Scaling up metallurgical builds and friendly hello

I’ve been building some metallurgical upright microscopes (for me + some others) and the main point of friction right now is building the beamsplitter. The first couple I built were based on some scrap half silvered mirror I had from old microscopes. However, to scale production up I’d ideally like to:

    1. Ideally buy pre-cut glass to size
    1. Alternatively have a very quick way to cut them to size

Long term I might talk to China optics vendors if I end up making a lot of them. Short term, I’m going to focus on cutting them down from the larger blanks easily available on AliExpress (30x30x1.1 mm is the cheapest). I know score + snap is the suggested way to do it, but I was also experimenting with machine methods to cut them down (ex: using a 50W fiber laser). Unfortunately no major breakthroughs yet. However, I also have access to a 1 kW fiber laser and maybe could also just CNC grind them.

Some background: I’ve been lurking a bit and should probably post a bit more here. I’ve been building OpenFlexure units for semiconductor applications / interest. This has ranged from general chip imaging with the metallurgical one to experimenting with low cost / computer controlled microprobing. I’ve been working on a number of mods including retrofitting it with bipolar steppers + GRBL to use with my own microscope software (pyuscope). However my main motivation is that I saw a lot of interest in this project and was trying to figure out how to get more units in the hands of interested people rather than to focus on significantly modifying the existing design. Professionally I do semiconductor focused consulting work and am also CTO of a small microscope company (Labsmore) specializing in computer controlled microscopes.

PS: is there a discord? Would be a great compliment to the forum for live project discussions

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A few more build photos…

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Great to see such an array of microscopes. I don’t think that I have heard of anyone using the reflection illumination on the upright before, how does it manage with stability with the off-centre mass of the illumination and potential off centre pull from the illumination wires?

From what I have seen, laser cutting glass is a tricky balance of parameters not just about power but also usually about the type of pulses. It would be beautiful to have slightly rounded corners though, like on a mobile phone screen.

This is really cool to see - thanks for posting! I am afraid I never got past the scratch and snap method myself - though Comar Optics in the UK can be very helpful for medium-quantity orders (i.e. if you wanted to buy ~tens of units, they might handle custom dicing for you, especially if it’s a beamsplitter coating they already stock). If that’s of interest I’d happily introduce you to my usual contact there - though I think the appropriate email is on their website (comaroptics.co.uk). They used to be great for one-offs, but they are increasingly focused on OEM supply rather than miniscule orders from Universities.

There isn’t a discord - we had a gitter for a while, but it’s been abandoned in favour of this forum. Quite a few of the developers are still a bit scarred from too-many-communiciations-platforms fatigue during lockdown, so we have shied away from adding any more in the last couple of years. It would be nice to have the occasional community call though - that’s something that comes up periodically and we never quite get round to organising. One of these days!

The objective is way heavier than the illuminator, so I don’t think it causes issue. The tests I ran seemed fine anyway

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Thanks I’ll keep in mind on scaling up mirror production. I am a microscope OEM though so might be worth talking to them just to find out more info even if not for OpenFlexure. Although admittedly we try to integrate as many COTS parts as possible and really try to avoid custom parts.

No worries on Discord, I know its not for everyone

Awesome work! Would you mind sharing the STLs you’re using for the metallurgical build?

I’d love to try to replicate it.

edit: Feel free to reach me on Discord, I’m not very active but I’m there - mzedp ; Oh, I just realized this is a standard upright microscope + the reflection illumination, I thought there had been some other modifications.

Thanks!

There was at least one issue with the posted STLs where I had to regenerate them from the OpenSCAD project. However this wasn’t super organized so it might take me some time to sort that out. Additionally I have a few small issues on the build such as camera at 45 degree angle and an illuminator built from a scrapped microscope. So bear in mind its a “good starting point” but may require some tuning

I’ve created a FOSS microscopy (OF, puma, etc) discord server, maybe that’s a good start to see if that gains critical mass: FOSS Microscopy

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I’ve a few discord channels I dip into occasionaly so I was going to join this one, but it says the link is invalid - did it expire?

Ah maybe, here is a link that is set not to expire: FOSS Microscopy

BTW I also did an OpenFlexure retrofit w/ bipolar steppers at supercon last weekend. This allows me to use GRBL + pyuscope. A small demo here: https://www.youtube.com/watch?v=WYZaU8rthiw

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Nice work, did you modify the normal steppers or did you find a bipolar version?

I had a version of the stage using Nema motors (nema11 I think), the motors are a lot more expensive but can move the stage a lot faster.

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Oh cool! I haven’t seen the NEMA stage build. Do you have info somewhere?

I modified the motors by cutting the middle PCB trace to convert them from unipolar to bipolar stepper motors. Its on the TODO list to document this process better, but IIRC I’m not the first person to do it, so there might already be info out there.

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