z has to do with this problem?

If you are picking the parts up or placing them down using a z value that is significantly different from the z value used in calibration AND your z axis movement is significantly off from perpendicular, you would get a constant offset error. But it doesn't sound like this is the problem.

Pickup this and place here are good, so it indicates that the needle calibration is ok. Are the parts picked up from the center or close?Does the measured position function show the parts accurately? (I'm trying to figure out if the issue is on the tapes or the PCB handling)

[majsta]

Hi, all day I m trying to fix this, one of the potential problem was needle and now I changed it, old one when rotation happened made huge circle so it was totally inaccurate, but not even that was a problem. Right now I have no idea where I m going wrong. Today I have made SMD holders, they work ok, not perfect but ok. But measuring PickupZ and PlaceZ was ok, problem remains. I ll continue tomorrow. I understand that working with 0402 parts is tricky and that maybe this machine needs tuning so precise because of this, we are talking about 0.1mm so small, but on my board there are over 60 0402 components so I m must solve this. I ll report tomorrow.

[majsta]

Hi, nothing new problem remains, I have tried to make X belt tighter but didn't helped. Today I have moved PCB closer to SMD feeders thinking that because bad assembly(don't see how that can be the case) during longer XY travel something bad could happen. Also I have tried to do squareness correction up to an value of 0.007981220657277, that did help but on upper side of the board, problem remains on the opposite side. Again I have measured mm/pixel and all is good in that area. I can get better result with using Job offset X but then I lose other stuff like needle cam distance precision. This is what is strange when using 0.007981220657277 with squareness correction I get problems on downside of the board, opposite side is ok, but by changing value to -0.007981220657277 then I have all good in downside of the board but upper side is then placed wrong. I have placed 8 fiducials(via or top silkscreen circles) all measured good.

[majsta]

Don't know or why, or what I have done but it is kinda started to work properly. As I recall all day I was doing number of fixings on various things so right now have no idea what solved most of the problems. Of course this will need confirmation and few more days of testings but I think that I m done.
I m uploading video, it will be up in 10 minutes
https://youtu.be/hZSFG2Sdnto

[majsta]

Ok found out what I was doing wrong, needle calibration and wobbling of the needle. This needs to be investigated more. I ll use baby's powder, cower one part of the desk with it and then put needle on it to leave mark, then move cam on that position. Then again measure everything with up cam.

[majsta]

I found where I was wrong and why I lost last 20 or more days.

You want the up looking camera lens to be 4 to 5 cm from the table top surface

Ahahha imagine I had it at 1cm and there it was, my problem with needle wobble and placement when needle rotates.
Why this could be problem I don't know. Right now my upper cam box is set at 13.00 mm and that's huge value and didn't see that someone here have such value for upper cam but all I can say that result is now much much better. Not there yet but much better.

[JuKu]

No idea why that matters so much. Anyway, I'm happy you found it. In general,

...why I lost last 20 or more days.

I hate hearing that I made customers loosing time. If any of you have issues, please don't hesitate getting in touch!

[majsta]

I think that from loosing time in founding this was true benefit for my knowledge because I learned so much in the process. So all good

[majsta]

Just to mention, I have ordered and received today this needles
http://www.ebay.com/itm/371508303043?_t ... EBIDX%3AIT
they can be used without any modifications, they are much better than plastic ones.