How to connect laser tube/power suply to the main board?

Hi everyone,

I started to build my own laser engraving machine and I'm having trouble with a few things. I have power supply, laser tube, main board. How to connect them all?
I have this power supply. 40W Co2 Laser Tube Power Supply - Mini Laser Machine Power Source Special Model from China
Do I use this power supply only for laser tube or for both (laser tube and main board)? If I use it for both, when I connect laser tube for power supply and power suply to main board, do I need to connect laser tube for main board (and how)? Example, if I don't connect laser tube for main board, how will laser tube turn on (on my cnc machine I move z axis with step mottor->driver->main board, but on laser machine I will not have z axis, actually, I will use z axis for turn on/off laser tube.....but I don't know how to do that if laser tube is not connected to main board)?

Thanks in advance.

You better call for somebody used to work with CO2 lasers.
You know nothing and this is best way to get hurt.

By your description, the power supply you have is for the laser tube only. A separate (usually 24v) power supply, is needed for the stepper motors and for the controller board. What are you planning on using for the controller board? Most use the DSP that LightObjects sells. The power supply that you have does not state if it PWM capable, which is necessary to be used with a DSP (digital signal processor). You have much more planning to do before deciding on what to purchase. Not planning will just cause you to waste money.

Milt

On power supply exist connectors (input/output) for main board.
I will use this main board. BREAKOUT BOARD IO3 (I'm from Serbia, so I bought this main board here in Serbia)

Zoran

Iknow nothing about this board, sorry, I am unable to be of assistance on this one.

Milt

Quote:

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Originally Posted by zoran0502

On power supply exist connectors (input/output) for main board.
I will use this main board. BREAKOUT BOARD IO3 (I'm from Serbia, so I bought this main board here in Serbia)

Zoran

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Hi Zoran
I also don't know any information about this board,
but could you please check this board if it as several interface control laser power supply,
such as WP, PWM, TTL-or TTL+ GND ports of Laser
If it has these interfaces
Please refer to the attached picture and connect the laser power supply to the board.
Also you will need to find a water protection switch and install it, it will can detect the laser tube's flow state.
During the installation process, please be sure to pay attention to safety,
Especially you are not so understanding of laser machine technology.(According to your description)
Good luck to you

Sincerely
Tom
Thunderlaser- leading provider of laser cutter and laser engraver from China
Attachment 235930

Brrrrr. Water protect shorten to Ground???
This is a crime.
Will never buy thunderlaser machine.

Hi Tom
Your scheme was helpful, but I still don't know how to connect tube and for what.. I think i know how to connect the red wire (you can see it on the pic http://www.co2-lasers.com/img/p/43-220-large.jpg ) but I think that is not all. I'm stuck there and I can't move it. And do I connect laser tube only for power supply or for something else?

Zoran

Zoran. You are trying to use a normal Cnc control not DSP. Most of the guys on this forum are using DSP. DSP is a specialized controller for use in lasers.

So your controller requires something like mach3 or the Linux version EMC. You are going to also need something to create the Gcode that drives Mach3.

So you create the shapes, then post the code in a form of Gcode that Mach3 can understand. Then your computer turns that into steps and direction signals that are used in the stepper controllers.

I don't know if the board is a breakout only or breakout and stepper controllers. It's both if you plug the parallel port in and also stepper motors into the same board.

Now how do you directly control the laser. Answer is that you can't. The laser PS is looking for a voltage to establish the power out of the tube.

These boards are designed to power steppers and the controls of a spindle but not a laser. Difference being that you turn a spindle on at a set speed then leave it there. A laser requires a much faster control then mach3 can produce.

So you were correct when you mentioned using the Z axis to control the laser. You just need to be creative and come up with something to turn a voltage on and off with the motion of the axis.

I'll leave it at that for now just in case your already convinced that you need DSP instead


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Quote:

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Originally Posted by cinematic2

Brrrrr. Water protect shorten to Ground???
This is a crime.
Will never buy thunderlaser machine.

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Hi Cinematic2
I have not said the water protect switch shorten to Ground,
The water protect switch will be connect to the controller with WP and GND ports, (so the water protection switch is controlled by the mainboard)
but the laser power supply with WP and GND ports needs to be shorten,
If not, the laser tube will be not able to work properly.

Quote:

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Originally Posted by zoran0502

Hi Tom
Your scheme was helpful, but I still don't know how to connect tube and for what.. I think i know how to connect the red wire (you can see it on the pic http://www.co2-lasers.com/img/p/43-220-large.jpg ) but I think that is not all. I'm stuck there and I can't move it. And do I connect laser tube only for power supply or for something else?

Zoran

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Hi Zoran
Yeah, you just need connect the laser power supply to laser tube(In general, the laser tube has two cable, a red cable and the other one is a cathode cable)
You can refer to the attached picture to connection from the laser power supply to laser tube.
Then connect the controller to the laser power supply, by the mainboard control the signal output of laser power supply.
But you need to make sure the controller is a DSP, it is a specially used for the laser machine as Mr. Dean said that.
If you use a normal CNC controller, it will be very difficult to direct control the laser to work for you.
Good luck to you

Sincerely
Tom
Thunderlaser- leading provider of laser cutter and laser engraver from China

Dean
Thank you for information. I just sent mail to my supplier and I'm waiting for response. (I asked him if the main board that I want to buy is DSP or normal CNC controller)
Board is breakout and stepper controller.
Is it possible to use spindle on/off to turn voltage on/off? For example, if I want to use always the same voltage??
Or to turn voltage on/off instead z axis?

Tnx for the answer, Tom. :)

Breakout board is a breakout board.
It has nothing to do with any DSP board.

Quote:

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Originally Posted by thunderlaser

Hi Cinematic2
I have not said the water protect switch shorten to Ground,

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You didnt. Your picture attached did.

Zoran
Breakout boards don't drive steppers. So your going to need some low cost stepper drivers Most lasers have small stepper so something capable of 2 amps or so should be enough.

Normal lasers have 2 Axis drive. If the height has a drive then that's three axis. Or just adjust it manually. You don't adjust the height while cutting. Then you need one more drive and stepper to turn the laser on and off. So you need three to four axis.

The z axis stepper can be mounted in a stand or something outside of the laser. It's there just to switch the laser ps on and off.

Now you want to convert the rotary motion of the stepper to turn a switch on and off. You aren't trying to create a voltage proportionately to rotation which is too complicated.

You turn a switch on and the laser is full power off and it goes off. By the way full power isn't 5 volts. You need to have a power meter on the tube and don't exceed the milawatt rating of the tube.

So you have a simple voltage divider circuit outputting say 2 volts when the switch is closed. Where is the switch? You could program the stepper to turn a quarter rev by telling the system to go in the z direction by a mm. 1mm is say 50 pulses which turns the stepper a quarter of a turn. Need to experiment. Anyway you now have a motion the turns the shaft a quarter turn so put an arm on the shaft or something that hits the micro switch at that position. Go up 1mm and the arm backs off the switch which is connected to the voltage divider circuit which is connected to the laser ps and the unit turns off.

Safety is critical in this. You need to have ways to disable the tube and also open the circuit. Bring everything to ground.

Let's stop here and see if you have questions or rethought the DSP option


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Quote:

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Originally Posted by Dean448

Then you need one more drive and stepper to turn the laser on and off.

Now you want to convert the rotary motion of the stepper to turn a switch on and off. You aren't trying to create a voltage proportionately to rotation which is too complicated.

You turn a switch on and the laser is full power off and it goes off. By the way full power isn't 5 volts.
So you have a simple voltage divider circuit outputting say 2 volts when the switch is closed. Where is the switch? You could program the stepper to turn a quarter rev by telling the system to go in the z direction by a mm. 1mm is say 50 pulses which turns the stepper a quarter of a turn. Need to experiment. Anyway you now have a motion the turns the shaft a quarter turn so put an arm on the shaft or something that hits the micro switch at that position. Go up 1mm and the arm backs off the switch which is connected to the voltage divider circuit which is connected to the laser ps and the unit turns off.

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Man, what you are talking about???
"drive and stepper to turn the laser on and off"
This is nonsense.
Have you ever mount any CO2 laser? No, you dont.
If you did you wouldnt write such humbugs as "convert the rotary motion of the stepper to turn a switch on and off"

You have no any odea how CO2 lasers works.

Hi Dean
I know that I need stepper drivers for cnc laser. I have two step motors, two stpper drivers...
I found this site blackTooth DIY Laser Cutter Engraver Assembly from buildyourcnc.com: Wiring the blackTooth and Power Supply Details
Is this scheme ok?

The stepper looks ok. The problem is that they are connecting +5 of the breakout board to the +5 of the laser PS which isn't a good idea. The 5k pot looks good. The wiring of the wp line to ground will work

So what turns the laser on is the direction signal 6 to the TL line on the laser PS. Problem is that it really isn't a circuit.

You need to use line 6 and the 5 volt on the breakout board to power a transistor circuit that pulls TL to the ground of the laser PS. So the current path of the breakout board is isolated from that of the laser PS.

Does this make sense?

This means you drive the third axis negative and TL goes low and the laser turns on. Drive it positive and it turns off. You have to add a pull up resister on the TL side to +5 to make sure TL is high when pin 6 is high

You could easily play with this without firing the laser. Just don't connect ground to the WP line


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Hi guys
Due to the floods in my country, I could not write. But now I'm back.

I have connected my laser. Attachment 238356
On the picture you can see how I connect power suply. I must say I'm proud, everything work fine. I have only one problem. The longer it laser tube work, it work low intensityreally. I still didn't connect coolant input/output, so....I don't know, can that cause the problem? Do I need to connect high voltage (H) somewhere?

PS Just to brag a little :) Attachment 238360 Attachment 238362 Attachment 238364 Attachment 238366 Attachment 238368