Datum point

[Bellybuster]

Hey folks, just got my laser up and running. Using pic laser, Picfrc and Picsender. 2.8 watt Jtech on an Xcarve.
With Piclaser..... why not have a datum point that can be in the centre of the stock I'm having a hell of a time with stock alignment. You have to change back to spindle mode to be able to move the gantry, then you lose the laser spot.
If I have a 4X6 image I want to burn onto a10X10 board, how do I centre it?
Thanks and bear with me, I'm new.....

[Bellybuster]

cancel last, I'm an idiot, you can jog in laser mode. Still would love to see a centre datum point though

[Picengravertoo]

10X10 minus 4X6 equals 6X4 divided by 2 equals 3X2. Pick up on the lower left corner of your stock with the laser beam at low power, zero the X&Y axis and jog X3 & Y2 and zero the X&Y axis again.

Our PicEngrave Pro 5 has a lower left, or center X&Y zero place option. It also lets you set a X&Y offset.

You don't have to switch to Spindle Mode to jog the X&Y axis. However, you do have to switch to Spindle Mode to set the focal height with the Z axis and then switch back to Laser Mode to run a Laser gcode file.

[Bellybuster]

thanks, yes, math, ugh! May have to upgrade later after I learn this stuff more. Nice thing is I'm lasering right out of the box. No issues with either the laser or your software.
Thanks again

[Picengravertoo]

What grbl are you using? Our PicSender works best with Larry's MultiMode grbl 1.0c which the hex can be downloaded on this forums main page. Or, the official grbl 1.1 that can be downloaded from Github. I prefer Larry's myself.

If you have not seen it on the inventables forum, here are instructions how to setup PicSender for either.

https://discuss.inventables.com/t/j-tec ... 1-0c/28493

[Bellybuster]

I am active on Inventibles (Robert Canning) and am using Larry's hex...amazing. I am having so much fun I still haven't changed any of the grill settings after the hex file change.

[Picengravertoo]

Hi Robert,

Without digging through all the forum member's names, I don't know who I'm speaking with.

Looking at the photo engraving you posted on the inventables forum, it looks like you need to make some performance settings changes to grbl for Laser use.

$0=30 (step pulse, usec)
$1=255 (step idle delay, msec)
$10=18 (status report mask:00010010)
$11=0.005 (junction deviation, mm)
$120=8000.000 (x accel, mm/sec^2)<--------I use a 12000 accel setting here, but I have nema 17 steppers on our Shapeoko 2.
$121=8000.000 (y accel, mm/sec^2)<--------And here.

These changes can be made in the GRBL menu Edit Settings window after selecting the GRBL Settings button. Then save them to the laser.txt file.

Jeff

[Bellybuster]

Thanks Jeff, going to make those changes now.
I still have questions regarding datum position. Using the lower left of the image is it based on the image width and height or the "engraved" image width and height. Thanks
This seems to be my only hiccup so far, having a great time. I am just so used to clicking a button to set my datum point using what you see is what you get software. (vectrics)
Thanks again
Looking at PEP5 as we speak

[Bellybuster]

answered my own question by measuring last burned image, its the "engraved" image size

[Picengravertoo]

As you may have realized, the Pixel Resolution setting effects the engraving size. If it's set to .01", it will engrave the same size as the image. The Pixel Resolution sets the stepover and it's based on the laser's burn line width so they lay down next to each other without any gaps or overlapping. When you set it less then .01, you have to resize the image in the editor with the Auto selection to compensate. Both in the Image Editor when resizing & the main screen Pixel Resolution settings should be set the same so it will engrave the desired size.

PicLaser was developed for the Hobbyist's budget, so that is why it does not have all the added features our PicEngrave Pro 5 program has.