Saturday, January 4, 2020

HP 42S & DM 42 Linear Progression of a Slider Crank

HP 42S & DM 42 Linear Progression of a Slider Crank

Introduction

Welcome to first post of 2020!  In today's post, the program CRANK will calculate the following:

*  Maximum (xMAX) and Minimum (xMIN) slider displacement of a slider crank using linear progression

* Connecting rod angle, slider displacement, the slider's velocity, and slider's acceleration given the crank angle

Input values are:



*  Connecting rod length  (L)

*  Crank radius  (R)

*  Vertical slider offset  (E)

*  Current speed of the crankshaft, in revolutions per minute (RPM)

*  Crank angle (θ)

The program does not dictate units of measure (such as inches, millimeters, etc).   However, all angles are measured in degrees and the program sets the calculator to Degrees mode. 

HP 42S/DM42 Program:  Linear Progression of a Slider Crank

00 { 317-Byte Prgm }
01▸LBL "CRANK"
02 DEG
03 CLMENU
04▸LBL 00
05 "LNGTH"
06 KEY 1 GTO 01
07 "ANGLE"
08 KEY 2 GTO 02
09 "LIMITS"
10 KEY 3 GTO 03
11 "∡ v a"
12 KEY 4 GTO 04
13 "EXIT"
14 KEY 5 GTO 05
15 MENU
16▸LBL 10
17 STOP
18 GTO 10
19▸LBL 01
20 "ROD LGTH:"
21 PROMPT
22 STO 01
23 "RADIUS:"
24 PROMPT
25 STO 02
26 "OFFSET:"
27 PROMPT
28 STO 03
29 "RPM:"
30 PROMPT
31 STO 04
32 "DONE"
33 AVIEW
34 GTO 00
35▸LBL 02
36 "ANGLE:"
37 PROMPT
38 STO 05
39 "DONE"
40 AVIEW
41 GTO 00
42▸LBL 03
43 RCL 03
44 RCL 02
45 RCL+ 01
46 ÷
47 ASIN
48 COS
49 RCL 02
50 RCL+ 01
51 ×
52 "xMAX="
53 ARCL ST X
54 AVIEW
55 STOP
56 RCL 03
57 RCL 01
58 RCL- 02
59 ÷
60 ASIN
61 COS
62 RCL 01
63 RCL- 02
64 ×
65 "xMIN="
66 ARCL ST X
67 AVIEW
68 STOP
69 GTO 00
70▸LBL 04
71 PI
72 RCL× 04
73 30
74 ÷
75 STO 07
76 RCL 05
77 SIN
78 RCL× 02
79 RCL+ 03
80 RCL÷ 01
81 ASIN
82 STO 06
83 "CRANK ∡="
84 ARCL ST X
85 AVIEW
86 STOP
87 RCL 02
88 RCL 05
89 COS
90 ×
91 RCL 01
92 RCL 06
93 COS
94 ×
95 +
96 "POS="
97 ARCL ST X
98 AVIEW
99 STOP
100 RCL 05
101 RCL+ 06
102 SIN
103 +/-
104 RCL 06
105 COS
106 ÷
107 RCL× 07
108 RCL× 02
109 "VELOCITY="
110 ARCL ST X
111 AVIEW
112 STOP
113 RCL 05
114 RCL+ 06
115 COS
116 +/-
117 RCL 06
118 COS
119 ÷
120 RCL 05
121 COS
122 X↑2
123 RCL× 02
124 RCL 06
125 COS
126 3
127 Y↑X
128 RCL× 01
129 ÷
130 -
131 RCL 07
132 X↑2
133 ×
134 RCL× 02
135 "ACCEL="
136 ARCL ST X
137 AVIEW
138 STOP
139 GTO 00
140▸LBL 05
141 CLMENU
142 EXITALL
143 RTN
144 END

Download:  https://drive.google.com/open?id=1z0Htza_-quZ4VLIddSqTg54pM_54_uFP

Instructions

1.  Run CRANK by pressing XEQ CRANK

2.  Enter rod length (ROD LGTH), crank radius (RADIUS), offset (OFFSET), and turning speed (RPM) by pressing the LNGT submenu.  After all the input values are entered, you will see a DONE message.  Use the [R/S] key to enter values. 

3.  To enter a crank angle, choose the ANGL submenu.  Enter the crank angle.  After the angle has been entered, you will see a DONE message. 

4.  Calculate the maximum and minimum slider displacements by choosing the LIMIT submenu.

5.  Calculate the rod angle, position, velocity, and acceleration by the ∠ v a  submenu.

6.  You can renter any of the inputs at any time. 

7.  To exit the program, press EXIT.

Example
(Fix 4 Setting)

Rod length:  8 in
Crank radius:  2 in
Offset:  1.3 in
RPM:  5000 RPM

Crank Angle:  15°

Results:
xMAX=9.9151
xMIN=5.8575

CRANK ∠=13.1326
POS=9.7226
VELOCITY=-507.0277
ACCEL=-634,997.3666

Crank Angle:  20°

(xMAX and xMIN remain the same)

CRANK ∠=14.3595
POS=9.6295
VELOCITY=-610.0807
ACCEL=-600,369.9284

Source:

"Linear Progression of Slide Crank"  HP 65  Machine Pac-1. Hewlett Packard.  1975

Eddie

All original content copyright, © 2011-2020.  Edward Shore.   Unauthorized use and/or unauthorized distribution for commercial purposes without express and written permission from the author is strictly prohibited.  This blog entry may be distributed for noncommercial purposes, provided that full credit is given to the author.