PDA

View Full Version : Fiber Laser Focus Tolerance



Jeremy Bolinger
06-25-2016, 2:21 AM
Hey guys, long time listener first time caller. New to lasers and looking to get a weike 30w fiber. A friends company has enough guaranteed work to pay for the laser in a couple years, but they don't want to buy one.

In yalls experience, what is the focal length tolerance?

The main thing I would be engraving for them has a convex lid, much like a casket. 1.5" tall numbers, 4 across the top then a large simple graphic all total roughly 6-7" wide x 9" long. Over that range from highest to lowest is 1/16". I assume set the focal length half way through the height change. So the furthest out of focus would be 1/32 high and 1/32 low. They want it to be roughly 3 thousandths deep. They aren't real sure on depth until they see examples.

Other question, would a 30w be big enough to do an engraving that size in a timely manner? Do I need to step up to the 50? I'm hoping for other work, besides them, to be mostly firearm related. NFA engraving, magazines etc.

Gary Hair
06-25-2016, 10:33 AM
For deep engraving you should have no problem with 1/16", I have marked anodized aluminum over about 1/4" range. The one problem I see with your parts, however, is the overall size. With a 30 watt machine you shouldn't use more than about a 175 lens (6.89"), and past about 4"-5" you shouldn't expect to do deep engraving. So, a 7" x 9" piece is way out of the size you could work with. Even a 50 watt machine with a larger lens may have trouble with that size. Can you do it in two, or more, sections?

Keith Winter
06-25-2016, 3:05 PM
I may have missed it, but what material is this convex lid made of?

I think you might get 5"-6" with a big Lense. 7" is too long, 6" is really too long too, it's likely going to distort and you will loose power at the edges.


Hey guys, long time listener first time caller. New to lasers and looking to get a weike 30w fiber. A friends company has enough guaranteed work to pay for the laser in a couple years, but they don't want to buy one.

In yalls experience, what is the focal length tolerance?

The main thing I would be engraving for them has a convex lid, much like a casket. 1.5" tall numbers, 4 across the top then a large simple graphic all total roughly 6-7" wide x 9" long. Over that range from highest to lowest is 1/16". I assume set the focal length half way through the height change. So the furthest out of focus would be 1/32 high and 1/32 low. They want it to be roughly 3 thousandths deep. They aren't real sure on depth until they see examples.

Other question, would a 30w be big enough to do an engraving that size in a timely manner? Do I need to step up to the 50? I'm hoping for other work, besides them, to be mostly firearm related. NFA engraving, magazines etc.

Rodne Gold
06-25-2016, 4:56 PM
I have a 20w with a 110x110 f-theta lens and also use a 200x200 f-theta lens
Power drop is a LOT between the 2
Get a 50w and then get a few lenses , that are about $300 .. best of all worlds 75mm , 110mm, and 200mm.. or maybe consider an XY table fibre laser rather than galvo if you need large area deep engraving.

Jeremy Bolinger
06-26-2016, 1:29 AM
Sorry material is aluminum. Not sure of the alloy.

Weike offers a 400mm lens. So I guess the power will be too low at the edges?

Gary Hair
06-26-2016, 10:27 AM
I was told the max you should consider for a 30 watt is 175mm. I don't know how much power you would need to accommodate a 400mm lens, but I would have to guess 50 may not even be enough to have full power over the entire range.

Jeremy Bolinger
06-27-2016, 6:50 PM
Thanks for the replies guys. Maybe I can work with them on changing dimensions of the large image. Possibly chop stuff up and mark in multiple pieces.