[ASPHIAX]

Hello,

I just bought a Gweike 1290 60 watt laser and i am happily cutting and engraving!
I have been able to get a large order that requires small pieces to be cut out of acrylic sheet.
The problem I am having now is that the pieces tend not to fall out of the sheet but tilt causing the laser head or auto focus to sometimes hit the stuck piece and move the whole sheet ruining the cut.

I did get a engraving table but the laser beam is being reflected by the width of the table maze and actually recut the underside of the acrylic.

Does anyone have experience with building a new and good airflow grid/ raster/ laser cut table ?
If so, what material did you use, dimensions, colour of material, etc?

Any help would be greately appreciated!

[bradlar90]

Newbie here too so unfortunately I don't think I'm going to be of much help.

I cut on a honeycomb aluminium bed, which I think is what you're explaining, and the little burn marks on the underside bother me endlessly. Google something called a 'Vector Pin Table', which allows you to support the sheet in different positions and not interfere with the laser at all. They're available commercially, but I've often thought of creating my own. I don't think it would be too difficult.

Occasionally I'll make a "ghetto" vector pin table by engraving what I'm going to cut on a piece of card and then strategically placing small blocks of MDF on the card staying well away from the engraved lines. I then place the sheet to be cut on top of these blocks and cut out the design. You have to get a bit creative with focusing and aligning the workpieces but in the end the part and the leftover sheet should be supported and stay in place.

Can I ask, it sounds like you've been engraving without the use of a honeycomb table? What is the sheet sitting on when you do this?

[fishface]

If the material is being cut on the underside by reflections off the table then that suggests that you have the power setting way too high (or the speed to feedrate too slow). Suggest that you try decreasing the power until it stops cutting all the way through, then increase it back up a little and see if that's any better.

[ASPHIAX]

Newbie here too so unfortunately I don't think I'm going to be of much help.

I cut on a honeycomb aluminium bed, which I think is what you're explaining, and the little burn marks on the underside bother me endlessly. Google something called a 'Vector Pin Table', which allows you to support the sheet in different positions and not interfere with the laser at all. They're available commercially, but I've often thought of creating my own. I don't think it would be too difficult.

Occasionally I'll make a "ghetto" vector pin table by engraving what I'm going to cut on a piece of card and then strategically placing small blocks of MDF on the card staying well away from the engraved lines. I then place the sheet to be cut on top of these blocks and cut out the design. You have to get a bit creative with focusing and aligning the workpieces but in the end the part and the leftover sheet should be supported and stay in place.

Can I ask, it sounds like you've been engraving without the use of a honeycomb table? What is the sheet sitting on when you do this?

Hi,
Thanks for the reply and sorry for the late response.
Yeah i have a honeycomb table, The one i ordered with the gweike laser.
The width of the pockets is great but its reflecting so much I can see the honeycomb recut on the bottom of the acrylic.
I will look into the vector pin table!

[ASPHIAX]

If the material is being cut on the underside by reflections off the table then that suggests that you have the power setting way too high (or the speed to feedrate too slow). Suggest that you try decreasing the power until it stops cutting all the way through, then increase it back up a little and see if that's any better.

Hi, thanks for you reply!
I tried setting the speed faster or the power lower.
That ends up with lines on the cutline (almost like chatter on a cnc cut line)
The used the same settings on my cut bed but that doesnt recut the acrylic.

[indyglassman]

I've also heard that the issue is too much power (or too slow speed). So, out of curiosity I tried to reproduce your problem. I couldn't get the same result as you.

I use a 50W machine with a honeycomb table and haven't had that issue. I cut acrylic both with and with out the paper on. The only problem I ever have is the smoke residue on the top. But never a reflective cut on the bottom.

You didn't say if you keep the paper on the acrylic or not -- if so, is it cutting through the paper mask as well?

[Bigbird48]

Hi, thanks for you reply!
I tried setting the speed faster or the power lower.
That ends up with lines on the cutline (almost like chatter on a cnc cut line)
The used the same settings on my cut bed but that doesnt recut the acrylic.

I to cut acrylic with a 40 watt laser on a honey comb table and do not have that problem. You just have to keep messing with the settings. Buying another table or making something should be a last resort. Its just a matter of getting the right power and speed settings. Keep your speed at 100% and keep cutting pwr till you don't cut thru then increase pwr just a bit .