A month or so back I needed help with laying out 3 bolt holes for a
project.
The long and short of it stirred up some great help by the group, and
MARV KLOTZ chimed in with a calculator formula. I am hoping to get
some hand holding help here with how exactly I need to enter this into
my calculator, because I am not getting the right numbers it seems.

For example, here is the formula that Marv posted::
The center-to-center distance is referred to as the 'chord'. If that's
known,
then calculate the 'angle' between adjacent bolt holes as:

angle = 360 / (number of bolt holes)


Then the bolt circle radius is given by:


radius=0.5*chord/sin(0.5*angle)


Regards, Marv
----
so I tried to type that into the calculator using the following data:
Number of holes = 3
ANGLE = 360 / 3 = 120
---
The center to center distance on the bolt holes for my newest project
is: 1.2335
SO.... if I follow the formula:
radius = .5 x 1.2335 then I hit the divide button followed by the SIN
button, then I hit the multiply button and entered 60 then = and the
number was 3437.813. That is obviously wrong.

Can someone shed some light on where I am going wrong? Maybe I should
be hitting the '=' sign somewhere, or doing it in a different order...
either way I am lost, thanks in advance for any help you can provide,
ron.

In article .com,
says...

SO.... if I follow the formula:
radius = .5 x 1.2335 then I hit the divide button followed by the SIN
button, then I hit the multiply button and entered 60 then = and the
number was 3437.813. That is obviously wrong.

Your calculator is probably not RPN, and you are not using
any parentheses.

Re-work the problem, and write down the interermediate
steps as numbers. I think you will wind up with a very
different answer.

The problem you are punching in on the calculator is a
very different one than the one you want to solve.

Using Marv's formula for example,

(.5) (your chord) = (.5)(1.25) = .75 or thereabouts.

and sin [(.5)(120)] = sin60 = 0.866

So it would seem that R in this case is going to be something
like .75/.866 according to that formula.

Jim

Jim


--
==================================================
please reply to:
JRR(zero) at pkmfgvm4 (dot) vnet (dot) ibm (dot) com
==================================================

Ron I e-mailed you a bolt hole and trig. program.Just enter the number
of holes then radius
and the starting angle of first hole and it will give you the xand y
locations.
Tim

Shameless plug alert...

If you own a PalmOS handheld device, download the free trial of "Geo-Matic
Complete for the PalmOS" from my website and calculate as many bolt circles
(plus triangles, circular segments/sectors, rings and ring sectors, regular
polygons, chamfers, fillets, parallelograms, etc) as you can in the next
five days. Find it at http://www.infosystemspro.com/palmosapps.htm


Carmine Castiglia
ISOFits! - ISO 286 on your PalmOS handheld
InfosystemsPro LLC
PalmOS apps for engineers and machinists
http://www.infosystemspro.com


wrote in message
oups.com...
A month or so back I needed help with laying out 3 bolt holes for a
project.
The long and short of it stirred up some great help by the group, and
MARV KLOTZ chimed in with a calculator formula. I am hoping to get
some hand holding help here with how exactly I need to enter this into
my calculator, because I am not getting the right numbers it seems.

For example, here is the formula that Marv posted::
The center-to-center distance is referred to as the 'chord'. If that's
known,
then calculate the 'angle' between adjacent bolt holes as:

angle = 360 / (number of bolt holes)


Then the bolt circle radius is given by:


radius=0.5*chord/sin(0.5*angle)


Regards, Marv
----
so I tried to type that into the calculator using the following data:
Number of holes = 3
ANGLE = 360 / 3 = 120
---
The center to center distance on the bolt holes for my newest project
is: 1.2335
SO.... if I follow the formula:
radius = .5 x 1.2335 then I hit the divide button followed by the SIN
button, then I hit the multiply button and entered 60 then = and the
number was 3437.813. That is obviously wrong.

Can someone shed some light on where I am going wrong? Maybe I should
be hitting the '=' sign somewhere, or doing it in a different order...
either way I am lost, thanks in advance for any help you can provide,
ron.

I have been using geo-matic since the beta testing. While I don't use it
every day, it is a handy application every time I do use it.

"Carmine Castiglia" wrote in message
...
Shameless plug alert...

If you own a PalmOS handheld device, download the free trial of "Geo-Matic
Complete for the PalmOS" from my website and calculate as many bolt
circles (plus triangles, circular segments/sectors, rings and ring
sectors, regular polygons, chamfers, fillets, parallelograms, etc) as you
can in the next five days. Find it at
http://www.infosystemspro.com/palmosapps.htm


Carmine Castiglia
ISOFits! - ISO 286 on your PalmOS handheld
InfosystemsPro LLC
PalmOS apps for engineers and machinists
http://www.infosystemspro.com


wrote in message
oups.com...
A month or so back I needed help with laying out 3 bolt holes for a
project.
The long and short of it stirred up some great help by the group, and
MARV KLOTZ chimed in with a calculator formula. I am hoping to get
some hand holding help here with how exactly I need to enter this into
my calculator, because I am not getting the right numbers it seems.

For example, here is the formula that Marv posted::
The center-to-center distance is referred to as the 'chord'. If that's
known,
then calculate the 'angle' between adjacent bolt holes as:

angle = 360 / (number of bolt holes)


Then the bolt circle radius is given by:


radius=0.5*chord/sin(0.5*angle)


Regards, Marv
----
so I tried to type that into the calculator using the following data:
Number of holes = 3
ANGLE = 360 / 3 = 120
---
The center to center distance on the bolt holes for my newest project
is: 1.2335
SO.... if I follow the formula:
radius = .5 x 1.2335 then I hit the divide button followed by the SIN
button, then I hit the multiply button and entered 60 then = and the
number was 3437.813. That is obviously wrong.

Can someone shed some light on where I am going wrong? Maybe I should
be hitting the '=' sign somewhere, or doing it in a different order...
either way I am lost, thanks in advance for any help you can provide,
ron.

Thanks Jim & all, that got me going in the right direction.
ron