Handmade using 5 main processes:

Sand casting
Tube bending
TIG welding
Turning/Lathing (turning down rods, drilling & tapping)
Milling (fishmouthing tubes, drilling & tapping)

Lyra’s Lunchbox

An elegant, elevated feeding station that holds my dog’s food & water bowls

Materials:

Welded steel tubing
356 Aluminum
Cherry wood
Steel rods
8-32 steel threaded rods
3/4" steel tube clamps
#14 steel phillips flathead screws

Inspiration:

Dogs mean a lot to me and have always been an important part of my life. I’ve had dogs my whole life, and tried to fill that void during college by dog sitting through Rover and volunteering at a local shelter. Over my gap year after high school, I trained sled dogs in Alaska and worked at a dog shelter in Guatemala. Dogs bring me so much joy, and it felt meaningful to dedicate a few months to making something for my dog, Lyra (center pic) —> and for all the dogs I have in the future.

Assembly plan:

Wooden platform with slots for the food & water bowls

4 steel tubes, bent and welded together

Tube clamps secure wooden platform to the steel tube structure

Steel cylinders press fit into tubes

Cast aluminum dog paws, screwed into steel cylinders

Process 1: Casting

I decided to sand cast dog paws to make my stand more whimsical and personalized for my dog — like a vintage bathtub with claw feet.

The first challenge was CAD — I ended up 3D modeling the paws using Blender (which I found easier to sculpt organic shapes) and then moving them into Fusion to slice, create exact dimensions, make it hollow & uniform thickness, and ensure proper draft angles for casting.

It took many attempts to sand cast my paws. The shape was complex, and I had issues pulling it out of the sand. I made a follow block to preserve the undercuts in my design, but the follow block kept sticking to the paws and getting stuck as I tried to pull it out. After many iterations and attempts, I finally had four decent cast aluminum paws.

3D paw model in Blender (top left), hollow & drafted paw model in Fusion360 (top right), paw model with follow block (bottom)

3D printing paw & follow block for casting pattern (left), Sand casting setup: two paws with a gate and runner between them (right)

Process 2: Tube bending

I used tube bending to create the legs/structure of my stand, using 1 inch hollow steel tubing. It took a few practice tries to nail the right angles and ensure that I was bending the two legs/shorter sections of the Us (pictured above) on the same plane. I ended up using a level to set it up (pictured below).

I also didn’t properly account for the bend radius in my calculations, which messed up my final measurements for the structure and affected my wooden platform, so I had to change some things later on to make it work (I’ll come back to this).

Me, tube bending (a great workout!)

Trying to get a perfect right angle bend

Leveling to bend on the same plane

Process 3: Welding

Step 1: I used an end mill to cut fishmouths into the edges of my tubes (bottom left pic)

Step 2: I practiced welding on smaller tube sections, creating mini right angle bend joints to imitate my actual weld constructions (bottom center pic). I attempted five oxy-acetylene welds and blew holes in almost every one before I decided to try TIG welding instead.

Step 3: I spent another few days learning to TIG weld and practicing on smaller tube joints. When the time came to weld my actual part, I felt very confident in my TIG welding abilities. I completed my first two welds beautifully and was very proud of myself (bottom right pic).

However, the next two welds were a lot harder. First, I had to do crazy setups to clamp the whole stand together and try to angle it so I could reach my weld joints (some of these crazy setups pictured below).

Also, at this point our lab’s TIG weld was being super wonky and nobody could figure out why. The electricity was sputtering around at the start of each arc. At this point I was all set up, and there was no other option, so I did it anyway… and made some very messy, ugly welds. Which means… more finishing!

Fishmouthing tubes on the mill

Practice welds on mini tube joints

TIG welding the first two joints

Attaching paws to tubes

Step 1: I used the lathe to turn down short steel rods until they were the right size to press fit into my tubes (which I tested a few times, starting with 3 thou larger than the hole, to find the perfect size).

Step 2: I drilled and tapped the steel rods and the tops of my paws (which I secured carefully on the mill using strap clamps) and screwed the rods into the paws with 8-32 threaded rods.

Step 3: I press fit my paws (with rods attached) into the tube legs. This was difficult, because I had tested my press fits on smaller sections of tubes, but when I tried to press fit the rods into the tube legs of the larger structure forming my stand, it was much harder to orient the stand in the press (because it was so big and bulky). I ended up using a hammer to press them in, which worked, but rotated the paws slightly as they went in (so they weren’t oriented the way I wanted them). To fix this issue, I used thread locker to lock the paws in the orientation I wanted.

Step 1: Turning cylinders for press fit

Step 2: Drilling & tapping rods & paws

Step 3: Press fitting rods & paws into tubes

Woodworking

As I mentioned in the tube bending section, I mis-estimated the tube bend radii (and also my welds weren’t perfectly straight), so it was up to the wooden platform, my final step, to even it all out.

Step 1: I cut a piece of paper to figure out the exact dimensions I would need for the wood to slot down between the long sides of my tube structure and rest on onto the lower, shorter sides (left pic).

The first piece I bought was too small (right pic), because the measurements had all changed due to my bend radius miscalculation, so I sold it and bought a new one.

Buying my wood

Cutting my wood to size

Laser cutting circle templates

Setting up my templates to cut holes

Sizing my platform with paper

Measuring my wood (too small)

Step 2: I used a saw to cut my new wood piece to size.

Step 3: I cut circles out of my wood for the bowls to slot into, which was not easy. I laser cut a hole template to guide the router, but it was super slow, so I tried a bunch of other methods. I ended up using a jigsaw to hand cut out a rough shape, and then finished them off with the router (guided by my template). Like everything else, this took much longer than expected.

Finishing

To finish, I angle grinded my messy welds to make the joints look smooth and perfect, and then wire brushed the whole tubing structure. I chose a wire brush finish because I like how it looks smooth and semi-matte. Also, the slightly lighter metallic color of the wire brushed steel matches better with the color of the aluminum paws.
I sanded and oiled my wood to bring out its natural cherry color, which matches my kitchen at home. Then I attached the wood to the tube structure with tube clamps.

Cast paws: filing, belt sanding, grinding, hand sanding

angle grinding welds

wire brushing tubes

oiling wood (& screwing it on with tube clamps)

I filed, grinded, and sanded my paws over the course of a few weeks. I was not striving for a mirror finish or a very high grit, just a natural, even, sanded cast finish. I wanted it to be clear that these parts are sand cast, and I think the slight impurities look cool – after all, dog paws are natural and imperfect forms.