AETNA ENGINEERING Tach Tape TT-100 User manual

TT-100
TachTape '-.-/
INSTRUCTIONS
SPECIFICATIONS
Temperature range: -30 F to +160 F. (-35 C to +70 C)
Gear pitch equivalent: approximately 7 dlametral pitch.
Maximumcontinuous len2th: 100 feet (30 meters)
Caution: Do not expose tape to strong AC or DCmagnetic fields and use only with Dynalco
magnetic pickups.
FUNCTION:
Provides a convenient, simple and low-cost means to activate Dynalco magnetic pickups in
speed and frequency measurements.
USE:
An inexpensive substitute for large split gears, slots in shafts, drilled holes in flywheels,
etc., for magnetic pickup speed sensing.
DESCRIPTION & CHARACTERISTICS~
Dynalco Tach Tape is a strip of flexible magnetic polymer. bn one side it has a pressure-
sensitive adh€sive protected by a peel-away backing. This adhesive will adhere to a wide
variety of surfaces, including most plastics and metals. "-.-/
Because of its unique magnetization and arrangement of slots, a series of alternate magnetic
poles are generated along the length of the tQpe. A Dynalco magnetic pickup becomes
activated when placed perpendicular to the tape surface.
Figure 1 demonstrates that the tape performance is better than an a-pitch gear when the
air gap is larger than .050 inch (1.2MM). This is especially welcome in cases where a
small air gap is difficult to maintain or space is too restricted. to install split gears
because the Tach Tape-Dynalco pickup combination is so well suited to large air gaps.
Because of centrifugal forces acting upon the tape when rotating, a safe maximum speed shoulq
be observed (shown in Table 1). If greater speeds are required, a fiberglass reinforced
plastic tape (such as one inch wide strapping tape #ST-40, Superior Insulating Tape Company)
may be wrapped over the magnetic tape (two layers as shown in Figs. 2&3), which quadruples
the maximum safe speed. (Pickup senses through reinforcing tape)
The tape should not be @xposed to strong AC or DC magnetic fields and should only be used
with Dynalco magnetic pickups to prevent possible de-magneti~ation.
~
This table assumes the Tach Tape has been applied according to the instructions which
folJow.
TABLE 1, MAXIMUM SAFE SPEED
SHAFT DIAHETER WITHOUT REINFORCED TAPE WITH REINFORCED TAPE
3 IN (7.5 cm) 2500 RPM 10,000 RPM
6 IN (15 cm) 1800 RPM 7,200 RPM
9 IN (23 cm) 1500 RPM 6,000 RPM
12 IN (30 cm) 1200 RPM 4,800 RPM
24 IN (60 cm) 900 RPM 3,600 RPM
36 IN (90 cm) 700 RPM 2,800 RPM

'-""
"-"
200V
PfAK
ro
PfOK 500 INCHE~!5ECOND
~ ~
(1270 CM/SECOND)
100K LOAD
I50V
100V
0.120 INCHES
GEAR PITCH IS THE NUMBER OF TEETH PER
INCH OF DIAMETER, AND IS A MEASURE OF
TOOTH SIZE.
"
"
'"
..
2
"
"
~5OV
,
'"
~
0
~
~.5
'"r
10 m
..,
00.020 IN 0040 IN 0.060 IN 0060 IN 0 100 IN
AIR GAP
Fi gl.}re 1
amv TO APPLY AND USE TACH TAPE
The following procedure should be used:
4.
'-"8.
Note:
1. Clean the surface area of the shaft, approximately 2 inches wide, to remove dust,
dirt, oil, rust, etc. Use a cleaner such as MEK, TRICHLOR, paint thinner, etc.
2. Before removing peel-away backing from the tape, wrap the tape around the shaft to
determine the length required.
3. Cut both ends of the tape squarely as shown in Figure 2.
through the slots. The tape must be cut
Peel away the backing and wrap the adhesive side aro~nd the shaft as straight as
possible.
5. After wrapping, press the tape to the shaft to ensure good adhesive.
6." If faster speeds are required, a reinfbrcing fiberglass tape may be wrapped around the
Tach Tape (see Table 1).
Starting at approximately the opposite end of the Tach Tape "joint", apply two full
turns of reinforcing tape as shown in Figure 3.
7. Use only Dynalco magnetic pickups. Other pickups may have reversed magnetic flux
direction that can demagnetize the tape.
Calculate frequency (Hz) or pulses per second as follows: Frequency =RPM X No. of slots
60
The number of slots should include the one created at the joint.

AVAILABLE FROM
AETNA ENGINEERING
800-776-7962
CQRRECT JOINT INCORRECT JOINT
I
:--'A>
REINFORCING
TAPE
IMPORTANT. " " .. )
DIMENSION cTO BE: A MINIMUM OF 3/16 (4.8mm.
Figure 2
Model TT-100i
Tach Tape
REINFORCING TAPE END
1/16 INCH
(1.6 mm)
.2 INCHES
(5.0 mmJ
.45 INCHES
111.4mm)
l7 r---'--
TAPE
I INCH
(254 mm)
L_-
:..--- I
.25 INCHES-,o
(6.4 mm)
SHAFT ROTATION
Figure 3 Figure 4