Summary

A toy made for my friend Dan, and mostly his 4 year old. They're both fans of the Ben 10 cartoon.

This is a watch toy, with a rotating dial and 10-step clicky ratchet. The ratchet is a cute mechanism and you might borrow that for elsewhere.

Instructions

Construction is simple, but it does use rather a lot of different materials

2mm fluorescent green transparent acrylic for the disk
2mm black acrylic for the triangle plates and main plates
3mm green or black acrylic for the spacers
4mm and 3mm acrylic rod for the pins
One small tie-wrap
Wide velcro for the strap. I used 2", but you can use smaller. Then you could even make the whole frame narrower.

The acrylic colours and thicknesses aren't crucial, but the spacers need to be a bit thicker than the disk to allow clearance. The Ben 10 colours are black and green and who doesn't like fluo green? The acrylic rod pins could easily be resized to use just one material.

The Corel Draw file has the whole thing in layers to show assembly, then separate sheets for cutting each colour. There's a PDF too, but it doesn't show the layers so easily. It's all easy vector cutting work.

Cut the pins to be about 51/2 sheet thickness (4 for the centre pin) long. Round the ends neatly on sandpaper and polish them a bit.

Study the assembly plan before proceeding and lay the parts out in order.

Use fine sandpaper to smooth the sharp outer edges of the outer parts.

Don't assemble it all in one go, or you won't get the strap and the disk in!

Assemble and glue four spacers onto the centre plate, with the four locating pins glued into place. Use the back plate (unglued) to gauge the protruding depth of the rear pins. Note that the outer corners of the spacers are rounded to match the plates, so put them the right way round. The spacer with the slots in need to go alongside the disk. As drawn, this lets the disk rotate clockwise.

Sew the ends of the velcro together with a small overlap. Leave it over-long as yet, you can trim it afterwards. Punch a hole in the centre of the overlap.

Place the velcro under the centre plate, between the spacers. Glue the rear plate in place, checking that the hole in the velcro lines up with the pin hole.

Add the centre pin, glued and allowed to dry. This also holds the velcro in place.

Make sure the glue on the centre pin is completely dry before placing the disk in place!!

Snip out a short length of a small cable tie-wrap, discarding the head and the tapered end. Place this into the two narrow slots, smooth side outwards. The length needs to be just right to act as a stop in the detents cut into the disk. If the length is right, this acts as a one-way ratchet too. (See photo)

Glue the triangular plates on top. The pins should protrude just enough to make a neat dome.

This was designed and made in a hurried morning. If you took a bit more time over it, there's room for a lot of improved detail. Certainly a few engraved lines on the triangle plates would be easy.

Dan 10 watch