Tiny spiro

Flip top spiro lighter

Following on from the success of my laser lighter I decided to try shoe-horning a few more parts into another flip-top laser project.

This time round I wanted a laser spirograph projector. As there are so many options for nearly all of the parts this is not an in-depth tutorial but there is enough information here to guide you should you decide that you need a flip-top lighter spiro.

I started with a number of drawings to see what the options might be. There are a lot of parts to get in so everything needs to be as small as possible.

I purchased another lighter and had it engraved.

Other parts required: (links to suppliers are all over this website)

5mw green laser module (from Deal extreme)

2 X 5mm rubber covered vibrator motor (from ebay)

3mm thick acrylic mirror (from ebay)

Miniature on/off switch, as used in radio control units (from ebay)

12mm thick block of Acytol (Delrin) (from ebay)

1 X 10440 battery

Magnet from the lens assembly of a PS3 sled.

Odds and ends of brass, plastic and wire.

Below are some of the parts ready for work to begin.

The first mod is to the case of the lighter, as I will not be using the insert the catch will no longer work, inside the lid is a metal bracket that operates the cam on the inner part of the lighter. This needs to be removed, use a drill to drill holes in the bracket where it bends out from the edge of the lid.

Using a pair of pliers bend the bracket back and forth until it snaps off, use a small grinding burr in a dremal to take off the burrs.

I wanted to use a magnetic switch operated by a magnet in the lid but the lighter is steel. not brass, so that would not have worked on this one. this means that a hole needs to be drilled and filed at the bottom of the lighter case, for access to the switch.

Using a tennon saw roughly cut the Acytal sheet roughly to the size of the lighter. then gradualy shape it until it is a slide fit into the lighter body.

Once it fits the bottom you will need to shape the top until the lid will close.

I gave some thought to how I would fit the major parts and decided that as the block is 12mm thick I would use 10mm diameter for all my holes and slots as this would make the machining easier.

The green module I used came from a Deal extreme keyring pointer.

This is where the fiddly part begins, the module is 12mm diameter so I turned it down to 10mm (after unsoldering the driver board).... the module fell apart at this point as it is screwed together with a 10mm thread, I had to join it together with super glue and was relieved to find that it still worked. (Smaller diameter green modules are available from o-like but I was working with what I had). The photo shows the module after I had turned the thread off the front end before removal of the driver board.

To get an idea of where everything will go I laid out the major parts on the plastic block.

I wired up the green module to see where the mirrors would need to be placed and found that the module would need to be at an angle, not straight up as shown.

I have detailed the slots and the hole diameters but the positioning is down to finding the best positions.

Green laser installed to check position for mirrors

The vibro motors are rubber covered 5mm diameter. The rubber needs to be cut off as shown.

The mirrors were stuck, with superglue, to an 7mm brass mandrel with a 0.5mm hole drilled through.

Once at the correct diameter the mandrel was removed from the lathe and using a pin chuck a 0.5mm drill was used to drill into the back of the mirror, taking care not to go too far. A craft knife will release the mirror from the glue.

Two motor mounts are required as follows.

The mirrors will be protected as they are inset into the housings.

The parts (note motor shafts have been shortened slightly)

The finished items, the mirrors need to be just very slightly crooked so that when a laser is shone on them the output is a small circle.

Modules and mirrors trial fitted. (The melal block, bottom right in photo, is a magnet which will hold the lid of the lighter closed).

With most of the mechanical parts made it is time to wire it all up.

The motors used on this build do not like to be wired to a pot for some reason so the pot (shown on the GA) was replaced by a spring loaded negative terminal. Wires were pushed into the back corners of the battery holder.

A better view showing the spring, this is the one removed from the green module.

To make removal of the battery easier the sides of the holder were cut away.

The driver for the green module was stuck in place with super glue.

As soldering progressed the switch stuck in place with super glue.

As can be seen there is not a lot of wasted space so wires need to be run carefully, if untidily :) The posative terminal was soldered to the laser module to keep it rigid.

A cutout needs to be drilled and filed into the base of the lighter case. Then, with the assembly inserted, the switch knob needs to be filed down so that the lighter will stand up.