Precision Prototyping

[Joe Pelonio]

We eventually managed to get the file correct for fitting, and this job has turned into production work, as they ordered a thousand+. I have a couple of the completed items so I could see what they turn into (yellow things).

All of the ABS has a warp to it, probably came off a roll. After a lot of thought and experimentation, I came up with the idea of a hole in the center, and wiring it to the vector grid, which has worked out nicely. There is some
scorching on top so I apply transfer tape before cutting so the sandblasted finish stays nice.

[Dave Johnson29]

All of the ABS has a warp to it, probably came off a roll.

Joe, I think you will find it is extruded sheet with rolled texture on top.

[Joe Pelonio]

Joe, I think you will find it is extruded sheet with rolled texture on top.

I don't know how it's made, but every 12"x12" piece has the same domed warp, about 3/8" higher in the center. I didn't think it was actually sandblasted, it's just what they call the finish.

[Doug Griffith]

Hi Joe,
since the parts are rectangular with rounded corners, you could probably shave off a bunch of time and get better yield if you kissed the parts together. I would first cut all the radiused corners as small squares with the sides curved inwards (plus the holes). Then run a second pass with just straight lines in a back and forth grid pattern. It makes sense to optimize the cut paths for large quantities. Usually I run it as you have it because it takes just a few minutes to set up. Then, while the lasers running, I optimize the file for future runs.

Cheers,
Doug

[Doug Griffith]

Joe, I think you will find it is extruded sheet with rolled texture on top.

From the photo, the texture looks like what is called "haircell". It is the most common texture applied to ABS as it is extruded. The warping seems odd to me. I've seen literally millions of pounds of extruded ABS and it is pretty darn flat. It could be the sheets were left in the sun or possibly put in a drying oven at some point. I doubt it though.

[Joe Pelonio]

Hi Joe,
since the parts are rectangular with rounded corners, you could probably shave off a bunch of time and get better yield if you kissed the parts together. I would first cut all the radiused corners as small squares with the sides curved inwards (plus the holes). Then run a second pass with just straight lines in a back and forth grid pattern. It makes sense to optimize the cut paths for large quantities. Usually I run it as you have it because it takes just a few minutes to set up. Then, while the lasers running, I optimize the file for future runs.

Cheers,
Doug

I kept them far apart because they tend to flare up some even with air assist if there's a cut close by to let air in.

Optimizing would save time but then it's only about 20 minutes/sheet now and gives me time to remove the transfer tape and pack them up, and work on other things before I have to change material.