It sounds like you don't have an instruction manual. The best thing that you
can do is to contact the original manufacturer for one. Otherwise post the
exact brand and model on Histonet and see if someone will Xerox it for you.
You need the manual so that you can look at the pictures of the proper knife
profile: blunt, good, or too steep. They're difficult to describe in words.
Even without a manual I'll say:
1. Make sure that you scratch the glass only once and that the scratch wheel
is sharp. If not, buy a Red Devil glass cutter and knock out the pin to get
a new wheel. Make sure that you have this kind of wheel first, obviously.
2. There should be indexing marks on the knifemaker bed. Even without
pictures of the knife profiles, you should be able to figure out what
spacing gives the best knives, but ONLY IF YOU TAKE NOTES AS YOU BREAK. To
begin with, write the breaking info on the knives with a Sharpie, then
you'll have it when you find a good knife.
3. The same goes for turning the break wheel fast versus slowly.
Find out which one is better and stick with it. I was told that slow is
best, but then on the maker I used, it wasn't true.
4. Bad knives: look at the edge under a dissecting scope. Tilt it back and
forth. If you see faint parallel lines, perpendicular to the edge, you have
a microscopic saw edge on the knife. It's only good for facing. A good edge
should be completely smooth.
5. The sections of plastic you could should look like saran wrap. If they
have any "texture" at all, your knife is not sharp.

That's all. I could show you this stuff and lots more in 5 min, but I'm a
bit far away.

Jeffrey Crews, HTL (ASCP)

------Original Message------
From: kwalters <kwalters@blue.weeg.uiowa.edu>
To: histo <histonet@pathology.swmed.edu>
Sent: June 1, 2001 4:50:42 PM GMT
Subject: ralph knives


Dear Experts,

I have a ralph knife maker and am trying to use it.  Does anyone know the
optimal clearance angle, best breaking angle, height from the top of the
holder (I use a Microm), and any sectioning bits of wisdom.  I have asked
the
vendor of the knife maker, but they don't seem to know.  I have also
searched
the archives, but the in the earlier thread this was not addressed.  HELP.

Thanks,
Kathy

Kathy Walters                                //
Central Microscopy Research Facility        / /
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University of Iowa                        / /\ \
Iowa City, Iowa 52242                    / /  \ \
Phone #:  (319) 335-8142                / /    \ \
Fax #:  (319) 384-4469                ______   ((0))
email: Katherine-Walters@uiowa.edu     |__|    / /
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