I’ll explain: Let’s say I want to create a size 7 ring, which means
the diameter should be roughly 17.3 mm. I file the hole on a ring
anvil wrapped in sand paper, while checking the size with a caliper.
Problem is for some reason the hole doesn’t come out perfectly round
while the diameter between two points is 17.3, between other
points it may be 17.1, 17.4, etc.
Question is:
Does this matter? will this bother the person with a size 7
finger?
Can anyone share his or her method for creating “the perfect
hole”?
Can anyone share his or her method for creating "the perfect hole"?
make the ring a tad small, within a quarter size, pound it on a ring
mandrel, polish the hell out of it, rounding off the corners. I
prefer to polish the inside of a shank with a small bristle brush at
60-90 degrees instead of parallel to the shank.
A size 7 ring will still be a size 7 ring whether it’s round or not.
If a ring goes to a size 7 on a mandrel, but there are gaps between
the ring and the mandrel, then it is larger than a 7. A rubber ring
mandrel helps, or just enough experience to “eye-ball” the gaps to
determine the size.
If you are casting, you could buy ring tubes from E-Wax, where the
holes are actually milled to perfect size and centered perfectly in
the tube…either Matt or Kerr, your choice…and the lowest price
for wax tubes in the industry. (630) 886-8814 Or you can start from
flat stock and use a boring bar, but that’s pretty wasteful.
If you are using abrasive on a mandrel, your mandrel is probably
tapered. You need to flip the ring frequently, but remember it is
not possible to make a hole with parallel sides by your method, so
inside measurement would vary, as you see.
But…who cares? A person’s fingers can vary by a 1/2 size easily
throughout the day, and even more from one day to the next. A person
does NOT have a “correct” finger size, thay have an AVERAGE size
which feels comfortable most of the time. So, why worry?
First off did you file the ring evenly before sanding it? It is
important to get the first steps done evenly and continue through all
the steps that way. Are you flipping the ring on the mandrel. Turning
it around as you sand so that both sides are even also if you sand
the ring around the inside 10 times are you sanding it ten times on
both sides. Do everything equally to all surfaces and it should come
out equal in the end.
Well, Jonathan, you come to my restaurant, you order a $50 steak, you
want it medium rare, so I cook it well done and just serve it
up… On the other hand, does anything HAVE to be anything? I have
always thought that if it’s a circle or a square, it should BE a
circle or square - if you want it oblique, make it oblique, not just
a crooked circle. I make “perfect” circles when I can on the lathe,
but I have a lathe. Otherwise, it’s pretty simple, really. I lay out
lines on a wax all over, but for the ring size I just get dividers
and mark a circle of the size or a little bigger on both sides.
Standard ring tube = 15mm hole, need 17mm, so mark a 1mm line around
it. Then I cut up to or nearly to that line, all around, and I use a
file to do it, and do it on both sides - then you know it’s equal and
straight. Finally, make it 1/2 size small, then you can pound it up
round and to size in metal…
make the ring a tad small, within a quarter size, pound it on a
ring mandrel, polish the hell out of it, rounding off the corners.
I prefer to polish the inside of a shank with a small bristle brush
at 60-90 degrees instead of parallel to the shank.
I do the same as Neil. I used to make them exactly the right size
and sometimes they weren’t as round as I wanted them to be. Then I
accidentally made one for my son and it was too small once I’d
soldered it closed. It started out as 3x3mm square stock which I’d
forged to about 1.5x4.5mm and soldered closed. I put it on the ring
mandrel and continued to hammer it (being careful at the solder
joint). Within a few blows, it was the perfect size. I now make all
plain band or hammer textured rings slightly small and “stretch”
them in this manner and they are perfectly round as a result.
Then I accidentally made one for my son and it was too small once
I'd soldered it closed.
I didn’t accidentally make a ring for my son - how ridiculous! I
made a ring for my son but accidentally made it too small, then
"stretched it up on the mandrel and it was lovely and round.
Problem is for some reason the hole doesn't come out perfectly
round - while the diameter between two points is 17.3, between
other points it may be 17.1, 17.4, etc.
Sounds like you are getting pretty good precision for hand work of
any kind. The only way I could imagine you would get a more perfectly
round hole is to bore it on a lathe or mill, then buff and polish the
result.
Your ring will be round to the eye, which is sufficient for
aesthetic purposes, and I don’t know anyone with a perfectly round
finger anyway.