Mobile Food and Apple Grinder Cart

Before building my biogas generator, I wanted to build an apparatus to grind up all the kitchen scraps and yard waste that I intend to put into the generator. Garbage disposal would do nicely. I also make hard cider, but I didn't want to use the same garbage disposal for grinding apples that I use for grinding kitchen scraps. Second garbage disposal would do nicely. Solution: Dual basin stainless kitchen sink I found on Craigslist. Bonus, the sink came with a working garbage disposal. Just need to build a cart for it, so here goes.

Once I got the sink, I measured right around the mounting rail on the underside of the sink's lip. The cleats that would normally grasp the underside of a counter needed something else to grasp here, and I didn't want to go find a whole section of countertop, so I cut some 1-inch wood trim to those dimensions. I then glued and nailed those trim strips to 1x4s that served as the upper frame for the cart. I built a lower frame out of 1x4s in identical dimensions to the upper frame to help provide stability to the cart.

Note in the detail photo of the upper frame that I notched the center 1x4 for the sink's mounting rail. As it so happened, I made the notch deep enough to pass the wiring for the garbage disposals through it as well, which will help keep the underside neat when I go to route the wiring.

If there's enough demand, I'll make up a diagram of the frames with dimensions.

I had to mount and unmount the sink to the upper frame countless times through this build. Easiest way to do it is upside down on a workbench (or, in my case, on top of an old dishwasher in the garage) - that gives the best access to the sink mounting cleats.

With the upper frame mounted to the sink, I clamped four 2x4s to each corner to serve as legs. This cart's going to have wheels mounted to the legs, so I made sure to orient the 2x4s as seen in the photos. With one screw holding each leg to the upper frame, I placed the lower frame over the legs and clamped/screwed the lower frame to the legs. Everything ended up square enough.

I used a couple Tractor Supply pneumatic tires (4.10/3.50-4), bolted to two of the legs. To make sure the bottoms of the legs cleared the scrub radius, I put scrap 2x4 sections under each leg before measuring for the axle holes. That conveniently left a 2x4-height void beneath the other two legs, so I added a crossbar both to brace the legs and to make the cart even.

Took it all apart. Stained it. Put it all together.

The stain's to make this thing last. I'll be using water to flush the disposals, and I know I'll spill a lot. Plus, I plan on wheeling this thing out to orchards come apple-picking time. No bare wood here.

I decided on combination switch outlets - one for each disposal - largely for straightforwardness.

There was plenty of space between the backside of the sink and the upper frame to mount both switch outlets in basic electrical boxes. As I mentioned before the notch in the center 1x4 on the upper frame worked well for concealing the wiring that ran between the two.

Note that I made sure to orient the switches so they're off when facing in. In an emergency, I would rather push the switch in to turn the disposal off than take that extra half-second to fumble around with pulling it out.

The switch outlets, by the way, are rated for 15 amps. I only plan on using one at a time anyway, so that shouldn't be a big deal. If it does become a big deal down the road, I may add a GFCI upstream of the switch outlets.

I'd seen this concept executed in RVs and thought it would work well here. As mentioned before, I only plan on using one side of the sink at a time, so I cut a piece of 3/4-inch plywood I had to fit atop one side of the sink, then cut a couple 2x4 remnants to fit just inside the sink. Glued them together. Stained the underside and soaked the top in food-safe mineral oil.

I won't be plumbing this cart for water, so I filled all the faucet holes with chrome plugs. The center 1x4 in the upper frame runs right beneath one of the faucet holes, so I clipped off enough tangs in the plug until it fit.

The disposal that came with the sink I'll use for kitchen scraps and yard waste. Pro tip: Clean it out before testing if you don't want ground up spiders shot out the outlet. I added a piece of plumbing I had in my scrap pile to direct the output past the lower frame. Perhaps I could have thought through placement of the lower frame a little better, but this works.

The brand-new disposal will be for the apples. That one, a stainless steel 3/4 horsepower continuous feed unit, I selected based on the recommendations at Whizbang Cider.

I considered something as simple as a bathroom grab bar for a cart handle, but I had some random black pipe bits laying around, and 3/4-inch black pipe, done just so and angled outward, could provide both handles and a means of stowing the cable neatly instead of in one big rat's nest.

Stopper to fill up a sink when washing apples. Stuffer to stuff stuff into the disposal. Strainer to separate out the larger debris, post-grind.

All set to pulverize any weed that dares grow in my yard and turn any apple I pick into mush. If I think of it, I'll grab a video of the thing in action and post it here.