[fishface]

I did a lot of searching on this forum before deciding to go ahead with my purchase. Now that I have done it, I thought I would share my experience in case it helps others....

I purchased a cheap Chinese 40W CO2 laser cutter/engraver for £505 delivered. It was shipped from Portsmouth by a box shifter on ebay so arrived in 2 days.
After unpacking it, I first had to put the carriage back on the X axis as it had come off presumably in transit. I took the opportunity to lubricate and correctly align, tighten and adjust all the mechanics.
The Y axis is moved by drive belts on both sides of the machine. The right hand side is connected to the stepper motor. The left belt is connected to the same stepper by a 330mm rod that runs along the front of the machine. This was badly bent and if you move the Y axis by hand with the machine turned off, it was noticeably 'lumpy'. In taking this out to straighten it, I damaged a 5x16x5 bearing which was easily replaced for £1.
Having re-built the mechanics, I then cleaned the optics. I noticed a black spot on one of them which I could not remove with isoproply alcohol. (The machine came with this defect). I then aligned the optics using thermal paper (old fax roll) in front of each mirror.
Next, I installed the supplied software: WinSealXP. It worked well enough for me to test the machine.
My first test was pleasing: I could cut paper!
My next test was disappointing: I could only cut 1mm into acrylic even at full power and on the slowest speed. I contacted the seller. First he said that I should cut 3mm acrylic without problem; just turn it up. I replied that I had done this. He then said that he had spoken to the manufacturer and it was only able to cut about 1mm!
I was suspicious of the black spot on the mirror so brought this up. After sending him a photo of it, he agreed to send a replacement mirror out to me (not received it yet, but it's probably coming from China). I couldn't wait for this, so instead made my own from the platter of an hold harddrive. Fitted this and re-aligned the optics because the hard disk is thinner than the 20mm original mirror.
Tested again: straight through 3mm acrylic - wahoo!

OK, machine basically working.
Now to add some safety features! Unfortunately, there are NO safety interlocks anywhere on the machine. You can open the lid whilst it is operating and put your hand in the way of the invisible beam if you like! I added two magnetic reed switches that are normally used as window open sensors for burglar alarms. One on the main top cover, and one on the back access cover for the laser tube. I simply wired them in series with the laser enable switch.

Next I discarded the main electronic control board (and software), and replaced it with a simple TB6560 3 axis stepper driver connected to my parallel port, and installed LinuxCNC. The TB6560 board includes a spindle motor control relay, but I thought that this would switch too slowly, so I replaced it with an opto-isolator instead.
Whilst trying to configure LinuxCNC to correctly control the motors, the PSU suddenly stopped working. Doh!
After half an hour of 'scoping around, I concluded that one of the fast switching diodes in the PSU had blown short circuit. This was replaced with a rough equivalent from a faulty inverter that I had in my junk cupboard, and the PSU was back up again.
I presume that I was either driving the motors harder/faster or the new control board was pulling more current. Either way I decided that a new, second PSU was required. A 24V 10A PSU for £33 from ebay was ordered.
Two days later, the PSU arrived. In the process of fitting this second power supply, I discovered that much of the machines mains wiring is held on by twisting it and covering it with insulating tape! In fact, one of the wires had already come off. Also they use the non-conventional colour scheme of earth=red, live=black, neutral=red! Twisted wires replaced by proper solder joints and covered with heat shrink. Colour scheme left as is, but notes taken!
With the second PSU fitted, and the current drive turned down on the stepper driver board, I was back in business.
I control the laser tube using digital output 0 from LinuxCNC. This means that I can turn it on with M62 P0 and off with M65 P0.
Next problem was to find a way to generate gcode with these controls in!
I eventually found dxf2gcode by Christian Kohloeffel. This has a reconfigurable post processor file so it was simple to add my laser controls to it.

I now had a working laser running of LinuxCNC with safety interlocks.
Time to add luxuries....
First was a height adjustable table. I made the table itself by bolting 1/2" aluminium angle to an aluminium sheet. To make it height adjustable, I have added an M6 set screw at each corner. One turn equals 1mm height adjustment.
It was during the testing of this that I discovered that the original table was at the wrong height for the optimum focus point! By putting a piece of plywood in sloping at an angle and cutting a line across it, I was able to find the height of the focal point. Once this was established, I cut a little height guide from acrylic. When the height of the table is exactly right, the height guide exactly fits between the surface of the table (or material on the table about to be cut) and a fixed point near the top of the mirror mount.
Second luxury was an air assist. This was made from a mains powered air-bed inflator (£26 Argos), some very flexible 4mm silicon tube (free from a kind pet shop employee!) and a screw on hose pipe adapter (free from the shed). The hose pipe adapter just fits nicely over the 1" diameter lens and is held in place with a tie wrap. The air tube goes to the back right of the machine and is kept out of the way of the laser beam by a single piece of elastic tied to about the half way point.

So in conclusion, if you're going to buy a cheap Chinese laser, be prepared to do a lot of work to it (fix the mechanics, make the electrics safe, fit safety interlocks). If you want it to be brilliant, then also swap the electronics, install LinuxCNC and add air assist and an adjustable table.
After about 3 days of tinkering, I now have a brilliant setup that cost me £505 + £1 bearing + £0 new mirror from harddrive + £40 stepper board + £33 second PSU + £0 open source software + £26 air assist + £10 adjustable table = £615 for a brilliant system that will cut up to 328mm x 226mm.

[DAVID ALVAREZ R]

I did a lot of searching on this forum before deciding to go ahead with my purchase. Now that I have done it, I thought I would share my experience in case it helps others....

I purchased a cheap Chinese 40W CO2 laser cutter/engraver for £505 delivered. It was shipped from Portsmouth by a box shifter on ebay so arrived in 2 days.
After unpacking it, I first had to put the carriage back on the X axis as it had come off presumably in transit. I took the opportunity to lubricate and correctly align, tighten and adjust all the mechanics.
The Y axis is moved by drive belts on both sides of the machine. The right hand side is connected to the stepper motor. The left belt is connected to the same stepper by a 330mm rod that runs along the front of the machine. This was badly bent and if you move the Y axis by hand with the machine turned off, it was noticeably 'lumpy'. In taking this out to straighten it, I damaged a 5x16x5 bearing which was easily replaced for £1.
Having re-built the mechanics, I then cleaned the optics. I noticed a black spot on one of them which I could not remove with isoproply alcohol. (The machine came with this defect). I then aligned the optics using thermal paper (old fax roll) in front of each mirror.
Next, I installed the supplied software: WinSealXP. It worked well enough for me to test the machine.
My first test was pleasing: I could cut paper!
My next test was disappointing: I could only cut 1mm into acrylic even at full power and on the slowest speed. I contacted the seller. First he said that I should cut 3mm acrylic without problem; just turn it up. I replied that I had done this. He then said that he had spoken to the manufacturer and it was only able to cut about 1mm!
I was suspicious of the black spot on the mirror so brought this up. After sending him a photo of it, he agreed to send a replacement mirror out to me (not received it yet, but it's probably coming from China). I couldn't wait for this, so instead made my own from the platter of an hold harddrive. Fitted this and re-aligned the optics because the hard disk is thinner than the 20mm original mirror.
Tested again: straight through 3mm acrylic - wahoo!

OK, machine basically working.
Now to add some safety features! Unfortunately, there are NO safety interlocks anywhere on the machine. You can open the lid whilst it is operating and put your hand in the way of the invisible beam if you like! I added two magnetic reed switches that are normally used as window open sensors for burglar alarms. One on the main top cover, and one on the back access cover for the laser tube. I simply wired them in series with the laser enable switch.

Next I discarded the main electronic control board (and software), and replaced it with a simple TB6560 3 axis stepper driver connected to my parallel port, and installed LinuxCNC. The TB6560 board includes a spindle motor control relay, but I thought that this would switch too slowly, so I replaced it with an opto-isolator instead.
Whilst trying to configure LinuxCNC to correctly control the motors, the PSU suddenly stopped working. Doh!
After half an hour of 'scoping around, I concluded that one of the fast switching diodes in the PSU had blown short circuit. This was replaced with a rough equivalent from a faulty inverter that I had in my junk cupboard, and the PSU was back up again.
I presume that I was either driving the motors harder/faster or the new control board was pulling more current. Either way I decided that a new, second PSU was required. A 24V 10A PSU for £33 from ebay was ordered.
Two days later, the PSU arrived. In the process of fitting this second power supply, I discovered that much of the machines mains wiring is held on by twisting it and covering it with insulating tape! In fact, one of the wires had already come off. Also they use the non-conventional colour scheme of earth=red, live=black, neutral=red! Twisted wires replaced by proper solder joints and covered with heat shrink. Colour scheme left as is, but notes taken!
With the second PSU fitted, and the current drive turned down on the stepper driver board, I was back in business.
I control the laser tube using digital output 0 from LinuxCNC. This means that I can turn it on with M62 P0 and off with M65 P0.
Next problem was to find a way to generate gcode with these controls in!
I eventually found dxf2gcode by Christian Kohloeffel. This has a reconfigurable post processor file so it was simple to add my laser controls to it.

I now had a working laser running of LinuxCNC with safety interlocks.
Time to add luxuries....
First was a height adjustable table. I made the table itself by bolting 1/2" aluminium angle to an aluminium sheet. To make it height adjustable, I have added an M6 set screw at each corner. One turn equals 1mm height adjustment.
It was during the testing of this that I discovered that the original table was at the wrong height for the optimum focus point! By putting a piece of plywood in sloping at an angle and cutting a line across it, I was able to find the height of the focal point. Once this was established, I cut a little height guide from acrylic. When the height of the table is exactly right, the height guide exactly fits between the surface of the table (or material on the table about to be cut) and a fixed point near the top of the mirror mount.
Second luxury was an air assist. This was made from a mains powered air-bed inflator (£26 Argos), some very flexible 4mm silicon tube (free from a kind pet shop employee!) and a screw on hose pipe adapter (free from the shed). The hose pipe adapter just fits nicely over the 1" diameter lens and is held in place with a tie wrap. The air tube goes to the back right of the machine and is kept out of the way of the laser beam by a single piece of elastic tied to about the half way point.

So in conclusion, if you're going to buy a cheap Chinese laser, be prepared to do a lot of work to it (fix the mechanics, make the electrics safe, fit safety interlocks). If you want it to be brilliant, then also swap the electronics, install LinuxCNC and add air assist and an adjustable table.
After about 3 days of tinkering, I now have a brilliant setup that cost me £505 + £1 bearing + £0 new mirror from harddrive + £40 stepper board + £33 second PSU + £0 open source software + £26 air assist + £10 adjustable table = £615 for a brilliant system that will cut up to 328mm x 226mm.

HELLO GREETINGS FROM MEXICO MY NAME IS DAVID , I HAVE A SAME TEAM , YOU CAN SEND ME YOUR TEAM PHOTOS.
HERE IN MEXICO THE PRICE IS VERY EXPENSIVE PARTS OR NOT sell them, there are only 2 SHOPS CNC.
Can you help me to modify my laser machine the same as yours?.
My machine has a problem, XY ENGINE INOPERATIVE, MS10105 V4.1 controller card DAMAGED. Can you tell me which card is the same.
My email is [email protected]
MANY THANKS
DAVID

[daweilaser]

Hi David,MS10105 V 4.1 controller card is available from us. I am sorry hear that XY ENGINE INOPERATIVE, could you send me more details about your machine ? the problem may be slove from us.
Web: Shandong Liaocheng David Laser Science & Technology Co., Ltd. - Laser Engraving
my email: [email protected]