**HP Prime & TI-84+: Bolt Pattern**

Bolt Pattern |

The program
BOLTPAT will calculate a bolt pattern given:

X = center, X
coordinate

Y = center, Y coordinate

N = number of
bolts

D = diameter of
the circle

No angle of
rotation is assumed.

Coordinates of
each bolt can be calculated by:

X_k = (d/2*COS(360*k/n)+xc)

Y_k =
(d/2*SIN(360*k/n)+yc)

Where k = 0 to
n-1

The OC-Distance
between each bolt is calculated by calculating the linear distance between
neighboring bolts.

Output:

Each point
where the bolt should be placed. In
addition, the on-center distance between bolts is displayed. Finally, each of the coordinates will be
presented in a list. For the TI-84+
version, the list will be stored in list L6.

**HP Prime: BOLTPAT**

EXPORT BOLTPAT()

BEGIN

// EWS 2012-02-28

// No pre angle tilt

// Degrees

HAngle:=1;

// Data

LOCAL z0,z1,xc,yc;

LOCAL
z,n,d,k,l,xp,yp;

INPUT({xc,yc,n,d},"Bolt
Spacing",

{"xc:","yc:","n
:","d :"},

{"x
center","y center",

"number of
bolts",

"diameter"});

l:={};

// Calculation

PRINT();

PRINT("x +
y*i");

FOR k FROM 0 TO n-1
DO

xp:=(d/2*COS(360*k/n)+xc);

yp:=(d/2*SIN(360*k/n)+yc);

IF k==0 THEN

z0:=xp+i*yp;

END;

IF k==1 THEN

z1:=xp+i*yp;

END;

l:=CONCAT(l,{xp+yp*i});

PRINT("("+xp+","+yp+")");

END;

PRINT("OC-OC:
"+ABS(z1-z0));

RETURN l;

END;

**TI-84+: BOLTPAT**

a+bi

Degree

Disp “X: X CENTER”

Disp “Y: Y CENTER”

Disp “N: NO. BOLTS”

Disp “D: DIAMETER”

Prompt X,Y,N,D

For(K,0,N-1)

D/2*cos(360*K/N)+X→S

D/2*sin(360*K/N)+Y→T

If K=0

Then

S+T*i→U

{U}→L6

End

If K>0

Then

Augment(L6,{S+T*i})→L6

End

If K=1

Then

S+T*i→V

End

Disp “POINT”,K

Disp S

Disp T

Pause

End

Disp “OC-OC:”

Pause abs(U-V)

Disp L6

Example:

Build a bolt
pattern with 5 bolts of a circle of diameter of 3 units. The center of the circle has the center (4, 1). (X = 4, Y = 1, N = 5, D = 3)

Bolts should be
placed at the following points:

(5.5, 1)

(4.4635,
2.4266)

(2.7865,
1.8817)

(2.7865,
0.1183)

(4.4635,
-0.4266)

OC-Distance: 1.7634

Note: Bolt Patterns can easily be calculated with
the Machinist Calc Pro, original (Model 4087) or Pro 2 (Model 4088) (including
angle of rotation).

This blog is property
of Edward Shore – 2015.