Mark 2 - Development Update

A project log for Edgerton, A High-Speed LED Flash

Affordable photography tool used to capture images of bullets with no apparent motion blur

tyler-gerritsenTyler Gerritsen 12/29/2019 at 15:430 Comments

The new high-speed flash is my pet project, but unfortunately it hasn't been at the top of my priority list recently.  Work and family life have used up most of my time, leaving very little for the Mark 2.  There have been a few developments recently and I wanted to share!

High-Power Lighting - WOW!

I finally have a working offline driver for the LED's based on the DI AL9910 driver.  Three LED's can handle all of the power from a 144W power brick from Amazon, so sharing the load among all 12 LED's will result in a very long lifespan.

Story time... I had three LED's powered up and was working on the unit.  So, I placed the LED's face-down on a shop towel.  Within two seconds I began to smell smoke... Turns out the shop towel was catching fire!  The LED's weren't even warm at this point, but the power output was enough to ignite paper!

Case Manufacturing Tooling

The new case front is going to be made from aluminum for its strength and thermal properties.  The cost of manufacturing the case is going to be an issue.  I had considered outsourcing the case manufacturing, but for the initial manufacturing run (maybe a dozen units?) I wanted to build the cases in-house to reduce cost.  Here's the tooling I came up with to produce the aluminum parts:

The case will be cut with a table saw, sanded with a belt sander, and the edges chamfered with a carbide router bit ($20 CAD on Amazon).  The bit works great!

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I bought a pricey Keo counter-sink bit for chamfering the LED holes.  The surface finish isn't perfect, but I'll try sanding it down later.  I'm happy with the result given the price, especially since the chamfered edge isn't designed for reflecting any light.

My mini mill is able to cut aluminum at low speed.  It will spend several hours to cut out the fine details in the case interior, then I can use a larger mill to hog out the remainder of the material.\

Power Converters - Finished

There are going to be several switching power converters in the new design.