[james2k]

Does anyone have experience cutting long objects with their laser using a pass through door? I'd like to be able cut long panels to make decorative door and window screens. The length dimensions would exceed the bed size of even the large cutters I'm seeing from G.Weike and the like. The material would be MDF and shouldn't be too wide for the cutting area of the larger laser machines but the length is way over the limit. Ideally, I'd like to be able to cut up to 48 x 96 inches. I'm hoping a pass through door is the answer since purchasing a laser with a bed table that size is out of the question.

My idea is to split the cut into two stages. The first half of the panel would be cut with the second half sticking out the pass through door. After the first section is completed, I turn the board around and cut the second file. My hope is with a level support surface and careful matching using the pointer laser, I could line up the two cuts on the single board without too much trouble.

I have some experience using smaller Epilog laser cutters but this kind of project is beyond anything I've taken on. I see plenty of machines that list a pass through door as a feature but I haven't seen anyone talking about actually using the feature, especially any reference to cutting twice on the same material after re-positioning. Anyone here have any experience with this?

Mahalo

[gweikelaser]

Hi Mahalo,
yes,with pass through door will make longer material more easier ,and our photoes for your refrence,the middle white door, can open for pass through,any others ,please feel free to contact us

Best Regards
Lucy Lee
G.WEIKE laser
[email protected]

Does anyone have experience cutting long objects with their laser using a pass through door? I'd like to be able cut long panels to make decorative door and window screens. The length dimensions would exceed the bed size of even the large cutters I'm seeing from G.Weike and the like. The material would be MDF and shouldn't be too wide for the cutting area of the larger laser machines but the length is way over the limit. Ideally, I'd like to be able to cut up to 48 x 96 inches. I'm hoping a pass through door is the answer since purchasing a laser with a bed table that size is out of the question.

My idea is to split the cut into two stages. The first half of the panel would be cut with the second half sticking out the pass through door. After the first section is completed, I turn the board around and cut the second file. My hope is with a level support surface and careful matching using the pointer laser, I could line up the two cuts on the single board without too much trouble.

I have some experience using smaller Epilog laser cutters but this kind of project is beyond anything I've taken on. I see plenty of machines that list a pass through door as a feature but I haven't seen anyone talking about actually using the feature, especially any reference to cutting twice on the same material after re-positioning. Anyone here have any experience with this?

Mahalo

[Rodney Gold]

Done it many times , the biggest problem is alignment of the other part , I would suggest you make roller supports either side of the laser which the board rests on and that has guide rails for easy registration , will stop any bowing or bending too. Use this rather than the laser bed as a support. Make em height adjustable to encompass focus and media thickness. Make sure your pass thru doors will actually allow you to achieve focus on the thickest material you use bearing your lens focal length in mind.
I did a roller/guide rail system on one of our lasers for engraving marble headstones and it worked a treat.
You will have a problem with your exhaust in clearing smoke if you do wood with an open machine , you might need a much more potent blower.

[pontiacg5]

To get the parts to line up you should cut a jig or something. I do this all the time with super cheap 1/4" ply. I usually just cut what basically looks like a square since the sides of my laser's table are out by a mile.

After you cut the square corner using the laser you will have a known good zero reference (the intersection of the x and y lines.) The whole corner will be perfectly parallel to both the X and Y axis. You can add some bolts or pins to the corner of the table as I did for this jig to line up against. Then, you can remove it and save it for the next time you want to run the same parts. If you keep the pins the same through all of your parts you can always reuse the same jigs again. All you would need to do to engrave something like an Ipad would be to grab the right jig, open the lasercut program using machine coordinates (Not set logic ORG, you need to use machine coordinates!) and go to town. I have some amazing results this way, and I'm almost to the point where I might try something crazy like an ipad without testing on scrap material first!

Personally, I would get a sheet of spoilboard and use some dowels or something to locate the part after you flip it. Cut or grade engrave some holes on your first engraving process and it will line up perfectly every time.

The red dot pointer is pathetically useless for alignment of anything. Don't count on it if you want things centered or anything. Trying to use it to line up two engravings will be far beyond impossible!

[james2k]

Pontiac and Rodney Gold,

Thank you for sharing your experience. I didn't realize the pointer wasn't going to be accurate enough. I'm not sure I follow 100% regarding the jig and the dowels though. The bolts and pins are mounted directly to the motorized laser table? Then the jig is bolted to the table when in use so when the board you want cut is inserted, it's perfectly aligned to the true machine 0,0 coordinate. Am I following?

I see how that will register the first cut on the x and y but how does it help lining up the second cut? If the board isn't exactly square, it seems like like spinning the board around to cut the other side and using the jig wouldn't necessarily mean the cut will line up. I think this would be easier to show in a drawing. I'll follow up with illustrations.

Rodney, I found plenty of roller supports. Did you make your own rails?

[pontiacg5]

Pontiac and Rodney Gold,

Thank you for sharing your experience. I didn't realize the pointer wasn't going to be accurate enough. I'm not sure I follow 100% regarding the jig and the dowels though. The bolts and pins are mounted directly to the motorized laser table? Then the jig is bolted to the table when in use so when the board you want cut is inserted, it's perfectly aligned to the true machine 0,0 coordinate. Am I following?

Yep, that's exactly what I was trying to say. I'm not the best at explaining things in text sometimes!

The jig doesn't necessarily need to be bolted to the table. One good thing about lasers is there is no cutting pressure, nothing will push the jig while it's being used so you really don't need to bolt it down. The dowels in the table I mentioned are only to give you a solid, non moving, reference point to slide the jig against.

I see how that will register the first cut on the x and y but how does it help lining up the second cut? If the board isn't exactly square, it seems like like spinning the board around to cut the other side and using the jig wouldn't necessarily mean the cut will line up. I think this would be easier to show in a drawing. I'll follow up with illustrations.

Unless your board is 100% true a jig of that type won't work, just as you have said. In this case I would recommend using the jig for the first half of the engraving. After the engraving is done and before removing the part from the machine cut two holes with the laser.

Now, you need some way to find those holes after the part is flipped. This is where the spoil board comes into play. Set the spoil board up so it can't move, either with bolts or just "butted-up" against the permanent dowels at the edge of your table. (If it does move you can always push it back against the dowels.)

Cut two holes in the spoil board, exactly the same as the holes you cut earlier and use one of the two as your new zero. Now you can stick dowels in the spoil board holes, flip your part and locate it on the spoil board with the holes you cut in your first laser cutting/engraving operation.

Rodney, I found plenty of roller supports. Did you make your own rails?

I was very disappointed with the extreme lack of ways to locate repeat work on my laser when I got it. The dowels are the best solution I've found so far. They're so simple and unobtrusive when they aren't needed. Wish I'd have thought of them sooner!

[james2k]

Now I'm getting it; the dowels become registration pegs for the new zero. I'm a bit of a novice so please bear with me. Lining up the holes with dowels makes perfect sense. It's a fantastic solution and exactly what I was looking for. For your spoilboard, did you just use a frame or a full sheet or material? I'm thinking about airflow and support of the board. I'll mostly be cutting mdf.

[pontiacg5]

The last time I dd something like that I was only engraving on some material around 8" wide. I just used another piece of the same material for my spoilboard, but I cut it to fit on the table as one piece. You need to keep stuff as level as possible, so you probably want to keep the spoilboard the same size as your workpiece.

The vacuum table works a heaps of a lot better if you cover more area. When I did this last I left an inch or two gap towards the front of the table to keep the smoke from getting at the tube. I was only engraving, if you were cutting I might run the same program or one that is slightly modified on the spoilboard to get some vent holes open.

Airblast is very very important on thick cuts. With the stock oilless compressor I could barely cut 1/2' MDF. I'm on shop air with a solenoid controlled by the laser now, at 50PSI I can walk through the same 1/2" MDF like butter. You'll probably need to have clearance in your spoilboard for this pressure, I could see it wanting to lift the part and push it all over if you didn't.

Hope all this is helping!

[james2k]

This is really helpful, thank you. It this point it looks like I'll have to experiment to see what works. My first concern was that it would have been prohibitively difficult. Now I need to figure out which machine will be best and make sure it can manage to still focus when using the pass through with 1/2 material.