Giant 100mm LED

Step 9 Find the Center and Drill

Now that you've cut and sanded down the nubs, you have a wooden version of the LED head!

Now we have to find the center so that we can drill 2 holes equidistant to it for the legs of the LED. This is probably not too necessary (because you won't be covering the base in silicone later, unlike me). Instead of following steps 9 and 10 you could just drill a hole in the vague center and insert a dowel rod (to give it support while creating the mold)

To find the center of a circle you need a ruler and a right triangle. Draw a random triangle into the base of the led and find the center of each line. Using the right triangle, draw a line that is the perpendicular bisector of each of the triangle's sides. They should all converge to a central point which is the center of the circumscribed circle, the LED. Geometry class actually helped in a real life situation! Who would have thought?

Now that you have found the center, draw in the diameter. Drill 2 (5/16) holes along the diameter, each 1.5cm away from the center.

Comments

[rpjamess1]

Another way to find center, and easier than using the triangle method, is to take a ruler that goes through a 90 degree angle, place the cylinder (of big LED) into the angle and draw a line. Rotate the cylinder, draw another line. The intersection is the center.

[_soapy_]

So, what you are saying is, "If you have a neat tool designed to find centres, use that, as it is easier"? It's only easier if you have the specialist tool. Otherwise a regular ruler is much, much easier.

[rpjamess1]

This is what I'm talking about: http://www.rockler.com/gallery.cfm?offerings_id=18997&r=2