Microtome object holder (Leitz 1212)

[iconoclastica]

I have acquired a rotary microtome, a c. 40kg black enamel beast by E. Leitz - Wetzlar, apparently an early, but not the first 1212 minot microtome. From the codes in the manual I guess it dates from 1953 or thereabout. It appears to be in good working condition, no rust, souple motions, even the knives look servicable.

Only the object holder is missing and I will have to think of a replacement. I haven't used a rotary before and I don't know the requirements of the object holder or even which type to use. Here's a photo of the 1960-ies version of the 1212, with an object holder in plain view:

newer version advertised on the web

Leitz Rotary Microtome 1212.jpg (80.72 KiB) Viewed 4040 times

It similar in design to the one shown in the manual of my version:

"Large minot rotary microtome No. 1212 [53-3/Engl]"

User manual-2.jpg (31.89 KiB) Viewed 4040 times

I suppose I could make someting similar, either from aluminum or 3d-printed. Does it need much strength?
I connects to the microtome by a circa 10mm diameter rod. A 10mm drill sits loosely, though. Anyone here who could measure the exact rod diameter?


The specimen holder illustrated in Purvis, Collier & Waqlls (Laboratory techniques in Botany) depicts a much simpler design:

Purvis et al, 1966

scan_07042023.jpg (43.78 KiB) Viewed 4040 times

On what grounds should I select a specific design?


thanks! --- W°

[Alexander]

Usually the specimen gets melted onto the holder. This is why I recommend the use of some metal, not plastic.

[iconoclastica]

Usually the specimen gets melted onto the holder. This is why I recommend the use of some metal, not plastic.

Something I had not considered indeed. But then, is the vice-construction necessary, or does the toadstool shaped contraption of the drawing suffice?

[Peter]

Hi iconoclastica,
I would recommend you use a small square block of wood to fit between the clamp jaws. The wax will stick to wood better than metal.
Hope this helps.
Peter.

[iconoclastica]

I would recommend you use a small square block of wood to fit between the clamp jaws. The wax will stick to wood better than metal.
Hope this helps. Peter.

Yes, that is helpful for wood is easier to work than metal or ABS. But what do I need a clamp for then? Wouldn't a square block of wood on a one inch, 10mm diameter stick work just as well?

[Alexander]

But what do I need a clamp for then? Wouldn't a square block of wood on a one inch, 10mm diameter stick work just as well?

It will do the job properly.

[MichaelG.]

This is [obviously] not specific to your instrument, but it’s a very useful reference document:
http://users.stlcc.edu/Departments/fvbi ... r_Care.pdf

MichaelG.

[MichaelG.]

Usually the specimen gets melted onto the holder. This is why I recommend the use of some metal, not plastic.

Something I had not considered indeed. But then, is the vice-construction necessary, or does the toadstool shaped contraption of the drawing suffice?

Yes, it will suffice if you are melting wax blocks onto it … but if you are cutting more ‘robust’ specimens, the vice can be useful.

… I have a Reichert-Jung 1120 which needs a lot of tidying-up: Here’s a snapshot of the vice:
.

C2A85B2A-746F-450B-95C2-1336BA71B17A.jpeg (140.1 KiB) Viewed 3963 times

.

If it’s any help, I could provide some dimensions.

MichaelG.

[iconoclastica]

This is [obviously] not specific to your instrument, but it’s a very useful reference document:
http://users.stlcc.edu/Departments/fvbi ... r_Care.pdf

MichaelG.

Excellent! Thanks!

[iconoclastica]

Yes, it will suffice if you are melting wax blocks onto it … but if you are cutting more ‘robust’ specimens, the vice can be useful.

… I have a Reichert-Jung 1120 which needs a lot of tidying-up: Here’s a snapshot of the vice:
...
If it’s any help, I could provide some dimensions.

MichaelG.

Understanding is dawning, I think. I foresee cutting soft plant tissue, so the large-head pin model will do. I'll only have to figure out the rod diameter experimentally.
When eventually I may want to cut e.g. rhizomes too, then the block might need more support, whence the vice. Seeing the details of your vice and the differences with the ones I included pictures of, I'd say that the vice-holder of the B&W image (so the one that came with my model) seems to clamp a 5 sided cubic container in which the wax block sits. Which would be a third way of attaching the object.

I can measure the dimensions from the photos, if necessary. Only when someone here has the Leitz holder, I'd still be interested in the exact rod diameter (and shape, if not strictly cylindrical).

W°

[MichaelG.]

My other Reichert-Jung [a smaller, slightly more recent, model] uses a plain 8mm shank on its wax-mounting head
.

430EC551-89E2-4923-B99C-98C85D9B56E1.jpeg (142.25 KiB) Viewed 3890 times

.

… which is clamped in a collet.

[note: the perspective is rather exaggerated in that photo]
… let me know if you want more dimensions

MichaelG.

[MichaelG.]

Just a ‘heads up’ for anyone interested in microtomes:

This ebay listing has some decent photos: https://www.ebay.com/itm/403428909128

MichaelG.

[iconoclastica]

I just found a 10.0 mm diameter rod that fits and sits tightly clamped. The 9.9mm drill sat too loose, a 10.3mm wooden rod was too wide. Its a hard steel rod that I can neither saw nor attach to a disk. But now I know what to look for.

So a plain shank indeed, and existing holders other than Leitz should not be expected to fit. So called 'universal' holders are not universal at all.

[MichaelG.]

Welcome to the Multiverse [or should that be Mulltiverses ?]

MichaelG.

.

P.S. __ It’s worth noting that the 1212 is described as Large Minot Rotary Microtome

Large being probably relevant to the present discussion, and Minot being its ancestor:
https://collection.sciencemuseumgroup.o ... microtomes

[iconoclastica]

Welcome to the Multiverse [or should that be Mulltiverses ?]

I am honoured
BTW, 10mm aluminium tube appears to be a good starting point for the shaft that fits after a minute of polishing.

---------------------

C S Minot

Nationality: French
active 1886-1892, inventor of a microtome, French


I thought minot referd to the specific kind of knives, but still.

[MichaelG.]

I thought minot referd to the specific kind of knives, but still.

.
A short [hopefully acceptable to the copyright holder] quotation from one of several articles I downloaded from the University Library last night should clarify …

MINOT's AUTOMATIC MICROTOME. — The principle of this Microtome is to obtain sections by moving the object to be cut in a vertical plane past the knife which is held in a fixed position

MichaelG.

P.S. __ This is our hero : http://www.nasonline.org/publications/b ... harles.pdf