Wednesday, 5 October 2011

In Focus

I've finally run out of the plano-convex lenses I bought last year from Surplus Shed. These were great as they had a 50mm or so focal length which resulted in a short IR focus tube. I've ordered some more lenses but these have a FL of 100mm, therefore I needed to re-design the focus tube of my tag guns.

I changed the tube design to be in two parts. One holding the LED mount, endcaps and focus screw. A second tube is designed to slide over the first, but also it can be lengthened/shortened or given a larger diameter to suit the lens being used.

I forced the two parts together in my carpenters vice.

The ridges produced by the RepRap process interlock providing a fantastic strong joint. No glue is needed, I'm not going to get these two apart in a hurry.

Here is a complete IR tube kit. These are now available at Tagbits:


Javier Perez Rabasa said...

Hi Tony,

I am also making one of these, but I am still experimenting with the lens. The problem I got is that after choosing the best lens and setting focal length, the accuracy that I get for my "shots" at 22m distance is too bad, about a circle of diameter 65cm.

I would like to know if this is normal accuracy or if for a laser tag accuracy should be better (smaller circle).

How much accuracy does your system have?

Thank you!

Tony said...

Hi Javier,
My posts on optical efficiency

may help....

Javier Perez Rabasa said...

Thanks Tony for your help. I will continue experimenting :-)