I'm trying to turn a front sight base that will fit a tapered barrel.
After some hand-to-calculator fighting, I came out with a 1/2 degree per
side angle. Start of the band is @.610, the end is @.630, looking at
tapered end mills in Wholesale tool, Grainger, KBC, Enco, and others
shows a decent range of prices, but the corker seems to be the front
diameter. Stock tapered end mill tips are in common sizes, like 3/8,
1/2, 5/8 and 3/4.

Thing is, moving the band rearward gets the band into the diameter of
..623, but the band will be over an inch and a half from the muzzle.

Looking at the iGaging digital protractor, the accuracy is listed as .2
degrees. Resolution is listed as .05 degrees, but look at the accuracy
and we're well into half the value of the desired angle.

How can I set my compound for boring? Angle plates? Adjustable angle?

Louis Ohland wrote:

I'm trying to turn a front sight base that will fit a tapered barrel.
After some hand-to-calculator fighting, I came out with a 1/2 degree per
side angle. Start of the band is @.610, the end is @.630, looking at
tapered end mills in Wholesale tool, Grainger, KBC, Enco, and others
shows a decent range of prices, but the corker seems to be the front
diameter. Stock tapered end mill tips are in common sizes, like 3/8,
1/2, 5/8 and 3/4.

Thing is, moving the band rearward gets the band into the diameter of
.623, but the band will be over an inch and a half from the muzzle.

Looking at the iGaging digital protractor, the accuracy is listed as .2
degrees. Resolution is listed as .05 degrees, but look at the accuracy
and we're well into half the value of the desired angle.

How can I set my compound for boring? Angle plates? Adjustable angle?

I think you should be looking for a tapered reamer.

On 2/21/2011 19:40, Pete C. wrote:

I think you should be looking for a tapered reamer.

Uh, yeah. Tapered end mills seem to be the only game in town, however.
The tapered reamers that I've seen are rated in inch/foot tapers.
Looking at Machinery's Handbook, the tapers are way too large.

Perchance a vernier protractor, dunno.

"Louis Ohland" wrote in message
...
I'm trying to turn a front sight base that will fit a tapered barrel.
After some hand-to-calculator fighting, I came out with a 1/2 degree per
side angle. Start of the band is @.610, the end is @.630, looking at
tapered end mills in Wholesale tool, Grainger, KBC, Enco, and others shows
a decent range of prices, but the corker seems to be the front diameter.
Stock tapered end mill tips are in common sizes, like 3/8, 1/2, 5/8 and
3/4.

Thing is, moving the band rearward gets the band into the diameter of
.623, but the band will be over an inch and a half from the muzzle.

Looking at the iGaging digital protractor, the accuracy is listed as .2
degrees. Resolution is listed as .05 degrees, but look at the accuracy and
we're well into half the value of the desired angle.

How can I set my compound for boring? Angle plates? Adjustable angle?

What I've done before is chuck up a piece of drill rod, indicate it true,
then mark off an inch or few inches and indicate the compound to taper the
desired thousandths per the distance I marked off. For example if I want a
taper of 0.008" per inch, I mark 1" on the drill rod and set the compound
with an indicator to move the desired amount per inch.

After getting close, you can use high spot blue to see if the taper fits
evenly or not, and work for a more perfect fit.

RogerN

Louis Ohland wrote:
I'm trying to turn a front sight base that will fit a tapered
barrel. After some hand-to-calculator fighting, I came out with a 1/2
degree per side angle. Start of the band is @.610, the end is @.630,
looking at tapered end mills in Wholesale tool, Grainger, KBC, Enco,
and others shows a decent range of prices, but the corker seems to be
the front diameter. Stock tapered end mill tips are in common sizes,
like 3/8, 1/2, 5/8 and 3/4.

Thing is, moving the band rearward gets the band into the diameter of
.623, but the band will be over an inch and a half from the muzzle.

Looking at the iGaging digital protractor, the accuracy is listed as
.2 degrees. Resolution is listed as .05 degrees, but look at the
accuracy and we're well into half the value of the desired angle.

How can I set my compound for boring? Angle plates? Adjustable angle?

Chuck the barrel up muzzle to the headstock - better yet use centers .
Mount an indicator to the compound and adjust until the indicator stays
steady when you crank it in and out .

--
Snag
Learning keeps
you young !

Chuck the barrel up muzzle to the headstock - better yet use centers .
Mount an indicator to the compound and adjust until the indicator stays
steady when you crank it in and out .

Almost there, but the barrel is in the action. Ooh, here's the
thought... cylindrical action, not perfect, but chuck it up, run the
muzzle very carefully onto a tailstock live center. Use indicator as
described. Snap, that's backwards. Unless I indicate the far side of the
barrel...

Louis Ohland wrote:

On 2/21/2011 19:40, Pete C. wrote:

I think you should be looking for a tapered reamer.

Uh, yeah. Tapered end mills seem to be the only game in town, however.
The tapered reamers that I've seen are rated in inch/foot tapers.
Looking at Machinery's Handbook, the tapers are way too large.

Perchance a vernier protractor, dunno.

The compound isn't intended for cutting accurate shallow tapers, that is
why taper attachments for lathes exist. You will likely have to go by
trial and error, test cutting some scrap and test fitting until you find
the correct setting.

My first preference was a tapered mill or reamer, because this only
changes about .010 over the inch I need.

On 2/21/2011 21:17, Pete C. wrote:

Louis Ohland wrote:

On 2/21/2011 19:40, Pete C. wrote:

I think you should be looking for a tapered reamer.

Uh, yeah. Tapered end mills seem to be the only game in town, however.
The tapered reamers that I've seen are rated in inch/foot tapers.
Looking at Machinery's Handbook, the tapers are way too large.

Perchance a vernier protractor, dunno.

The compound isn't intended for cutting accurate shallow tapers, that is
why taper attachments for lathes exist. You will likely have to go by
trial and error, test cutting some scrap and test fitting until you find
the correct setting.

Louis Ohland wrote:
Chuck the barrel up muzzle to the headstock - better yet use centers
. Mount an indicator to the compound and adjust until the indicator
stays steady when you crank it in and out .

Almost there, but the barrel is in the action. Ooh, here's the
thought... cylindrical action, not perfect, but chuck it up, run the
muzzle very carefully onto a tailstock live center. Use indicator as
described. Snap, that's backwards. Unless I indicate the far side of
the barrel...

Machine a plug that is a very light press fit in the action ?

--
Snag
Learning keeps
you young !

On Feb 21, 10:17*pm, "Pete C." wrote:
Louis Ohland wrote:
...
The compound isn't intended for cutting accurate shallow tapers, that is
why taper attachments for lathes exist. You will likely have to go by
trial and error, test cutting some scrap and test fitting until you find
the correct setting.

Maybe you could you attach a sine bar set to 0.5 degrees to the
faceplate and use a square to transfer the angle to a bar clamped into
the compound dovetail.

I tried to cut a taper for a grinding wheel spindle adapter with the
compound and found that I needed to refit the dovetails so the gibs
were evenly tight throughout the full travel.

jsw

On Feb 21, 5:56*pm, Louis Ohland wrote:
* *I'm trying to turn a front sight base that will fit a tapered barrel.
After some hand-to-calculator fighting, I came out with a 1/2 degree per
side angle. Start of the band is @.610, the end is @.630, looking at
tapered end mills in Wholesale tool, Grainger, KBC, Enco, and others
shows a decent range of prices, but the corker seems to be the front
diameter. Stock tapered end mill tips are in common sizes, like 3/8,
1/2, 5/8 and 3/4.

Thing is, moving the band rearward gets the band into the diameter of
.623, but the band will be over an inch and a half from the muzzle.

Looking at the iGaging digital protractor, the accuracy is listed as .2
degrees. Resolution is listed as .05 degrees, but look at the accuracy
and we're well into half the value of the desired angle.

How can I set my compound for boring? Angle plates? Adjustable angle?

Make a D-bit reamer, it's easy enough.

Stan

On Feb 22, 7:53*am, wrote:
On Feb 21, 5:56*pm, Louis Ohland wrote:
...
How can I set my compound for boring? Angle plates? Adjustable angle?

Make a D-bit reamer, it's easy enough.

Stan-

Yeah, just set the compound to 0.5 degree and turn one from drill rod.
They'll cut a little while without being hardened.

jsw

On 2/22/2011 06:53, wrote:

Make a D-bit reamer, it's easy enough.

Stan

Oddly, that came to me while drinking coffee. Except the D-bit part.

Is this like a spade bit with a removable blade? Excuse the bad analogy,
still looking.

Jim Wilkins fired this volley in news:193fe058-9df9-
:

Yeah, just set the compound to 0.5 degree and turn one from drill rod.
They'll cut a little while without being hardened.

jsw

Umm... Jim?

this was a joke, right?

LLoyd

On Feb 22, 7:13*am, Jim Wilkins wrote:
On Feb 21, 10:17*pm, "Pete C." wrote:

Louis Ohland wrote:
...
The compound isn't intended for cutting accurate shallow tapers, that is
why taper attachments for lathes exist. You will likely have to go by
trial and error, test cutting some scrap and test fitting until you find
the correct setting.

Maybe you could you attach a sine bar set to 0.5 degrees to the
faceplate and use a square to transfer the angle to a bar clamped into
the compound dovetail.

I tried to cut a taper for a grinding wheel spindle adapter with the
compound and found that I needed to refit the dovetails so the gibs
were evenly tight throughout the full travel.

jsw

Or, just attach thge sine bar to thge faceplate and an indicator to
the compond. Adjust the compond angle until you can run it in and out
along the faceplate without moving the needle.

On 02/22/2011 05:05 AM, Jim Wilkins wrote:
On Feb 22, 7:53 am, wrote:
On Feb 21, 5:56 pm, Louis wrote:
...
How can I set my compound for boring? Angle plates? Adjustable angle?

Make a D-bit reamer, it's easy enough.

Stan-

Yeah, just set the compound to 0.5 degree and turn one from drill rod.
They'll cut a little while without being hardened.

Surely you mean set the tailstock over?

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

On 2/22/2011 13:20, Tim Wescott wrote:
Make a D-bit reamer, it's easy enough.
Yeah, just set the compound to 0.5 degree and turn one from drill rod.
They'll cut a little while without being hardened.

Surely you mean set the tailstock over?

Setting the tailstock over the few thous has the advantage of
simplicity. Run between centers. I assume moving the tailstock toward me
will reduce the tailstock end. Set for zero off the tailstock end, then
move the tailstock to me by .005 (roughly).

Get 6" of A-2 (cheap), face and center drill both ends, set up with dead
center/dog at headstock, live center at tailstock. Indicate so its
roughly parallel (what's a few thou between friends?), turn about 1/2
inch at tailstock to 9/16 (@.5625 dia) so it will pass through the small
end of the reamed section, then set the tailstock to me roughly .007 or
so, turn the taper over 1.000", then measure.

Still ditzing with the base size, initial impression is an .875 OD x
..500 ID by 1.000 inch long chunk of aluminum tubing. Drill out to 15mm
(just over .610). Then things get fuzzy. Check chuck concentricity. Set
tailstock back to dead on. Chuck up base, ream with D bit.

Tubing wall thickness is important. Lyman 93 center of aperture is .550
above bottom of clamp. I can get mounting blocks in various heights, up
to .500 high. Sight has to be @1.1" above bore, so .550 (sight) + .375
(base)+ .310 (to bore center) + .125 (7/8 OD thickness) is 1.081. I
think that is close enough.

Snap, no stock downstairs with a diameter that will work in steel that
will hold up. 16mm will be .639+. Use D bit like a tap, base in chuck,
spring loaded center in tailstock, D bit in tap chuck, ream to depth.

On Feb 21, 6:38*pm, "RogerN" wrote:
"Louis Ohland" wrote in message

How can I set my compound for boring? Angle plates? Adjustable angle?

What I've done before is chuck up a piece of drill rod, indicate it true,
then mark off an inch or few inches and indicate the compound to taper the
desired thousandths per the distance I marked off. *For example if I want a
taper of 0.008" per inch, I mark 1" on the drill rod and set the compound
with an indicator to move the desired amount per inch.

Yep, dialing in the compound with an actual gage indicator running
along
a known cylinder is the best way. It's a little slow, though,
so if the angle is going to be reproduced later, it pays to cut a
reference
(cone, in this case) and adjust for zero gage indication on the
reference
instead of variable indication against the cylinder.

There are other techniques possible; an amusing one is to zero the
compound angle, then mount a laser pointer. The laser spot on a
distant wall (2 meters) will indicate d*tan(theta),
or (assuming perpendicular incidence at theta = 0)
(2000 mm) sin(1/2 degree) = 17.45 mm
when the compound is adjusted to the correct angle.

"Pete C." wrote in message
ter.com...

Louis Ohland wrote:

On 2/21/2011 19:40, Pete C. wrote:

I think you should be looking for a tapered reamer.

Uh, yeah. Tapered end mills seem to be the only game in town, however.
The tapered reamers that I've seen are rated in inch/foot tapers.
Looking at Machinery's Handbook, the tapers are way too large.

Perchance a vernier protractor, dunno.

The compound isn't intended for cutting accurate shallow tapers, that is
why taper attachments for lathes exist. You will likely have to go by
trial and error, test cutting some scrap and test fitting until you find
the correct setting.

Some of the tapers I used to turn on the lathe compound were .0025" taper in
~3" for facing 33rpm record dies IIRC. First I'd cut the face with the
slight taper, then grind with the tool post grinder feeding 0.0002" at a
time. The compound can work for cutting shallow accurate tapers if set up
properly.

RogerN

Hmm, rechecked my math, looks like the .750 OD is what I want for the
base, wall thickness @.0625, sight block of 3/16 (.1875), sight .550,
barrel CL to surface .312, add em up and it's 1.112, minus the concave
sight base (.005 or so).

Tool post grinder. Erk. Lessee, start looking through the usual suspects...


I think you should be looking for a tapered reamer.

Uh, yeah. Tapered end mills seem to be the only game in town, however.
The tapered reamers that I've seen are rated in inch/foot tapers.
Looking at Machinery's Handbook, the tapers are way too large.

Perchance a vernier protractor, dunno.

The compound isn't intended for cutting accurate shallow tapers, that is
why taper attachments for lathes exist. You will likely have to go by
trial and error, test cutting some scrap and test fitting until you find
the correct setting.

Some of the tapers I used to turn on the lathe compound were .0025" taper in
~3" for facing 33rpm record dies IIRC. First I'd cut the face with the
slight taper, then grind with the tool post grinder feeding 0.0002" at a
time. The compound can work for cutting shallow accurate tapers if set up
properly.

RogerN