Microscope arbor size, 25mm or 32mm?

[prollie]

Apologies if this is a little long, just wanna cover my usecase, and put out what I already understand and what not. So responding can hopefully be less of a hassle for you guys n gals.

I'm getting an Eakins (same form factor as the common AmScopes) trinocular/simul-focal microscope and adjustable focus-holder for it, primarily for microsoldering work. I intend to DIY fabricate a mounting bracket for it to attach to a sturdy "gas" monitor arm I have lying around, for the time being. Getting one of the dedicated for-purpose ones is just way out of my budget for now. But I'll probably experiment with different mounting solutions as time goes on.

I've only really worked with the common double boom stands before (what was already in house before my arrival), and those had 32mm arbors. But I see there's a very significant price difference between microscope focus mounts, and other mounts and parts, between 25mm and 32mm versions (the latter more costly). Anyone know why? Is there some significant difference to them other than "bigger number more better"? Is there some standard I don't know about? I do see 25mm steel and aluminium pipes are way more available and cheaper than 32mm, should I want to DIY those kinds of mounting parts later. 32mm connecting parts seem to be less offers for, so a bit "worse" for both cost and availability. The microscope head itself, even including lenses, a meaty camera and ringlight, is just on the thick side of 3'ish kg. Is there notable less flex in 32mm pipes and rods, vs 25mm (within this use and scale context)? I'll probably never use this setup for any larger magnification than 90X, most often 15-30X, so I'm don't know if any rigidity benefit would even benefit me..?

Anyone that have used / worked with both, or otherwise have relevant insights to share? (And yes, afaik I understand I can make a "spacer"/solid bushing insert to fit a 32mm focus mount on a 25mm arm/boom etc, if needed. But I'm not equipped to go the other way and drill out a 25mm mount.

In advance, thank you for your time.

[jfiresto]

25mm hardened steel shafts are pretty common and quite stiff. How long is the shaft?

[Overspeed]

Hello

You can also ram rod hard chromed which are available as industrial supply

Carefully check if that 25mm and 32mm metric or 1 inch and 1 inch 1/4 imperial dims are close but not at all the same

Regards
OS

[thm_w]

Sorry to give life to a dead thread but I'm too looking for answers to this question right now.

https://www.aliexpress.com/item/1005004000273775.html

Seeing as the OP has mentioned 25mm is cheaper re equipment wise I'll probably go with a 25mm.

But the link you've posted has the same price for 25 and 32mm.
And the size different is on the microscope end, which is specific to the microscope you buy. So you would just buy the one that matches your microscope...