I bought a copy of Ken Folk's book, to see what other plans he has for children's toys.
A couple of people on Lumberjocks.com have built this toy. They all "beefed up the design" so it would withstand play by children. The original design is pretty flimsy using 1/4" thick materials for most of the components.
I entered the design into Google Sketchup. I plan on beefing up the design, and adding spoked rear wheels to the unit(s) I am going to build. I can use Sketchup to easily modify the design, and print out full-scale paper patterns to make the parts.
I think 2 spoked rear wheels will "dress up" the design of the toy. The plain design rear wheels are 1-5/8" diameter. I will change the design to fit 1-3/4" spoked rear wheels.
I went ahead and tried to draw the spoked wheels in Sketchup. It does not handle small parts well, and you usually have to scale them up 10X or even 100x, to get the Follow Me command to work..........then scale them back to original size. I tried this and the program would hang up and never reach a solution after executing the Follow Me command. I Googled it, and discovered you should reduce the number of elements in any curved lines to make it work. I reduced the number of circles in the arc to 30 versus 200.......and Voila..it worked!!!!!!
I think the 1/4" thick parts are too flimsy for a child to play with and abuse the toy. I was going to increase the size of the 1/4" thick parts up to 3/8" thickness, or scale them up by a 1.50 factor. Then I thought, why not just scale the whole model up by 1.5X, which avoids a lot of design time in Sketchup (if you change the part thickness, then for example the dowel diameters stay the same, etc). So I decided to build a model at 1.5X scale of the original pattern.
I also decided to paint my model, so I am using plain pine for the parts.
On the other parts, I used my 14" band-saw when I could, then used the scroll saw where I could not use the band saw.
While I was doing dry assembly fit-ups, the main body of the bicycle broke where it has the notch to fit into the vertical forks. This is a short cross-grain area, therefore inherently weak. I glued it up and repaired it. We will have to see if it holds up being played with by the grandchildren. If it breaks, it would probably be best to replace it with 3/8" thick plywood, since I am painting this toy.
The spoked wheels come with their axles. The wheel is supposed to spin freely on the axle, but they lock up if the axle pin is pushed all the way in. I used a round hand rasp to slightly enlarge the axle hole in the wheels, then they spun freely.
I used these paints from Hobby Lobby to paint the model.
To see this model in action, I made a Youtube video.........
This was a fun little project to build. The finished toy is pretty sturdy, since I doubled the scale size of the original pattern. The pieces are now 3/8" versus just 1/4" thick, and are much stronger.
Using the oven at about 115F to dry the glue and painting, really speeds up the assembly of the toy.
I am going to have my grandson try it out as a pull toy version first. He is able to break about any toy, so this will be the real test to see how well it holds up over time!!