I bought a wooden ladder toy in Mexico when I was young, in fact I have always — incorrectly — called them Mexican ladders. The toy had about 8-10 flat rungs over which a wooden peg would “climb” down. I have no clue where my old toy went, but I had it on my list to build one one day for my kids.
Last month Steve at Woodworking for Mere Mortals issued a challenge to shoot a video showing how the wooden ladder toy worked and seeing his failure to build one sparked my curiosity. So even though I didn’t plan on submitting a video, it kicked me in the butt enough to build one of my own. Above is a picture of my prototype ladder. Please excuse the picture quality, photographing the ladder turned out to be difficult. I think it was because of the angle at which I needed to use to get the entire ladder against the white backdrop.
I ripped the ladder rails from a 32″ long scrap of 1/2″ thick white lobby wood aka maple I found at Home Depot. To make the rails the same width, I built a quick thin rip jig (the final version will be the topic of an upcoming post.)* To setup the jig I used a 3/8″ brass setup bar and set the table saw fence so the edge of the maple was even with the brass setup bar against the blade. Then I tightened the jig and cut ripped the piece. To rip the second piece I just butted the maple against the thin rip jig and moved the fence over until it hit the maple.
*The one problem with this version of the thin rip jig was that I couldn’t move it out of the way when I was making the cuts. That made it harder to push the maple through.
I used the same setup to rip some 1/8″ thick strips out of a piece of 1/4″ purple heartwood.
Cutting purple heartwood is interesting. When it’s been sitting around in the shop for a while, it is a purple color. When you cut it, it turns a brownish color, but if you burn it while cutting, the burn marks are dark purple. Then it turns purple again after a while in the shop.
Rather than making a little slot for each rung, I just cut a groove along the inside of the ladder rails with a 1/8″ router bit. There must have been some internal stresses in the maple when I cut it because the thin strips of maple warped visibly as soon as I ripped them. To counteract this I had to keep the rails in check with two featherboards.
Even with the featherboards, it was hard to cut a clean groove down the center of the rails. The wood just didn’t want to follow a straight line. Even though I had the dust collection on, the thin groove became packed with sawdust and chips that were hard to remove.
Before I could put the ladder together, I needed to figure out how far apart to space the rungs. To make the pin, I used a piece of scrap 4/4 walnut that I got for free from Rockler because it was badly checked.
I trimmed the chunk to approx. 2-1/4″ long by 1-1/4″wide. Then I drilled two 5/16″ holes about 7/8″ apart in the on the center line of the pin.
I cut a slot from each end to the hole with my scrollsaw, and then used a file to file tune the size of the slot. Then I went back to the scrollsaw and opened up the end of the slot with some 60° cuts.
After determining what I thought was the optimal spacing of the rungs for the peg I just made, I cut a few spare rungs to act as spacers between each rung. Then I started from the top and glued the rungs in groups of two, clamping the sides of the ladder to hold them in place. To save time I only waited about 10 minutes for the glue to set before I started on the next pair.
I stopped after nine rungs. Then I cut the ladder to 20″ long, leaving 2-3/4″ past the last rung on the bottom of the ladder. This left enough room for me to mount the ladder in a base and get the peg out of the bottom.
For the base, I used another piece of 1/2″ maple that was 3-1/2″ wide. This width seem to be in good proportion to the width of the ladder. I drilled 1/2″ holes with a Forstner bit centered on the base to hold the ladder.
I originally made the base 6″ long, but the ladder was too stable — I’ve found that the peg walks down the ladder better if the ladder can rock a little bit. I ended up cutting the base to 4-1/4″ long.
Once I figured out the best length, I routed an ogee profile around the perimeter
To get the ladder to fit into the holes in the base I knocked off the edges of the bottom with a chisel. I just paired off enough wood to give the legs a good friction fit — I didn’t want to glue the base to the ladder.
When the ladder was assembled, I rounded the top and bottom of the rungs with a strip of sand paper to make the peg climb down a little smoother. The final result, the peg climbs down the ladder unassisted 2 out of 3 times, when it doesn’t it just requires a little nudge and it keeps on going. I spaced the rungs just slightly too far apart of the length of the peg.
Next time I make a ladder toy, I’m going to sand all the pieces to finish grade before I glue it together.