Introduction: Cooler Cart
So you have a nice big cooler and it is awesome... except when you fill it with ice, beverages, and snacks it weighs nearly 100lbs! It makes you sad because you want to take your cooler with you on outdoor adventures but it is unrealistic to carry that much weight very far.
Solution: Make a simple, cost effective, and robust cart to carry your cooler!
Skills Needed: Basic understanding of how to safely use battery powered saws and drill.
Personal Protective Equipment Needed: Safety Glasses (always), dust mask (use when spray painting hardware), hearing protection (use when sawing).
Step 1: Gather Tools and Supplies
The supplies and tools outlined below are just what I used to complete this cart. I think there is many different ways to complete this project and be creative in the design and fabrication of it. All said and done it took me about three and a half hours and cost me about $50.
2 Boards - Dimensions: 1"x6"x8'
2 Boards - Dimensions: 1"x4"x8'
2 Casters with Large Diameter Tires
1 Piece of Rope - Dimensions: 1/2" x 18"
1 Piece of PVC - Dimensions: 3/4" x 6"
8 Bolts - Dimensions: 1/2" x 2.5"
8 Washers and Lock Nuts
A box of #6 x1.5" dry wall screws
About 10 #10 x 1" screws
A Can of flat black spray paint.
Some kind of saw for cutting boards to length (I used a cordless circular saw and reciprocating saw)
1/2" twist drill bit
3/4" Spade, forstner, or twist drill bit
Two 3/4" wrenches (or other tools to tighten and loosen axle bolts on Casters)
Step 2: Disassemble and Paint
The casters and hinge were originally a shiny silver but I really liked the idea of flat black hardware. So I disassembled and painted them. The disassembly only required undoing the lock nuts from the bolts used as axles in the casters. I then prepped the casters for paint by taping the surface on the axles that contacts the bearings inside of the wheels. I also stuffed paper towel inside the bearing area on the wheels themselves. This was done to eliminate any interference issues upon reassembly. Usually it is a good idea to protect threads while painting as well but in this case I wanted the end of the axle that stuck out of the lock nut to have the same flat black tint. Besides a sticker removal the hinge was ready for paint when bought.
Painting was done in three coats applied about fifteen minutes apart.
Step 3: Measure, Measure Again, Cut and Begin Fabrication
In between coats of paint I was very carefully measuring my cooler and planning my design.
It is important to remember that the sides of the cooler are likely tapered. The boards forming the outer walls of this cart are 5.5 inches wide (even though they are advertised as 1" x 6") so I measured the length and width of the cooler at 5.5 inches from the bottom of the cooler. To increase the rigidity of the mounting points for the casters I wanted to use two 1" x 6" boards fastened together with the 1.5" long drywall screws. The bottom runners are made of two 1" x 4" boards fastened together with 1.5" drywall screws. The bottom runners were double up to increase rigidity and toughness of the frame.
In order to accommodate the height of the casters the end plates of the cart were mounted to the top of the bottom rails This means I needed to add an addition 3.25" (the boards are actually 13/16" thick though nominally advertised at 1") to the measurement of the length of the cooler. Follow the old rule of "measure twice (or three times) and then cut" and you will do great. If you are really unsure lay uncut boards on the ground and physically use the cooler and other boards as a jig to triple check your measurements.
Once you are satisfied with your measurements cut enough pieces to put together a working prototype and see if your cooler will fit. If it doesn't you will not have cut all your material and can make subsequent adjustments.
In my case I realized after assembling the bottom rails and end plates that I had not accounted for the drain on my cooler. So I measured the distance from the bottom of the cooler to the drain and then marked this distance from the top of the bottom rails on one of my end plates. I used a combination square to mark out a correspond drain slot and a reciprocating saw to make the cut.
Finally, I attached the side boards and the main box where my cooler would sit was complete.
TIPS: When cross cutting boards with a circular saw it is a good idea to speed up slightly at the end of the cut. This will reduce the chance of the board binding against your saw blade helping eliminate tear out at the end of the cut.
It you want here is a really good video with some useful tips:
Step 4: Mark, Drill, and Mount Casters
The first thing you will want to do is reassemble the casters.
After the casters are reassembled set the frame flat on a table like it would be sitting on the ground. Determine the horizontal mounting position you like for your casters. Generally I would encourage anyone using this guide to mount the casters as wide as possible. Extra width will make your cart more stable on side hills and uneven ground. The vertical mounting position will be determined by the diameter of the wheels on the casters as well as the mounting geometry of the caster's frame. The goal is to have the tires just touching the ground when the cart is sitting flat on the ground.
Once you have your casters positioned just where you want them mark the mounting slots or holes using a sharpie, pen, pencil, etc.
Make sure you leave enough room for subsequent drilling of mounting holes.
Drill a small pilot hole using a 1/4" drill bit. Using the smaller drill bit will allow you to be steadier and more accurate with the positioning of the hole location. With pilot holes complete you can now drill out holes to their final dimension which will be slightly larger (1/16" - 1/8") than the diameter of the bolts you chose to mount your casters. To prevent tear out when drilling these holes you may want clamp a piece of scrap wood to the back side or your hole locations.
Use your drill and 3/4" twist drill bit, spade bit, or forstner bit to be able to create countersunk pockets for the caster mounting bolt heads to sit flush inside of the main frame (this will prevent any marring, or scratching on your cooler). If you end up using a regular 3/4" twist drill bit to countersink the holes you need to be cautious of the drill bits tendency to grab and twist your wrist or the work piece. To avoid problems like this be diligent in stepping up drill bits (start with a smaller bit and slowly work your way up to the desired larger hole).
With holes complete go ahead and mount the casters. To make your life easier you may want to use a ratchet with an extension to tighten nuts on mounting bolts. However if you do not have a ratchet no worries two wrenches of the appropriate size (or adjustable) will do.
Step 5: Getting a Grip!
To be of any use this cart is going to need a handle.
The design of the handle should be structurally sound, ergonomic, and able to be folded back for storage when the cooler is not in use.
The handle is made of two 1" x 4" boards fastened together with 1.5" drywall screws.
The hinge is standard hinge used on garden gates (Can be purchase at any building supply store). It is mounted to the bottom side of both the handle and the main frame. For storage it folds back completely out of the way. To mount the handle measure the front face of the main frame and mark the half way point. Do the same thing for the hinge. Now match the marks and fix the hinge to the main frame with #10 X 1" screws. Finally mount the handle with the same #10 X 1" screws.
The grip is made out of the 18" piece of 1/2" nylon rope and a 6" long piece of 3/4" diameter PVC. Drill two holes slightly larger than a 1/2" in the end of the handle. Feed the rope through one hole then through the PVC tube and then through the other hole. Tie a knot at each end of the rope. To better secure the knots use a lighter to slightly melt the knot together. Try to keep the flame away from the handle so you do not char the wood.
Step 6: Finishing Touches and Fill the Cooler
Finally cut some foam noodles to fit the perimeter of the cart that will come closest to contacting the cooler. Fasten the noodles with some more of the #6 X 1.5" drywall screws. This will protect your cooler from any scratches and keep the cooler from sliding or shifting in the main frame when you are wheeling all over the countryside with your cold beverages.
The design of this cart will allow it to roll freely when the handle is lifted but remain stationary when the cooler is allowed to sit on the wood frame. This design is robust and should have plenty of structural integrity even if the heaviest of your friends decides to sit on the cooler.
Whewww, you've worked hard making this cart and now its time to enjoy. Set the cooler in the cart, fill that bad boy with ice, beverages, snacks, and go exploring!