Laserscript user forum

Your on about frequency Pete, changing it can do some funky things to the PSU (including kill it)

cheers

Dave

Spooky wrote:Your on about frequency Pete, changing it can do some funky things to the PSU (including kill it)

cheers

Dave

Does that include when trying to decrease the frequency ?, I remember having some success with the 1290 when cutting lightweight paper/silk after lowering it.

I'd get impoved edge definition with less charring and smoke stain, I dont recall any system warning or software overide notifications or having to enter admim usernames or passwords.

Peter

Hi Pete,

There are some issues with CO2 sealed tubes and changing frequencies, not that it bothers the tube(within limits) but it can damage the supply. The admin password is saved on the HPC machines so the settings can be changed (assuming you also update the firmware by download config) it's just a really bad idea (somebody reading this is going to increase it and kill a PSU)

Tweaks posted a few words on it last week,

http://oplaser.co.uk/opsupport/viewtopic.php?f=22&t=926

Soon as time allows I'm going to be putting up a lot of the science behind the statements that should make sense to pretty much everybody (without causing number blindness) but until we get chance it's not a good idea to play with tube / PSU frequencies.

cheers

Dave

Ofcourse , and I'm totaly aware of Tweakie's post on your forum, however I'm not talking about increasing the value and possibly killing the PSU but decreasing it well within the parameters of a DC tube (0 to 20kHz) and never exceeding the 20,000 value.

Having worked with Epilog's this was something simple to adjust within the print driver itself and adjusting to betwenn 5 and 10 khz was the optimum for cutting lightweight paper, I know RF tubes are an exception in this rule but I was under the impresion that it also applied to DC excited tubes.

On my 3020 you cant play with the PWM as this is admin protected by the manufacturer, nor would I try to overide it as I would likely kill the PSU anyway !.

I think your right , untill there is a definative answer it's best not play with these setting's if you dont understand the science and number crunching involved leave well alone.

Regards

Peter

under the impresion that it also applied to DC excited tubes.

It does, it's the PSU's that are the problem not the tubes

cheers

Dave

Spooky wrote:

under the impresion that it also applied to DC excited tubes.

It does, it's the PSU's that are the problem not the tubes

cheers

Dave

Blast and damit, them pesky PSU's ! !. I guess the only way to get round it is to have a twin tubed laser then ?, lower wattage for nice etching and higher for profile cutting.

Regards

Peter

Preferably with a nice big gap between them too, say 35 watt or so 600mm tube for engraving and a solid 150 watt - 180 watt for cutting.
I've seen twin heads with a 60 and a 100 fitted, pointless really as the difference between them doesn't really justify the cost of the bigger tube, that aside I'm not a huge fan of twin heads, the technology just isn't quite there yet on Chinese twins with half bed use etc...maybe two machines would be better and give a certain amount of redundancy.

If I was ever going to start over again (and Galvo's weren't an option) I'd probably get a 3020 with a DSP and a 35 watt tube for engraving and a 2515 with a 180 - 240 for cutting. Chris is really bang on the money with the EFR tubes, the beam profiles are incredible for DC tubes! I can get the same Kerf from my 180 as I would get from a mid priced 40 watt tube.

cheers

Dave

Well I've already got a 3020, not DSP but I'm not that bothered. It has served me well for3 years and the 35 watt tube can produce nice engraves even on fine script fonts. If I ever replaced my 3020 I would go for the next 30 series up that has a linear rail as I find no matter what I do my 3020 wanders over time. Now if only they did a DSP 3020 with a linear rail then that would be worth considering given it's min character forming is 1mm x1mm compared to 1.5mmX1.5mm on everything else there on up.

For my second machine I worked out that a 60 watt 6090 was the probably the biggest I need, but the differance in cost to step upto an 80 watt 1290 is pretty negligible in the great scheme of things and would mean I could cut bigger projects if they ever presented themselves.

So in summary I'll keep my 3020 for predominantly engraving acrylic, and a get a 1290 for mostly profile cutting full sheets of material for example 2mm mountboard laserply 3 and 4mm and 3mm/5mm perspex. Occasionaly low volume 10mm acrylic components.

Pedro

That was a handy topic, came looking for pretty much exactly the same thing Lots of 3mm MDF to cut.

I had finally decided on the 6840 but have just been asked about cutting 15-20mm MDF. Presumably that would that be way too thick for this and I would need to look at the 6090 or even something with an 80w tube?

Thanks

Matt

ps, I'm new to this so apologies if I ask any obvious questions

Hi Matt,

18-20mm MDF is going to be multi kilowatt (1,000 watt+) range with Nitrogen high pressure gas assist.

Anything over 9mm MDF isn't really suited to budget lasers unfortunately.

cheers

Dave