Galvo laser questions

[Keith Winter]

I've been playing around with a 30 watt fiber galvo laser - IPG laser source - 175x175 mm lens - running EZ Cad 2 for a few couple days.

A few things I've run into, hoping you guys have some experience that might help:

1) What's the max variance I should expect? What's my depth of field variance on a galvo like this when going around a slightly curved object?
2) Polished stainless steel - My annealing is turning out spotty instead of black on the polished stuff only. The matte stainless seems to work ok, but the polished stainless I'm having trouble with, any tips for polished stainless that might work?
3) Any tips/tricks for stainless steel in general?
4) How do you keep track of job height so you don't have to remeasure every time? A good way of knowing the focus distance exactly every time...

[Scott Shepherd]

Keith, I'm sure someone like Matt from the UK can chime in and help. What might help him is knowing what settings you are using for those different items. What power, speed, Hz, and hatch distance would probably help those that know to be able to help.

[Keith Winter]

What has worked on stainless steel matte so far: 4 loops (passes), 1300 speed, 30 HZ, 0.015 hatch distance. Hatching 3 ways at 0, -45, 45 doesn't work on the polished though.

[matthew knott]

1) What's the max variance I should expect? What's my depth of field variance on a galvo like this when going around a slightly curved object?
depends on the material and what you are doing, on anodized i would expect +/- 3mm, deep engraving +/- 1mm, it is what it is as you cant adjust the beam expansion on your machine, best you can do is set focus in the middle

2) Polished stainless steel - My annealing is turning out spotty instead of black on the polished stuff only. The matte stainless seems to work ok, but the polished stainless
I'm having trouble with, any tips for polished stainless that might work?
Tricky this one, what frequency are you using? focus can make a big difference for annealing, slightly out can work better

3) Any tips/tricks for stainless steel in general?
hard to advise over the net but get some material and play, record the best settings and try to get a fell for how the machine work

4) How do you keep track of job height so you don't have to remeasure every time? A good way of knowing the focus distance exactly every time...[/QUOTE]
do you have a programmable Z? how is focus adjusted ? A simple method is to have a stick that is the correct length, the focus distance is always the same

Hope you get on well with it, the software is very good, you just need to know how to use it
Matt

[Keith Winter]

Hi Matthew I've tried 20-35 frequency on the polished stainless steel using the settings from the matte stainless above also varying speed 900—1300 with little success.

Z is a manual square crank shaft with a wheel on top for up and down for the laser head. I have a focus stick but I'd rather be able to repeat the job quickly on different days. (stick doesn't always equal success seems to be more picky than a co2 laser). I was thinking about attaching some sort of digital readout but I haven't got that all figured out yet. Suggestions?

[matthew knott]

something like this ? http://digital-caliper.co.uk/product_info.php?products_id=463

[Keith Winter]

Yes something like that I think would work, just have to figure out how to a fix it.

Any thoughts on the polished stainless?