Chinese laser making strange noise and now laser head doesn't move

[Kori Korina]

Hi,

I am new to this site and to laser engraving.
I bought an 80w chinese laser and so far i have not been able to do a single operation with it.
The first day i started the laser,you can see what happen in the video. https://www.youtube.com/watch?v=mbHOUgXZrMQ&feature=youtu.be
The belt started vibrating like someone was playing a guitar.
After sales service told me the problem was a malfunctioning inductor (the one on the far right on the screen).so they sent a replacement.we installed it.the same thing happened,try bending the inductor several times and restarted the machine.The 5 th time,the main board was no longer working and the laser head wasn't moving anymore. https://www.youtube.com/watch?v=_WgttLTNDTI&feature=youtu.be

Been 2 weeks since i have been trying to get a solution with no success.
Hope to find some help here.
Thanks.

[Keith Winter]

Cannot tell 100% because I cannot see the right side, but in that first video it looks like the vibration doesn't start till you hit the corner. Like you are running into the max top range of the laser and continuing to push it up after that. If so, your starting x y coordinates might be off making the machine think it has more room to run than it really does running into the side / end of the belt and continuing to turn causing the vibration. Does it vibrate like that in the middle of the table?

[Kori Korina]

Hi,
Thanks for your interest.
it only vibrates as from when it hits the corner.and it gets worse as it goes from right to left

[Jess Phiz]

Ours does that when the sensor doesn't activate, is there a switch or anything that the arm hits when it reaches the top to tell it that its the top and to stop trying?

[Keith Colson]

Hi Kori

The first video shows the y axis is failing to register on the home limit switch. This can be the limit switch, the placement of the switch or the electrical connections of the switch.

If your machine has been doing this a too many times it may have blown the stepper motor driver or power supply. Seeing as neither the x or y axis is working now it makes me think the power to the stepper motors is not there. Sometimes there is a fuse for the stepper power supply.

My first step would be to put a volt meter on the y axis limit switch and manually push the y axis on and off the home position and measure the voltage across the switch. I would expect it to switch between at least 5 volts and 0 volts. Probably 12 volts to 0 volts.

My second step would be to locate the stepper driver chips and make sure they have power which would be around 24 volts or so. It you need help here, post a photo.

Cheers
Keith

[Bill George]

Going with what Keith said. The machine needs to find Home using a switch of some type and then wait. Not seeing that happen. I am assuming there was never a test run done at the facotry. If so I would start looking for loose wire connections, on All terminals. On my Chinese laser I had several I found loose, tightened and all was well.

Other than connections, it could be a bad driver board or stepper motor and who knows what else? I do hope you have a VOM meter and how use it.

[Kori Korina]

Hi everybody.
Thanks for your input.You were right.It was a loose connection on the switch.Got it fixed and the vibration are gone.As for the main board not working,another loose connection.The laser head now run smoothly only problem is it stops in the middle of the Y axis instead of the far left.I guess i will just use the mainboard to position it to the right place.
Another question,is your laser head going beyond the honey comb when it is operating?

[William A. Foster]

Which chinese laser is it? Who is the manufacturer?

[Bill George]

Hi everybody.
Thanks for your input.You were right.It was a loose connection on the switch.Got it fixed and the vibration are gone.As for the main board not working,another loose connection.The laser head now run smoothly only problem is it stops in the middle of the Y axis instead of the far left.I guess i will just use the mainboard to position it to the right place.
Another question,is your laser head going beyond the honey comb when it is operating?

Do you mean a Stepper motor was replaced?

I don't know what you are calling an Inductor?

Using the Mainboard to reposition, are you meaning the Keypad?

Maybe it needs the setup parameters reset or re-entered. Yes it would really help to have the brand name and model of your laser. Was it purchased off eBay or where?

[Kev Williams]

Where you laser head is "parking" may be a simple parameter adjustment.

My Triumph likes to park at the upper left corner of the bounding box of the item(s) I'm engraving. Sometimes this is desirable, but usually not. As a compromise, in Corel I have a 1300x900mm table saved as my Triumph workspace. I have the perimeter of the table outlined with a 30% gray outline. Then any work I do in corel and export to the Lasersoft program is now in the exact same place as it was in Corel instead of somewhere in the middle. My procedure is to put the work in the machine where I want it, locate the work or where the engraving will go ON the work using the machine, then transfer the coordinates to Corel. From there I can work in "inches". When I'm done in Corel and export it, it's ready to engrave, no re-positioning necessary.

As for the border, I just exclude the 30% gray from any engraving process, but because it's there, the machine considers it the bounding box, and the head parks in the upper left corner when it's finished.

If I'm doing repeat work somewhere in the middle of the table (it's a long reach to the upper left corner), I just delete the large border, and now the head will go to the corner of the work I AM doing, saving time & a lot of head movement. But normally, I like the head parked upper left, out of the way.

The 30% gray thing has other advantages, I can send notes, dimensions, other parts of graphics in the export, it all just disappears when I un-check the 30% color box...