Theatre Design & Technology - Winter 2005 - 28

Pipe and hose thread standards.
Tapered threads are the most common type of thread available. As the name implies, they have a slight taper. When mated together and tightened, the
threads compress to form a seal. The mating threads both hold the fitting in place and seal the connection. The most widely used pipe threads in
North America are National Pipe Taper threads (NPT). Some confusion may result from the use of NPT, FPT, and MPT in describing
threads. Both FPT and MPT are NPT threads, with FPT meaning female threads (internal) and MPT meaning male threads (external). NPTF
(Dryseal) threads are modified NPT threads, which are less likely to leak without a sealant. For a leak-free seal, we recommend using a
sealant compound or PTFE tape. You can use NPTF threads with NPT threads, but you'll lose some of the leak-free characteristics.
Straight (parallel) threads are used for mechanical joining. They serve one purpose-to hold a fitting in place. As a result, an O-ring (elastomer), hard metal seal, or soft metal seal is required. When used together, the threads and sealing method provide a better overall seal
than tapered threads. Straight pipe threads include NPSM (National Pipe Straight Mechanical), NPSL (National Pipe Straight Locknut), and
NPSH (National Pipe Straight Hose) threads. Unified screw threads (UN/UNF) conform to SAE (Society of Automotive Engineers) specifications. Sizing and pitches differ from the NPT threads. Less common straight threads are garden hose (GHT) and fire hose coupling (NST).
[Source: McMaster-Carr catalog #110, page 3.]
For this study we purchased two hoses. The first came with NPSH threads for which we bought adapters and reducers to meet the 2˝ NPT thread
of the hydraulic power unit and that of our domestic water supply system. The second hose, which we located locally when the first was
punctured, came with NH threads (also known as NST), which are not compatible with NPSH. We were forced to buy yet another set of
adapters to complete the study. Hydraulic standards include a plethora of thread and fitting designs, including the common NPT type,
which we selected for its availability and ease of adapting to common plumbing fittings.

of various types of threads.) Finally, with the hose pulled into
the Gauntlet and the ends clamped down with our specially
designed hose clamps (fig. 15), we ran Rover with nothing attached. Following its movement from the sound of the track
creaking, it was a real delight to see Rover pop out the end of
the track like some alien gopher. No leaks! We then attached a
flag to Rover so that we might follow its progress more easily.
We ran Rover back and forth numerous times, checking for
leaks after each circuit. We discovered none. It was time to try
another run with someone aboard. Uncertain of the hose's lineage, I was not willing to let Matt ride the skid again-the
hose would stretch too much and push too hard against the
track walls. We located a diminutive young lady in the scenic
art department and persuaded her to ride the magic carpet.
And ride she did. There were a few bumps and hesitations as
Rover passed over seams in the track segments, but otherwise
she had a smooth ride-actually several as it turned out.
Results and Conclusions of Reverse Peristaltic Motion Control
The title of this study indicates that our research was intended
to test the feasibility of reverse peristalsis for theatre automation. The result of our efforts over the last two years suggests
that, yes, reverse peristalsis is one of the many options a technical director might employ to solve a tricky theatrical motion
problem. We hope that the narrative above may assist a technical director when, up against those immutable deadlines, he
must weigh the value of "tried-and-true" over "new-and-untested." Reverse peristalsis is no longer untested. Both Elbin
Cleveland's research and this current project demonstrate that
reverse peristalsis may just be a good solution in search of a
problem. The system works-but there are a few caveats.
A reverse peristalsis system is inherently slow. The actual
area of the hose acting on the rollers is roughly twice that of
the hose itself. Even with a 1˝ hose (which is available from

Key Fire), 2 feet per second would still require around 10 gpm
and a little over 2 hp. Force at the roller would be reduced to
around 624 pounds. This is not substantially different than the
ability of a stage winch of similar horse power, so there is no
advantage to the additional complexity of a reverse peristaltic
system powered by a hydraulic power unit-except for the
unusual motion profiles.
That being said, a reverse peristaltic system powered by a
domestic water supply has a substantial cost benefit when
compared to a typical stage winch, provide one has adequate
drainage and no need for sophisticated computer control. A
simple system using sprinkler valves for control and pallet
truck wheels for rollers can be constructed for less than $450,
or about one tenth the cost of a complete electric stage winch
and drive. (We discovered, belatedly, that on the same page as
the cut-to-width rollers, McMaster-Carr lists pallet truck
wheels of nearly identical dimensions to our Rover rollers for
only $42 apiece. There was no need to manufacture our own
aluminum rollers.) The construction of each of the roller
cages was rather simple, requiring only a hacksaw and a drill
press. It is well within the budgets and skills of most theatres.
We produced eight iterations of the Rover before finding
a workable design. Regardless, Rover remains a prototype
whose design may still be improved and miniaturized. At
present, our Rover is a large, ungainly device that requires a
deep and sturdy track to operate. One must weigh the additional cost of decking the stage to a depth of 11˝ just to accommodate the Rover's bulk-not to mention the complexity of a
serpentine or spiral track. Plus the track must be capable of
handling the maximum anticipated load on the system, particularly in the turns, since the hose will attempt to move if
Rover cannot, and push against the side walls of the track with
all the force available. Furthermore, the hose is the weakest
link in the system. It takes very little to render a hose unusTD & T

W I N T E R

2 0 0 5

27



Table of Contents for the Digital Edition of Theatre Design & Technology - Winter 2005

Contents
Theatre Design & Technology - Winter 2005 - 1
Theatre Design & Technology - Winter 2005 - 2
Theatre Design & Technology - Winter 2005 - 3
Theatre Design & Technology - Winter 2005 - Contents
Theatre Design & Technology - Winter 2005 - 5
Theatre Design & Technology - Winter 2005 - 6
Theatre Design & Technology - Winter 2005 - 7
Theatre Design & Technology - Winter 2005 - 8
Theatre Design & Technology - Winter 2005 - 9
Theatre Design & Technology - Winter 2005 - 10
Theatre Design & Technology - Winter 2005 - 11
Theatre Design & Technology - Winter 2005 - 12
Theatre Design & Technology - Winter 2005 - 13
Theatre Design & Technology - Winter 2005 - 14
Theatre Design & Technology - Winter 2005 - 15
Theatre Design & Technology - Winter 2005 - 16
Theatre Design & Technology - Winter 2005 - 17
Theatre Design & Technology - Winter 2005 - 18
Theatre Design & Technology - Winter 2005 - 19
Theatre Design & Technology - Winter 2005 - 20
Theatre Design & Technology - Winter 2005 - 21
Theatre Design & Technology - Winter 2005 - 22
Theatre Design & Technology - Winter 2005 - 23
Theatre Design & Technology - Winter 2005 - 24
Theatre Design & Technology - Winter 2005 - 25
Theatre Design & Technology - Winter 2005 - 26
Theatre Design & Technology - Winter 2005 - 27
Theatre Design & Technology - Winter 2005 - 28
Theatre Design & Technology - Winter 2005 - 29
Theatre Design & Technology - Winter 2005 - 30
Theatre Design & Technology - Winter 2005 - 31
Theatre Design & Technology - Winter 2005 - 32
Theatre Design & Technology - Winter 2005 - 33
Theatre Design & Technology - Winter 2005 - 34
Theatre Design & Technology - Winter 2005 - 35
Theatre Design & Technology - Winter 2005 - 36
Theatre Design & Technology - Winter 2005 - 37
Theatre Design & Technology - Winter 2005 - 38
Theatre Design & Technology - Winter 2005 - 39
Theatre Design & Technology - Winter 2005 - 40
Theatre Design & Technology - Winter 2005 - 41
Theatre Design & Technology - Winter 2005 - 42
Theatre Design & Technology - Winter 2005 - 43
Theatre Design & Technology - Winter 2005 - 44
Theatre Design & Technology - Winter 2005 - 45
Theatre Design & Technology - Winter 2005 - 46
Theatre Design & Technology - Winter 2005 - 47
Theatre Design & Technology - Winter 2005 - 48
Theatre Design & Technology - Winter 2005 - 49
Theatre Design & Technology - Winter 2005 - 50
Theatre Design & Technology - Winter 2005 - 51
Theatre Design & Technology - Winter 2005 - 52
Theatre Design & Technology - Winter 2005 - 53
Theatre Design & Technology - Winter 2005 - 54
Theatre Design & Technology - Winter 2005 - 55
Theatre Design & Technology - Winter 2005 - 56
Theatre Design & Technology - Winter 2005 - 57
Theatre Design & Technology - Winter 2005 - 58
Theatre Design & Technology - Winter 2005 - 59
Theatre Design & Technology - Winter 2005 - 60
Theatre Design & Technology - Winter 2005 - 61
Theatre Design & Technology - Winter 2005 - 62
Theatre Design & Technology - Winter 2005 - 63
Theatre Design & Technology - Winter 2005 - 64
Theatre Design & Technology - Winter 2005 - 65
Theatre Design & Technology - Winter 2005 - 66
Theatre Design & Technology - Winter 2005 - 67
Theatre Design & Technology - Winter 2005 - 68
Theatre Design & Technology - Winter 2005 - 69
Theatre Design & Technology - Winter 2005 - 70
Theatre Design & Technology - Winter 2005 - 71
Theatre Design & Technology - Winter 2005 - 72
Theatre Design & Technology - Winter 2005 - 73
Theatre Design & Technology - Winter 2005 - 74
Theatre Design & Technology - Winter 2005 - 75
Theatre Design & Technology - Winter 2005 - 76
Theatre Design & Technology - Winter 2005 - 77
Theatre Design & Technology - Winter 2005 - 78
Theatre Design & Technology - Winter 2005 - 79
Theatre Design & Technology - Winter 2005 - 80
Theatre Design & Technology - Winter 2005 - 81
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2020winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2020winter_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2019fall_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2019fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2019summer_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2019summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2019spring_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2019spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/usitt_techexpoguide_2019_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/usitt_techexpoguide_2019
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2019winter_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2019winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2018fall_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2018fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2018summer_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2018summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2018spring_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2018spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2018winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2017fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2017fall_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2017summer_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2017summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2017spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2017spring_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/usitt_techexpoguide_2017_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/usitt_techexpoguide_2017
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2017winter_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2017winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2016fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2016summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2016spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2016spring_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2016winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2015fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2015summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2015spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2015winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2014fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2014summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2013winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2013summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2013fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2013spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2012winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2012fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2012summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2012spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2011winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2011fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2011summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2011spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2010winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2010fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2010summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2010spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2009winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2009fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2009summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2009spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2008winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2008fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2008summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2008spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2007winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2007fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2007summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2007spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2006winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2006fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2006summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2006spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2005winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2005fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2005summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2005spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2004winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2004fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2004summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2004spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2003winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2003fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2003summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2003spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2002winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2002fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2002summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2002spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2001winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2001fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2001summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2001spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2000winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2000fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2000summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2000spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1999winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1999fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1999summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1999spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1998winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1998fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1998summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1998spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1997winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1997fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1997summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1997spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1996winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1996fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1996summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1996spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1995winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1995fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1995summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1995spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1994winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1994fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1994summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1994spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1993winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1993fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1993summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1993spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1992winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1992fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1992summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1992spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1991winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1991fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1991summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1991spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1990fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1990summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1990spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1989winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1989fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1989summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1989spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1988winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1988winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1988fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1988summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1988spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1987winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1987fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1987summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1987spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1986winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1986fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1986summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1986spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1985winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1985fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1985summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1985spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1984fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1984summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1984spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1983winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1983fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1983summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1983spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1982winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1982fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1982summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1982spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1981winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1981fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1981summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1981spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1980winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1980fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1980summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1980spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1979winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1979fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1979summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1979spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1978winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1978fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1978summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1978spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1977winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1977fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1977summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1977spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1976winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1976fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1976summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1976spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1975winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1975fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1975summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1975spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1974Dec
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1974Oct
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1974May
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1974Feb
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1973Dec
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1973Oct
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1973May
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1973Feb
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1972Dec
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1972Oct
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1972May
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1972Feb
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1971Dec
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1971Oct
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1971May
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1971Feb
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1970Dec
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1970Oct
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1970May
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1970Feb
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1969Dec
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1969Oct
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1969May
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1969Feb
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1968Dec
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1968Oct
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1968May
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1968Feb
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1967Dec
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1967Oct
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1967May
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1967Feb
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1966Dec
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1966Oct
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1966May
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1966Feb
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1965Dec
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1965Oct
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1965May
https://www.nxtbookmedia.com