Erratic cutting for vls3.50

[tecnick]

Hi, we have been using our laser cutter for about 8 years now. We have just started having trouble cutting multiple pieces from a full size sheet of 3mm acrylic (304x608). For example we wanted to cut a full sheet of discs with a hole to make little wheels.
The problem is, it only cuts about 10 discs then seems to run out of puff and just engraves the surface instead of cutting through.
We have: cleaned the optics, cleaned the extraction pipes, hoovered out under the platen, reset focus using z.
If we cut a few at a time all goes well. We are stumped, any advice?

Cheers Nick

[Martin]

It sounds like a classic case of the laser tube. You will need to get a service exchange unit.

[TDIPower]

We just had the same issue, managed 10yrs from ours so not bad going really.
Once the new one was fitted and calibrated (just reset the axis as per the instructions) job is a good one!

I have found recently a massive variance in acrylic thickness. With sheets being 2.7mm at one end and 3.4mm at the other.
So setting at 3mm can at times lead to not cutting correctly. Well worth getting a calliper or micrometre on the acrylic and setting it correctly.

Pete

[tecnick]

Thanks for replies,

What sort of money are we looking at for a tube?

Cheers Nick

[TDIPower]

Not sure on yours, I think ours may be and older VL, but it was about £1100/1200 (we got new mirror/lens and honeycomb bed too so the bill was a lot more) it was a case of take out the old 'box' fit the new and Denford collected the old one 'service exchange'.

Pete

[Martin]

It's around £1000 depending on wattage. Graham would need to know the machine type, serial number & serial number of the laser tube (to get the laser tube serial number remove the back cover (2 screws from underneath))

[tecnick]

Thanks people, contacted Graham who agreed with diagnosis.

Quote for spares with the head teacher

Cheers NIck