Another tab for WebCam

Hi

Update re the camera - sorted out the inaccuracy pretty much.

The lens unscrews / screws in, to provide the focus / zoom feature.
In typical state of the art Chinese engineering fashion, it is actually quite loose and I found its only attachment was to the plastic lens ring and this by a single piece of double sided tape on one side!
The plastic lens ring is just a push fit into the non-concentric adjustment tube.

No wonder I could not get repeatable absolute positional accuracy.

I have 'solved' the shortcomings of the design, by focussing the lens to approx 50mm (2") and then potting the whole lens and adjustment tube in epoxy resin glue.
Any fine focus can be achieved by winding the knee up or down.

The camera is glued solidly into the aluminium holder, which in turn is fixed using post-installation Loctite (very thin, gets into small gaps by capillary attraction, then sets) into my old R8 20mm collet.
This can be mounted repeatably thanks to the collet groove and my spindle locking indent.

Testing by zeroing over a ruler clamped to the mill bed, then G28 followed by g0 x0 y0, took it back precisely to the same spot.
Re-mounted the camera carefully and it returned to the same spot again. That will do me.

If making the holder again, I would make the bore deeper to enclose the entire camera tube and adjustment ring and glue the whole thing into it for extra rigidity and protection for the camera.

That said, for £10 plus a bit of aluminium from the odds box and some time, works pretty well.

regards

Looks good, so how accurate/repeatable is it?

Rick G

Hi Rick

I didn't do extensive testing.

I zeroed on the very end of an etched graduation of the ruler, giving a very fine x,y, set G54 zeros to that point, homed which entailed about a 250mm X move and 80mm Y move and then returned to X0 Y0 and found myself at exactly the same point on the ruler.

I then very carefully removed and then remounted the camera and collet, homed and then went to X0,Y0 again and was back at exactly the same spot.

To some extent it is as good as my home switches, but I know they are good (proximity sensors).

It is still possible to move the crosshairs slightly by pushing the focus tube, but they return to the same point.
This is why I would completely encase the camera in the holder and then 'pot' everything with epoxy resin if I were doing it again.
I may yet make a sleeve to extend the holder and pin and glue this to eliminate it.

What looked like a good feature (adjustable focus /zoom) turned out to be its Achilles heel!

regards

any idea why the webcam pic would flicker (flash)when embedded?
works fine if you fire up camview-emc standalone but flickers when embedded in axis or gscreen.
it's unuseable as is.

Also any reason this couldn't be addded to linuxcnc source so it's more mainstream and maybe would get more fatures?
it seems very useful.

Chris M

have you the config to embed in gscreen Chris ,
i can test here , is this flickering whilst running machine or just in selecting the cam screen

I'd like to be in source, but seems that someone decide that this doesn't worth time to do.

I'ts not in the source due to dependencies - currently camunits is not available from official repositories.
Probably it's possible to add camview-emc and friends into linuxcnc.org debian repositories but mixing sources is not good idea.

cncbasher
I pushed a patch to gscreen to embed.
I am running a simulated EMC.
the flicker is when webcam is embedded whether in Gscreen or AXIS.

Psha
Couldn't we put a snapshot of camunits into linuxcnc source like we do for classicladder?

camunits, python bindings, what next?
It's important to make life easy for user. But that's solved by including packages in main repo.
But including everything into emc2 source will not affect user.
As for devs - I don't see any problems in cloning one more repo. And for me that looks easier to understand - separate repo - separate project.

hi ppl, im totally new to linux so pls excuse my noobness.

im trying to get a camera to work with my emc however i am stuck at the first step of the whole proccess in these instructions: wiki.linuxcnc.org/cgi-bin/wiki.pl?Axis_Embed_Video

i can't download camview....

i open a terminal window, login with sudo su and then use 'apt-get install camview' which tells me that the package could not be found

any one can help?

btw got this camera, looks good at least when hooked with a windows PC and on the box it states that works with linux:

www.ebay.co.uk/itm/220874384983

-edit-

ok somehow managed to install camunits, the repository and camview

while running camview however, i added my camera convert 8-bit to rgp, opengl to the chain and the screen is showing an image, however it is all made up of highly distorted vertical lines

-edit-

camera works fine with cheese but cant get camview to work properly, still getting messed up vertical lines