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*Smith, Harvey
Message 1 of 5 (93 Views)

# Battle Of The Bulge Factor

93 Views, 4 Replies
11-19-1999 12:55 PM
The Bulge Factor, long a mysterious function (at least to me), is now EXPOSED! I
mean besides my stomach. John Nolte, a noted Ozmaniac, pointed this out in a
recent previous post with a remarkable solution to the circle/hemisphere/Fill
issue, initially posted by Jim Weir.

Briefly, a segment of a polyline can be made to bulge out a predetermined
amount. You can see some information about it in the User's Guide for V6, p112.
(A bit dicey to interpret) There is a definition relating to the tangent of 1/4
of the total angle subtended, but this is an obscure way to use it. And another
where the factor is equal to two times the bulge height times the distance
between the ends of the bulge. ANOTHER obscurity. I decided to use it by trial
and error, the last refuge of scoundrels.

I have recently used it to detail a wooden Shaker knob, but it looks like the
principles can be used for any design drawings for machinists, etc. For the
wooden knob, I set up a series of vertical lines of known length representing
the various diameters at the correct distances along a center line. I connected
the lines at their ends with straight segments using Line Single. I used Trim
Join on the parts of the knob containing the line(s) I wanted to bulge. Then
Double RightClick to bring up the vertices. I then Selected the segement I
wanted to bulge, went to the Edit Bar and began to experiment with numbers until
I got the bulge of a reasonable appearance. I added a few extra vertical
components to get the smooth bulges that I wanted. The values I used were ±0.13
to ±0.15. The large radius was around 0.4.

One of the nice features of this Bulge is that the program will allow you to
specify the radii or diameters of each area so it can be duplicated on a lathe.
Or a template can be made from the print out. I put an SKF drawing in customer
files so you can skewer my efforts or (god forbid) make suggestions about other
ways to use it or improve what you see. It's called SmallTable. Noodle with it
and take a shot. I might learn something else. I want to know as much about this
V6 program before I can it and get the V7 Upgrade.

Harvey
--
http://www.westnet.com/~harvey/
*Scharmann, Fred
Message 2 of 5 (93 Views)

# Re: Battle Of The Bulge Factor

11-19-1999 02:36 PM in reply to: *Smith, Harvey
Okay Harvey,

I was going through life blissfully not knowing about bulge. Now I have to
go and figure out how to use it!

Fred

Harvey Smith wrote in message
news:3835B947.BA8CBFB5@westnet.com...
> The Bulge Factor, long a mysterious function (at least to me), is now
EXPOSED! I
> mean besides my stomach. John Nolte, a noted Ozmaniac, pointed this out in
a
> recent previous post with a remarkable solution to the
circle/hemisphere/Fill
> issue, initially posted by Jim Weir.
>
> Briefly, a segment of a polyline can be made to bulge out a predetermined
> amount. You can see some information about it in the User's Guide for V6,
p112.
> (A bit dicey to interpret) There is a definition relating to the tangent
of 1/4
> of the total angle subtended, but this is an obscure way to use it. And
another
> where the factor is equal to two times the bulge height times the distance
> between the ends of the bulge. ANOTHER obscurity. I decided to use it by
trial
> and error, the last refuge of scoundrels.
>
> I have recently used it to detail a wooden Shaker knob, but it looks like
the
> principles can be used for any design drawings for machinists, etc. For
the
> wooden knob, I set up a series of vertical lines of known length
representing
> the various diameters at the correct distances along a center line. I
connected
> the lines at their ends with straight segments using Line Single. I used
Trim
> Join on the parts of the knob containing the line(s) I wanted to bulge.
Then
> Double RightClick to bring up the vertices. I then Selected the segement I
> wanted to bulge, went to the Edit Bar and began to experiment with numbers
until
> I got the bulge of a reasonable appearance. I added a few extra vertical
> components to get the smooth bulges that I wanted. The values I used were
±0.13
> to ±0.15. The large radius was around 0.4.
>
> One of the nice features of this Bulge is that the program will allow you
to
> specify the radii or diameters of each area so it can be duplicated on a
lathe.
> Or a template can be made from the print out. I put an SKF drawing in
customer
> files so you can skewer my efforts or (god forbid) make suggestions about
other
> ways to use it or improve what you see. It's called SmallTable. Noodle
with it
> and take a shot. I might learn something else. I want to know as much
> V6 program before I can it and get the V7 Upgrade.
>
> Harvey
> --
> http://www.westnet.com/~harvey/
>
>
*Smith, Harvey
Message 3 of 5 (93 Views)

# Re:

12-14-2003 06:51 AM in reply to: *Smith, Harvey
Fred.

In the face of potential post deletion, I have enclosed a jpeg of a quick lamp
profile you can create in about 2 minutes. Not designed wonderfully but it does
show a use of bulge factor.

H
*Nolte, John
Message 4 of 5 (93 Views)

# Re:

12-14-2003 06:51 AM in reply to: *Smith, Harvey
Sorry Fred, I've created a monster. Harvey, your lamp is sideways. Oh, BTW, I'm
not an Ozmaniac, I'm from Wisconsin. You drive through here on your way to get a
ticket from Jim.

John

Harvey Smith wrote:

> Fred.
>
> In the face of potential post deletion, I have enclosed a jpeg of a quick lamp
> profile you can create in about 2 minutes. Not designed wonderfully but it does
> show a use of bulge factor.
>
> H
>
> ------------------------------------------------------------------------
> [Image]
*Smith, Harvey
Message 5 of 5 (93 Views)

# Re:

12-14-2003 06:51 AM in reply to: *Smith, Harvey
I take back everything nice I ever said about you, Cheesehead. Now you have to
do something even MORE spectacular before you're redeemed. Like how and when to
use the Fitted or Spline Curve, Open or Closed. One can of CheezWhiz if you do
it.

H

Some national parks have a long waiting list for camping reservations. I think
when you have to wait a year to sleep next to a tree, something is wrong.

John Nolte wrote:
>
> Sorry Fred, I've created a monster. Harvey, your lamp is sideways. Oh, BTW, I'm
> not an Ozmaniac, I'm from Wisconsin. You drive through here on your way to get a
> ticket from Jim.
>
> John
>
> Harvey Smith wrote:
>
> > Fred.
> >
> > In the face of potential post deletion, I have enclosed a jpeg of a quick lamp
> > profile you can create in about 2 minutes. Not designed wonderfully but it does
> > show a use of bulge factor.
> >
> > H

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