Gearbox Lamp

Check out the video to see how the gears move to turn the light on/off and also acts as the dimmer.



This was a result of a need for me to create an example GCSE Engineering project for my students and I really wanted to make something from scrap engine parts I bought of ebay.......Somehow I ended up with this, I am soooooooooooooo pleased with the outcome I thought I would share the joy :)

The project took me 4 days and cost less than £20......... best 20quid I ever spent :)    I also like the fact that most of the main components are reused (gears, bearings, acrylic etc...) this keeps the cost down and encourages creative thinking.

I bought the following
Gears + crank + conrods + bearings - £2
Dimmer switch - £4
Braided flexi hose - £2
Transformer + bulb + holder £4
Bolts £3

Freebies
Acrylic - from a storage unit
Aluminium - offcuts donated to my school from local engineering company
Steel tube - offcuts from our scrap bin
Old speaker wire
Old 240v plug and double insulated wire

The more components you can harvest the better, look in junk yards / boot sales / garage sales / or even look for instructables treasure in your own garage......you will be surprised what you can find, we all keep stuff as one day it might be useful.....guess what this is that day :)

Please note this instructable's dimensions and working drawings are based around the gear box I used (from an FJ 1200) its likely you will have different components and will have to tweak the dims/drawings/design to fit your materials.


 

You need the following components:

Gears
Bearings
Con-rods
Dimmer switch
Braided flexi-hose
12v Halogen transformer
MR16 bulb holder
MR16 12v Halogen bulb 20w
240v plug + double insulated mains cable
Old wire....speaker wire is ideal
Terminal block
Selection of materials to make the base etc....

Degrease the engine components using a solvent based degreasing product, a paint brush is good for getting into the difficult areas.

• Cut a strip of aluminium 330mm  x  50mm
• Mark out the measurements as per the working drawing.
• Centre punch the hole positions
• Drill all holes at Ø4.5mm

• Roll the aluminium until the ends touch
• You will always be left with flat ends where the rollers are unable to reach, use a leather mallet and a Ø2" steel bar to tap the ends into shape.
• Use a long strip of abrasive paper (150grit) to sand the sides to achieve a 'brushed look'

• Cut three Ø15 x 52mm long aluminium rods
• Face off one side, the when facing the other side ensure the part measures 50mm long (same height as the aluminium strip you just rolled.
• Centre drill all 6 ends
• Drill all 6 ends Ø4.2mm x 30mm deep (this will create a hole all the way through the component.
• Tap both ends at M5

• Measure and mark the holes on the side
• support the work in a V block
• Centre punch the two hole positions
• Drill a Ø3.2mm hole half way through the rod
• Tap holes at M4

• Sand the three rods
• Assemble the three rods to the strip using M4 bolts
• The joint needs to overlap on the strip and the bolts go through both holes

• Using Ø25mm aluminium centre drill on a lathe
• drill Ø8.5mm 40mm deep
• Use a parting off tool to part off at10mm
• repeat the drilling and parting off until you have 4 components.
• Tap the holes at M10
• De burr the holes in a vice
• Cut 90mm of M10 threaded rod
• File the rough sawn edge
• Assemble

• Use Ø25mm aluminium
• Face one end
• Centre drill
• Drill Ø10mm 60mm deep
• Sand the sides
• Part off at exactly 50mm
• Repeat until you have 4 identical components

• Use Ø25mm aluminium
• Face off 
• Chamfer @ 45°
• Part off at 20mm
• Turn the component around and centre drill
• Drill Ø8.5mm x 15mm deep
• Tap a M10 thread in a metal vice

• Using Ø12mm aluminium rod
• Face off
• Centre drill
• Drill Ø6mm x 20mm deep
• Countersink to accept a M6 countersink head
• Chamfer the edge @ 45°
• Part off at 10mm
• Repeat until you have 6 components (3 feet & 3 caps)

• Use Ø12mm aluminium rod
• Face off 
• Centre drill
• Drill Ø5mm x 30mm deep
• Part off at 50mm
• Turn component around and repeat drilling on other side
• Repeat until you have three components
• Tap both sides of each rod at M6

I laser cut my base from 9mm thick acrylic, you could use the following alternatives.

• 3mm acrylic - It might be worth doubling up the layers to give it a thicker look, could be cut using laser or by hand
• Hard Wood or Ply wood - Could be cut on a CNC router or by hand.
• Aluminium / steel / brass sheet - This would be cool but very time consuming to cut by hand, a water jet would be useful :)

The first thing you must do is create a template to gauge the size of the base and more importantly the centre positions of the gears.

When you are happy create a 2D CAD file based on the dimensions of the template.

• Cut out the base
• Assemble all the components you have so far, carefully position the aluminium cylinder so it is centred around the dimmer switch hole
• Mark where the three holes need to be drilled
• Drill three holes at Ø5mm
• Countersink the holes to accept the head of a M5 countersunk bolt
• Screw in the three bolts and then mark the three holes underneath and repeat the drilling / countersinking so both top and bottom halves of the base are attached to the cylinder.

This is the gear that goes between the dimmer gear and the main gear shaft.

The bearing was slightly too small to fit into the gear so I laser cut a spacer ring to fit them together

It is all attached to the base with Ø25mm aluminium drilled and tapped to take a M6 countersunk bolt.

• Take the dimmer switch apart to harvest the electrical hardware and the white dial, get rid of the white square faceplate
• Accurately measure the diameter of the dial and drill the appropriate size hole in Ø25mm aluminium
• The hole needs to be a friction fit (tight fitting)
• Assemble the rod, bearing and gear and check it all turns, dont worry about the dimmer mechanism yet i will cover the wiring of that later 

• Use the clamps you made earlier and assemble components together
• The gear shaft has a spring clip, this sticks out and is what the clamps hold onto

I found some steel tube that fitted tightly on top of the gear shaft, I wanted a curve in it but didn't have a pipe bender so i did the following.

• Cut rod to desired length
• At the point of the bend make a series of cuts 10mm apart, they need to be most of the way through the rod.
• File off any sharp edges left by cutting
• To make life easier heat the back edge until bright red then quickly move to a vice and hammer so the gaps collapse and the tube bends
• Its likely you will need to repeat the heating / bending process a few times.

After making it i decided it was a bit too long so I chopped some off.

• Bolt the con-rods together in the arrangement shown in the photo
• The Flexi-hose just sits in the shaft and is threaded into the top of the light assembly
• I also machined a cap to hid the top of the bulb and act as a support for the bulb holder.

The cross sectional drawing should be self explanatory on how to create the lamp arm.

Because the acrylic was used it had a lot of surface scratches so I sanded it with 150grit paper to remove the scratches and give a frosted look

To keep things neat you must always sand in the same direction.

NOTE: MAINS VOLTAGE CAN KILL YOU OR IF YOUR WIRING IS DODGY, SOMEONE ELSE....... YOU MUST ONLY TRY WIRING PLUGS & DIMMERS IF YOU ARE QUALIFIED TO DO SO! 

The wiring schematic is shown in the images.

Ensure the dimmer wires go though the base before you attach them.

Assemble the lamp in the order shown.

Instructables contest info asks what I would do with a shopbot..........our CNC router at school is on its last legs, we cannot afford a replacement...... this would be ideal :) 

It would be used on projects across all year groups including GCSE and A-Level.

Any questions about this build...please ask

Jonny