8020 table top instead of aluminum slab?

[analogman]

I am currently building a Data Cut machine, which calls for a 1/2" aluminum tool plate for the table top. It requires holes to be drilled and tapped for fixtures.

I spoke with some other users, and they would rather have a T-slot type table. So I am looking into using the 8020 stuff as a table top. It turns you that the deflection of the 8020 material (specifically the 1545 lying flat) is actually less than aluminum, as long as I can attach them together reliably.

Anyone else look into or use an extruded aluminum top? Pros and cons?

The size of the top is 38x60, and is supported by a frame of 8020 underneath.

thanks!

[PEU]

I did it, check my build log:
http://www.cnczone.com/forums/showth...=10927&page=11


Pablo

[analogman]

Nice build.

I wonder how it would work for a larger top - mine is going to be 60" x 38" and it will be holding the x rails underneath - anyone done something like this?

[MRM RCModels]

Originally Posted by analogman Nice build. I wonder how it would work for a larger top - mine is going to be 60" x 38" and it will be holding the x rails underneath - anyone done something like this?

I'm building a machine very similar to yours and have thought of using the 8020 as a table top as well. It will be very difficult to level the all of the rails while also controlling flex between them at the same time. You could mount the rails on the sides to the 8020 frame and use a sealed 5/8" sheet of MDF as a table top. You would have to strengthen the frame though.

Can't say that I don't understand why you want to do it. My 0.5in thick Al table top cost ~$1000 total. It's a little bowed in the center, but I'm hoping the frame and rails will true it out.

MRM

[analogman]

Now that looks familiar - have a build log going somewhere?

I spoke with Chris last night, he says he found the tSolt table a real pain, and that the flat table top with a pattern of holes much more useful as he can clamp anything down quickly with some basic flat straps, or quickly put down any jig or fixture he has, as some of the holes are used as known dowel pin locations. He really likes using a vacuum hold down.

Turns out the 8020 top would be around ~$800, the aluminum top ~$900

[Riceburner98]

Have you seen the T-slot table tops by Techno-Isel? I Just saw them the other day online, they look to be a pretty decent option, and you don't have to worry about joining small 80/20 sections... (I was going to use 1030 80/20 sections myself, then found a free 12"x24" "optical breadboard" which is a 1/2" thick AL plate with a 1" grid of 1/4-20 holes) The Techno-isel tables are all one-piece T-slot things that have also been milled flat..
The 375mm (14.76") wide sections are about $340 a Meter.. Don't know how that compares to 80/20 though..

http://www.techno-isel.com/LMC/Extrusions/

[analogman]

Hey cool suggestion. I would need about four 1m sections, which would total $1320. So about 400-500 more than 8020, but it would be flat.

[Riceburner98]

Dayum that's a lot of surface. You could fit my entire machine on the bed of yours. lol Also have to wonder how much shipping would be on 4 meters of the stuff...

[analogman]

Yeah, when I was deciding on which machine to build I was all over the map, from the fireball to big 4x8's. Turns out I could afford $6000, so that pretty well dictated this build. I'll get precision (for engraving and faceplates), but still can do a 1/3 sheet of ply for cabinets and large semi-hollow guitar bodies will fit fine.