Status of Big Thunder 3/2023

Laser
#1

So because I don’t think I remembered to put a comment about this recently, I’ll go ahead and do that now.

Anyone who’s been near the lasers may have noticed that Big Thunder’s bed has been removed. We’ve determined that the fire warped it to such extremes that it was impossible to get any part of it to lie flat sufficiently to use the machine. That leaves what’s referred to as the ‘knife bed’ in the machine, which is a series of triangular slats. These can be used as a standard bed and cut on, so at the moment Big Thunder is up and ready for use.

If you need to do something smaller, you can either use Blitzen (or Donner once we figure out the chiller issue), or place it on top of some other sort of temporary backing material.

A request has gone out to Thunder to see about replacing the bed. So far no response. I hope to have more info on it soon.

2 Likes
#2

Does the temporary backing material need to be anything specific in order to avoid a fire?

#3

I would say just make sure that it meets the same standards as anything you’d put in there to cut or engrave. No banned materials, basically.

The ideal suggestion I’ve seen if someone’s planning on buying something, is that lots of companies make these perforated metal disks for cooking pizza, of all things. It should act very similarly to the honeycomb bed we’ve had to take out. But honestly, even something like a sheet of plywood would work fine, I’d imagine.

#4

I’ve laser cut more than one layer at a time before and it always results in a fire. That’s why I wondered if having a layer of wood under another layer of wood would start a fire …

#5

I’ve never personally experienced a fire using that technique myself, but I don’t think I’ve attempted it but once or twice. That’s… problematic, if it always results in a fire.

2 Likes
#6

I’ve been using thin stock. Perhaps that’s the problem. But I guess people should be alert to the possibility …

#7

I forget if the smaller Thunders beds are exactly 1/2 of Big Thunder’s bed size, but if so, it may prove easier (or cheaper?) to get two of those to sit side-by-side in B/T. (I assume they would be flat/level w.r.t each other.)

#8

They are not. 1600x1000 vs 900x600

#9

They are not. 1600x1000 vs 900x600

#10

I tried Big Thunder earlier today. The results were not spectacular.

I’ve included pictures of the 3mm birch plywood (bottom sheet was the backer). One pass only for the wood; the acrylic pieces took me several passes. Note that it did not cut all the way through the plywood.

I uploaded an archive containing the lightburn project file. If you figure out what’s wrong with my setup, post it!
aanne3_lbrn_proj.zip (9.1 KB)

rDSC07280
rDSC072801000×562 213 KB

rDSC07286
rDSC072861000×562 137 KB

#11

With the bed out of whack I wonder if anyone has bothered to check or refresh the optics.

#12

I am no expert in such things but I can not help but wonder if a new bed could be created in metal shop…

#13

We’ve discussed this between a couple members in the past. The answer is to a large extent yes.

I know a couple people are looking into some different honeycomb options that we could buy raw and then weld to a frame ourselves.

#14

Random thought: Would it be possible to mill one or both surfaces of the current one to flatten it? The SO3 is 32" - 33" wide and the Multicam is larger still.

#15

3 posts were split to a new topic: Donner - Status Inquiry 4/2023

#16

Just to be clear, we can use big thunder without the bed? There was a purple cone on top of the machine and the bed was out, so I wasn’t sure we could use it. This was last night. 04/27/23

#17

Interesting, the purple cone wasn’t there the other day.
If there isn’t a piece of paper next to the cone or blue tape with a reason and since it doesn’t seem to have been posted on here I’m going to say it’s fine…

And yes, you can technically use it without the bed. It has some quirks then since more stuff falls through. If you generate a bunch of mass, try to get a shop vac and reach down and clean up after yourself.

If there is a reason for a purple cone on it/it being down - please add a note to the machine, or create a issue report on here.

#18

My apologies, I forgot to write up the problem. I put the cone on top. Something is off with the bed leveling. I tried to do some engraving and cutting but the engraving faded the further to the right it got until it disappeared. Then on the cut, it didn’t cut all the way through but that was all the way around the piece, even in the areas it successfully engraved, it wasn’t a clean cut. It was pointed out to me that the bed is physically higher on the right than on the left if you look at the position vs the frame. Anyway, I’ll generate a repair request.

#19

I’m coming up today to do some maintenance. I’ll level the bed while I’m there.

Thanks for letting us know.

Chris

1 Like
#20

I did a test cut on BT on Wednesday, and the power was definitely down (50% lower) at the same settings compared to Donner.