Schnitter Advice Needed: Junk hand cylinder microtome...

[Michael Cytrynowicz]

Dear Microscopists,
(and I hope in a few months I can carefully start posting in German :-)

My old Jung hand microtome, the cylinder type, is playing tricks on me.
The screw movement seems to have a bit of looseness and recoil.

If I turn the base wheel 360-degrees counterclock-wise (that is, 50x 10 µm intervals) it will (as measured by a caliper) correctly go up by about a ½ mm.

But rotating the base say just 5 units, which I would like to be able to do in order to obtain good 50 µm botanical sections, this doesn't seem to be precise at all.

What usually happens is the first 2 or 3, 10 µm intervals, the microtome's inner cylinder doesn't seem to move up at all. I can feel it in my fingers that the movement seems "not engaged".

Then I turn one or more ticks, and often the movement engages again.

This does not happen extremely consistently, though, so it is a guess game.

Right now, I only seem to be able to consistently get cuts that are 100, or 120 µm thick - and I do that by rotating 10-12 intervals straight. Any less intervals is completely imprecise.

Any ideas?

Thank You from Porto!

Mike

[Michael Cytrynowicz]

Oops I noticed I typed "Junk" - instead of "Jung". This was NOT intentional, but a big Freudian Slip :-(

Mike

[beamish]

Did you unscrew it completely and checked the thread for damage? And wash off the old grease with petroleum ether and replace it with fresh one.

Regards
Martin

[Michael Cytrynowicz]

Thank you Martin - how do I take the bottom out to expose the screw?
Also, would you know what the 2 little holes in the inner cylinder are?

Thank you!

Mike

[liftboy]

Hello Mike,

Oops I noticed I typed "Junk" - instead of "Jung". This was NOT intentional, but a big Freudian Slip :-(

thats quite a joke  :-)
remember: "The syringe is your wife, till the rest of your life".

best regards
Wolfgang (not on turkey)

[beamish]

Well, this looks different as I had expected (below a picture of the device as I know it). You have disassambled it completely. Where is the lower part with the microthread?
I don't know the function of these holes. Sometimes holes are only a an outlet for air when compressed.

[Michael Cytrynowicz]

Ah! Martin - thank you. I figured out the base was just removed by continuing to unscrew it all the way. Today I fell not especially smart.

Anyways, mine looks a much older version than yours, my father gave it to me in 1967-68 I think.

Here are the photos of it completely disassembled, and showing the entire screw. Does not seem to be damaged, but someone smarter than me can readily tell what's wrong :-)

Schönen Dank!

Mike

[Michael Cytrynowicz]

I remembered a case where the doctors forgot a syringe inside the patient's body ;-)

Not on turkey? Hm, Ich habe das nicht verstehen...

Hello Mike,

Oops I noticed I typed "Junk" - instead of "Jung". This was NOT intentional, but a big Freudian Slip :-(

thats quite a joke  :-)
remember: "The syringe is your wife, till the rest of your life".

best regards
Wolfgang (not on turkey)

[Michael Cytrynowicz]

...und nur die Bildungen  (hope my German is ok?)

Grüß

[Michael Cytrynowicz]

Ach. Die Bilder.

[beamish]

if no damage visible, maybe cleaning and re-lubricating will do the job...

[Michael Cytrynowicz]

Thank you Martin - I don't have Wundbenzin, but I do have

Special Blade Degreaser (bought years ago)
WD40
Xylol

what is best?

and for re-greasing, Teflon Nye (grease better than oil, correct?)

Grüß aus Porto

Mike

[beamish]

for cleaning puposes any grease solvent will do. As for relubrication I hope that other experienced users will answer...

[Aljoscha]

Hi Mike,

To clean the stuff, isopropanol or any other alcohol will do the job.

Avoid oil, high viscosity grease is a much better option.

Best regards

Alexander

[Michael Cytrynowicz]

Thank you dear Alexander and Martin! - I have both the Isopropanol and the high-viscosity grease here with me.

I will do it and report back soon. Excited to get my microtome working finely again!

Best Regards,

Mike