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View Full Version : Is there a better/faster way to do big jobs?



Robert Alexander
12-21-2007, 10:52 PM
Hi everyone,
I just finished doing a job for a customer, and it was larger than the table size of my laser, which is 24" x 18". The part was 20" x 28". The way I did it was to first put the exact size of the part in on the workspace in corel 12. Then I put in the vectored image exactly centered on the workspace. Then I laserd out the vectored image almost to the full width of the laser table. I stopped where there was a break in the image. I turned the part around and put the bottom half of the part (which has not been laserd) on to the laser grid. I then I send a 2nd job to the laser with the bottom part of the image, which I turned around 180 degrees in corel. This 2nd job I only do part of the image which is right next to the area of where the first job ended so I don't need to do the full half of the job and I do it at low power and 200 d.p.i. And before I start lasering I put a piece of paper taped down to the part, and only engrave the paper. I allways have to move the image in Corel a few times to get every thing to line up(this is where it takes me some time) with the 1st half of the part. Some times if I get nervious that I might accidently burn into the wood I put a piece of thin 24 gauge metal between the wood and the paper above it. Then once everything looks like it is lined up I take offf the paperand send a 3rd job to the laser and finish the last half of the part. So any input from fellow creekers on some possible ways to do it better? Or faster? whould be helpful.:D

Mike Null
12-21-2007, 11:36 PM
My way is similar except that I do the entire job in Corel positioning it with the work piece. I then create a "white box" in Corel to cover the portion of the drawing which can't be engraved.

I cover the part to be engraved with transfer paper and set my laser to test settings (low power and resolution) so that it will just mark the paper and I check for positioning. I then engrave, flip the drawing and the work run the test again for positioning and finish the job.

I forgot to mention--you did a great job!

Paul Brinkmeyer
12-22-2007, 9:32 AM
What I have done a few times is to lay out the whole job, find a good break point, and look for an area I can burn 2 dots at low power that will be engrave after I turn the part. Then I engravre the first half. I then just burn the 2 little dots in the feature that will be engraved on the 2nd phase. I burn the referance dots at low power and make note of postion. When I move the part I move it about the same in Corel. Now I look up the postion the dots move to and I put the red dot on each of the programed points and move the part to match. This works if I just move the part or rotate it.
I once had a really funny shaped part and had to do a rotate of 75 degrees for the 2nd phase, using this method worked the first time and no one could see any misalignment.

Stephen Beckham
12-22-2007, 10:00 AM
Robert,

I do about the same. First off - you dog.... I have the Mini 24 and only get 12 X 24 for the deck. I've had things as large as 26 X 25 1/2 in there.:rolleyes: And I stop to dream about the day when I've got my second laser that's big enough to put a Yugo in...

The main thing I count on is having my Corel CDR set up as a 12X24 to match my deck. So what I see positioned on the screen is pretty darn close to the same place on my deck.

Next - I create a box the same size as my item. Put my whole project to be place on the target in that box. Burn down to the 12" mark or a break point pretty close to it...

Group all the items together and rotate the 180 degrees on the screen. Your vertical positioning should be exact unless your rotation point is off center.

Turn off the X/Y on the Epilog. Put the part back in upside down. I move the pointer down to the last line/item etched. Using the X/Y position information from the Epilog, I draw a GUIDE on the screen at the exact decimal point of the Y position. I move the whole group up/down to match that item on the GUIDE as it lays in the laser. When I'm confident they line up - I ungroup all...

The only other thing you have to worry about is white box over stuff you don't want etched or using your PRINT SELECTION to select only the remaing items that need to be etched...

Boy I chose a bad day to quick sniffing glue... Have fun!:)

Mike Hood
12-22-2007, 10:46 AM
There are often arguments on here about the value of larger tables, but even with a 38" x 20" I run out of real estate all the time. I've had really good luck indexing parts through the pass through doors. You just need to place accurate index marks in a sacrificial area and register the part through in sections.

It takes a little forethought, but I've run single parts through that were over 9 feet long and 3 feet wide (UAV fuselage plugs). I've also used the screw points in the table bed as fixed index positions. You just need to bolt through the materials in predetermined positions and then index material in for the next cut. Really helpful for long pieces when working by yourself.

Gary Hair
12-22-2007, 12:35 PM
Like Mike, I have a 38" x 20" bed and doors front and back. I am in the middle of two projects that are quite large and the indexing was pretty simple.

The first is a 30" aluminum plate with about 28" of engraved area. I drilled and tapped holes in the back and fastened two plates on the back. One was at the very top edge and the second was 9.75" down from the top. All I had to do was engrave the top then slide the piece up until the second piece hit the upper ruler - perfectly aligned. This was very critical since I had to laser a mask, sandblast, apply cermark and laser the outline of the text and logo leaving the inside of the letters and logo sandblasted. A very cool effect and impossible without an alignement system of some sort.

The second piece is .050 aluminum that is 16" x 49" with 14" x 47" of engraved area. I used the same technique but instead of drilling and tapping, kind of hard on .050, I used double stick tape to fasten the indexing plates.

I'll post pictures when they are done - the 30" piece had to be redone - they mis-translated something into Latin and it has to be repolished and re-engraved - a costly mistake for them as the engraving alone is $450!

Gary

Mike Hood
12-22-2007, 6:23 PM
It would be interesting to see Gary.

I do mostly large cutting work and the ability to get oversize stuff into the machine is really important. I use the doors quite often. maybe it's because I have them... but I don't know how I'd get buy without them.

Bill Cunningham
12-23-2007, 10:09 PM
My Epilog TT table is 12 x 24, (rarely needed anything larger)but the odd time something long comes in.. The side of the TT comes off, and there is a hole you can stick things through, like a baseball bat, or paddle.. I took the side off the first time and thought 'hey' this is silly.. So I took it into the workshop and cut a hole in the side panel the same size as the hole in the side of the machine, when the panel is off. Now, because the TT cools by pulling air over the tube at the front, a hole in the side will reduce the airflow, and the cooling. The panel itself, is aluminum, so I used double sided tape to tape a 1 inch wide steel strip around the parameter and cut a piece of plastic for a cover, lined with sign magnetic to hold it in place when the hole is not being used... Now when I'm doing a paddle, I can half cover the opening with the cover, and a few more pieces of magnetic finish off most the opening, allowing the air to flow through the front normally, while the paddle or other long object sticks out the side.. By the way, if you have a TT and are going to do this, you can ONLY do it on the left side, the hole on the right side, is lower than the focus depth of the table and the side track hits the object before it gets to the focus depth..

Mike Hood
12-24-2007, 10:50 AM
LaserPro machines have drop down doors (front & back) that are a few inches wider than the width of the table (38"). You can loosen two screws and feed anything you want through the machine that will fit through that 38" opening.

The only design issue I've seen is the height of the doors. When cutting large sheets of 1/8" ply, the material obstructs just as the table is coming up for the top of an auto-focus. But, that's as simple as focusing the machine before feeding through the doors.

I cut UAV parts with mine and being able to insert long / wide parts on mine has always been a plus.