MicrobeHunter.com Microscopy Forum

Like most microscopists I have had 'electronic flash' on my wish list ever since I realized that blur and cilia were synonyms without one.

After a false start with some prisms, bought without a clear idea as to how I was going to utilize them and which therefore are still in a drawer, I decided that getting hold of a 'dual head cube' (beam splitter) was a more practical potential solution.

The idea is to attach the cube directly to the lamp-house connecting tube, which would give two 90 degree ports.

The cube has Telan lenses, as it is designed to take finite 160 binocular heads.

This means that in order to be able to attach the lamp-houses I need to place a spacer under the dovetail in order to clear the protruding Telan lens.

To do this I need longer versions of the original screws. Unfortunately I don’t know the screw designation.

I read that with the screw diameter and the number of threads per cm it is possible to identify it.

If anyone knows what it is or can calculate it via the photos below I would appreciate it.

Images:
1) Found one on ebay. As can be seen the cube was missing the dovetail and the tightening screw sleeve. As I had these spares, I crossed my fingers hoping there would be no unpleasant surprises and put in an offer.
2) Cube with dovetail and tightening screw sleeve added.
3) Lamphouse as it should be attached.
4) Cube in place.
5) Simulated position of the lamphouses.
6) screws (diameter is 2mm)
7) screws + dovetail

Happy to report that both the cube and the Siedentopf binocular head were in excellent condition.
Have placed the Siedentopf on my microscope and given my Jentzsch a vacation. It was due some R & R and a very thorough clean.

Images 6 and 7:

There are machine experts around here, but may I just try to suggest. If the screw diameter is 2.0mm, and the cube manufacturer is not American, and the front ruler scale (13,14, 15... marks) is centimeters, it might be an M2 screw. BUT, this is only my guess.
One of the many nice things at Home Depot is that in the machine screws department, they have standard nuts fixed to the shelf, clearly marked (like 8x32, 20x4 etc) so the customer can approach it and try turning his own screw in the nut, to verify the pitch and find the same type of screw in the store...
Please do report the progress and results of this project! I have for some time pondered the addition of flash light for my setup.

Thanks Hobbyst46,

I live in a small spanish town, not much choice here.
There is a small city an hour away but with petrol prices in europe ... that is a long long way.
Screw is from a Zeiss, so german/european and metric. Might be a bog standard size but don't know if it is.
Need it to be standard and to come in various lengths.

Found this:
https://www.amazon.com/Metric-Screw-Che ... B0006NFUK6

Just a hint.. The length of a screw is measured from under the head... The last numbers is the pitch of the thread in mm... (.i.e.) the distance between points...

BillT

I am sure you have seen this article..

http://www.microscopy-uk.org.uk/mag/ind ... lash1.html

75RR wrote:Like most microscopists I have had 'electronic flash' on my wish list ever since I realized that blur and cilia were synonyms without one.

[ ... ]

To do this I need longer versions of the original screws. Unfortunately I don’t know the screw designation.

I read that with the screw diameter and the number of threads per cm it is possible to identify it.

If anyone knows what it is or can calculate it via the photos below I would appreciate it.

Great project! ... I wish you well.

Metric screws [unlike British and American ones] are specified by pitch, which is the inverse of 'threads per mm' ... so all you need is the distance between two successive crests. The easiest way to do this is to measure the distance that [say] 10 threads occupy, then divide by 10.
It is important to remember that you are counting from zero! [i.e. counting fence panels, not fence-posts]

If the diameter is 2mm and the pitch is 0.4mm then that should be a standard [coarse] M2 thread.
http://www.metrication.com/engineering/threads.html

If you are still struggling, please post a more detailed photo, if you can.

MichaelG.

@MichaelG

This is what I thought, but when I look at some old Zeiss screws, at least the brass ones, it seems like are of some uncommon standard rather than simple metrics.

That looks to me like a M2-0.4 by 8mm long. It's called a fillister-head type in the U.S., usually meant to go into a counterbore.

M2 meaning a metric 2mm diameter screw, with a 0.4mm pitch (peak to peak on the threads), and about 8mm length (threaded portion length).

Zeiss used that screw size here and there on their scopes. If you buy some, go for stainless steel if available (it's stronger).

Good luck, great project.

Thanks billbillt, for hint and link.
Thanks Hobbyst46, have heard that Zeiss used a variety of threads and lengths - perhaps too many!
Thanks MichaelG and wporter, it is looking like a M2 0.40 which would be good news.

Posting better image, please feel free to confirm:

Looks good to me.

MichaelG.

Thanks MichaelG.

Good luck with your project 75RR. I look forward to your progress as I have closely followed different ways to achieve flash photomicrography.