Monday 18 July 2011
James Hatter's fab toy for kids
The popularity of toy scooters is very evident, with the abundance of youngsters eagerly fizzing along pathways. A particular increase is with versions for children that can be enjoyed by three-year-olds, although some two-year-olds are getting in on
the act! With parental guidance, these are also a useful learning tool for
balance and coordination. A recent development has been the lean and steer type, with two wheels in the front and one at the back. These use a sprung pivotal system. Alternatively, a scooter with two wheels at the back and one in front gives a similar stabilising effect, but are steered in the normal way.
This project looks at two designs:
one with two wheels at the back and one in the front; the other had two wheels in the front and one at the back, although both versions had the normal steering function. Both versions have been tested and proved to be strong and stable in use, and both versions are described. Both versions are intended for three- to four-year-olds.
First, cut the deck blank to size using 12mm plywood. Then cut out the indents that will recess the rear wheels
A table saw can be used to remove the unwanted pieces, alternatively use a bandsaw or hand saw
Cut the front sides of the blank to a taper
Cut a reinforcing plate using 6mm ply and attach to the bottom of the deck using screws and adhesive. Make sure that the threads of the screws have adhesive on them to reduce the risk of a screw coming loose
The deck can now have the edges painted and varnish applied. Use safe water-based finishes. Cut support blocks for the rear wheels, using a hardwood for strength. Then drill 6mm diameter holes to take the wheel spindles
Attach the blocks to the top of the deck using adhesive and screws
Cut the components for the front steering column support. Use a hardwood for strength and durability
Drill the holes for the cross dowel bolts and cross dowel, plus an additional 6mm hole for a wooden dowel and one screw hole at the top. Add an extension piece to the front of the support
Drill an 8mm diameter hole through the front of the support to take the steering spindle. Round over the front
Assemble the front support using adhesive and one counter bored screw to attach the top piece to the lower piece
Insert a cross dowel and screw, and tighten firmly using an Allen key. When assembled, soften all edges
Insert a wood plug to cover the screw head. This method is used with most other visible screws to ensure the screws will not loosen
Support the front steering upright in a vice or similar, making sure that it is plumb. Drill a 8mm hole to a depth of 30mm, for the steering spindle
Cut the components for the front steering column. Cut matching size 20 biscuit slots and additional screw fitting holes. Drill an 8mm hole centrally in the small lower support block. This, together with the hole drilled in the front steering upright, are used to support the steering spindle
Join the components together using the biscuits and adhesive, and additional screws.
Join the final outside components then cover the screw heads with wood plugs. The completed assembly can have a clear acrylic varnish applied
Cut the handle bar support to size and use a 25mm Forstner bit to neatly bore the hole. Join to the top of the front steering upright using adhesive and screws
The steering swivel spindle is 8mm diameter. Use a plain rod if you have one available. Alternatively, use a length of 8mm threaded rod and wrap plumbers' PTFE tape around the threads. This will give a better tolerance and provide slight lubricating properties
Place the spindle in position with a washer at the top and bottom of the front of the steering column support. Engage the spindle in the holes drilled in the bottom of the steering shaft, and the lower support block
Push the lower support block firmly so that the front of the steering column support is a snug but free moving fit. Tighten screws into the block to secure in position
The wheel is positioned midway in the gap. Use an M6 x 100mm roofing bolt that uses nuts and washers to centralise and secure. Use a final nylon insert nut
Attach the bottom of the front steering support column using adhesive and the cross dowel fixings. In addition, a 6mm wood dowel is positioned between the cross dowel fixings
The rear wheels use M6 roofing bolts as spindles. PTFE tape is again used
Feed the remainder of each bolt through the blocks
Secure each wheel spindle in position, ensuring that the wheel can be rotated with minimal friction. Use a nylon insert nut and
a touch of adhesive to lock the wheel spindle in position
Attach a wheel shield strip into position
Feed a length of 25mm dowel through the hole bored at the top of the front steering upright, and secure with a screw and adhesive. The scooter is now complete
Construction differences for scooter with two front wheels
For the scooter with two front wheels, the deck is narrower and a slot is cut at the rear to take a single wheel.
The wheel chosen was a 50mm fixed castor. Alternatively, a larger wheel could be used and mounted through the slot, with support blocks either side.
Cut and attach a reinforcing plate to the bottom of the deck as with the other scooter, but making allowances for the single wheel.
The castor is fitted on with angled spacers which are glued, screwed and finally bolted in place, before a thin wood cover is added.
The angled spacers allow the wheel to be raised so that the deck is about 35mm above ground level.
Attach a wheel on each of the front steering column legs using M6 roofing bolts, washers and a nylon insert nut.
Attach the steering column support to the deck using cross dowel fixings and adhesive. And there we have the alternative build.