Tiny LED Torch

To me, the handiest place for a torch would be on a key ring or somewhere you could find it easily if indeed a situation arose where you needed to use it.

The Tiny Torch dimensions are 32mm Lgth x 15.5mm Diameter and weighs a few grams.

Another proviso is that it needs to be unobtrusive, many of the smaller torches available are made of metal, and when on a car key ring say, you wouldn't want a torch banging about when driving or in your pocket.

I have thought of all these scenarios when designing this Micro Torch, the torch uses an LED twist to operate module which are readily available online and are really inexpensive £5.99 or $8 for 20, the LED Module uses 3 of the CR41 watch type batteries and can give up to 5 hours of light which in itself is incredible really, with my initial prototype the tolerances were too tight and I couldn't twist it off after turning it on, so I put it to one side, the LED was still energised after a full 24 hours albeit not as bright but still bright enough to find something in a dark tent etc, over 1 week later and its still on but very dim and it finally gave out after about 1.5 weeks, this was on full time which is nuts!

The design has provision for another set of batteries to be stored for future use giving up to 10 hours + of light when needed.

I have added a handy Magnetic clip for the Tiny Torch this can be clipped to a peaked cap or similar and can be used on top of the cap peak or below, and not forgetting the magnet, which can attach to any metal object.

My initial thoughts for usage for such a torch would be camping, or hiking when weight and bulk needs to be kept to a minimum, you could have a couple of these in easy to get to places and not know they were there until you needed one of course, but could prove useful in any given pastime or situation.

Although not fully waterproof, the torch body is fully enclosed in plastic which would make the ingress of water harder to penetrate.

An additional feature of this Tiny Torch is that it is 3D printed in PLA Glow in the Dark green, which is optional but really handy in the dark and again could prove to be very useful in a situation.

Onto the design stage.

Fusion 360

3D Printer

Micro LED Modules (Amazon)

PLA Glow in the dark Green(Optional) Any color PLA

Key Chain/Ring

CA Glue

5mm x 2mm Neodymium Magnet

In this section I cover my thoughts on how this Tiny Torch could work with a 3D Printed shroud and body

To energize the module, you simple remove a small tab which allows the connections to be made and then it's just a case of screwing the body clockwise whilst holding the shroud to turn on Anti clockwise to turn off, the led, the module in itself is a torch, the 3D printed holder is a means of carrying the torch and making it less easy to turn on by accident as the screw fitting is quite loose.

My thoughts are that we can use the existing LED screw threads to turn the torch on and off but incorporate it into the 3D printed shroud and body, creating friction and making it harder to turn on by mistake as the original screw threads are pretty slack.

Please see the attached screen shots for design progress.

Dimension were take from the led module, and using these dimensions we can transfer them to the first sketch created on the Top plane, I want to make the torch light but sturdy so wall thicknesses would be kept to 1mm.

A center circle is sketched to the outer dimension of the led module plus a 3mm offset, this is extruded to the extent of the module including the end cap.

Using the top face we can now sketch the center circle to the dimension of the module which is 10.7mm and extrude this down leaving 0.5mm at the front face, a further centre circle is sketched to the top face of 12.7mm extrude this down the depth of the top section of the LED Module, the top section of the module will be a snug push fit into this recess.

The next thing is to create an opening on the front face for the LED to shine through, this center circle is 7.3mm and extrude to create the opening, a chamfer is created from inner to outer face to allow the led to give a wide beam effect.

To create the body for the torch, we can extrude top face of the recess made for the led module body and extrude this up to the dimension of the end cap of the module which is 3.8mm make this a new body and using the top face of this extrusion we can now project it and blank it off so to speak, we can then sketch from this face to create the void to house the spare batteries, plus an end cap which is 18mm with a 2mm wall thickness to accommodate the threads within the top end of the body for the end cap.

So with this torch body we now have a recess which will accommodate the end cap of the module, and also a recess which will accommodate 3 of the CR41 Batteries to be stored should they be needed for future use.

We can now create a screw in end cap for the torch which will also have means for a key ring attachment or lanyard.

Using the top face of the body we can project this and then extrude inwards 2mm and create a new body, using the same projection we can un check the main body of the torch and create an end for the cap of 1mm we can now use the thread tool to create threads on both the end cap and the inside of the torch body, the dimensions are 10mm so I opted for a 10mm x 1mm thread on both components, I also created small off-sets on the thread faces to ease fitment.

At this point I thought how could we create a means of attachment to a key ring or lanyard, I opted for a flanged peg with a slot through it, I created a center circle in the end cap and then projected this to create a new body with a flange at the bottom, I then created a tangent plane on the peg and used the overall slot tool to create the slot, I added small fillets to the slot, the peg would be a tight push fit into the end cap once printed.

I wanted to add splines to the shroud, main body and end cap for better grip when energizing or unscrewing and tightening the end cap, these were create using Tangent planes on all 3 components and then sketching a vertical line, I used the pipe tool to create a 1mm pipe, then filleted ends and sides to create the spline, then used the circular pattern tool to create 12 of the same on each component.

Small fillets were added to top and bottom edges of the shroud and the top edge of the end cap.

We can now move onto the printing stage.

I try to design models which don't require any supports and the same applies to this torch, all components are oriented as such that they don't require supports, the Shroud is printed face up, the body with the thread facing up and the end cap and flanged peg facing up.

As mentioned, on the first Prototype the tolerances on the shroud were too tight, so offsets to faces were applied.

Assembling the torch is easy, the led module is inserted into the end of the main body, I used a little CA Glue to secure in place (although it is a snug push fit and then pushed into the torch shroud), the flange peg can then be pushed into the end cap, screw the end cap on.

If the shroud is a little tight on the body, apply a little Vaseline to the top edge of the body, it needs to have a little friction to avoid turning it on accidentally, the Magnetic cap clip requires a 5mm x 2mm Neodymium magnet, I secured with a dot of CA Glue, clip can either be with the torch on a key ring or without.

3D Print files are attached.

Thanks for Looking.