What are you using for a bed?

[ajf]

I've been having trouble finding a good material for a bed.  Tried hardware cloth and expanded steel, but they are both galvanized and the beam reflects and ruins the underside of cuts.  Haven't found a local source for honeycomb metal or even metal louvers for lights.

What are you using? 

[Jeremy G]

Well since I haven't cut anything yet. I was thinking of buying some honeycomb for the bed.

[LJ]

I was planning on buying the 12x12 3/4thick sheet from here http://www.mcmaster.com/#aluminum-honeycomb-sheets/=u8ouyz

Or I saw online someone using these instead.  http://www.homedepot.com/p/Simpson-Strong-Tie-MP36-20-Gauge-3-in-x-6-in-Mending-Plate-MP36/100374920 But they are galvanized so I'd be cautious of the zinc gas that is sure to offgas when heated if you don't remove the zinc beforehand.  An hour in vinegar should be able to take all the zinc off, then scrub off the surface rust and reoil to keep rust away.

I'm probably going to buy a sheet of plain aluminium and then use the honeycomb  or mending plates instead.  I need to decide if it's worthwhile to make or buy an adjustable z height table/bed.  I may go for building an adjustable focus lens holder like here instead https://www.youtube.com/watch?v=CC9kGOlxlHs

[ajf]

I hadn't thought to check McMaster. Kind of pricey though... I have a piece of perforated aluminum with 1/2" holes, but I'm not sure how that will work.  Used to have hundreds of sheets of perforated mild steel, but my dad was in my shop while I was on vacation a few years ago and literally threw them all away! 

I'm eyeing the air registers in my office's drop ceiling with ill intent...  Or, I might try stucco lathe from Home Depot, it's like $9 for a 4' x 6' sheet.

[ajf]

One of the 'egg crate' listed under 'returns' here might work.

[ajf]

After a bit of searching, I think I'm going to go with a pin table.  Had some N50 neodymium magnets (4x8mm cylindrical) which were not strong enough to use for making rod-ends for my delta printers.  Put three each on the heads of 3" screws that I had lying around, and ta-dah:

[Jeremy G]

Nice looks like it will work.

[ajf]

Worked quite well. Still having loads of issues with LMN Marlin, but I'm pretty sure this is the way to go for a bed, at least, for vector stuff.  I don't want to spend too much on the K40, but I plan on building a bigger cutter (1Mx1M?), with a more powerful laser (150-200W), and will include a pin table.

[Jeremy G]

Wow 200w, that's gana cost you a bit. Less you know whare to find a cheap tube with that much ouput power let me know. You gana do solid state or co2?

[DogP]

Currently, I just use sacrificial material underneath whatever I'm working on... but I'm thinking about using rivets as the pins in a pin table (ideally steel rivets so I can hold thin stuff in place with magnets).  I need to do something about an adjustable table first though.  I'm considering this: http://www.lightobject.com/Power-table-bed-kit-for-K40-small-laser-machine-P722.aspx# , and dropping rivets in some of the holes.

DogP

[ajf]

Yeah, I might be getting a little carried away. Actually considering making my own tubes. Have always wanted to learn glasswork.

[ajf]

I thought about getting that table too, but I'm now leaning more towards building my own.  

I started out trying to use pop rivets, but the ones on hand were too short and it have would taken more work/parts to get it working.

[ajf]

Was at a local carbon fiber shop today discussing another project and they hooked me up with some AL honeycomb for free! Now I'm going to have to get my lazy ass to work on building a proper motorized z-table.  Anyone roll their own yet?  I'm thinking of trying a scissor lift setup, seems like the simple route...