Ettienne's Laser build

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Ettienne's Laser build

Postby ettienned » Thu Jun 28, 2012 2:22 pm

My hobby is building and flying model aircraft. With the recent high costs of laser cutting here in South Africa i searched and found this website. I am glad i did as it got me thinking about building my own machine and that it will be about a quarter of the price of commercial machines. I have been collecting information on all aspects of the build. I knew that the laser tube and accessories will have to be imported but the rest must be sourced from South Africa for obvious reasons, easy repairs, and cost saving as well as lead time to import parts. I have managed that and got the makerslide equivalent from a company called Provey (does not look like makerslide but has the same idea) i will post pics once i have it back from machining, the frame for the enclosure i got from connect-it. I also wanted a laser cutter that is quite configurable so i opted for an usb interface. The problem is the controlling software and the electronics. I have to thank Van Tredoux from Cape Town for all that. His help and patience with this was invaluable.

Currently i have a completed electronic control system with stepper drivers as well as controlling software. I will keep the drivers and usb interface but being a programmer i will re-write the controlling program as the experimental one that Van wrote is optimised for his router. The stepper drivers and usb interface is all homemade at a fraction of the cost of commercial stepper driver. The 24v 12amp power supply i made from 2 pc power supplies connected in series and works very well. These were from scrapped pc's. I am waiting for 2 scrapped wide format cannon printers to see if the pulleys and belts will work otherwise there is a local company called Cobrel that would supply ex stock.
The main reasons i chose to go the usb route was because i can now get data and display it on the screen like water temp, water flow, voltages, amps etc. As well as controlling the laser power easily using PWM.

Van’s drivers and controllers are unfortunately not open source. I will ask for permission to publish as it is his work.
Attachments
USB_interface.jpg
Usb interface (breakout) using a PIC18F2550
Stepper drivers.jpg
Stepper drivers using a PIC16F628A
24 v 12 amp power supply.jpg
24V 12Amp power supply made from 2 scrapped pc's
ettienned
 
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Re: Ettienne's Laser build

Postby ettienned » Thu Jun 28, 2012 2:24 pm

I will post pics an the build progresses
ettienned
 
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Re: Ettienne's Laser build

Postby edmond22 » Thu Jun 28, 2012 7:15 pm

Your build is looking good, will be following my fellow south african friends build very closely.
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Re: Ettienne's Laser build

Postby RSWeaverAz » Fri Jun 29, 2012 5:20 am

@ettienned
Some good work there using a PIC16F628A to drive the steppers,
did you fabricate those yourself? Massive heat-sinks. :o

I see 2 light bulbs, possibly used for early testing of the drivers,
or to load the 3.3 / 5 volts of the PC supplies,
I understand PC supplies can become unstable (or have lots of noise/ripple) if not lightly loaded.

I'd be interested In how you interconnected the 2 PC power supply's 12 volt outputs together to get 24V,
any special circuitry to do that?
I Launch Rockets, aka High Tech Welfare for Engineers
Your tax dollars have to go somewhere ... right!
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Re: Ettienne's Laser build

Postby ettienned » Sun Jul 01, 2012 4:57 pm

@RSWeaverAz
Yes they were fabricated by myself but not designed by myself. A guy in Cape Town called Van Tredoux designed them and they work 100%. The light bulbs are actually part of the design. It helps keep the stepper motors from overheating by absorbing some of the current and it does not affect the steppers performance. Van has given me permission to share his work with serious builders.

For the power supply .I have tapped the red and a black wires from one power supply to get 5 and 12 volt, for 24v it is a simple series connection between the black and yellow wires from both power supplies and because it is a switching power supply i put a dummy load of 27ohm between a red(5V) and green, also connect a black(-) to the green. One thing you must cut the ground to chassis of the second power supply otherwise it will short when you connect in series and the chassis of the 2 power supplies touch
Attachments
Powersupply2.jpg
Power supply1.jpg
Dummy load.jpg
Dummy Load
ettienned
 
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