2015 Designer's Notebook - 140

Sofstep® Selection
To properly size a magnetic particle
brake, clutch or clutch/brake, two factors
must be considered:
1. Torque
2. Watts

1. Torque
Use the torque equation to determine
your required torque in pound-inches.

2. Slip Watts
When a brake is providing resistance to a
rotating shaft, or when a clutch is
slipping, mechanical energy is being
converted to thermal energy. The rate
that energy is being converted is
expressed in terms of slip watts and is
a function of torque and slip speed.

Magnetic Particle Clutches & Brakes

For continuous slip applications, such as
tensioning, use the appropriate selection
example to determine your slip speed.
Once slip speed is determined, use the
quick selection chart to choose a unit

that will be thermally sufficient.
In cycling applications, heat is being
generated intermittently. However,
the brake or clutch acts as a "heat
reservoir" that continuously dissipates
the heat to the environment. Therefore,
use the cycling example to determine
average slip watts. Then, use the
performance chart to select a unit that
will produce the required torque and
dissipate the average slip wattage.
In cycling applications, peak watts may
be high enough to cause temperatures
to temporarily exceed recommended
operating temperatures. For unusual
environmental conditions or applications,
call your MAGPOWR sales engineer.
Tension

Unwind Tension Control
Information Required:
Full roll diameter = 10 inches
Tension* = 2 lb
Velocity = 200 fpm

How to size:
Torque (lb-in) =
Tension (lb) x Full Roll Diameter (in)
2
2
x
10
=
= 10 lb-in
2
12 x Velocity (fpm)
Slip RPM =
π x Full Roll Diameter (in)
= 12 x 200 = 76 RPM
π x 10
Slip Watts = .0118 x Torque (lb-in) x RPM
= .0118 x 10 x 76
= 9 Watts

Roll

Select brake model PSB-15 from
quick selection chart below.

Torque

*Note: If tension is unknown see section on
calculating web tension.

Sofstep
Brake

Quick Selection Charts
(Continuous slip only)
First find slip rpm on vertical axis, then
locate torque on horizontal axis. Find
intersection of two lines. If below line
and in blue area, the brake is thermally
sufficient to handle the generated heat.
If it lands on the line or in the white
area, the a larger unit is required.

PSB-15
PSC-15

PSB-70
PSC-70

PSB-2
PSC-2
PSB-120
PSC-120

140 Magnetic Particle Clutches & Brakes

PSB-240



Table of Contents for the Digital Edition of 2015 Designer's Notebook

Table of Contents
2015 Designer's Notebook - Cover1
2015 Designer's Notebook - Cover2
2015 Designer's Notebook - Table of Contents
2015 Designer's Notebook - 2
2015 Designer's Notebook - 3
2015 Designer's Notebook - 4
2015 Designer's Notebook - 5
2015 Designer's Notebook - 6
2015 Designer's Notebook - 7
2015 Designer's Notebook - 8
2015 Designer's Notebook - 9
2015 Designer's Notebook - 10
2015 Designer's Notebook - 11
2015 Designer's Notebook - 12
2015 Designer's Notebook - 13
2015 Designer's Notebook - 14
2015 Designer's Notebook - 15
2015 Designer's Notebook - 16
2015 Designer's Notebook - 17
2015 Designer's Notebook - 18
2015 Designer's Notebook - 19
2015 Designer's Notebook - 20
2015 Designer's Notebook - 21
2015 Designer's Notebook - 22
2015 Designer's Notebook - 23
2015 Designer's Notebook - 24
2015 Designer's Notebook - 25
2015 Designer's Notebook - 26
2015 Designer's Notebook - 27
2015 Designer's Notebook - 28
2015 Designer's Notebook - 29
2015 Designer's Notebook - 30
2015 Designer's Notebook - 31
2015 Designer's Notebook - 32
2015 Designer's Notebook - 33
2015 Designer's Notebook - 34
2015 Designer's Notebook - 35
2015 Designer's Notebook - 36
2015 Designer's Notebook - 37
2015 Designer's Notebook - 38
2015 Designer's Notebook - 39
2015 Designer's Notebook - 40
2015 Designer's Notebook - 41
2015 Designer's Notebook - 42
2015 Designer's Notebook - 43
2015 Designer's Notebook - 44
2015 Designer's Notebook - 45
2015 Designer's Notebook - 46
2015 Designer's Notebook - 47
2015 Designer's Notebook - 48
2015 Designer's Notebook - 49
2015 Designer's Notebook - 50
2015 Designer's Notebook - 51
2015 Designer's Notebook - 52
2015 Designer's Notebook - 53
2015 Designer's Notebook - 54
2015 Designer's Notebook - 55
2015 Designer's Notebook - 56
2015 Designer's Notebook - 57
2015 Designer's Notebook - 58
2015 Designer's Notebook - 59
2015 Designer's Notebook - 60
2015 Designer's Notebook - 61
2015 Designer's Notebook - 62
2015 Designer's Notebook - 63
2015 Designer's Notebook - 64
2015 Designer's Notebook - 65
2015 Designer's Notebook - 66
2015 Designer's Notebook - 67
2015 Designer's Notebook - 68
2015 Designer's Notebook - 69
2015 Designer's Notebook - 70
2015 Designer's Notebook - 71
2015 Designer's Notebook - 72
2015 Designer's Notebook - 73
2015 Designer's Notebook - 74
2015 Designer's Notebook - 75
2015 Designer's Notebook - 76
2015 Designer's Notebook - 77
2015 Designer's Notebook - 78
2015 Designer's Notebook - 79
2015 Designer's Notebook - 80
2015 Designer's Notebook - 81
2015 Designer's Notebook - 82
2015 Designer's Notebook - 83
2015 Designer's Notebook - 84
2015 Designer's Notebook - 85
2015 Designer's Notebook - 86
2015 Designer's Notebook - 87
2015 Designer's Notebook - 88
2015 Designer's Notebook - 89
2015 Designer's Notebook - 90
2015 Designer's Notebook - 91
2015 Designer's Notebook - 92
2015 Designer's Notebook - 93
2015 Designer's Notebook - 94
2015 Designer's Notebook - 95
2015 Designer's Notebook - 96
2015 Designer's Notebook - 97
2015 Designer's Notebook - 98
2015 Designer's Notebook - 99
2015 Designer's Notebook - 100
2015 Designer's Notebook - 101
2015 Designer's Notebook - 102
2015 Designer's Notebook - 103
2015 Designer's Notebook - 104
2015 Designer's Notebook - 105
2015 Designer's Notebook - 106
2015 Designer's Notebook - 107
2015 Designer's Notebook - 108
2015 Designer's Notebook - 109
2015 Designer's Notebook - 110
2015 Designer's Notebook - 111
2015 Designer's Notebook - 112
2015 Designer's Notebook - 113
2015 Designer's Notebook - 114
2015 Designer's Notebook - 115
2015 Designer's Notebook - 116
2015 Designer's Notebook - 117
2015 Designer's Notebook - 118
2015 Designer's Notebook - 119
2015 Designer's Notebook - 120
2015 Designer's Notebook - 121
2015 Designer's Notebook - 122
2015 Designer's Notebook - 123
2015 Designer's Notebook - 124
2015 Designer's Notebook - 125
2015 Designer's Notebook - 126
2015 Designer's Notebook - 127
2015 Designer's Notebook - 128
2015 Designer's Notebook - 129
2015 Designer's Notebook - 130
2015 Designer's Notebook - 131
2015 Designer's Notebook - 132
2015 Designer's Notebook - 133
2015 Designer's Notebook - 134
2015 Designer's Notebook - 135
2015 Designer's Notebook - 136
2015 Designer's Notebook - 137
2015 Designer's Notebook - 138
2015 Designer's Notebook - 139
2015 Designer's Notebook - 140
2015 Designer's Notebook - 141
2015 Designer's Notebook - 142
2015 Designer's Notebook - 143
2015 Designer's Notebook - 144
2015 Designer's Notebook - 145
2015 Designer's Notebook - 146
2015 Designer's Notebook - 147
2015 Designer's Notebook - 148
2015 Designer's Notebook - 149
2015 Designer's Notebook - 150
2015 Designer's Notebook - 151
2015 Designer's Notebook - 152
2015 Designer's Notebook - 153
2015 Designer's Notebook - 154
2015 Designer's Notebook - 155
2015 Designer's Notebook - 156
2015 Designer's Notebook - 157
2015 Designer's Notebook - 158
2015 Designer's Notebook - Cover3
2015 Designer's Notebook - Cover4
https://www.nxtbookmedia.com