Just wanted to introduce myself...

[Travis Reese]

I've been reading this forum for a couple of months now even though this is my first post. Thanks to everyone who has taken the time to answer questions for those new to laser machines. The reason I've not had to ask any questions yet is because of those of you who have answered others.

I had been looking to purchase a laser for a while now. My purchase was for hobby use and not a business. Would I eventually like to recoup a little of my investment? Sure I would. But it's not necessary. While I've never worked with a laser I had a CNC Haas Mini Mill for several years. For anyone that knows the Haas machines you'll know that a mini mill by Haas is anything but mini for a garage workshop. I'm a tinkerer. I spent most of my time with the Haas making parts for my other manual machines. I read all the posts about the big 3 as well as the Chinese machines. I finally settled on what I think is a good choice for me and went with Ray at RabbitLaser in Ohio. The machine arrived about a week ago and sat in the garage waiting for his technician to arrive to set it up. I ended up buying the RL-60-9060. I needed something that would come apart to fit through a standard 36" door. The tech was finally able to come from Los Angeles to my house in Houston to get it set up yesterday.

So, now I have a laser! Let the questions begin! Again, I've done a tremendous amount of reading here. I'm doing my best trying not to ask questions that have been answered. I'm sure I'll manage to fail occasionally in that regard.

What I'm curious about at the moment is setting the pulse value in the LaserCut 5.3 software. The technician set it up such that when cutting a thin (guessing about 1/16") Rowmark that a drawn 1" square produces a part that's 1" square. Is that how machines are typically setup? Or should the part plus the kerf equal 1" such that the square left in the material is 1"?

[Kev Williams]

You want 1" to always equal 1", if for no other reason than text. Small offsets add up to large offsets after 900mm of table...

Kerf offsets caused by the laser are very minimal and are usually a non-issue. However, if you find it is an issue, you can use Corel's contour tool to offset your cut lines. An outside offset of .003" perfectly covers a .006" diameter laser kerf... :)

[Bert Kemp]

Hey Travis welcome to the forum and Congrats on your Rabbit Laser. Fine Choice:D as you can see in my Sig. I have one and have been very happy with it so far.As far as part size I would leave it the way the tech set it up. I haven't changed any settings it the year plus that I've had it. Kerf size will largely depend on how good your focus is. The better the focus the thinner the kerf and the better the part size accordingly.
I suppose if you want the part to be 1" sq then you would set the size in corel or laser cut so you get the size you want. If you find that you set it for a 1 inch part and it cuts a little smaller because of kerf then set the size a little bigger to compensate. It also depends on how accurate you have to be in what your making.
Don't be afraid to ask questions we all do and sometimes they have been answered . I find the search function here not a big help.

[Ross Moshinsky]

Most people operating a laser are not thinking about tolerances the same way a machinist does. When you bump the power, you'll see the beam get a big wider. When you cut, different materials, you may see slightly different kerf. You may find one side of your table cuts slightly different than another.

Basically, I'd recommend dialing down your machinist brain.

[Travis Reese]

I'm starting to figure that out. I guess I need to quit measuring to the thousands of an inch. Kev, you said you always want 1" to be 1". I agree, but should the part that comes out of the hole be 1" or should the hole be 1"? That was my dilemma. Seems like I need to quit worrying so much about the kerf.

[Braden Todd]

I'm starting to figure that out. I guess I need to quit measuring to the thousands of an inch. Kev, you said you always want 1" to be 1". I agree, but should the part that comes out of the hole be 1" or should the hole be 1"? That was my dilemma. Seems like I need to quit worrying so much about the kerf.

that depends on the part, do you need a 1" square or a 1" hole in the material? When I run parts that have a tight tolerance I adjust for the inside and outside cuts. Then you are guaranteed that you produce the cut that is needed.

Welcome to the group!

[Ross Moshinsky]

I'm starting to figure that out. I guess I need to quit measuring to the thousands of an inch. Kev, you said you always want 1" to be 1". I agree, but should the part that comes out of the hole be 1" or should the hole be 1"? That was my dilemma. Seems like I need to quit worrying so much about the kerf.

You bought a Chinese machine designed to cut and engrave. Expecting mill/machining like tolerances will just drive you crazy. You'll find certain things you can do with the laser that you never dreamed of doing with a mill. Go cut a letter A and check out the interior angles. They come to a point. Pretty amazing stuff when compared to cutting with a bit.

Every machine has it's pros and cons. If you need to cut a perfect 1" square, you can most likely do it. It will take a little tweaking and measuring, but you can get there. It's just not necessarily what the machine is designed for. It's designed to cut what 99% of the population would consider 1" squares fast with a much better material yield.

[Bob Davis - Sturgis SD]

Travis,

Welcome to the party! Anxious to see what you can do with the Rabbit.

Bob