A part of my mis-spent youth was mis-spent aboard a crawligator. Crawligators (the original ones) are long off the market, so I decided to make my nephew one.
I found another DIY one on the net at : http://daddytypes.com/2009/02/23/can_your_mother_in-law_make_a_crawligator_this_awesome.php . I went in a somewhat different direction.
Step 1, rough cut. Step 2, measure kid. Step 3, tell kid he is too big. Step 4, choose final dimensions, make final cuts. Mine ended up about 20 by 9-3/4 by 3-1/2 inches [ 500 by 250 by 90 mm ], but I would actually make it longer – maybe 24 or 28 inches long [600-700 mm] if I was making it again.
Note that the slope blocks (the short pieces in the middle) are sloped, not square. Mine are sloped about 1/8 inch [3 mm] over their thickness. My pieces are about 7/8ths of an inch [22mm] thick, and 4 by 2 inches [100 by 50 mm] length & width.
Step 5, glue the slope blocks to the legs, then trim the top of the legs flush.
Note that the blocks are not flush to the tops of the legs.
I used a plane to trim the legs down once the glue dried.
Step 6, glue up the whole body. Note how the slope blocks provide a dished shape, which hopefully will keep the kid on board.
Step 7, paint. I used milk paint from Lee Valley, with some craft paints for the details. I covered that all with a coat of 100% Tung oil. The intent was a chew-safe coating….
Step 8, add foam and casters
I hope the intent of the slope blocks is now clear. The foam is nicely curved, and hopefully will keep the tyke centered.
The casters were from McMaster Carr, their “6460K11 stud mount ball transfers” type, which seem to roll nice and freely. They were screwed into brass inserts, which were bought at Lowes.
The foam is a reasonably stiff, close celled type I had lying around. I used Liquid Nails silicone adhesive to glue it on. Warning – it will not stick to oiled surfaces, so keep those surfaces clear of oil or sand the oil off.
Step 9, chase after kid. Hopefully.