LAOS Laser

Aha well later on i discovered that i also had turned the POT 1 and 1/2 times (maybe a bit more). So thats normal see this overview of the powersettings needed
http://redmine.laoslaser.org/projects/laos/wiki/Materials_and_settings
Btw 1 turn is 10%.

Does the pcb.svg show up in visicut (change the material setting to 300 x 200 so U can beter see if it will fit).

The 0 point(the top left corner) is also still a bit off on my machine (that can cause some problems to) and i have no idea how to change this, maybe thats in the config.txt but witch setting ;-)
i am using http://redmine.laoslaser.org/attachments/download/72/config.txt these setting (the same as James) and that works for me

The 0 point(the top left corner) is also still a bit off

Yes, I just guessed for now, Will try to get more accurate values - the values to tweak are x.home and y.home, I think.

I use the same config file. I remember you (Pieter and James) are using the pololu's in stead of the StepSticks. May that make a difference?

Strange is also that the HOME position is top right.

In VisiCut I can see the square, but the arts is cuts seems to be larger too. ASo I think here s a ranging issue.The lasercutter wants to be bigger than it is. Poor thing!

Strange is also that the HOME position is top right.

That's where the limit switches are, which it needs for absolute positioning.

The origin is top left, the X axis moves from left to right, and the Y axis moves towards the front. See HPC LS3020.

Indeed the HOME is top right. I tried a different cutting file. The file seems to be a factor larger and not mirrored. So the x/y directions are OK, I think. So, there may be a scaling issue.

In a earlier mail Jean-Claude mentioned different settings for the Pololu's in the config. see quote:

""With the Pololu boards, the motor stays handwarm, and both Pololu's are completely cold. My hunch is that the StepSticks are not 100% compatible, perhaps the microstepping is different or something.
The Y scale needs to be set negative. And both X and Y need to be doubled in the config file, because these stepper motors are 400 steps/rev instead of 200.
Attached, the config file which we've been using at this point. Note that DHCP has been enabled.""

Perhaps I must change back the 200 / 400. However I don't know exactly where.

There is a difference between the STEPSTICK and POLOLU drivers, for those who have not noticed:
The POLOLU can do 16x microstepping
The Stepstick can do 8x microstepping

There is a difference of a factor two (stepstick is two times larger, meaning larger movements)

This should be reflected in the config.txt file in the mbed (the x and y scale).

To add to the confusion: there are also two types of stepper motors used by HPC (200 and 400 steps/revolution): again a factor two.

The scale is specified in "steps per meter", and if set correctly, should result in laser dimensions that match the drawing.
All other positions in the config file are set in micrometers, and allow you to modify the origin of the workfield and minimal
and maximum travel postions for the axis.

In the Visicut software the paper size should me set correctly, or the laser would move out of range.

THERE IS CURRENTLTY NO CHECK IN THE SOFTWARE TO LIMIT THE MOVEMENTS IN THE HARDWARE BETWEEN MIN AND MAX.

Also: there are no limit sensors on the axis of the HPC, it will continue to move at the end of travel, causing your motors to skip.

So: make sure the page size is correct, and your drawing is within range.

Some improvements to be made in the firmware....

Thanks all for the responses. I got the laser running now!!!!

I made some nice examples of molecular jewelery that will be made at Llowlabs, Lowlands in august. Nice showcase for the LaOS.

Today I'll spend some time in finetuning, As soon I've all setting right, I'll share these as soon the numbers are right.

picture or it did not happen ;-)
btw would be nice to share hour config.txt and describing your configuration (as good as posible)
is think i will have to change my config.txt to cuz my setting are a bit weird (y.scale and y.home negative witch is not normal but i could be wrong)

I changed the y scale to 80,000. That solved the problem of scaling.

Still have to sort out the exact position of the object. Attached the config.txt