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Tuesday, 26 September 2017

Prototype X-Y Table

 The new microscope came with a nice XY stage, but the slide holder was missing. I made one from a cheap XY table. The XY stage is manual, which is fine for adhoc looking at dies, but for photographing dies and then stitching photos there's a lot of photos. It's tedious doing it manually. So I prototyped an XY table from DVD drive stepper motor assemblies.






I had an arduino and two stepper drivers, so connected it all up;
The result is here, the two stepper drivers are being driven with the same signals.




And another view.





I'll have to make a stage block with a dovetail to mount this on the microscope. I may also remove material from the top table as it could do with being a bit lighter.


Wednesday, 20 September 2017

New Microscope

I've been looking at a lot of ICs under my microscopes recently, and realised that it was a way that I could do better reverse engineering. This will let me look at the ICs on a PCB without datasheets, so the PCB could possibly be re-used.
Reverse engineering the IC is an interesting thing in itself, as well.

So, I had a look on ebay and bought a metallurgical microscope. This has a lighting system that can illuminate a subject from the top, so it works on opaque samples like ICs.





It came with no objectives, so I'm now hunting for decent objectives for it. It has a proper X-Y table which is good for moving samples about. This is especially useful for die-shots which are large arrays of photos.

The USB microscope is still useful for soldering and so on, as this microscope has a working distance from objective to sample of between about 0.5mm and 10mm. That's not a lot of room for soldering!

The X-Y table didn't have a slide holder so I bought a cheap X-Y table mechanism on ebay and used some melted down food trays cast into an ingot :




After machining into a block, I drilled some holes and mounted the slide holder from the cheap XY mechanism:


So I now have a nice spring loaded slide holder:



It's not perfect, and has a bit of a broken drill in it, but it's decidedly better than my first attempt:


Thats a bit of sheet metal bent into a holder shape. It's much better now.

Next projects are a camera mount and an LED based illumination source.


Saturday, 2 September 2017

Maslow L298 Failure

Maslow L298 Failure

My Maslow motors stopped working, so I removed the IC from the PCB, decapped it and had a look. One of the transistors has overheated, maybe shorting some rails out:





For reference, the full chip looks like this: