According to Joseph Gwinn :
In article ,
(DoN. Nichols) wrote:
According to Joseph Gwinn :
In article ,
(DoN. Nichols) wrote:
[ ... ]
I thought of building a little vapor degreaser as described above that
would use some available but flammable solvent, and running it only in
the middle of the back yard. Someday.
That makes sense.
The plan was to use some vitrified power resistors as the boiler, and a
loop of copper tube soldered to the rim with garden-hose water flowing
through as the cooler.
That should do it. The longer the skirt of the chilled top, the
less vapor escapes (given protection from wind, of course).
FWIW -- I can testify that silicone oil (supposedly
non-flammable) *will* ignite and burn if the vapors from a heated beaker
of it curl around into the still-hot elements of the hotplate on which
the beaker is sitting. (There was some dry ice in the beaker to hasten
it back to the starting point of a temperature coefficient run.) And,
when that vapor burns, the result is very fine sand all over the place. :-)
I'll have to try this someday. In the backyard.
Be sure to have a CO2 fire extinguisher handy. I'm not sure
what a hose would do for that -- possibly float and spread the burning
silicone oil.
Note that this was a mix of two silicone oils -- one which was
normally used for measurement at -50C, and the other which was normally
used at +150C. The first would boil at the high temperature, and the
second would set up into a grease at the low end, making it hard to
equate the temperature at the thermometer with that in the device under
test. The low-temperature oil, when it hit the bubbles from the dry ice
in the beaker evaporated quickly, and spilled over the edge and curled
into the heating elements.
We would have been better off letting the beaker cool down on
its own -- but we had quite a few more devices to test -- ones returned
from the customer, because while they met specs at -50, +50, and +150C,
they were out of spec at some points between those temperatures.
In the meantime, I soaked it in WD-40 plus acetone, spinning the bearing
while immersed in solvent, and blew the bearing off with compressed air.
O.K. As long as you don't spin the bearing with the compressed
air. *That* can be disastrous.
How so?
It can spin up to a fast enough RPM so the centrifugal force (I
know -- there really is no such thing) will cause it to fly apart --
turning it into shrapnel -- and *you* into a target. I don't know
whether there is any size limit for this to happen, but it has been
known to happen and to harm or kill people nearby.
[ ... ]
Or, perhaps I can press the bearing race into place.
That would be better if possible. Can you turn up a cylindrical
pusher to press only on the inner race?
Not yet, but soon. There is a cylindrical sleeve already there. I
think it is supposed to rest on the bearing inner race on one end, and
one flange of the two that hold external grinding wheels on the other.
O.K.
[ ... ]
I would just have at it, and use the opportunity to clean the crud out
of the bearings. It isn't all that tricky or hard; I've had zero
trouble.
O.K. -- Other than getting things fully back together with the
caps fully tightened. (Which I gather was a pre-existing condition. :-)
Perhaps there is some grit stuck between the inner race and the spindle?
Yes, it was pre-existing, and I bet it was that way when Grandfather got
the unit. There is lots of dirt in the way at present.
O.K. You get yours back together properly, and then I will take
mine apart -- assuming that the manual does not turn out to say *don't*
in big bold letters. :-)
Mine has an unthreaded nose with axial hole and grub screw.
Hmm ... "grub screw"? You're posting from the UK? I think that
is mostly a UK term. :-)
[ ... ]
I did pick the term up from RCM. Sounds better than setscrew,
Well ... it works nicely if you understand where the term
originated -- but the "setscrew" term is more descriptive of the
function.
[ ... ]
O.K. But the other fellow who has jumped into the thread has a
spindle like mine, and has screw-on collet adaptors -- not replaceable
spindles.
I wonder. I think that all Series 11 grinders have removable spindles.
It may depend on what you call "removable". Certainly the ones
which started this thread were designed to screw into a hollow spindle
with a taper, based on the photos. (Hmm ... has that auction closed,
yet? :-)
[ ... ]
Well, lots of special-purpose tools were made of maple, and it isn't all
that more costly than oak in small quantities at HD, and the grain is
very fine and uniform.
I had to go to a specialty wood shop to get my maple -- of
appropriate thickness for making replacement concertina pieces.
Ouch. I bet it is *very* good wood. There must be other sources.
Probably -- but this is a nice quality wood, for not that bad a
price, and it is a lifetime supply for the parts which I need to make.
[ ... ]
15,500 RPM no load
8,000 RPM full load.
This sounds plausible, from the sound while it spins.
You don't have a strobotac? I've recently discovered that they
are on eBay for fairly reasonable prices -- except that I already got
mine at a hamfest.
Thought of it, haven't done it yet.
O.K. If you can -- try to pick up on another auction of FX-6A
flashlamps -- these darken with use, and are now *very* hard to find. I
finally won an auction for enough to keep me going for a while.
Pulleys
Wheel size RPM Spindle Motor
=====================================
1/8" to 3/4" 30,000 #1 #2
2" 6,900 #2 #1
My pulleys are 2.165" and 0.906" in diameter, so the available ratios
are 2.39:1 and 0.418:1, for loaded speeds of 19,117 rpm and 3,348 rpm
respectively. No-load speeds are about twice that.
Hmm ... I don't have the measurement for the larger pulley, but
the smaller one has a maximum diameter of 0.9245" -- measured to make
that ring spanner wrench.
I rechecked the diameters, this time with a micrometer (not a caliper).
They are 0.906" and 2.184" in diameter, more or less as reported.
O.K. This shows a difference between our TP grinders, as does
the nature of the spindle.
[ ... ]
It will rust things *if*:
1) The surfaces are not first wiped down with Vactra No. 2.
2) The wet newspapers are left on for longer than a work day.
Newsprint is somewhat acid. That's why it yellows so fast.
Yes -- but that is a *very* low amount.
Vactra #2 seems to be the universal elixer of machine tools.
Yep! You should always have plenty on hand, after all.
[ ... ]
Actually -- setting it to 5-3/4 degrees by eye should get you
close enough. You are only going to be making very small reductions in
diameter, so frequent checking with a good micrometer should suffice in
addition to this. This simply lets you make adjustments in finer steps,
and it would be useless for turning, as there is often more spring than
that in even a good rigid lathe.
Right. This only works for grinding on anything other than a Hardinge.
Agreed. Though it works *sometimes* with really sharp cutters
and non work-hardening workpiece materials on the Clausing. When I want
to work to precise dimensions, I often use one of the carbide insert
tools from my Emco-Maier Compact-5/CNC. It is a very small 55 degree
diamond insert, and I lucked into a batch of inserts which are very
sharp and not TiN coated, so the edges are not rounded off. Certainly
the inserts which came with the lathe were not so sharp.
Would HSS, well-sharpened, be better?
That depends on the material -- but it potentially would be.
This is good enough so I don't feel the need to make HSS tools for that
specific purpose.
[ ... ]
Both. I don't think that Grandfather was an employee, as all his
patents were his, and were not assigned to anybody.
O.K. Which explains why he had a shop at home, and could (and
did) do such precision work -- for the prototypes, so he was not
obligated to anyone else, and could license his patents to who he
wished.
Sounds right. Wonder what became of his lathe et al. I didn't inherit
any of it. Though I don't recall his basement being crowded with
machine tools. He must have had a machine shop or at least access
somewhere else.
O.K. Interesting that you wound up with the toolpost grinder.
Lucky for you.
[ ... ]
I bet there is a patent covering the Dumore grinder. Are there any
patent numbers on anything? My unit has nothing, but then again it's
pretty spartan.
Hmm The only data source which I have is the motor label, and
all it says on the subject is "Trade Mark Reg US Pat Off" in the upper
left and right corners. :-)
Protects only the trademark "Dumore".
Yep -- but that is all the information that I have from my
grinder. And I wonder how much of it would be patentable by that time.
Perhaps not enough to make it worth while hanging patent numbers on it,
if the patents were all expired.
[ ... ]
He also says that they told how much oil and what grade (which
they specified as their own brand, of course. And the oil is supposed
to only be added at the center.
Yes, Dumore type 0 oil, which sounds to be pretty low viscosity.
I wonder if one can buy new wicks.
I suspect that one would need to make new wicks at this point.
You can get appropriate felt from McMaster Carr for the task.
[ ... ]
Did the MGA manual mention how to reassembly this little beauty?
Sure -- the same way they had to reassemble *any* part. The
last paragraph of each section would read:
"Reassembly is a reversal of the above."
Unh.
:-)
Hmm ... I replaced the ones on my second MGA (1600 Mk II), and I
don't remember it being particularly difficult -- unlike some other
things, including replacing the clutch plate and pressure plate. :-) For
*that*, you have to remove the engine and transmission as a unit. And
to do that as indicated by the manual, you have to remove the
transmission tunnel, and to remove *that* you first had to remove the
floorboards -- plywood floorboards secured by screws which stuck out far
enough through the floor to get dinged and rusted.
After doing it by the book *once*, I figured out how to remove
the motor and transmission without removing the trans tunnel. But it
required small hands and blind dexterity. (It still beat doing it as
intended. :-)
Sadly, I never had the pleasure. GF got rid of that card first. Or
crushed it; don't recall which. Saved by the bell in any case.
O.K. The MGA was a fun car, and I suspect that the B was as
well. (I preferred the appearance of the A.)
Enjoy,
DoN.
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