Shiny MDF problem

[Kris and Dave]

Hi,

We've been using our cutter to cut 2mm MDF for a while which has been great, settings at 6mm/s @98% power has always given a quality cut...until now. Our supplier has sent MDF which feels more glossy and when I try to cut it produces a flame and doesn't cut through. I have tried various adjustments to speed and power but as yet everything has actually made things worse. Anyone got any ideas please?

Thanks in advance

kris.

[Spooky]

Kris,

Hindleys by any chance?

The shiny stuff is standard mdf and is resin bonded, I had 100+ 1 meter sheets come in and the stuff is worthless. Black soot all over the place an near double the power to get reliable results.
The fumes from it are also pretty unplesant as they contain formaldehyde and will block bofa units quite quickly.

If it is indeed standard MDF I'd recomend calling your supplier and sending it back, it really isn't worth working with the stuff on a laser.

best wishes

Dave

[Spooky]

Just noticed kris,

6mm a second and 98 power??? woaaa thats way high for 2mm mdf of any kind.
Even a 40 watt tube should manage 2mm mdf @ 20 speed 75 power.

what machine do you have?

best wishes

Dave

[Kris and Dave]

Thanks for the responses Dave,

The supplier was Hobarts. I've spoken with them and they say they've tested the MDF and it cuts well on a 25 Watt laser.

I'm interested / concerned / intrigued by your second response, we've got a 3060 40 watt A3 cutter. If we could get anything like you suggest it would help productivity immensely. We've tested the power of the laser (admitedly with a crude tester designed for much more powerful lasers) and it came out at about 37 watts, alignment has been checked, as has cleanliness of the mirrors. We've never had great performance, initially because the air inlet was blocked but thought we were getting somewhere until this latest setback

Kris.

[Spooky]

Something surely isn't right Kris , those power figures are way high, on a 40 watt tube you should really be able to cut 6mm plywood at those settings.

How old is your tube?
What temperature is the water running at ? (aquarium thermometer is good)
Any particular time for this problem or is it one that has just "built up over time" kind of thing?

best wishes

Dave

[Kris and Dave]

Dave,

The tube isn't old at all, we only got the machine in the summer and only really started using it mid September. I'll check the water temp but it should be basically room temperature. It's on our list of jobs for this Thursday to get a freezer for the office so we can keep the temperature down a bit using the highly sophiticated method of freezer blocks in the water.

Kris.

[DukeEuphoria]

Hi all, reading back through all the things looking for "innformation"

I'm also running a 3040, and the settings 6mm/sec and damn near 100% power are the kind of numebrs I'd expect to reliably cut 2mm MDF on my machine.
3mm plywood/mdf needs 100% power and a max of 3.5mm/sec

Could it me that something ain't right with both our boxes ?

[Spooky]

I'd suggest focus may be the problem,

2mm MDF should cut reliably at 20 speed 80% power on a 40 watt

best wishes

Dave

[Daven]

If after checking the focus as Dave said and as daft as it sounds, try cutting at a lower power - I have just had similar problem so set up a test file with different layers cutting a square and a hole at different speed/power settings to find the optimum. I have been cutting 3mmMDF at 15mm/s at 45% power - if I went for 20mm/s at 80% it was no good so dropped speed back to 15 to see what happened and it still didn't cut!

Cheers

Dave

[robburge@sky.com]

I too have a 3060. I found out by accident that it cuts 2mm MDF much better at lower power. So try 10 at 35%, with a corner of 12%. Make sure the air assist is on and you are using decent MDF, and it is focussed at optimum. On those setting the parts should just drop out cleanly.

Rob