A good number of projects I work on are centered around improvements in the robotics studio. In the studio I’ve got a decent number of tool-boxes, Mostly older Craftsman and Grizzly Industrial. Recently, during a reorganization project to make room for a new CNC lathe, I decided I wanted to add a bit more medium weight shelving for two of the toolboxes.
There are any number of ways to add shelving into the studio, and 1/2 of the choice to go the route that I ended up taking, was based on the way the shelves would look when completed. As such, the construction methods used here definitely won’t be right for others / most, this is just, ‘what I did’, not particularly a recomendation of what you should do. 
I started out in the garage where I hacked up some thick wall 0.125" x 1" square steel tube on the chop saw.
For a cut list I shot from the hip as I went knowing the final length / dimensions I had to work with, and that as long as all the cuts were the same, I could be off by up to +/- 1in and everything would work out fine.
The cut ends of the parts were then cleaned up on the 2x72 belt grinder. I also hit all sides, all the way down on the slack belt (up top) to clean up mill scale. It is hard to think how many years I went without one of these, belt grinders, and now here in the last few years since I picked this one up, I use in most of my projects, often multiple times per-procject.
Not time to sit back and rest, the next step was right over to setup and start welding! I’m using a fireball tools mega square to get things lined up. I had multiple of these clamped in there before I was ready to start welding. As you can see in the picture, for this project, I went with a simple ER70S6 MIG welding process. (0.030wire with 75/25 gas and contact transfer for penetration)
I’m definitly a hobby welder, but if you’ve seen many of my other projects posted here, you’ll know this weld passes as “good enough” in my garage. The design is such that all joints are fully ;welded=out’ on 4x sides to afford me the ‘medium’ loading weight on these shelves. Of course I went back and hit it with a wire brush after taking this photo. This is a raw picture right after I set down the MIG welding gun. I have no delusions of winning any internet beautiful weld awards, and yet, for a self-taught hobbyist, this makes me smile.
Once I had the frames dialed in square, fully fabricated and final dimensions measured I headed over to the computer to design the shelf-‘skins’ and some mounting brackets. It might seem a little backwards to do it in this order, but it leaves more opportunities for faster fabrication. Cut, measure and adjust as I go…
Mounting brackets: The two holes centered horizontally are so that I can add a rosette weld for extra strength.
Shelf Skins:
With two CAD files in hand, I pre-processed them into some G-Code. The brackets will be cut from 10Ga. material (0.135in) and the shelf skins will be cut from 14Ga (0.078in) material.
The G-Code is processed through a small program I wrote to add in all of the plasma control commands that my legacy CAD system does not know about. It adds in considerations for material thickness, material type, consumables, etc by varying travel speed, amperage and voltage in the G-Code and aksi inserts ohmic-touch-offs (G31 & G92 in z) and, pauses / moves away from the area just cut so that the torch doesn’t blast into the water table while clearing tip-ups. Kind of slick to have this all automated now, I used to do this by hand.
And then it was down to the 1/2 of the AVIDcnc set up with a water table for the plasma cutter. The torch heigh controller is engaged, zero’s are set using the laser on the plasma torch and everything is ready to run. If you care to see the laser alignment setup I posted a small blurb in the forums, here: https://forum.avidcnc.com/t/laser-alignment-guide-for-cnc-plasma/1450/2
I say it each and every time (and I’ve used this thing a ton since buying it in 2019) but that just never gets old. It is almost tooooo easy, and ever soooo fast!
No time to kick back and relax, these pieces came right off the water table, went under the chipping hammer for minor slag removal, over to the belt grinder for mill-scale removal and directly to the welding bench where they were attached to the frame. Slag removal is almost not a thing for anyting 1/4in or under if one takes the time to set the voltage, cut height, engage the THC use the proper consumables and get the travel speed right. I let the automated program do all that for me now and it is just a dream. I only show 2 of these above, but there are 8 of these parts in total. Yup, more welds, below that just leave me smiling.
After this I ran the frames into the studio, got them mocked up precariously on an Ice-Chest with some larger shop made machinist jacks and some Tupperware bins + 123 blocks. With this I was able to trace through the holes in the mounting tabs, onto the reenforced corner posts of each of the tool boxes, thus identifying exact alignment. That is just another fast fabrication technique that makes each one unique but I didn’t have to hit an exact dimension while cutting, welding, etc.
The corner posts on the tool chests were then drilled and 5/8-16 steel riv-nuts were inserted. These have a yellow zinc-chromate plating to give them a minimal amount of corrosion resistance over the years.
Here 1/2 of the riv-nuts have been installed. With Steel riv-nuts ~5/8-16 it is a good workout to install 16 total of these.
And a 2’nd check-fit, this time mounted into the newly installed riv-nuts.
After this it was back out to the the water tank on the plasma table side of the AVIDcnc to knock out some shelf skins. Mentioned above, this is 14Ga. (0.078in) thick mild steel.
In the Photo, below, you can see that I left corner notches in the shelf skins where they will go ‘around’ the welds in the frame. That way I don’t have to grind those welds flush and can maintain much more strength. It is just a cosmetic and design choisce that fit hand in hand.
This material was older and the mill scale was largely dried out (no oil transfer by touch) but I did not want it to interfere with the finishing steps, so I went ahead and hit each shelf skin with the burnisher to clean them up and prep them for the follow on steps. This import/clone/eBay special burnisher is pretty cheap / underpowered and it burns through motor brushes very quickly. I have nursed it along for the past ~8yrs. Seems like I repair it ~once a year and had to replace it completely here only ~3yrs back. Just this past fall, I went back and picked up an intermediate brand (Eastwood) burnisher, so it isn’t $1,400 but so far I’m reasonably pleased with it and it seems to be holding up better than the one used for this project. It is nice that I can use all of the same media drums on the new one.
And then it is time for some Cleco-magic and match drilling.
Since I had taken the time to put all the holes into the shelf-‘skins’ with the plasma cutter before cutting the outlines, it was easy enough to line them up, plop down the mag drill and match-drill through each of them, leaving a train car track of cleco’s behind as I went. The only tricky part is that I had to use a close tolerance hardened screw length drill to hit the target 0.133in size for an 1/8in rivet as I’m not going to (easily) be able to reach down in that steel tubing an put a rivet washer on the back side.
After this it was time for finishing. The frame received the rattle can dance with 2-coats of acrylic about 6-days apart with a 2-hr heat soak in the middle to aid in polymer chain cross linking and give it some extra hardness at the beinning of its life…
The shelf ‘skins’ were powder coated. These will receive much more abuse over the years as things are slid in and out of these shelves.
Red and black wouldn’t not be my first color combination choice, but they are ~sort of similar~ to the color scheme of the craftsman toolboxes (once that black fades in for a few years.) The powder is set to flow out at 450F for ~10mins and then reduced to 400 to cure (polymer cross chain linking similar, but much more so, to that of baking out the acrylic paint) for ~20mins.
Just a quick peek in the oven. The powder had not ‘flowed-out’ yet.
Color comparison. Not perfect as the toolbox to the left (not visible in this image) is ~40yrs old(first one I ever bought), and this one is 2005vintage. Close enough for the robotics studio.
Finally, it was time for installation. I seated the pop-rivets and knocked them all in. One thing that can be helpful is to install all the pop-rivets upside down (skinny end in the hole) all the way around all of the holes to get a good close general alignment, then go back one by one with a pair of pliers and flip each one over (fat end in the hole). The tolerances are very tight, since I had to use a close tolerance drill and cannot get a backing pop-rivet washer in there, and doing this working from one end to the other makes sure everything is going to fit up with the match drilling. Basically the same process one uses in laying down an aircraft skin on over a curved frame. After ‘ALL’ of the pop-rivets have been flipped one can come back and pop-pop-POP with the rivet gun. Some people also do the inital step with Clecos as well. Both work well.
I did this project in 2-stages. The first stage included the first two shelves, shown below:
In the 2’nd phase I made a 2’nd set of shelves to go with this first set. Since I didn’t want to tie these into the top-boxes, of the toolbox stack, this 2’nd set is designed to be free-standing with clips that lock into the shelf below, rather than screw into the tool-box from the sides, like the first set did.
This 2’nd set recieved all of the same match-drilling, finsihing/powdercoating, riveting, etc as the first two shelves. Black aluminum pop-rivets tie this all together. I also used black ABS end-caps pounded into the open steel tube ends. I could have welded these out, but these end caps are just fast/easy.
I have not yet fully loaded these shelves up yet. There is a large amount of re-arranging yet to be completed down in the studio. I unexpectedly had to replace and SUV so my new CNC lathe looks suspiciously like a Toyota SUV. It is kind of nice to have the extra time to finish out he studio re-org and I’ll bring the new CNC lathe in next year.
So, yeah, … definitely not the way most people will put up shelves in their studio/workshop, but this is the way I went for some extra medium duty toolbox shelves and it worked for me.
-Kenneth