Howto connect a Laser

[Gazza]

ok lets clear things up ...

My laser is of the 2 pin kind which is pos and neg...
The board or boards are in theory all the same with options of 3 pin...12V, GND and PWM for the laser and a 2 pin for a laser stop confusing the issue about boards its not important guys its just a 2 pin connector 12v pos and neg
if you have a 2 pin it says to connect to the 12v Fan

I cannot supply a data sheet there is NOT one but the picture which is a different one i know but you can see the pins for a 12v laser conneted to the FAN yes it works the same end of

but enough of this its a 2 pin laser connection 12v pos and neg
right hope that clears a few things up and in case the next person ask...

its a chinky cheapo board ..yes it may have 3 pin and a 2 pin

BUT MINE IS a 2 PIN as per post number 1..
and i need to connect it to this some how ?
its a cnc4 you break out board

https://cnc4you.co.uk/resources/KK01.pdf

[cncdrive]

If your laser has only 2 pins 12V and GND then what you can do is you can power it and unpower it.
This is what I was talking about in one of my previous post that some chinese laser controller boards do not have a laser modulation input (TTL PWM input).
Unfortunately you can't use it then to engrave, because applying and removing the power is far too slow for operating CNC cutting or engraving properly, for that you would need a board with PWM control.
The maximum you could do with this board is you can switch the laser on or off with removing and applying the power back, but this is not enough for laser engraving or cutting.

[Robertspark]

Gazza,

Thanks for the clarification.

The problem was you did not provide enough information earlier and it seems that you've not been able to understand that there are two variants available, one that modulates (TTL / PWM 3 pin able to be controlled / its output varied [by imitating 0-5v with a PWM signal]) and one that is all on and all off (2-pin)

Given you've got the 2 pin variant, have you opened up the controller, it may be possible that you may be able to gleen how / if it has a 3rd pin internally, it may be a TTL input that has been soldered up to a 5V feed / pair of resistors so that it emulates being on 100% (i.e. fed with 5V)

Open it up and provide some photos someone may be able to help.

Alternatively (and what I did).... buy one from CNCdrive that works out of the box...
http://shop.cncdrive.com/index.php?productID=736
.... depends what you want to use it for I guess...

[cncdrive]

Rob,

Usually these cheap laser driver boards only contain a current controller, a switching regulator or LDO with adjustable current limit.
That could probably be hacked to make it on/off control, but for that you have to see the circuit and to understand the circuit and to have some knowledge in electric engineering,
because if you don't know how it works and how to modify it properly then you can easily end up with a burn out laser diode, so it is then much cheaper to search for the proper laser controller board and buy a board for the existing laser diode module.

I'm not saying to not hack it, just wanted to give a warning that laser diodes are sensitive, they can easily damage even from ESD. (human touch : electrostatic discharge.)

[Robertspark]

Hi all

well i have been playing in me workshop a few yrs now and cutting out model planes ...boats etc I was looking at the new LASER cutters and thought hmmm so bit the bullet and got a Chinky one of good ole ebay its a 5.5mw blue laser tried it
...
Im looking at two wires that feed it ...12v pos and neg that was plugged into the usb controller board that goes into a power plug ?

I thought I'd read the original post again...

It does say laser cutter... I guess this setup would still work fine as a laser cutter. (12v on / off via high speed relay)... Same as a plasma cutter

Pwm would only be required if it was an engraver....
______________
All depends how much sunk cost you have in it if you are tempted to look inside the box I guess

It may be cheaper / easier to just get the right one with the right board and sell it onwards to the next bargain hunter

[Gazza]

Hi guys

Many thanks for all the input this is helping me understand what your all saying....
as I'm not interested in engraving only cutting as in 3mm plywood... Depron and foam board.... so now we are all on they same page is there any one who can say connect this to this on pin xx of your break out board with this setting on uccnc...
I have read the uccnc manual and seen the pictures and seen the laser pin... Port etc.... But no where does it say how to connect it....
I'm sure someone on here can upload a picture of uccnc configuration settings with pin out and a picture of the break out board and say use / connect....
As we all now no it's on /off so cutting is going to be easy....

Regards Gary

[cncdrive]

You could use a Mosfet to switch the power to the laser controller.
E.g. use an N-channel mosfet with a relatively low on resistance.
You could drive the mosfet from any output pins of the motion controller, just add a resistor in series with the gate of the FET to limit the dI/dt into the gate and so the switching dV/dt.
And another resistor to between the gate and the source of the mosfet, e.g. 10k to 33k Ohm value and that will keep the mosfet closed when and if the motion controller output is not energised or disconnected.
The series resistor should be OK in the 100R range for this and you could use a logic level N-channel mosfet like the IRL540N or similar.

Like this: http://www.electronics-tutorials.ws/tra ... tran21.gif

[dezsoe]

We are talking about everything in the world, but none of us recognised that it is an Arduino Nano controlled 2 axis + laser on/off board! It is a complete solution with its PC side software. So, Gazza, the question is:

- Did you build the whole stuff or just bought the controller with the laser?
- Do you have a complete machine to fix the laser on as only a laser module?

If you want to replace the Arduino Nano with UCCNC, you have to pull out everything from the main board (also the Nano and the 2 axis controllers!) and start to find the pins for the axes step and dir, the enable and the laser output. (If the PC side program has these infos, then you are ready with this part.) Then make a cable or a little board to connect to the UCxxx controller you have instead of the Nano. Then it will work after you set up UCCNC.

[Robertspark]

I think his intention is to bin the board and use a UC motion controller (not sure which one??)

+ a cheap BoB as given in one of the earlier posts.

https://cnc4you.co.uk/resources/KK01.pdf

i.e. uccnc will control the axis + laser.

on that bob is a relay, use the relay to toggle the laser. (pins marked NO + COM)

I'd suggest starting out using M3/M5 to toggle the laser on and off.

UCCNC has a more "advanced" laser control although I'd suggest that you don't use it because you will need to use overburn codes to get best use of the M10/M11 functionality.

you will need to buy 3x stepper motor drives in order for your stepper motors to be controlled.
you will also need a power supply which is compatible with your drives.

You will need to try to find out the specifications for the drives (ampage, and mH), this can normally be found via google if there is a part number on them (or you can roughly estimate it if you can find one of similar dimensions).

My experience, cleaper the drives, the poorer the finish you end up with.... but that is your choice.... then again those drives do not look exactly likely to have much of a current rating hence something cheap will probably work fine.

{I have a set of unused TB6066 drives + BoB + power supply you can probably use.... where are you roughly?}
such as these:
http://www.haoyuelectronics.com/Attachm ... dule-1.jpg
http://www.mycncuk.com/attachment.php?a ... 1495398422
They are sat in a box and won't be used
I'll have to check on the power supply.... but you may be able to use the one within your present setup.

It may be possible to remove the arduino board and plug in some fly leads so that you can use the existing drives.... the catch is you need to work out which pins are the step + direct pins on that Board you posted in one of the first posts.
http://img.banggood.com/images/oaupload ... b4f8a8.jpg
It all depends how much you want to tinker and if you just want it to work..... quick + easy as possible.

[Gazza]

Gazza,

Thanks for the clarification.

The problem was you did not provide enough information earlier and it seems that you've not been able to understand that there are two variants available, one that modulates (TTL / PWM 3 pin able to be controlled / its output varied [by imitating 0-5v with a PWM signal]) and one that is all on and all off (2-pin)

Given you've got the 2 pin variant, have you opened up the controller, it may be possible that you may be able to gleen how / if it has a 3rd pin internally, it may be a TTL input that has been soldered up to a 5V feed / pair of resistors so that it emulates being on 100% (i.e. fed with 5V)

Open it up and provide some photos someone may be able to help.

Alternatively (and what I did).... buy one from CNCdrive that works out of the box...
http://shop.cncdrive.com/index.php?productID=736
.... depends what you want to use it for I guess...

yes i never knew there was so many variables to a laser and now understanding the 3 pin is better