# Glow in the Dark Keyring

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Awesome, Awesome, Awesome mini project that i recently discovered on this web site:

http://start-model-engineering.co.uk/2012/01/glow-in-the-dark-keyfob/

It will be my next project for my after school engineering club. Check the vid to see the key rings in action!

Learning Objective

By following a detailed set of instructions and videos from the Instructables website, yr9 students (13 year olds) will make a glow-in-the-dark key ring. The students will recall previously learnt skills on the metal lathe, e.g. facing off, centre drilling, and drilling to a given depth. This project will introduce the students to a milling machine and an indexable head. The project teaches how to use these precision tools to a high degree of accuracy and the students must aim to work within a tolerance of +/- 0.1mm. To achieve this tolerance the students will have to use basic mathematical calculations of linear measurements and angular divisions.

## Step 1: Cut Material to Length

• Use a hacksaw to cut either Ø9mm brass or aluminium to 90mm long

## Step 2: Drilling

• Centre drill
• Drill Ø6mm x 50mm deep
• Drill Ø6.8mm x 8mm deep

## Step 3: Tapping the Thread

• Put a M8 tap into the chuck and manually tap the thread. Do not turn the lathe on!
• Once its started remove from the lathe and complete the rest in a metal vice.

## Step 4: Y Axis (centre)

• Remove the work piece from the lathe and secure in the indexing head.
• Put in the centring bar (this can be any rod with a known diameter)
• Slowly advance the rod towards the work piece, using a thin piece of tissue as an indicator......keep moving the tissue, when the rod grips the tissue you know its exactly on the edge of the work piece.
• Lower the machine bed and zero the Y axis dial.
• Use the following calculation (Ø of centre rod + Ø of work piece / 2)
• 8mm + 9mm = 17mm       17mm / 2 = 8.5mm
• Move the Y axis dial 8.5mm
• If done correctly you should be within +/- 0.1mm of the centre

## Step 5: X Axis

• This does not need to be as accurate as the Y axis
• So put in the Ø10mm centre drill and align it over the end of the work piece
• Zero the X axis dial and move it 8mm to the right

## Step 6: Drill

• Use the drilling head to drill to a depth of 5mm.....its important each hole is exactly the same depth.....ensure you pay close attention to the numbers on the Z axis dial.
• Once the first hole is drilled rotate the indexing head by 8 holes, drill the 2nd hole
• rotate another 8 positions on the indexing head.
• Move the X axis by 8mm
• Move the index head by 2 positions
• Repeat the process until you have four sets of holes

## Step 7: Finishing the Component

• Put a chamfer on the end of the work piece
• Use 100 grit abrasive paper to clean up the surface
• Part off the component at 55mm

## Step 8: End Cap

• Measure 15mm into the rod and centre punch
• clamp the other half of the rod into the v-grove on the machine vice with the punched mark perfectly vertical
• Use a centre drill to start the hole
• Use a Ø4mm drill to complete the hole

• Parallel turn the end, Ø8mm x 10mm
• Use a M8 die, start the thread using the tail stock of the lathe
• After a few turns complete the thread in a metal vice

## Step 10: Parting Off

• Test the thread by screwing on the other half, you will find that the thread is a bit long.....face it off until its the appropriate length.....approx 5mm
• Part off the component, 5mm past the hole
• Screw the two halves together

## Step 11: Shaping the End Cap

• Wrap the main body in paper to protect the surface finish
• Shape the end using the cutting tool
• Use 150 grit abrasive paper to tidy up the surface

## Step 12: Glass Tube

• I got this Ø6mm glass tube from the science department....... you can use any glass or plastic tube....even fish tank air hose would work.
• The glow in the dark powder was purchased on ebay.
• Cut the tube to 45mm
• Use the glue gun to seal one end
• Clamp the tube to stand upright....alternatively ask someone to hold it
• Carefully fill the tube using a folded piece of paper
• Glue the other end to seal the tube
• Put the tube in the brass holder
• Screw on cap
• Enjoy :)

Runner Up in the
The Teacher Contest

Participated in the
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## 38 Discussions

Very nice version.

Not too sure about the glass if you drop it? Acrylic rod is cheap :-)

Glad you liked the idea ;-)

Ralph.

4 replies

Hi,

The glass is pyrex so its pretty tough and when bought through the schools science department its surprisingly ......cheaper than acrylic!

You should definitely put your LED torches on instructables people will love them :)

Jonny

Hi Jonny,

Fair enough, just a thought on the glass :-)

Not upto speed on how this all works yet.... But the torches will be possibly the only thing I try as the keyring projects are the simplest things I make.

Glad you can link to videos on here. That'll save hours. The torches are a little more complex than these! :-)

Ralph.

Ahh, good man :-)

Well if I can't get this site figured out I'll let you know.... you'll have to post that build too! lol

I like your gearbox lamp BTW. Top job.

Ralph.

Amazing. Are you going to sell these? I would love to own one.
P.S. I voted for this and for your aluminium keyring. Good luck!

Hi, thanks for the vote.....unfortunately all my spare time is consumed by instructables.........Robot, please can i have my life back!

Hi, yeah sometimes that is possible and saves loads of time, however, tubes are no good if you need a solid end..... or..... the internal diameter of the tube can sometimes be too big....or....the wall thickness too thin. But occasionally tubes are awesome :)

Hi, thanks :) the idea is not mine :( if you go to the intro there is a link to the website where i found the idea jonny

what about using tritium vial with a plastic coating? outstanding project by the way! i hope to get a lathe and milling machine in the future.

6 replies

Thanks.... get them sooner rather than later........ Lathes and mills are the coolest machines..........dare i say it even cooler than laser cutters! if you are in the uk and want advice on where is best to get the machines from, let me know :)

Well i live in the united states, but i will definately ask you if i have any questions! i need to buy a new belt sander (i just burned the motor out on mine) then i need a knife belt grinder and a forge. after i get that equipment i plan on buying the milling and lathe gear.

I live in the south east of England. do you know where i could get a cheap lathe or milling machine as i am a student.

There are a few different options, what's your budget? And what sort of things are you interested in making?

My budget is as cheap as possible. i really wanted to make small projects like your glow in the dark key chain above and some small model steam engines etc. so its nothing too big.

Hmm then i would suggest ebay or gumtree and buy a second hand one it just requires a bit of time to wait for one to come available...however.....if you are unable to collect a heavy lathe or just want a new one then dont spend less than £600 or it will be rubbish...... the cheapest machines are from axminster or chester tools. if you are looking at a particular machine, and would like my opinion of it just email me on my instructables account.