Wheels for a Foldable Ladder

Folding extendable aluminum ladders are handy because they allow the user to configure the ladder to fit many situations. But, they are also awkward to move to the place where one needs to be used. I wanted to add wheels that make moving the ladder easy, but do not get in the way when using the ladder.

Materials

1. Two 5 inch casters (straight, that is: non-swiveling)
2. 3/16 x 1 inch bar steel
3. 1/4 inch rod
4. Washers and hex nuts

Tools

1. Hacksaw
2. Drill
3. Welder (optional)
4. Angle head grinder and grinding disc
5. Wrench
6. Felt tip marker
7. Spring clamps
8. Thread die for 1/4 x 20 threads and die stock

While the ladder is folded for normal storage, stand it as near to vertically on a floor as possible without it falling over. Place a caster over the lower part of the ladder just above where it meets the floor. Use a square to align the caster wheel. While holding the caster in place, use a felt tip marker to scribe the angle at which the lower part of the ladder crosses over the caster frame. See the second photo. Do the same for the other caster from the other side of the ladder. Notice the semi-circular mark. On my ladder there is a head from a pop rivet. I want to inlet an opening so the frame of the caster fits around that rivet head.

I cut a piece of rod to weld over the mark made with a felt tip marker. It will rest against the leg of the ladder to align the caster. (This is a nice feature, but not totally necessary. If you do not have a welder, and do not want to be bothered with it, do not worry about it.)

Grind a semi-circular opening. Fit it to the pop rivet head on the ladder legs.

It will be helpful to see the end goal so procedures make more sense. A "U" bolt of sorts will go around the leg of the ladder and pass through existing holes in the frame of the caster to hold the casters firmly in place. Notice the semi-circular inlet cut into the caster frame to accommodate the rivet head.

I could have purchased four hex bolts of suitable length. But, I have a welder and chose to make "U" bolt assemblies from flat bar and 1/4 inch rod I threaded myself with a die. Choose according to what is easier for you. Measuring indicated I needed bolts about 3 5/8 inches long. If you purchase bolts, look for 3 3/4 inches in length.

The die stock for holding the die is one I made for my own use. It holds a standard six-sided die. It is something I did because I have a welder and could do it. If you choose simply to buy hex head bolts all of this is of no concern to you.

The distance between the two holes that is needed to fit the "U" bolts on these casters is 3 1/2 inches on center. I tack welded two pieces of flat bar together, marked the centers with a punch, and drilled holes in both pieces simultaneously. Later I had to grind away the tack welds. Using flat bar for the transverse portion of the "U" bolts insures the ladder halves will close fully without interference from the "U" bolt's structure. See the photo in step 3.

I welded the 1/4 inch rods into the holes in the flat bar. The second photo shows the welded "U" bolt assemblies loosely fitted into the frames of the casters.

Hold each caster in its proper place and orientation. Slip the threaded ends of the "U" bolts around the leg of the ladder and through the holes in the frame of the caster. Use a locking nut; or washers, lockwashers, and nuts. Tighten sufficiently, but do not over tighten.

Grasp the folded ladder near the red locking knobs. Let your hands hang at your side. The casters should be supporting the lower end of the ladder and ready to roll when you pull or push the ladder. Move the ladder to the location where you want to use it.

The casters will be under the ladder. Push the red locking knobs inward until they click. Raise the end of the ladder that does not have the casters. It will click to a stop. While holding the end of the ladder push the red locking knobs in again. Continue to open the ladder fully as shown in the photo.

Walk the ladder up from the top end and maneuver it into the precise place you want it with very minor adjustments. I had to move the bottom end of the ladder away from the building just a little so the top would pass under the eaves and rest against the building.

To move the ladder back to its storage place, walk it down until it is on the ground as is the photo from step 10. Use the red locking knobs to fold the ladder again. Raise it by grasping near to the knobs. Push or pull the ladder back to its storage location.