Weight Capacity of Bed

qa

#1

Another thread discussing engraving got me curious about the weight capacity of the laser bed.

For example, a 16x20x0.5" piece of granite or marble is a little over 15 lbs. Steel would be about 45 lbs, although I don’t see a lot of 1/2" steel plate being pushed through :slight_smile: Obviously, things going through the pass through have the opportunity to weigh more.

Is weight going to be any kind of concern?


#2

Unknown. Pass thru is designed for 1/4" material. Believe I read that the opening is 3/8" but can’t confirm.


#3

Correct on passthrough, to my knowledge, but same general question will apply. Either way, I don’t think we’ve really seen any heavier materials placed on the bed.


#4

Pretty sure that it is:

Material being cut
Honeycomb
Crumb Tray
Plastic Shell

So your main question would be if you can put enough weight on the honeycomb to deform it (structurally, it is nicely built to distribute weight, so this would be a hefty number).

After that would be question if you place enough weight to drive the honeycomb into the crumb tray (this is made of a material which Dan said would stand up to hot embers dropping off cutting material, and the occasional beam passing through to strike it. So something strong-ish. So again, should be a high number.

Final question would be if the shell supporting all of this can continue to support all of it without buckling. But then the shell shouldn’t actually be supporting all of the weight, you should have a sturdy table immediately below the shell. So you are back to compression resistance. Plastics don’t fare quite as well here, but you have the weight distribution of the honeycomb and crumb tray to hopefully spread the load reliably.

I suppose if you have the air filter you have one last component to worry about between shell and table. This is the one place I would start to worry slightly. It is already supporting a 50 pound laser cutter chasis and guts. But should be designed to support everything on the outer walls, and keep the electronics and moving bits safe between.


#5

I wondered about this as well. I was thinking about getting those sawhorse looking things with the rollers for my pass through (pending wife approval of my upgrade) like we had in wood shop to support whatever weight I had at both ends.
It would allow longer materials to glide through as well as possibly keeping weight off the forge.
Thoughts?


#6

Roller supports might work nicely, but you’ll have to make use of autofocus because it’s almost impossible (my experience on wood) to get the vertical alignment exactly right.


#7

I am wondering if it would really be necessary or even helpful to have rollers for this, given that the material will be thin and light for the most part, which has a tendency to sag under its own weight. The rollers are a single point and have to be far enough away to support the material at its furthest out, and are no fun to use with thin flexible stock because it sags on the way out and so won’t play nicely with a roller you did manage to get set to exactly the same height as the Glowforge’s tray.
Also, not only is it frustrating to get the height right on those things (especially the cheap ones), but it can also be a bear to get them aligned parallel with the front/back of the machine, so that they don’t rack the piece off to the side as it goes across the roller. They make ones with the line of large ball bearings instead of a single wide roller specifically to avoid that issue, but those cost a lot more too, and still have the height issue.

I have been thinking it might be best to place 12"/30cm deep supports (or more if you need more support than that) right in front of and behind the Glowforge to support the extra material. If you have the means to build your own in-feed and out-feed supports, you could make them to the exact height needed, with a chamfer on the front edge of the out-feed one and a side rail on the in-feed one to keep the material aligned as you advance it. You could even use a length of a yardstick/meterstick as the side rail, (or use your Glowforge to etch measured markings into a plain wooden slat instead) to help you keep each material advance consistent.


#8

If you make these out of surplus smooth laminate countertop material it should be about perfect.


#9

I’m not sure but I think it’s about as much as a duck.


#10

Well that’s a lot of good points to think about now. Do you think having it inset into a table might be a way to do it? I saw someone do that with a planer type tool. Had a table made of a big solid core door and cut a big window out for the tool do drop into so the unit’s pass through could sit flush with the table top. Not sure what supported the unit underneath.


#11

I had thought about that option too, but then realized that whatever we use in front will need to be removable, in order to provide access to the larger front door to pull out the honeycomb & crumb tray when necessary for taller objects. I am not sure if they could also be lifted out through the lid opening or not, but the fact that they are including a slide out opening suggests that would be difficult at best.


#12

You’ll need some kind of lift. I wonder if the ones they use for sewing tables would do it. (Oops, a little checking says 40 pounds, so I guess we’ll have to design our own.)


#13

Failing that, you may also be able to make the infeed portion of the table removable to get access. I am leaning more towards having it either fold down out of the way or be removable with a storage slot under the table top. This would allow us to stand closer to the Glowforge when the pass-through is not in use, which will likely be most of the time. Easier on the back when enjoying watching it do its thing that way!


#14

We’ve only tested it with Proofgrade material - which is generally less than 2.5 lbs for a full sheet of 1/4" acrylic, if I remember correctly. It can likely handle significantly more, but I don’t have any data.


#15