TinyG controller running a JTechPhotonic laser

Laser Cutting
1

I am Just wondering if any one is using a JTechPhotonic laser with a TinyG controller.
I am very keen to buy the 2.8w kit butt there is not a lot of info I can find as to how compatible the TinyG is.
I would like to use it predominantly for cutting balsa wood but engraving would be fun to.

2

Us at www.picengrave.com has been working with Jay at J-Tech developing a DAC circuit. It will take the step & direction signals and output PWM to control the J-Tech laser driver with depths of cut settings in a gcode. Since the TinyG has a 4th axis, it could be wired to it’s step & dir and PicEngrave Pro 5 & PicLaser Lite can generate the gcode for it to engrave photos.

We developed the DAC circuit for use with Mach3 and analog modulated laser drivers. The new DAC version is more advanced with higher voltage change resolution and it will output both analog and PWM from the same board.

Keep an eye out on J-Tech Photonics web site for when it’s offered for sale. Jay mentions it on the Mach3 page in Using Mach3 with PicLaser Lite.

3

Hello,
Do you know if anybody is using the tinyg controller with picengrave yet?
I am planning to use tinyg for two purposes. Use it to mill foam and wood and also to be able to do laser engraving. I have built the OX CNC and currently using only for milling. I was wondering if one could use the laser with its PWM output?

4

We do not know of anyone using the tinyg to laser engrave photos with it’s PWM. Here is a video of the DAC J-Tech Photonics developed that excepts and axis step and direction signals for analog modulation or PWM out to a laser driver for varying the laser’s intensity.

5

Thanks John for responding,
The board is out of stock but I would also like to build one first from scratch. I found out this recent post with John Champlain’s DAC board (recent one: Shapeoko CNC Router, Rigid, Accurate, Reliable, and Affordable) - do you have the circuit diagram for this board?
I found this online on your website : http://www.picengrave.com/Pic%20Programs%20Page/PDF%20Files/misc/Laser%20Setups.pdf

I think in this PDF its a little different as there are 2x 10k resistors used.
Sorry if these questions are basic but I am a hobbyist and these things are new to me :smile:

6

The circuits in the two PDF documents are basically identical. The 10K resistors you refer to are multi-turn potentiometers used to adjust the zero and full scale output voltages. They were necessary only due to my use of the 741 op amp I had on hand to use when I made the first prototype referenced in the PDF.

The second prototype DAC I made referenced in the image posted by Jeff on the other forum, and used for the J-Tech DAC, uses a different op amp that requires fewer parts in the output stage, and also uses a simpler power supply. This circuit is no longer available.

The J-Tech DAC also has a PWM output stage. I suggest you contact Jay at J-Tech to see when his DACs might be available again.

John

2 Likes
7

Thanks for replying John :smiley:
I am also wondering if this laser driver would work?
http://www.ebay.com/itm/3Amp-analog-PWM-laser-diode-driver-with-thermal-protection-445nm-638nm-520nm-/151881555827?hash=item235cd89f73:g:zkcAAOSwDNdVyTv2

I have a 3W laser from DTR laser shop. I have the Arduino Uno/gshield setup…
What do you think?

8

I am planning to make your DAC board for now until the Jtech DAC board is back in stock.
Do you have the circuit design image or board schematic (made in EagleCAD or similar) so that I could use it to make the PCB myself? Would you mind sharing it?

Thanks in advance :smiley:

9

Sent you a message yesterday.
John

10

Hi John,

I don’t think I got your message…
Got the MAX5451 and the LM741 along with other components today…
My email is kmalu87@gmail.com

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Email sent. Please let me know if you do not receive it.
John