Tuesday, August 9, 2011

Machine Parts, Two Versions

I am working on building a machine for my PhD, which is designed to hold a glass slide, and stamp it very carefully against a rubber stamp with ink on it. But it was not working - the ink was not transferring from the stamp to the slide like it was supposed to. So I did my best to look at what WAS happening, and try some quick experiments to test the process.

I was not sure if my machine was the problem, or whether it was the basic process that was the problem. To try and figure out what was causing the issue, I tried doing some experiments by hand without my machine, and then the same experiments with my machine. Those "by-hand" experiments were pretty bad, but at least I got some results. I was getting NO results with my machine. So how to figure out what is wrong with the machine? Well, there is a problem.

See, here is what the holder for the slide looks like:

Figure: Note, solid metal construction.
 The three holes are vacuum holes to hold the slide while it is upside down during stamping. The outside ring is to provide a good seal with the round stamp. The problem here is that after I put the stamp over the vacuum holes, and turn this thing upside down on top of the stamp, I can't SEE anything.

Figure: The holder, pretending to stamp something.
 The holder is all metal, with a heater in there, and a ceramic block to deflect heat from the handle. But with all those opaque layers, I can't see what's going on while I'm trying to stamp. So what to do? Well, off to the machine shop!

Figure: Thing 1 and Thing 2
 I made a clear version of the original holder. It doesn't have a heater in it for two reasons - one, the heater is ceramic and not clear, and second the plastic can't handle high temperatures. But it will allow me to see what's going on.

If you look closely, the vertical cloudy line is where I drilled, and the drilled surface is not perfectly clear. But I had to get access to the vacuum holes somehow. The outer ring is also visible, as in the metal version.

And look! One can see through it! So now, I should be able to actually watch as the slide contacts the stamp, and the ink does (or does not) transfer.

Crossing fingers...

1 comment:

  1. This concept is exactly what I need to do for my project - I'm having to guess at what's happening because I can't see through metal. Unfortunately, I don't have the time or knowledge to change it, so I am just ending up with a rather large theory and discussion section...