u/Ecstatic_Loss_8668

I have two older stereo microscopes used for micro mechanics and watchmaking. I recently got aftermarket reducing Barlow lenses (0,5x) for them both. As far as I can tell, no purpose made Barlow lenses can be found for these anymore.

I have to make a mount for both but I’m noticing some interesting effects of moving the lenses closer to and farther from the optics of the scopes. Am I imagining that the working distance (IE reducing effect of the lens) increases the closer I bring the Barlow to the scope optics? It’s been a long time since I did optics theory and I’m struggling to explain why this would be. Help?

I’m trying to wrap my head around how the different sensors in the units work. Mine is a Hall sensor-version. Is that for the filament buffer? The rod magnet? There is also a radial magnet on the extruder shaft. What function does that have?

Also: most kits I’ve seen have had a steel ball bearing for the filament sensor. Mine has glass balls. I’m thinking that sensor is optical and the material of the ball shouldn’t matter?

I recently bought parts from Cousins for a vintage Alpina 586 movement. The parts I received (mainspring barrel and ratchet wheel core amongst others) were clearly from a donor movement and not new, with markings in the barrel and the ratchet wheel core was badly rusted.

I’ve bought from Cousins before and I’ve been happy with them but it’s been a while since last time. Has anyone had similar experiences with parts from them? Is this what to expect from them now?

Of course this should be addressed by Cousins, I’m just looking for what other have experienced and if I should adjust my expectations. Cousins also do not have a customer support email, just a returns form. Plus they’re outside of the EU (I’m in Sweden) and I’ve already paid close to 20€ in import fees on these parts so I’m not too keen on paying it again.

Hello! I’m just getting started with TIG welding and I’m looking into solutions for grinding my electrodes. Most that I’ve come across are open systems like bench grinders or the Eastwood grinders. The tungsten dust doesn’t seem to that great to breathe. Especially lanthanated or thoriated versions. Maybe not as bad as tungsten carbide dust but close enough.

How do you manage dust? Shop vac? Mask? Is it a concern for you at all? There are closed dedicated grinding systems but they are very expensive. Is there a decent hobbyist version that’s reasonably safe?