Page 1 of 1

Table material

PostPosted: Tue Mar 29, 2011 8:20 pm
by LeonS
I saw a screen door grill at Lowes HW for about $25 bucks that looked stiff enough and flat enough to make a good surface for the table. It is aluminum and has a honey comb look to it. I don't think it is just a perforated sheet, though. I think the material between the holes alternates between being dimpled up and down slightly.

This probably would be fine for solid material but might not work directly for paper, cloth, and other softer materials.

The good news is that the table will be flexible as far as working surface goes.

What were the rest of you planning on using in your builds?

- Leon

Re: Table material

PostPosted: Tue Mar 29, 2011 10:18 pm
by r691175002
I went all out and used aluminium honeycomb. You can see it here: viewtopic.php?f=16&t=391&start=10#p2424

Flexible Approach

PostPosted: Tue Mar 29, 2011 11:33 pm
by twehr
I am taking a more flexible approach. I want to be able to swap in/out different surfaces, depending on what I am working on. For example, anything that I am scanning (thin or thick) can live comfortably on 1/2" MDF or particle board. I plan to have several tops, with different jig setups for some of my standard projects. Put the top on, place the material into the jig, load the job and hit start.

For cutting, I am going to use true aluminum honeycomb - purchased at McMaster Carr. It is one inch thick and will easily support anything that my system is capable of cutting. The inch thickness won't steal any usable height, as I can cut anything over 1/4" or so, anyway.

So the obvious question is, how do I swap in/out these different tops? I drew up an idea last week. It works on the principle of having fixed positions for locating pins on the table frame. The table tops have matching holes. The pins are actually 5mm socket head screws with a 10mm x 5mm high spacer. The whole pin then is 10mm high and remains below the surface of the 1/2" table top material.

[photo - removable table top drawing]
Table Top Mounting.png


I actually implemented one top over the weekend and it works great. Since the spacers are plastic, I dropped the table top in, snugged up the 5mm screws just enough to slightly expand the spacer's diameter and it "locked" the board into place. I made a drilling jig so that the holes in the tops will always be located exactly where they need to be. Don't want to have to move the pins for the different tops - they have to be the same every time.

The only thing I have left to do is decide how to frame up the honeycomb so it can drop in as easily as everything else. I suspect some type of aluminum z extrusion frame with the honeycomb in the center.

One major advantage to this approach is the ability to remove the top altogether and pick up about 2.5" extra material height, when necessary - like when I want to drop in a rotary attachment.

When I get the cutter top worked out, I will do a post with pics of everything in action.

Re: Table material

PostPosted: Tue Mar 29, 2011 11:42 pm
by bdring
I think swappable tops is a great idea. My latest go around with the rotary attachment drops it through the table to get it lower. That gains almost 1.5 inches more in the diameter.

The only reason you need height for flat things is if you are engraving something thick, but that is probably rare.

Re: Table material

PostPosted: Wed Mar 30, 2011 1:40 am
by LeonS
I like Tim's approach too. The idea of making custom jigs, specialized beds, and the like is pretty cool.

Looking forward to hearing how it works after you get the kinks worked out.

Cheers,
Leon

Re: Table material

PostPosted: Wed Mar 30, 2011 1:43 pm
by hoda0013
@Tim: I really like the swappable table idea. I have run into a few instances when I would definitely want different table surfaces. My advice with the aluminum honeycomb would be to get the smallest cell size possible (I think McMaster's smallest cell size is 3/8"). I bought some 3/4" from a different company and it has proved too fragile to be of use.

Your multiple table idea reminded me of something I saw on the Trotec laser site. They have swappable table surfaces on some of their lasers for doing things like cutting, engraving, etc... However the feature that I really liked was a catch tray under that table that could easily be cleaned out. There's basically a flat surface under the table that can be accessed through a little opening on the side of the machine that allows the scraps on tray to be cleaned out. There is a video of it here:

http://www.troteclaser.com/en-US/laser_ ... dy500.aspx

It looks really slick and is something I wish I had included on my system. Nothing like having a bunch of kindling sitting in the base of your machine :lol:

Re: Table material

PostPosted: Wed Mar 30, 2011 2:07 pm
by trwalters001
Well that's just slickern' snail snot! :lol:

I've been wondering how I'm going to do my table since it's about 5 feet square...

I think I'll do it in removable pieces (2' x 2' maybe). But, I have to figure out a way to support those pieces too.

Tim

Re: Table material

PostPosted: Wed Mar 30, 2011 3:57 pm
by twehr
hoda0013 wrote:My advice with the aluminum honeycomb would be to get the smallest cell size possible (I think McMaster's smallest cell size is 3/8"). I bought some 3/4" from a different company and it has proved too fragile to be of use.


I bought the 1" - thinking the larger area allowed more less opportunity for trapped smoke to mark the underside of my materials. As to being fragile...I can see how that might be a problem if you were using it as an all-purpose table - meaning putting all laserable materials on it. It would be easy to damage it. Since I will be using it only for cutting paper, 1/8" plywood, thin acrylics, etc., I think (hope) it will be fine for that. I will have to remember to be careful when loading/unloading.

I like the idea of the removable tray. I'll have to give that some thought and see how I can incorporate it. The natural place to access it on the 2x would be from the left end. It could be as simple as a thin sheet of aluminum (1/32"-1/16"). Could try it without any sides. If too much falls out, a small lip might help. Of course, we would have to modify the left end skin to accommodate this, unless you only clean it out once a month or so, in which case you COULD just remove the skin for cleaning and replace it.

Another thought... Since I have removable table tops, I could also just pop out the top and use a shopvac to pick up the pieces.

Re: Table material

PostPosted: Wed Mar 30, 2011 4:05 pm
by LeonS
The shop vac would work unless the pieces that fell through were the ones you wanted to keep :)

The covered slot on the left hand side is a good idea.

Another idea would be to make the removable beds quicker to remove and replace. A 3D printed clip or two that could secure the bed on the table still using the registration pins would make removing the bed quick and easy. I am thinking a big binder clip might work in some cases.

- Leon

Re: Table material

PostPosted: Wed Mar 30, 2011 4:38 pm
by hoda0013
One other notable thing from the Trotec video is the ability to open up the cover on the back of the machine to allow a long piece of material to slide through. This could be useful to accommodate stock that was at most the full width of the machine, but longer than the full length of the machine. Technically you could handle a full width x infinity piece of material. I don't know how much use this would get, maybe for doing engravings along a long piece of material, however, the feature probably wouldn't be too hard to add to a new revision of the laser cutter.