[mpa542]

Hi All,

I've had a bit of a hunt around and can't seem to find any discussion on my problem (sorry if I've missed it).

I have a Chinese laser (50w) which I've been using for about 2 years very happy with it.

The current problem is that I am having issues with cuts in MDF not going through in different places on the bed.

EG: top strip (y axis) first 3 cm is patchy ie. cut is dotted. For the rest of the Y axis cut is fine.

So just to be clear when I cut a 50cm x 30cm sheet: 50cm x 3cm is not cutting through the remaining 50cm x 27cm is cutting fine.

I've spent 3hrs aligning the laser and think it is close (bugger of a job!).
The bed is level.
Laser tube has been replaced about 3 months ago.


Before I pull it apart and do it all again I'm just wondering if it could be anything else?

[LEC]

Si el problema de corte es siempre en el mismo sitio es problema de regulación de los lentes
de todas maneras prueba remplazar el archivo de corte que estas usando por un nuevo
suerte
lec

[RCaffin]

Seems to me likely that your laser is taking some time to get up to full power.
That could be a laser system problem, or it could be a parameter in the laser controller bening set wrong.
Mind you, I am a bit puzzled by your saying 'cut is dotted'. Is the laser pulsed? Is the PRF ramping up slowly?

Cheers
Roger

[Gozzie]

I believe he is saying it is almost cutting through in spots ( ie dotted)
MDF lays pretty flat so I would double check the table for level again.
I would try tests on thinner materials in the same spots both where it cuts good and where it cuts bad.
Measure from the table to the head in those spots and I bet you find a difference in the measurements.
It doesn't take much to be off, especially with a shorter focus lens.
After 2 years the table has likely tilted enough now for you to start noticing it.

Gozzie

[mpa542]

I've just cut new supports for thee laser tube to make sure it is 100% level....I still thinking it is an alignment issue. How important is it to centre the beam in each mirror?

The other thing im thinking is maybe the tube is on its way out....my first tube just stopped...I've heard they can loose power and I'm wondering if average alignment coupled with loss of power might be describing my problem.

I don't think it is the bed, I check its level every week or so which has included leveling the individual guide arms etc. checked it again tonight and it is good.

I normally cut MDF at 60% power at 10mm/sec. Tried 80% power and 7mm/sec. cut was a bit better, but got a lot of scorching.

[mpa542]

I've just cut new supports for thee laser tube to make sure it is 100% level....I still thinking it is an alignment issue. How important is it to centre the beam in each mirror?

The other thing im thinking is maybe the tube is on its way out....my first tube just stopped...I've heard they can loose power and I'm wondering if average alignment coupled with loss of power might be describing my problem.

I don't think it is the bed, I check its level every week or so which has included leveling the individual guide arms etc. checked it again tonight and it is good.

I normally cut MDF at 60% power at 10mm/sec. Tried 80% power and 7mm/sec. cut was a bit better, but got a lot of scorching.

[Gozzie]

If you are cutting through in one position of the table and not in another position it just about has to
be an alignment issue being either at the mirrors or the table, especially if it is repeatable in the same
place every time.

Gozzie

[mpa542]

Ok,

so I've fixed the problem.....Not 100% if it was alignment...lets just say I'm really good at mirror alignment now! Anyway interesting note I found a micro hole in one of the hoses Between the water jacket and the lense...I replaced the hose and it is now working well....Of course I also realigned the laser at the same time...so its probably the alignment!

Anyway. Thanks for the help and advice.

Mike