LitePlacer.com forums

Hello,

several people had asked for the STL and Gerber files to replicate the upward camera case and LED light I have built for my LitePlacer:
I finally decided to share my design under CC BY-NC-SA 4.0 license.

Find the GERBER files here:
http://malte-randt.de/hexagonal-led-light/

An improved version of the STL files is available here:
http://malte-randt.de/improved-3d-print ... era-mount/

If you don't have the tools or time to make, populate and reflow the PCB or print the case yourself, I might be able to help and make one for you - send me a PM or e-mail if you are interested.

Best regards
Malte

Nice upgrade.

Other than looking better did it also provide a camera accuracy improvement?

Hi RWB and welcome to the LitePlacer community - I also read your other posts and will reply as soon as I find the time

Regarding the camera:

In my opinion, the USB borescope cameras which Juha includes in the kit are a compromise between price and image quality. Juha probably chose them to keep the machine affordable and easy to build.

I trust they work fine for needle alignment and fiducial recognition - but once it comes to more elaborate computer vision they will fall short.

Image resolution, light sensitivity, auto exposure, noise etc. are all not very good on those cheap USB borescope cams.

The image quality of a C270 webcam (or better camera with HD resoltion) will be much better. Surprisingly, this relatively cheap webcam has a good CMOS sensor, nice controller and even the optics are almost perfect for the upwards camera.

Check this thread to find a few more pictures:
http://liteplacer.com/phpBB/viewtopic.p ... rt=10#p230

Camera chip is only one aspect; lighting is almost as important for computer vision. I chose red LED to elminiate or reduce the influence of ambient light and this worked well so far. Also, the hexagonal LED boards which are tilted at an calculated angle illuminate the components very evenly and without shadows.

I will likely change to white light though, as I plan to upgrade to Juki nozzles and these have a green vision shield which can be eliminated in image processing using chroma-key techniques.

For the downcam I am using the Andonstar USB microscope which thereza recommended. Make sure to get the 2MP (or better) version if you decide to go down the same route. It is not cheap (around USD 60 from China) but well worth the money.

Best regards
Malte

mrandt wrote:Hello,

several people had asked for the STL and Gerber files to replicate the upward camera case and LED strip light I have built for my LitePlacer:

case.jpg

table_mount.jpg

hex_led.jpg

light.jpg

I finally decided to share my design under CC BY-NC-SA 4.0 license.

Find the GERBER files here:
http://malte-randt.de/hexagonal-led-light/

An improved version of the STL files is available here:
http://malte-randt.de/improved-3d-print ... era-mount/

If you don't have the tools or time to make, populate and reflow the PCB or print the case yourself, I might be able to help and make one for you - send me a PM or e-mail if you are interested.

Best regards
Malte

Hi mrandt,
That's a great design, Please can you tell me from where I can get these LED Lights.

You can get the LEDs from almost any distributor, I used Digi-key as they're close to me and shipping is fast. Part number is 475-1185-1-ND.

I found that the 22 ohm resistors were too low and at 12V the current was nearly 80mA per section/LED. Fortunately none burned out, but I increased resistance to 27ohm and put a series diode inline to protect against reverse voltage. With that configuration I get almost exactly 300mA (50mA/section) at 12V.

I also wired up a FET and optoisolator to turn on the LEDs only when the camera is active. I removed the C270's green LED and used the contacts to feed the optoisolator's input, the output pulls the gate of a N-channel MOSFET up to 12V and turns on the LEDs. The photo below shows everything assembled minus the cover before I gobbed it up with hot glue to prevent things from shorting and provide some strain relief. It works great and is fun to watch the pickup head move over the camera and the light turn on automatically.

I ordered PCBs from OSHpark.com, shared files here: https://oshpark.com/shared_projects/eqmooXnr

dmwahl wrote:I removed the C270's green LED and used the contacts to feed the optoisolator's input, the output pulls the gate of a N-channel MOSFET up to 12V and turns on the LEDs.

Now THAT'S clever (Digs out soldering iron again)

GilchristT wrote:

dmwahl wrote:I removed the C270's green LED and used the contacts to feed the optoisolator's input, the output pulls the gate of a N-channel MOSFET up to 12V and turns on the LEDs.

Now THAT'S clever (Digs out soldering iron again)

Thanks, it was one of those "aha" moments as I was removing the green LED and thinking about how warm the LEDs get after a while. I attached a schematic for how I did it, the Opto is a LTV-352T from a past project that I stripped off the board. FET is IRFR7740, way overkill but was sitting in my box-o-parts. The gate-source resistor value doesn't matter much, I chose 3k because (surprise) it was nearby. I wouldn't go much lower, but anything up to 100k should be fine depending on leakage through the opto.

mrandt wrote:Hello,

several people had asked for the STL and Gerber files to replicate the upward camera case and LED light I have built for my LitePlacer:

case.jpg

table_mount.jpg

hex_led.jpg

light.jpg

I finally decided to share my design under CC BY-NC-SA 4.0 license.

Find the GERBER files here:
http://malte-randt.de/hexagonal-led-light/

An improved version of the STL files is available here:
http://malte-randt.de/improved-3d-print ... era-mount/

If you don't have the tools or time to make, populate and reflow the PCB or print the case yourself, I might be able to help and make one for you - send me a PM or e-mail if you are interested.

Best regards
Malte

Hey,
Nice upgrade.