sloth linear rail (deprecated)

Just for documentation of the evolution/progress. Don't use this, there is a better version, have a look at the derivative. This uses 30x30 aluminium extrusion as linear rail. But it is not strong enough to be used as a z-axis for a resin printer. I already wrote about this thing in my blog: http://blog.krieft.de/2012/05/03/z-achse-in-fertig/