Hm
So
An AFM / STM isn't *that* hard to build, right?
Dang why does everything have such a high CTE
50 nm per K in Z.... maybe that can be compensated with the right materials to even out... kinda.
Maybe I just build everything out of fused silica and invar
Ohhh I can build it in a way that the CTEs cancel each other out perfectly(ish)
This looks... ok?
Provided I can cut the glass, that V-Groove is going to be fun. I have an idea or two.
Tests to be done!
The Piezo (why does fusion render brass blue??) does X/Y/Z for the actual raster, the micrometer provides rough (maybe too rough?) Z travel and the kinematic coupling between both plates in combination with the right material choices *should* cancel out most of my thermal expansion to keep it all stable.
Piezo - Glass rod - Needle are one replacable assembly.
The basic kinematic coupling is already soooo satisfying to play with!
Hmmmnice.
It works as expected, and the kinematics reduce the mvement by a factor of ~3, so every Division moves the center by ~3 um.
Should be just about ok, meaning that the piezo can do the rest of the Z travel.
Issue is that I now need to constrain the ball on the micrometer, which means that I either have to grind a cup in the micrometer shaft or buy a different micrometer with a rounded tip to take the ball out entirely.
...maybe I should build a dremel tool mount for the lathe.
@gigabecquerel
Where did you buy the micrometer mechanism?
I might have a use for a few small one's and I'm interested in what they usually cost.
Well, what the one's that are not from Puuilo or Lidl.
@ftg This one is an original one from mitutoyo, I think I found it at a flea market?
But there are similar ones on aliexpress for around 5 €, I've ordered a few and will report back!
@gigabecquerel
Excellent, thank you!
My potential use a little bit different. As I want them for fine tuning some mmW Gunndiode oscillators I plan on building at some point in the future.
When I get better at machining.
@ftg They're... ok!
Not great, but for around 5€ a pop you really can't complain.
The grease they're packed with was a bit thick for my liking, so I swapped it for something thinner (the prusa lube that comes with the printers), which revealed some wiggle room and a few rough spots on the threads. Nothing deal breaking at all!
I'm happy with them.
@ftg Also: The shaft isn't hardened, which saves me a lot of work, not having to grind the mitutoyo!
@gigabecquerel
Excellent. Threw one into the alibasket for the next order.