Nothing wrong with it but I never say anyone who worked in a shop use
anything like that. In the Airforce shop we used to have the kids just
starting out make a little sheet metal gauge with the various angles
on it to check their tool bits but by the time they were a journeyman
they didn't use it any more.
========================you might like this
FWIW a quick way to cut a groove type chipbreaker, even in
carbide is with an air or electric die grinder (drimmel
tool) using a cut off wheel. I have had good luck with
these. Doesn't have to be a deep groove, just deep/wide
enough to catch the tip of the chip as it curls to cause it
to break off.
Works with both carbide and HS, although a little faster wer
On Thu, 12 Jun 2014 22:56:53 -0500, F. George McDuffee
Yup, one shop had one. The Shop Chief was quite insisted that it was
solely for grinding carbide.... which nobody used :-)
Yes, but I didn't understand the mention of a need for a follower rest
(we called it).
Well, chip breakers aren't really a precision thing and they do vary
in efficiency depending on speed and feed so we used to just grind a
notch on the top of the tool, or a little flat to lower the cutting
edge a bit and try it. If it worked, Wonderful! And if it didn't than
make another visit to the pedestal grinder :-)
I made a shifter knob for my old Mini when I was 16 out of a chunk of
that crap.. The "rough cut" sure lived up to it's name and made the
10" south bend grunt. The finish cuts made gobs of wool.
Don't know if I would want to do it on my Myford Super 7.
On Monday, June 9, 2014 12:57:31 PM UTC-4, Cydrome Leader wrote:
I tried to hold a magnet by the cutter to catch some of the
A good idea that I read here is to turn a zip lock bag inside out and put a magnet in it. Pick up the magnetic smarf and then turn the bag right side out so the smarf in inside the bag and the magnet is on the outside.
Sorry , but I do not remember the original poster.
One of the old books Lindsay sold described the Cincinnati Milling
Machine Company's experiments with feeds and speeds back around WW1,
before carbide and flood coolant(?). They said that cast iron machined
about the same with or without cutting oil and suggested milling it
dry only to minimize the oily mess.
Some of that dust is graphite and not magnetic.
the home machine type forums go back and forth on this. "Machine cast iron
dry" seems to be the mantra, but people with huge machines in large shops
do appear to use flood coolant, which isn't going to be happening with any
of the tabletop stuff I use.
I can't wait to see what sort of mess flycutting the stuff makes.
Any favorite durabar or equivalent cast iron barstock internet suppliers
people suggest? onlinemetals.com doesn't seem to carry the stuff for some
On Mon, 9 Jun 2014 16:57:31 +0000 (UTC), Cydrome Leader
====================Be reminded that fine cast iron dust/graphite is
flamable/explosive. It is an ingredient in sparklers and
fireworks. *FINE* cast iron dust/graphite in an explosive
charge makes a much louder bang and a bright white flash, e.
g. firecrackers, most likely due to the fuel/air effect.
Grain dust/flour in air will also explode under the right
It needs LOTS of oxidizer. With gobs of barium nitrate (which is a good
one), iron dust barely burns. THAT is what sparklers are made of.
Cast iron dust doesn't become pyrophoric until it's down below 1/4-
micron, and then only if it's deliberately cast into the air.
There are some 'toasted' mixtures of coarser iron powder and sulfur that
are more pyrophoric -- enough that they reliably burn when cast into the
But, then, sulfur is a very effective oxidizer for iron.
The rest of that post was silliness. Iron is about useless in flash
powders, and mixtures of iron and oxidizers won't explode without extreme
measures to contain them.
Iron has never been used to increase the power of an explosion or to make
a white flash. That's aluminum... Iron makes branching yellow sparks.
Yeah... well, SOMETIMES it's fun. Sometimes it's cool. The rest of the
time, it's spending your time figuring out how to automate something and
still meet all the codes and regulations controlling how you CAN'T have
electrical machinery in explosives environments. (worse when Mil specs
must be met)
Actually, that's simple, too, if you have an unlimited budget. My
clients usually don't, and I SURE don't! So we have to 'figure a way' to
satisfy the inspectors, and it's different every time we put together a
It's still fun burning up stuff for a living. I'd have done it for free
in my youth, if someone had let me.
Fine dust in the right concentration in air is adequate.
See the cited videos. Remember that a fair fraction of cast
iron dust is graphite, in effect coal dust, which is highly
explosive, and if this flashes, it can be enough to ignite
the iron dust. See how it sets the shirt on fire in the
Years ago CI dust build up was a problem in line shaft drive
machine shops. When I worked at Carter Carburetor in the
mid 60s, there was still a area with line shaft drive
machining cast iron, the WCFB cast iron four bore flange
line. About every 6 months or so, when everybody had
forgotten about the last fire and let housekeeping slide
[place was like a coal mine], there would be a fire along
the overhead shafts, with star bursts when it got to the
spinning pulleys with the larger dust build up and better
air flow. No serious injuries as I recall, just some
superficial burns from the falling "sparkles," but several
people were hurt running for the door or the line motor
On Monday, June 16, 2014 12:39:52 AM UTC-4, F. George McDuffee wrote:
Remember that a fair fraction of cast
Carbon can be Diamond, Graphite , or amorphous . Diamond is not easy to bu
rn. I have heated diamond when speltering a bit for trueing grinding wheel
s and it did no burn. Graphite in any reasonable sized pieces is also hard
to ignite. In fine dust it maybe close to acting like amorphous carbon, b
ut I have used graphite as a base for silver soldering without it burning.
Fine dust is something else. Next time I machine some cast iron , I will p
ut some of the chips on a fire brick and see how hard it is to ignite.
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