Starting laser engraving- What type to use

[Alex Kirsopp]

Hey guys,

What I'm planning on doing was sinking some money into a laser engraver to do one-of, hobby type work on irregular and round surfaces of anodized aluminum. I have researched into several companies, and I understand that most popular machines have auto-focusing features. However, would this system also compensate for the nearly continuous changing in height of the metal I would be working with? What type of engraver would you guys recommend? As far as I know, I wouldn't need anything above a certain wattage, probably something fairly low as I won't be cutting anything.

Thanks,
Alex

Ninja edit: I can provide example pictures of the metal and finished products if needed.

[Bruce Volden]

Most (all I know of) auto focus features are to be used on flat surfaces. It would be a nice feature to see added someday, probably would need to "probe" the object first and then "burn".:confused:

Bruce

[Pete Simmons]

Do not let auto focus sway your laser decisions.

I wish you could buy a new laser without auto focus and save a few $$.

I removed my auto focus sensor long ago. I like the increased vertical clearance I have without it much better than I enjoyed the gimmick of auto focus.

Instead of auto focus I would like to have a digital readout of table height.

Most of us engrave the same items over and over and just moving the table to the known correct height would be fine.

[Scott Shepherd]

With the new drivers on the Universal systems, you can assign different colors for different heights, so you can have the machine move the table up and down during cutting automatically, or at least that's the way I understood it.

[Alex Kirsopp]

Only problem is, most of the engraving would be done on metals with 3D surface milling.

Here's an example- My apologies for the massive picture.

http://gruntbull.com/images/d07/DSC03088.JPG

[Scott Shepherd]

Alex, you won't have any problems with that, there are several examples on this forum of that same thing. Search for paint ball guns or similiar and you'll find them. I think Dave Fifield (sp?) is one of the people, but that's strictly from memory, I could be wrong.

It's doable for sure witout too much hassle.

[Alex Kirsopp]

Really? Great, thanks. I spoke to a couple anodizing/laser engraving places locally (non-paintball related) and they gave me the distinct impression that it would be very difficult to do this type of work.

Thanks for the quick response everyone!

[Scott Shepherd]

http://www.sawmillcreek.org/showthread.php?t=53911&highlight=paintball

[Mike Null]

I not so sure that's doable at least in one file. Judging from the picture the object can't be engraved on the rotary tool and if you wanted to engrave the sloping surface you would need a jig to permit focusing.

My machine will allow computer setting of depth and engraving by color but I don't see this as a one file job.

I would also be interested in Dave Fifield's comments.

[Joe Pelonio]

Do not let auto focus sway your laser decisions.

I wish you could buy a new laser without auto focus and save a few $$.

I removed my auto focus sensor long ago. I like the increased vertical clearance I have without it much better than I enjoyed the gimmick of auto focus.


I took mine off too. Have also done paintball gun parts. I made a jig so I could do 100 at a time. A little prep time save a lot of production time.

[Rodne Gold]

Your part looks a lot more curvy than the other paintball gun? so I dont see how the laser will work on that object with any ease
There is a limited "depth of field" to the beam , ie a portion where its power density is enough to make it work , and on a normal lens that would be like 4-6mm or so. If you surface varies more than that , you wont get good results. You might be able to position the part and use a long lens , with a greater "depth of focus" (a 4" lens will be 8-10mm) so that you can engrave it and minimise the variations in height of the part to less than the DOF. Even then , you might not get good results.
There is no laser in the class we are looking at that has a continously variable z-axis that will follow contours. You could do this another way by getting a 3d scanner , scanning the part and projecting the artwork atop it and then using a diamond burnishing tool in a 3 axis interpolation engraver
Your cheapest way would most likely be a Roland setup? Still wont be that easy tho.

[Scott Shepherd]

It really depends on what and where he plans to engrave, doesn't it. Yes, it's a curvy gun, but you could easily engrave many things on that gun from what I see. Certainly if you plan on doing things that cover high and low points, it could be an issue.

He didn't say what type of stuff he was talking about, so I'm not sure. Could just be people's names (not so bad), or could be complex art work, which, could be quite difficult.

Alex, what type of things are you thinking about engraving on them and where on the gun?