Does anyone have a favorite jig or process for sharpening very small
bits such as those numbered #65 - #50?
Thanks in advance.
J Collier
Metalsmith
Does anyone have a favorite jig or process for sharpening very small bits such as those numbered #65 - #50?
i use an optivisor and a bench grinder, make the tip red,
problem is the web, which you can re-create with a separating
disc, or use center drills to start your holes,dp
There is a tool at the specialty tool stores called the drill
doctor, or drill bit doctor, which is a drill bit sharpener that is
supposed to work well costs alittle bit but never buy them again?
Probably find it on ebay or google
Frank
Just a warning: I just searched on Google as you advise, and went to
the US Drill Doctor site; a warning came up on my computer from
Norton Security saying that site’s security was not guaranteed, I
moved away from the site and 3 minutes later a Norton notice came up
saying that program had just blocked an attempt to attack my
computer. Just letting you know!
You can also try Lowes and Home Depot
called the drill doctor, or drill bit doctor, which is a drill bit sharpener
Forgot to reply to this yesterday… The Drill Doctor is a respected
machine, but it only goes as small as 1/8" or something - ten times
the diameter of a #68 drill bit. I used to use a separating disk,
holding the bit in my hand. Then I changed to a diamond wheel that I
happen to have, which is 220 grit and also used, so it’s softer. I
use #68 and #72 for most everything small, and then bigger as needed.
It’s not very difficult (under optivisor) to get the hang of the
angles after a bit, and actually there’s a fair amount of leeway from
the “ideal” angles they come ground at. I generally put a steeper
overall angle and they cut faster… I’ll put out one little tip:
to make sure the main facets (I forget the drill nomenclature at the
moment) are centered on the axis of the shaft, turn the bit in your
fingers so they catch the light, and they should be the same size.
Actually, when you look at one and it looks like ~more~ than half and
then turn to the other one and it also looks like ~more~ than half,
then you know it’s centered. Sounds crazy but it’s a kind of illusion
I’ve noticed… It’s not hard to do, once you get the hang of
it…
There is a process using nitric acid to sharpen tool bits and
drills. I watched this at New Approach Jewelry School in Virginia
Beach. The instructor is Blaine Lewis.
Ther is a tool called a wishbone drill sharpener. I have one and
used to use it a lot. I was drilling 0.8mm holes in thin sheet
titanium and they would break at 80 holes, so I sharpened them at 70.
It takes a bit of practice to get proficient, don’t know where you
would get one now, E-bay?
Here is a link to more info
http://cnczone.com/forums/showthread.php’t=693
regards Tim Blades.
There is a tool at the specialty tool stores called the drill doctor, or drill bit doctor, which is a drill bit sharpener that is supposed to work well costs alittle bit but never buy them again?
It is a Drill Doctor, it works fine on larger bits but is not so
good on smaller than 1/8" diameter drills.
Hand sharpening seems to be the only way to go on these small bits,
the tools used by the manufacturer are way too expensive to buy for
a goldsmith. Some machine shops have the precision drill grinders but
you got to sharpen a lot of drill bits to pay for a $3K-$5K tool.
JIm
James Binnion
James Binnion Metal Arts
Does anyone have a favorite jig or process for sharpening very small bits such as those numbered #65 - #50?
I sharpen them freehand, under a good loupe, with the side of a
seperating disk. The very thin disks have smoother sides, which work
better than standard sep disks, but both work. The trick is holding
the disk (in the flex shaft) at a fixed angle, and rotating the drill
bit, either in fingers or a pin vise or a #30 handpiece, etc, Grind
one face of the tip, and rotate the bit 180 degrees. You judge this
by observing the position of the flute grinds. Grind the other face
of the tip till looking down on the end the two are even sizes and
the junction of the two faces is centered. Easier to do than to
describe… As the drills get shorter, you may have to use the edge
of the sep disc to thin the web a little. With a good ten power eye
loupe or microscope to work under, I sharpen up to #80 bits this way
(though those really small ones are a pain to hold onto…)
Peter
There is a process using nitric acid to sharpen tool bits and drills. I watched this at New Approach Jewelry School in Virginia Beach. The instructor is Blaine Lewis.
Sharpening with acid is not true sharpening. It creates quasi
serrated edge, which does not last long. On small drills there is an
accuracy problem as well.
Leonid Surpin
I wonder if a small drill bit could be mounted in a pin vise and then
the pin vise mounted in the chuck of the Drill Doctor.
Bill
Reactive Metals Studio, Inc
I also do it by hand with a thin separating disc, as I regularly use
.50mm drills. You just touch it gently to the flat surface for a
split second. First I do the ‘v’ to get it symmetrical–to get the
point in the exact center; then I go back and angle each leg of the
’v’. All in all: 4 split-second touches. To get a good sense of what
you are aiming for, look at a great big bit (preferably new)–it’s
tremendously helpful in getting the angles in your head. I was amazed
with the results the first time I sharpened a tiny drill bit–it
worked better than new ones…:-)…! So I resharpened all my old
broken ones, and have never bought a drill bit since…
I use 0.8mm drills all the time to drill through titanium.
I find the best method to sharpen small drill bits is not using
mechanical
methods:
ie. sanding or other disks. There is always a possibility of
overheating the tip. Also it is easier to control and see what you are
doing. I use a medium ‘easylap’ diamond file.
1st, it is important to remove any nasty ends from broken drill bits
or any blued, or overheated areas before starting the sharpening
process. 2nd, position a strong light at such an angle so that the
light reflected from the faceted tip will shine into your eye when you
place the blunt tip against your bench pin. Wear magnification lenses.
Indeed take a new sharp drill and hold it against your bench pin and
observe the shape of the facets of the sharp drill. Try to copy the
angles, or establish the angles you require for the metal you are
using, with the reflected light shining of the facets.
Test the sharpened drill before doing something important. Use lots
of lubrication.
A pin vice is helpful.
David Cruickshank
I also do it freehand. I find that a seemingly exaggerated alignment
of drill to cutoff wheel works best. And I find that if I don’t get
the alignment right first off, adjustments just seem to make it
worse. At which point I’ll grind the tip square and start over again.
The Drill Hunter…one shot.
The other day I needed a .010" diameter drill bit so I grabbed a
junk bit and after cutting down its diameter, sharpened it. Not so
easy when its that small. It didn’t cut like a champ but it did cut
and didn’t shatter and that would be my biggest concern at that size.
I wonder if a small drill bit could be mounted in a pin vise and then the pin vise mounted in the chuck of the Drill Doctor.
I doubt the results would be very good, The drill Dr uses a setting
jig on the front of it that grips the flutes of the drill and
orients the bit to the proper angle in the collet for sharpening in
the Drill Dr. Very small drills will not have enough contact area to
get correct alignment from this jig and even on larger bits the
alignment this jig provides is not always correct and is the biggest
problem with the Drill Dr… Darex, the company that makes the Drill
Dr makes very nice high performance drill sharpening tools but they
are around $5K.
You can buy what are called single point tool grinders that can
sharpen small tools like drills or lathe tools single flute mills
etc for a few grand but there is just not any tool that I have seen
that will sharpen small tools with the necessary precision that is
not fairly expensive.
Your best bet is to learn how to do it by hand or use something like
the small jig that Tim Blades posted about above at this URL
http://www.cnczone.com/forums/showthread.php?t=693&page=2
Jim
James Binnion
James Binnion Metal Arts
this is all done very easily with an optivisor and a fine bench
grinding wheel, and water, you must match the profile that you see
on a new drill, try many, start with large ones, you must match
the angle from the center, they are obviously symmetrical, and then
the tilt back(rake) of the blades, same length on each side, get a
small pamphlet on how to do it from grainger or somewhere, and
match the new one, practice practice with large drills, best to
paint the tip in red marker, and paint it after each pass so you get
a feel for where the wheel is hitting the drill until you get it,
and good light, don’t forget to dip it in the water after each
second or 2, try not to let it turn blue also, like i already said in
the first post, you will lose the web on the drill so you will most
likely have to use a center drill, spring loaded punch etc to make a
divit, satrter hole, dave
Has anyone ever tried the ‘Drill Doctor’? I think Lee Valley carries
it. Not sure
Simone
Thanks to everyone for the input. At this point I believe that my
most practical solution for the very tiny #65-#80 bits will be
replacement. Larger sizes may allow me to “hack” a new cutting edge
onto them when more proficient at the task.
In searching the net this link came up which has decent diagrams and
a procedure to sharpen bits. http://tinyurl.com/2wfcjhp
One might consider this info from the text: / While it is worthwhile
acquiring the experience in grinding twist drills by hand, it should
be noted that this would not be tolerated in any engineering works
where accuracy is required: the drills would be properly ground in
the tool room or proper drill-grinding equipment would be available.
/Again, thanks!
j
J Collier
Metalsmith
grinding twist drills by hand, it should be noted that this would not be tolerated in any engineering works
Probably the biggest single reason for that is having the tip
precisely on- center with the shaft. If it’s even a tiny bit off,
the drill will pull off the center line of the hole being drilled.
When punching holes through 22ga silver or maybe drilling a spot just
to string your sawblade through, it really doesn’t matter much if
it’s a bit off. When you get into drilling #72 holes through 3mm of
white gold, it can be a real factor, though. Just FYI.