3040 requires slow cutting speed

[DukeEuphoria]

Hi all.
I've been reading the posts on the board and find myself a little perplexed.
Mostly with the way that people are reporting sucessful cuts of 3mm ply at speeds and power settings I can only dream of.

I'll dump a load of information here in case there's anything useful...

If I want a 95% successful cut I need to run the laser at 100% power and 3mm/s speed to cut 3mm ply.
(if any part of the ply has been glue filled or has a knot it doesn't matter what power/speed/number of repeats I use it will _not_ cut through)

Acrylic is similar, but I can sometimes go to 4mm/s depending on the colour of the plastic.

If the laser is set to less than 25% power it doesn't even fire.

The mirrrors and lens are, to the best of my ability, clean and and haven't been poked since they were fettled by one of the excellent chaps from HPC.

I'm getting good clear results with engraving, and nice focused lines when using low power cuts for marking.

Any power level above about 50% priduces a similar result, a cut _alomost_ all the way through halting about 0.1mm from the back edge of the wood.


Suggestions ? Advice ? Sympathy ?

[Daven]

How old is the tube and what power is it? Do you do the basics and check for bubbles, alignment etc.?

Having just had similar problem I would say it was the tube if the optic are fine.

Cheers

Dave

[DukeEuphoria]

Tube is about 3 years of light use old. Nowhere near burnout just by time used.
40watts nominal (no ideal of actual, never had a meter to test it)
Never spotted any bubbles in there.

But this isn't a new problem, it's been like this from day 1. It's only reading other people's tales that have made me think it might not be normal...

[Spooky]

Hi Duke,

Is it laserply or generic ply?

cheers

Dave

[PhillyDee]

Make sure your focus is spot on, work it out from the location of the lens holder (measure the head) as my 3020 was out by 2mm. When i found the perfect distance it was much better

I know you say you have not touched it, but physically check the alignment of the optics.

I just sold the 3020 and when showing how it worked, i was cutting at 70% and 15mm/s

[DukeEuphoria]

Hi Dave, in theory it's laser ply. Got it from here
http://www.mindsetsonline.co.uk/product ... ts_id=1249
I've used ordinary ply in the past, some cuts just fine, some just chars.

Not sure how to tell if my focus is right, (aside from looking at the sharpness of the burnt laser dot) I've been cutting with the head at 57mm
from the top surface of the material, (using amogst other things the pre cut laser measuring square from HPC).

I'll take a peek at mirror alignment and have a fiddle with different cutting heights.

More news as it happens...

[Daven]

Try a ramp test - Tweakie has posted a guide here which explains it.

To be honest if you have ran a 40w tube at high power on and off for 3 years my money is still on the tube - I would think about getting a 60w fitted. I have just done the same and not regretted it

Cheers

Dave

[DukeEuphoria]

a 60w tube ?
Not sure it would fit inside the 3040 case, and the power supply would need an upgrade too I suspect.

Worth looking into though

[Spooky]

The PWM supplies for the 60watt and 40watt are the same units

Tube length may be a problem though

best wishes

Dave