Example of a 3 way adjustable camera mount

[Juha Kuusama]

The LitePlacer was recently updated to use a HD camera module. The form factor of the camera module I chose is very similar than the ELP camera that is popular here. I wanted a camera mount where you can trim the rotation, left-right and front-back angles easily so that the camera is looking exactly down. I get positive feedback of the mount design, so I'll share. I wrote a blog post that talks about the camera I chose and the adjustable mount design, with links to STLs and CAD designs. Enjoy! https://www.liteplacer.com/hd-camera-selection-and-mounting/

[Mike Menci]

Hello Juha, 

Very nice work - as usual from you :-) Can you post some results which you are getting with this camera and vision? 

Thanks

Mike

[Juha Kuusama]

Any screenshots will have to do until I return from my vacation. You can see some (not much) on the video on my site front page. resolution is 1280 x 1024, and measurements are good to half a pixel (which is 0.01mm, better than my hardware). the camera meets its specs. Focus is good, but the depth is not very large. What else?

-Juha

[Mike Menci]

Ok Noted Juha - Enjoy your holidays! 
mike

[Marek T.]

The lens visible there is not looking to good. Maybe only impression. Expect poor plastic "glass" quality, in effects distortions and problems to get same good focusing over all FOV area. But maybe I'm wrong. Guess possible to replace it as it looks like using standard M12 lens holder, isn't it?

Impressing multi directional adjustment idea :-).

Without enthusiasm with leds ring. I have tested many different lightnings and definitely best effects got with angled leds like Malte R. design. Also missing any diffusor is not promising some good picturing.

[Juha Kuusama]

There is a diffuser, just not showing until the last picture. And yes, that is really necessary.

[Jason von Nieda]

This looks very nice Juha! Thank you for posting it. The concept is similar to how the lens and mirror adjustors on a laser cutter work, and you can get very fine adjustments. Great work!

Thanks,

Jason

On Fri, Jun 29, 2018 at 9:32 AM Juha Kuusama <ju...@kuusama.com> wrote:

There is a diffuser, just not showing until the last picture. And yes, that is really necessary.

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[Jt Whissel]

I recently bought one of your PnP machines as you probably know (or maybe not who knows lol). The biggest issue I am running into with these cameras is the auto exposure/auto brightness it does. I really wish there was some way to turn that shit off, it would make image processing so much easier. 

[SMdude]

Nice camera mount!

You could probably even get some of the bits made from pcb, or aluminum pcb.

[ma...@makr.zone]

Hi

I bought the new Liteplacer camera holders & modules as an upgrade kit. I already built holders for the ELP 6mm 2MP Full HD High Speed MJPEG USB Camera Modules. So I made some comparison shots, tried to post them here but the group won't take that many images, it seems. And they don't make sense if scaled-down, so they?  :(

The 3-way mount is brilliant. Being spoiled by the ELP's quality, I must say I'm less impressed with the cameras. But please see for yourselves:

https://makr.zone/camera-selection/262/

Thanks to Juha for the brilliant 3-way mount idea, the clever design and for making the design files available!

_Mark

[Marek T.]

Great comparison Mark!

So shortly: perfect holder and poor camera?

Btw: it is not so that only the center is important for bottom camera. If you have FOV like 40x40mm and use it for small SMD then it's right, but when you need to use it for big parts (modems, BGA etc having 25-30mm) then lack of focus or distortions in corners are leading to madness while making pipelines and aligning.

[ma...@makr.zone]

So shortly: perfect holder and poor camera?

I would not be so harsh. The new cameras are a great improvement compared to the endoscope cams originally in the Liteplacer kit. And as I said - and as one can see - I think the cameras are most probably sufficient for PNP. After all, most of the times we're just detecting harsh contrasts and differential edges. Often the CV pipeline actually adds a rather strong Gaussian blurring stage at the beginning, so the focus issue should not be overestimated. In bottom vision, also note the MaskCircle stage immediately following. It cuts out a circular part of the image. Most if not all of the blurring in the corners will be ignored anyway.

Like I said, it's more in my head, in my eyes - being spoiled :)

_Mark

[Marek T.]

Harshing was not the intention, just my English rather ;). Anyway, Juha's job which is holder not camera is really very fine!

However, I had a lot of problems with large BGA detection just because of the problem like that. It was ELP camera but the problem was the lens of poor quality (not from ELP). I couldn't to reach an equal focusing on whole area. Bluring in one of the corners of the part was the reason of moving the center of the part to the second side direction for 0.02-0.05mm (different at different snapshots). Not any magic pipeline of excommunicated guy couldn't help me with this too. Only mainly changing the lens let to remove the problem. That's why I've paid attention on it when saw the picture of this camera lens and found your little confirmation on your comparison pictures.

But to be honest, maybe it is completely not important in Liteplacer. Maybe the max size of the part is there very small comparing to the FOV and this bluring in corner is not the problem at all (except impression).

[Marek T.]

MaskCircle is for nothing if the part takes some 90% of the picture are...

[Jason von Nieda]

Great post Mark! Thank you for making this comparison!

Jason

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[ma...@makr.zone]

However, I had a lot of problems with large BGA detection just because of the problem like that.

Yeah...  I completely underestimated the needed focal distance of the bottom camera. See my doc about the "Bottom Camera Scare" (near end of article) this created in my case :)

Normally you want to be able to rotate a part to any angle. This means that only a circular centre area of your bottom camera can be relevant. I now have a 40mm focal viewing diameter at the narrowest image dimension i.e. height with some margin. I have no BGA (yet?) but I plan to use a LPFQ144 which is ~30mm in diameter.

_Mark

[Marek T.]

Modem 40x40 need more mask diameter than 40:-(. Generally it's hard to find good compromise between resolution and FOV for both very small 0402 and large parts. Probably the best would be two cameras. But let's leave it, it's out of thread probably.

[Mark]

> Modem 40x40 need more mask diameter than 40:-(. Generally it's hard to find good compromise between resolution and FOV for both very small 0402 and large parts. Probably the best would be two cameras. But let's leave it, it's out of thread probably.

I would not be unthinkable to detect a large part by two, three or four of its corners, moving the part in the process and doing separate corner vision shots.

For a BGA with its uniform grid this seems quite easy to implement. One could go for a "DetectFixedCirclesHough" to get the individual balls instead of the "MinAreaRect" to get the contour. From the circles it would not be hard to detect the grid and calculate the part centre and angle from multiple corner shots.

For other parts with peripheral/irregular pads or pins etc. this might be much harder (or even impossible) without knowledge of exact footprints.

_Mark

[Marek T.]

It was some time ago already and not all details of the fight I still remember :-). We were seeking the balls not the case shape but we had in that moment also some other problems on the machine and all this gathered together was crazy. Remember the bluring was part of the problem.

[Daniel Dumitru]

what I like at this design it's that cand be easy adapted to be lasercut.

Daniel

On Tue, Jul 3, 2018 at 10:38 AM Marek T. <marek.tw...@gmail.com> wrote:

It was some time ago already and not all details of the fight I still remember :-). We were seeking the balls not the case shape but we had in that moment also some other problems on the machine and all this gathered together was crazy. Remember the bluring was part of the problem.

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