First Laser Project, raises more questions

[Walt Langhans]

Hi Guys!

Well I found a place here in Atlanta that I could rent a laser, and I got my initial designs done.

DSC05076-001.jpgDSC05085-001.jpgDSC05081-001.jpg

In case you wondering what happened to the windows on the brick building, I was a bit heavy handed while cleaning the residue off it, and took a bit of the material off in the process. If your wondering what the heck the middle building is all about, it's a style called SteamPunk.

The material is 1/8 MDF, the laser is an Epilog 30 watt Zing 24 (07 I think).

While doing this I had a long chat with the Daniel (the guy who owns the laser) about the pros and cons of different lasers, and laser systems. The biggest thing that stuck out for me what how long it took the laser to get these jobs done. It was around 2 hours to get all that cut and engraved. I realize that a big part of that was the settings that we used on the laser, but it got me wondering how much faster a more powerful laser would actually be? Obviously the 30 watts handled the job, but after the initial "this is cool" watching the laser work, it soon turned into watching paint dry. Also, Daniel mentioned that the different types of laser tubes can effect how quick you can get a job done as well and that all laser tubes are not created equally so to say.

So... in a nut shell, now that you can see what I'll be doing, what kind of laser will get it done quickly, or at least quicker

Thanks!

[Steve Busey]

So... in a nut shell, now that you can see what I'll be doing, what kind of laser will get it done quickly, or at least quicker

There are only a zillion variables to that question, but the basic answer is: get as much power as you can afford!

[Joe Hillmann]

If your goal is speed it may be worthwhile to change the detail of the parts. The laser slows way down on curves compared to straight lines so the curves on the bottom of all those shingles and the circles on all the rivets add a lot of time. Also I would assume that of that 2 hours it took to make the parts only 20 minutes of it was actually cutting and the rest of the time was engraving the detail (I am assuming that you vector engraved the detail rather than rastored it).

With that in mind even if you step up in power you won't save a whole lot of time, the only place the extra power will make much of a difference is where you are actually cutting. With all those short lines and curves the laser never has enough time to get up to speed to make having more power make a difference.

As a side note I had played with making some castle toy kits and decided that If I wan't to actually make them to sell I will screen print the detail onto the wood then use the laser to cut the parts out. Of course using screen printing would mean you would have to do quite a few sets at one time to make it worthwhile.

[Bruce Dorworth]

Walt, Very cool!! I have an 80 watt laser and I think when doing the bricks and roof you can run faster with a more powerful machine. If you want someone to do a test send me a file and I will test cut it.

Bruce

[David Fairfield]

Ditto what Joe said. Everything you add to your graphic will add to machine time, its cumulative. You might save time by using commercial brick and shingle material. Architectural and hobby suppliers carry it in various scale. Also in some cases you can orient parts and use color mapping to take advantage of the side to side engrave speed.

Dave

[Walt Langhans]

Yes, the majority of the time was in the engraving. I was kind of afraid that the additional power wouldn't result in a big savings of time.

One of the questions I'm now debating is would it be better to get 2 lasers from some one like hurricane at $7-9K a pop or spend $20k on a single Epilog, Universal, or Trotec???

I read in one of the treads around here (it was about doing architectural models) that printing out the details was an option, but I don't remember if it was screen printing or not.

[Joe Hillmann]

Another way to speed up the engraving time may be to rastor rather than vector. On my machines rastoring thin lines doesn't look very good but on an epilog it may look okay. When rastoring I figure it takes about 10 minutes per square foot. Compared to vectoring where it can take hours to do a square foot if there is a lot to engrave. And since Bruce is offering I would suggest having him run the file and see how much faster an 80 watt machine is.

[Joe Hillmann]

Walt.

What are you planing to do with the models? I assume since you are looking at buying a laser to make them you plan to sell them? Also how big are they? I am guessing about 3 inches wide and 6inches long? Knowing the size and there final use may help people to give you ideas.

One idea, if they are as small as I think they are, is to use iron on transfers to put the detail onto the parts after you have ran the transfers through a regular printer.

Another idea, if they are larger than I think, would be to make stencils and paint the detail on that way.

[Walt Langhans]

Walt, Very cool!! I have an 80 watt laser and I think when doing the bricks and roof you can run faster with a more powerful machine. If you want someone to do a test send me a file and I will test cut it. Bruce

I think I'll take you up on that, thanks!

https://docs.google.com/open?id=0B_f...FFDbGhpSmN4Y2s

Walt.

What are you planing to do with the models? I assume since you are looking at buying a laser to make them you plan to sell them? Also how big are they? I am guessing about 3 inches wide and 6inches long? Knowing the size and there final use may help people to give you ideas.

The models here are examples of the styles that I'll be doing, the finished product (which I do intend to sell) with actually have a second layer of MDF that will be puzzle pieces, so you will be able to take the buildings apart for easy storage and transportation as well as make them bigger and mix the styles. I'm going back to do some more work next week and I'll post some more pictures so you can see exactly what I mean. The foot print of this building is 4 * 6, but the finished one will be in more pieces. I need the detail cut into the MDF because the people that buy them are going to want to paint them. They are people who like to build models from kits.

[Joe Hillmann]

I make quite a few wooden toys and before I start on them I have a price in mind that I want to sell them for. Lets say $5. When I design it, it might take 10 minutes to make on the laser. In order to sell it for $5 I have to get it down to 5 minutes to make, so then I start taking detail out of it and lining up the parts so they nest together in a way that one cut can be the ends of two pieces rather than one, and getting rid of curves in order to be able to make the toy in 5 minutes.

When I first started to modify my designs like that I felt guilty about producing something that wasn't the best I could make but my sales went way way up because I was able to price my stuff at a point that my customers were willing to pay. You may want to look into redesigning your items to see if you can make them quicker that way rather then by using more power.

[Bruce Dorworth]

Walt, do you have any idea how long it will take to do the wall that you attached? For a comparrison..

Bruce

[Walt Langhans]

Yeah... you and I think along the same lines. I have a pretty good idea what my people want, and it's what I made with the good detail. I too feel guilty not doing the best I can. And I know I can sell these around the $15 - $20 mark, so it's how quick can I get them done, or am I willing to let it take the time that it needs and set up a TV and lazy boy in the garage so I can kick back while I keep an eye on it to make sure the house doesn't burn down, lol.

[Walt Langhans]

For the individual wall, not a clue. I figured I'd see what yours did, then when I go back, run just that wall and compare.

[Rich Harman]

I ran the file on my machine. A couple of observations.

1. There are overlapping lines. The wall is made up of four sections, the ends of the bricks overlap.

2. The lines do not match up exactly. There are several places that that the horizontal lines do not meet evenly. So instead of the laser treating the two lines where they join as a single contiguous line, they are engraved separately making for a visible line where the laser stops/starts.

Total time, including cutting out the windows and the outline of the wall was 2:50. This was using a 2.5" lens. If I were doing more of this type of thing I would switch to a shorter lens (or use the beam expander) for finer detail.

[Walt Langhans]

Thank you very much Rich!

Before I did these I didn't understand that the laser will cut / engrave if there is more than one line. I'm going back and redoing a lot of stuff because it was copied and pasted and lead to things like that and the misalignment. But I wanted you to have the same file so I was comparing apples to apples.

And now for my next noob question. 2.5" lens???? and switch to a shorter lens or beam expander???