Trimming from a larger piece than the bed?

qa

#1

I was looking into materials for the Glowforge and noticed that a 24" width is a fairly standard measurement when desiring material above 12". Would it be feasible (enough room in the bed) to place the 24" wide piece in the bed and trim to the right size? Since the laser has a 1/2" focus, if it is a tight fit, could the piece be placed at a slight angle (upward) and cut to the right size?

Thanks.


#2

Maximum diagonal for a 12" x 20" field would be ~23.33" (Pythagorean Theorem).


#3

We would have loved to hit 24" wide, but that would have triggered a whole different category of shipping charge that would have made it even more difficult to afford! So unfortunately no, you’ll have to get the material cut to 20" before inserting it.


#4

Super sad, as most materials come in sheet sizes that make cutting them 12"x24" super easy. That 20" is going to mean a lot of wasted material in my shop, and a lot more manual cutting of material that would otherwise fit. Unfortunate to cripple the product’s lifetime capabilities just to save on one time shipping.

Great example of this is we use a lot of thin plywood in our Epilog laser that we get cut from 4’x8’ sheets down to 12"x24" sheets with 0 waste.


#5

@chris I agree 12"x24" would be an awesome bed size and really easy. But I think one of the advantages of the Glowforge and the software (and cameras) is that the sheet size doesn’t really matter. You can just throw in an odd ball size and drag on a design to cut, heck does the piece even have to be a rectangle?

When I used my schools laser cutter for projects (not sure on make or model) I hated having to set up my job in their template that was always 12"x24" … especially when all I needed to cut was could be done on a 6"x6" piece. I felt super wasteful there because I was required to provided a full sheet no matter what I was cutting and to make it worse I couldn’t being back the partial sheet to cut another job. It basically became junk.

But then again maybe thats why this product is designed for the maker and not for manufacturing.

Not trying to start an argument, just the other side of the coin.


#6

Any reason you couldn’t just cut those 4’ x 8’ sheets down to 12" x 16" instead for 0 wasted material?


#7

Because 16" is less than 20" or 24" meaning less viable space for cutting parts, which restricts you to even smaller parts or smaller runs of parts. Both are less than ideal.


#8

Sure, I understand that, but that’s the tradeoff you make against wasted material. You have to choose one to optimize for, and in this case the concern you raised was one of wasted material. The wasted material here is a tradeoff you decide to make in the name of efficiency with regard to the number of parts you can cut on a single material change.

The good news is that you have a lot of options available. You could get the pro machine and run an entire 16" x 48" or even 96" sheet through the passthrough slot. With the automatic registration that the Glowforge can do, that should be pretty straightforward.

If you do need 20" x 12" parts, and are set on the Basic instead of Pro, you don’t have as many options. That said, unless that’s the only type of job you cut, I bet you can figure out ways to layout other smaller parts in the smaller sized left-overs from your sheet goods to improve material utilization.

If none of those is an option, and the material costs are high, the Glowforge may well not be right for you since the cost of wasted material would quickly overwhelm the cost savings for the lower priced machine.

Everyone’s use case is different, and it seems likely to me that you know everything I just said above already since you have experience with your Epilog setup. I just wanted to point out some potential solutions for other folks who may have less experience.

For me personally, the 20" x 12" size is just fine, considering I already have an X-Carve CNC Router (1m x 1m). The larger scale work will be done on the X-Carve and I’ll use the laser for more detailed or smaller work. I’m really excited about the combination of the two.

Anyhow, food for thought!


#9

Not accounting for loss due to blade thickness, a 4x8 sheet should yield Sixteen 12x20" sheets and Four 12x16" sheets.
If the first cuts are the long way…

I have been trying to think how I can use this to cut out my mag racer track (slot-less slotcar), and have the largest sections possible. I intend to do 20" wide by 20 to however big I can get sections with the pass through.

What I am curious about is, is the available bed actual 20x12? or is it some decimal larger, or smaller?
Is a 20.1 board going to fit, or will we actually have to cut them smaller then 20 to fit?


#10

How often do you really think you will need a full 12x20 sheet? If I were to buy a sheet of plastic in 24x48, I would plot out my cuts to optimize the stock before hand. But I still see the scraps being more usefull with the glowforges camera system.


#11

Making efficient use of scrap is something I love about GF - easy to nestle parts in between holes in other parts.