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
Oops I noticed I typed "Junk" - instead of "Jung". This was NOT intentional, but a big Freudian Slip :-(
Mike
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
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
Hello Mike,
ZitatOops 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)
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.
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
I remembered a case where the doctors forgot a syringe inside the patient's body ;-)
Not on turkey? Hm, Ich habe das nicht verstehen...
Zitat von: liftboy in Juli 01, 2024, 13:35:11 NACHMITTAGSHello Mike,
ZitatOops 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)
...und nur die Bildungen (hope my German is ok?)
Grüß
Ach. Die Bilder.
if no damage visible, maybe cleaning and re-lubricating will do the job...
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
for cleaning puposes any grease solvent will do. As for relubrication I hope that other experienced users will answer...
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
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
Dear friends,
Success! All cleaned with Iso, greased with Nye Synthetic grease. Note the most useful Tempo paper :-)
Movement is now very precise and smooth, and I can feel even 1 unit - 10 µm - going up.
Now for the Botanical Schnitte!
Many Thanks!
Mike/Portugal
Congrats!
Hi Mike,
in use the cylinder microtome can get into contact with water so it is a good idea to apply a little oil on the bearing surface between inner and outer cylinder to prevent corrosion.
It is a nice microtome and you would have to look for a while to find a second one of this quality.
Take care,
Bob
Ah! Bob, thank you for the advice! - will do (yes, it does get water).
I know it's a great microtome - but to be honest, I am still struggling to get good thin sections :-(
I am using the carrot method, but it seems that the carrot, even if it is held very tightly, it seems to recoil, and move down in the clasp. I don't SEE any obvious movement down, but it must be doing this. And I try to be very careful with the Leica disposable blade, wet, etc.
I know this is happening because, with the microtome cleaned and re-greased, the screw now works nicely and precisely - but, if I make a cut then move it up 5 ticks, 50 µm, and slide carefully the Leica blade again, it does seem to be higher than the sample.
If I instead turn the screw 10 ticks, 100 µm, then a cut will be made, but of course thicker than I want.
This is driving me nuts :-)
Mike
Hi Michael,
sorry, I just now found the time to have a look into the forum again.
Acheiving a proper slice of the specimen is the result of two cuts, the one before and the one now. So you have to make sure that your cut before actually took off a slice and not just rubbed over the specimen. It also it helpful to carry out the two movements in identical speed and way of travel, like a machine woul do.
50µ works for many samples but sometimes it is too little. In this case I start with 100µ and work my way down. It is worth to look closely when the cut is started: Does the blade really enter the specimen or does it just deform it or rub over it? I sometimes help to increase the sideway component of the movement right when entering the specimen.
Some samples are difficult to section nicely, in this case it is better to move to something that is easier to section. We are amateurs and it should be enjoyable! :)
Cheers
Bob
Dear Bob, many thanks! - this is very helpful, and I will pay a lot of attention next cuts - to see whether a cut has actually been made, and to increase the lateral component of the move when touching the sample. I will report back!
Cheers,
Mike