Large logo on small machine

[Tom Sieczkarek]

I have a large logo that needs to be lasered onto a 24" x 24" Wooden circular piece.
My eplilog helix (table is 24" x 18").
I was going to break the image into tiles and flip the piece to do the remainding 6".
Is this the best way to do it? I figured I'd ask here first as there I always find a "better way" on this forum after I do it.
I am a little concerned about aligning it when I rotate the piece.

[Ross Moshinsky]

Outsource the work. The chances of it lining up perfectly are slim. If it was a square, it would be easier to achieve. A circle, you're just asking for trouble.

Will the piece even fit in the machine?

[Dan Hintz]

If the design is not continuous, find a good breaking point smaller than 18" and break the design there... note the breaking line itself does not have to be continuous, i.e., created by a ruler, it merely has to be unbroken from one side of the piece to the other. A break line that travels 5" inwards horizontally, then jogs upwards a few inches before continuing horizontally the rest of the way is perfectly acceptable.

Alignment will be very difficult to avoid seeing a line if the design is continuous, however. In such a case, I would mount the substrate in a jig that covers most of the table and mark one side with a fine line (tape or whatever is handy). Use the laser to engrave a line on both sides of the jig at the halfway point. Engrave the top half, then spin the substrate around so it matches up with the mark on the other side of the jig. Engrave the lower half. I would suggest a couple of test runs at light power on tape to make sure the jig is properly sized.

It would be worth it for the right money...

[Mike Null]

I think it might not be necessary to make a jig. I would make marks E-W-N-S on the piece and align it with the rulers. I believe I would also engrave more than half on the first pass but I like the idea of an irregular line. If you happen to have transparent transfer paper that would be a big help in alignment.

[Martin Boekers]

Your set up for sandblasting, how about making a mask and sand etching?
It should be easier lining up masking "tiles" than playing with registration
on the laser.

[Tom Sieczkarek]

I did explain the lining up issue to the client. I had his design department come up with some overlay pieces that will make it look 3d. It also gives me some hidden break points. I am able to mark a cross in the center for re-alignment.I do like the jig idea for better alignment and painters tape is my best friend in these projects. I knew if I posted here there would be some great suggestions to help focus me in the right direction. Sometime you just over think these projects.

[Richard Rumancik]

I have made a large sign in two parts but in my case I can open the back of the laser. I used the ruler as a guide and lasered section 1, then advanced the part y" and moved the graphic in the file by y" in CorelDraw. (Of course you need some kind of break in the file or use white masks etc to separate into 2 sections.)

Quite honestly, if I had to flip the board around 180 degrees to do the second part of the image I would not even try, as the chance of success is very remote. You can't use the ruler method described above to establish a datum, as you would be picking up on the opposite side of the board when rotated. That edge will be offset from the centerline and non-parallel so in effect you would just have a random placement of the board. There is no simple way to reorient the part 180 degrees from the initial setup. Sure, I could come up with a method but would not be willing to put in a day's worth of time to do it; and it would still not guarantee that the join would be invisible. To do this properly, you HAVE to overthink it, or you will just waste your time and material. If the item is viewed at 20 feet then perhaps it is more forgiving but for anything else you need to reposition the item within a tolerance zone of less than .002 wide or it will show. This is not a simple task.

If you really want to do it, and are willing to position by trial and error, I would use a sheet of clear mylar taped over the board, rather than tape, as it is easier to see alignmnent (or lack of.) Then I would jog my image in x and y by .001" at a time till I was satisfied.

But there is still the problem of getting the x-axis aligned so that the first new line is parallel to the last plotted line. It would be bad to rotate the graphic in CorelDraw, so you would have to rotate the part instead till it is aligned with the laser axis. Otherwise, you will have a wedge-shaped overlap or a wedge-shaped "missed" area.

[Bill Gailey]

I noticed in your signature you various woodworking equipment. If you have the ability to cut the circle after the project is finished and you have a planer/jointer and a few other other tools then you can do this with 100% accuracy. No matter what size your laser there will always be a need for something bigger, trust me, I have the Epilog 120 with a 24x36 table and it is normal for requests to exceed size capabilities. Back to the suggestion. If you can create a panel or buy a panel that is about an inch larger all the way around you can set it up and cut the panel in half. Set up your art so that you can engrave to exactly the center on the first piece. On the second piece you want to engrave the second half plus an eigth so that you have engraved area to remove. Use the planer to take that piece down a few passes at a time until you have removed the excess engraved area and the 2 pieces align. At that point all you need is a biscuit joiner, clamps and glue to put the pieces together and everything lines up. Of course you will need to cut the circle out after that and put a lacquer or some finish once you are done.

I have used this process to make pieces up to 3 feet wide x 4 feet tall. It takes some patience but it works. Good luck!

[Joe Pelonio]

It's always good to have a business associate with a larger machine. You can still do the job and keep the customer, though make a little less by farming it out. I have a guy I use who is local and has a 24"x36" machine for this kind of thing. The customer doesn't need to know you didn't do it, but in this case he will let me use his machine and do it myself for a fee so I keep more of the revenue.