Instructables

Handy ring light for extra hands

Featured
Picture of Handy ring light for extra hands
CIMG3315.JPG
This is probably one of the most used tools in my workshop, the "extra hands".
It is the ultimate tool for soldering and prying in the very small range. But over time I found that I do not have enough light on my work when using this tool. Actually all the benefits you would expect from having a magnifying glass for easy reach are over shadowed by the shadow cast by the rim.
And honestly I haven't managed to position my desk lamp in such a way that I was able to conveniently light my tiny work.
So I decided it is time for some upgrades.

As usual you will find all G-code and other  files included so you can reproduce this easy on your own CNC machine
 
Remove these adsRemove these ads by Signing Up

Step 1: Materials & equipment

Materials
PCB prototype board unstructured (rs-components)
Resin cored solder
PCB LED's warm white 40pcs (old LED tube light)
Old 12V DC transformer (anything with more then 3W will do fine)
E-wire (some scraps)
Glue sticks
Double sided tape (carpet tape)
Some Acrylic sheet scraps

Equipment
CNC mill + computer
45deg engraving too or 0.5mm flat end mill
2mm centercutting flat end mill
Soldering iron
Tweezers (forceps)
Some crocodile clamps
Hot melt gun

Extra hands with magnifying glass

Step 2: Design

Product demands:
I would like a nice uniform light source around the magnifying glass of my extra hands.
Low voltage, compatible with common power sources (12V)
Robust 
Low power consumption

Measurements:
The outer diameter of my magnifying glass is 62mm
An LED is approximately 5mm long
An LED is approximately 3.5mm wide
An LED has 0,75mm wide contacts on its underside over the width of the LED
Each LED needs 3V


Knowing this I will put 4 LED's in series. To minimize human mistakes I will make sure all LEDs can be mounted in the same orientation.
To get a nice even distribution of light I divided the ring in 40 segments leaving each led with plenty of space so I can poke around it with my soldering iron. This gives one LED every 9 degrees.
To connect them there will be a 1mm conductive path on the inside of the ring and one on the outside. Within these rings I will fit the series groups. (see picture)
Between the series groups and the main power rings there will be 1mm space (for the convenience of my thick fingers)

After finishing the design in Sketchup I exported it to DWG format to convert it to G-code



Step 3: Mounting and aligning

I mounted the PCB board on a piece of 3mm acrylic glass with some double sided carpet tape, the type without the foam core. I use these quite often to put under my workpiece. They are cheap (leftovers) and very flat and smooth.
I found that the trick is to apply a nice smooth surface of tape to sick your workpiece to. Covering the entire surface will prevent any warping of the prototype board.
Next I clamped it down on my milling table.

All programs are aligned to the centre of the ring
Load the 2nd code file for the 2mm flat end mill to check the clearance.

Load the first program named 1ringlight engrave.nc
Insert a 45degree engraving stylus or a 0.5mm centercutting flat end mill, touch off the top of the stock as z0
set a spindle speed of 5000rpm and a feed speed of 300mm min

in my case I used an engraving stylus so I set the plunge rate also at 300mm/min

After running the first program
Change tools, insert a centercutting 2mm flat end mill
touch off the top of the stock as z0
Spindle speed 5000rpm
feed speed 300mm/min
plunge rate 300mm/min


After running the programs it is time to dust everything off and unstick your ring.

Note that all programs have a higher feed rate, I have used these programs at 50% of the feed speed.

Step 4: Solder

Set your soldering iron at the appropriate temperature.
I use a lead core solder with rosin, altough not most environmentally friendly this is a faily easy solder to work with at a low temperature.
Set your soldering iron at 260 deg Centigrade

Next I have applied a small dot of solder to each contact
After this I soldered on the LED's (thats what the tweezers are for)

Every small LED had a tiney tiney marking as if one of the corners is missing (look for it in the picture)
This marks the polarity of the LED, I have made sure all leds where oriented with the marking nearest the outer ring.

I also applied a dot of solder to the big contact pads so I can make easy contact with some crocodile clamps or solder wires to.

Tada your done.......
Well I did not manage the first try...
The LEDs are so tiny that it is very hard to align them properly and solder them correctly with my big ass needle solder tip, compared to this tiny LED its huge any way.
richms1 year ago
There are "angel eye" LED boards available on eBay and Deal Extreme that are basically a round PCB with LEDs on it if you dont have the equipment to make a PCB. However getting decent size information from the sellers can be a bit of a hassle sometimes.
cold_steel (author)  richms1 year ago
that does take all the tinker fun out but fair enough, thanks for the tip
snotty1 year ago
If those are anything like the surface mount LEDs I've been using, they are a huge score. I paid like $2 a piece for mine.
cold_steel (author)  snotty1 year ago
Wauw, well maybe I cheat a little bit because im import/develop tube lights. On average I pay about 40 euro's for 500pcs smd led of this type, maybe a bit less even. As a private person you should not pay more then double that I guess (local sellers need to eat too). So 20 cents each sounds fair to me.

On top of that I used high efficiency LED's with a light output of more then 100lumen/Watt giving this tiny ring I build here about the same light output as a good 50W halogen spot.
cold_steel (author) 1 year ago
I used google sketchup to make the PCB design.
sorry im new in that~is that normal sketchup or google sketchup Pro?
i already download it but dunno how to use = =
cold_steel (author) 1 year ago
Sketch up pro in my case. I think normal sketch up does allow for exports in 2D.
Just check file>export>2D. For PCBs this would do, for sure you need pro for 3d exports.
Hope this helps
FakeSheep1 year ago
may i know what is the PCB drawing software tat u used?
Pro

Get More Out of Instructables

Already have an Account?

close

PDF Downloads
As a Pro member, you will gain access to download any Instructable in the PDF format. You also have the ability to customize your PDF download.

Upgrade to Pro today!