Custom CNC Laser Downdraft Table: Design (Part 3 of 3)
I’ve now actually cut out this design in the shop, will be assembling this week so here is the final part of the design process behind the custom CNC laser downdraft table.
Another thing I saw on many downdraft tables are extra high walls to stop debris from flying all over the shop when using high RPM sanding and polishing tools, this will be no different, thus using the extension at the top-level for custom “walls” that can be easily used and put away when not needed on the side of the table itself!
By making these walls out of acrylic, no air will be able to go through it so in effect, the MDF suction will keep them in place while closing-up the sides from suction leak. These are 6 mm thick so they have some strength to them and they rest on the table tabs themselves all around. Easy to put together, easy to put away.
Where will those side walls be stored when not in use? Well, on the side of the table itself! So, they are easily found and put away when not required. This is ultimate efficiency! At the same time, I made a bottom acrylic plate inside the vacuum top so that there is no suction leakage there, so in effect, I’ve completely sealed the top box. I’ve also increased the strength further INSIDE the box as this is where there will be the most downward pressure while sanding.
At the same time, I did some measurements for my extraction hose and I’m using 2.5″ (5.1 cm) outlet so now I’ll be cutting the extraction hole exactly to spec while the outlines and other aspects of this table are done. It’s now a turn-key design!
I’ve now added the basket on one side of the table that will hold all the acrylic pieces when needed, found on the top of the table. I only have the basket on one side because I want freedom when sanding, sometimes I’ll have all the panels up for small pieces, other times, just one or two for larger projects.
That’s also the reason why I made the two acrylic side pieces different heights so I have a higher blast shield if needed. I’ve also increased the number of holes in the table itself for better air circulation.
I’ve decided to line the entire inside in 1/4 inch (6 mm) acrylic, this means that I won’t have to seal the MDF and at the same time, it adds more weight to the table (good thing in this case) and lots more strength overall.
Doing this means that the side panels can be modified as I don’t need them to be so big anymore. I’m thinking of just a simple slot-in system would work great. Where I will leave acrylic though is on the front – I’ll make that into a CNCROi.com sign!
I have a table “on top” with holes so I designed slots into it so that these pieces of acrylic can slide right in when I need them and put in the side when not. When I’m not using these shields, the holes left by these not being inserted just provide extra intake holes along the edges and when they are in, they are being sucked into the table. I’ve decided to put the piece of acrylic that was in the front actually inside the vacuum table like the rest of them, I’ll just engrave the face plate.
The back plate was made into a square to capture the most dust and will just be stuck on the back flush. I also made a bunch of additional alterations so that the new design worked in the real world and flushed other components to make assembly easier.
Next blog post will show the cutting through assembly of this Custom CNC Laser Downdraft Table.