This is an
inexpensive and robust prototype of a sip-and-puff controlled fishing rod
designed for a quadriplegic. Since this is a prototype, the sip-and-puff
input controller is simulated by switches mounted on a separate input console.
¨
Snoopy
kit PN: 3278401281 – Meijer’s
¨
Motorola
68HC11 EVBU board
¨
Shimano
LX cantilever brake set – Alger Schwinn
¨
Solenoid
PN: 28-I-12D – Newark Electronics
¨
Motor
PN: SR-65S (model # 273-0256) Radio Shack
¨
Motor
reduction unit PN: MOTRED-1 – Plastruct Inc.
¨
34:1
worm gear set PN: GEAR-280 – Plastruct Inc.
¨
R/C
replacement gear – 41T / 20T – Riders Hobby Shop
¨
White
plastic gears – 48T, 42T/17T – Riders Hobby Shop
¨
Brass
gear14T pinion gear PN:9335026 -
Riders Hobby Shop
¨
Hose
clamp modified worm gear PN: 7874231023 – Walmart
¨
Popular
Mechanics 16” tool box PN: 2002700983 – Walmart
¨
2 brass
door hinges PN: 34286540 – Godwin Hardware
¨
2- 10K
Potentiometer PN: 2711721- Radio Shack
¨
1-Momentary
push button(3A) PN: 2751556 -Radio Shack
¨
Male 15
pin monitor connector- Radio Shack
¨
Female
15 pin monitor connector-Radio Shack
¨
Small
plastic project box- Radio Shack
¨
15 pin
6 foot monitor cable- Radio Shack
¨
Mini
toggle switch PN: 2750634- Radio Shack
¨
1- Snap
Swivel size 10 model SS-10 PN-39364 Target
¨
1- Brass
Flex Ferrule PN: OCFSF1818 -Hobby World
¨
12”,
1/8” Flex cable -Hobby World
¨
TIP31
Transistor PN: 276-2017- Radio Shack
¨
741 OP
AMP PN- 276-007 – Radio Shack
¨
Component
PC board PN: 276-149A – Radio Shack
¨
8 ¼-20
Thumb Screws – Ace Hardware
COMPONENT DETAILS:
Reel-in Motor and Gear Box
Pull Solenoid to Engage Worm-Gear for Reel-in
Solenoid Pull Force Diagram
CONSTRUCTION:
Remote Control Console:
Toggle
switch is used to activate/deactivate pull solenoid.
A
Potentiometer is used to adjust release angle of fishing pole.
Momentary
push button is used to real in lure.
Casting Arm Assembly:
Fishing
Pole is mounted to RH bicycle caliper brake arm using Aluminum U-channel
brackets.
Button
Release arm is mounted to LH caliper brake arm using Aluminum U-channel
brackets.
Potentiometer
is mounted to pivot point of RH caliper arm to determine pull-back position for
casting distance.
Gear Box Assembly:
U-channel
was constructed to mount motor and
2-torque amplifying gears.
Last
gear in gear box is attached to worm (from the inside of a hose clamp!).
U-channel
is mounted to main base plate using 2 small hinges.
Pivoting
gear box is mounted to pull solenoid to engage worm-gear for reel-in.
Reel-In Assembly:
Motor
is mounted to worm gear assembly on extension arm.
Flex
cable is mounted to axle of fishing pole and to worm gear assembly.
Pull Back Assembly:
Spool
axle is mounted to worm-gear in 2 side-by-side U channels
Pullback
leverage extension is mounted to main spool axle.
Line is attached to spooled axle around lever extension and to bottom rung of fishing pole.
CONTROLS:
Casting:
The distance of the cast is controlled using a Motorola 68HC11 EVBU board. Two potentiometers were used to set and read in the angle the pole is pulled back to. The first potentiometer is attached to the same axle as the pole. Five volts is directed across the pot so as the pole is pulled back the voltage readout will increase. The second pot is located in the control box. It is set up in the same way, with five volts across it so that as the dial is increased the voltage readout will increase. The 68HC11 is used as a voltage comparator. Two analog input pins read in the voltage from the two potentiometers. The program that is burned into the chip will compare these two voltages and turn on an output if the pot on the control box is at a higher voltage than the pot on the reel axle. When the voltage readout from the axle becomes more than the voltage readout from the control box the output (pull back motor assembly) is turned off.
Releasing the rod:
The reel back motor and gear box are attached to the base by two hinges. A solenoid is used to pull the motor assembly down to contact the spool axle. The solenoid draws about half an amp so the power could not be routed directly through the control box. Instead the toggle switch was wired with five volts from the control box to the base. A reed switch with a five volt throw was used to apply a full twelve volts to the solenoid. When the toggle switch is ON the solenoid is pulled down and the spool axle is engaged.
Reeling in:
The reel in motor is controlled by a momentary pushbutton switch on the control box. Twelve volts are applied to the momentary push button switch. When the button is pushed the motor is activated and the reel pulls in the line.
MOTOROLLA 68HC11 PROGRAM:
********************************************************************
** FISHING
**
**
**
** The purpose of this
program is to read in two analog voltages
**
** and compare them. If
the ROD voltage is smaller than the POT
**
** voltage it means that
the rod is not at the angle that we would
**
** like it at. It will then activate an output to pull
the rod
**
** back. When the ROD
voltage becomes greater than the POT
**
** voltage it means that
the rod is in the correct position. When
**
** this happens the output
is turned off.
**
********************************************************************
OPTION EQU $1039
*System option register
ADCTL EQU $1030 *A/D control
register
ADR1 EQU $1032
*Location of ROD input
ADR2 EQU $1033
*Location of POT input
ORG $0000
ROD RMB 1
*Memory set aside for storage
POT RMB 1
ORG
$B600
*Start of program
MAIN LDAA #$80
STAA OPTION
*Power up the A/D converter
JSR WAIT
*Wait 100usec for converter to stabilize
LDAA #$31
*Scan on, Multi on, four channels
LDY #ADCTL
STAA 0,Y
*Write and start first conversion
BRCLR 0,Y,$80,*
LDAA ADR1
STAA ROD
*Read in and store both initial analog values
LDAA ADR2
STAA POT
ISEQ JSR WAIT
*Wait 100 usec for converter to stabilize
LDAA ADR1
STAA ROD
*Load and store both analog values
LDAA ADR2
STAA POT
JSR OUTPUT
*Jump to output subroutine
BRA ISEQ
*******************************************************************
** This subroutine will
take approximately 100 usec to complete.
This gives
** the A/D converter time
to stabilize before the next value is read in
*******************************************************************
WAIT LDX #35
WAIT1 DEX
*3 E-Clock cycles
BNE WAIT1
*3 E-Clock cycles
RTS
******************************************************************
** The OUTPUT subroutine
is a voltage comparitor. It will
compare the two
** analog value that are
read in and turn on an output if ROD is greater than
** POT. If it is not
greater than the output is set to zero.
******************************************************************
OUTPUT LDAA ROD
CMPA POT
*Compare the analog values
BHS LEAVE
LDAB #$01
STAB $1004
*If ROD is smaller than POT turn on output
RTS
LEAVE LDAB #$00 *If
ROD is larger than POT leave the subroutine
STAB $1004
RTS
CONTROL BOARD:
COURSE LAYOUT:
FISHING LURE:
20 gram lure
FISHING POLE:
ASSEMBLY:
PROBLEMS ENCOUNTERED:
Gearbox precision:
Mounting
gears in gear box was very difficult.
Alignment of gears was very critical to minimize the friction so that
the maximum output torque could be applied to pull-back of the fishing pole.
Flex cable location and
power transfer:
Originally
the reel-in motor was mounted to the base plate. The resultant reel in power was transferred around a 180
deg. Due to the originally smaller
diameter flex cable, upon reel in, left over power was stored causing the lure
to not cast properly. To alleviate
this problem, a larger diameter flex cable was used and installed on an
extension bracket off of the base plate to reduce the bend in the flex cable to
90 deg.
Limited cast stroke:
Upon
initial design, the rod was pulled into casting position by a direct link to
the spool axle. It was determined
that to increase the casting distance, a larger leverage was needed to overcome
the spring force. An extension was
manufactured that the pullback line runs through to increase the leverage and
the distance the pole can be drawn back.
Adjusting tension in
casting arm:
A problem was encountered at noon on the day of the presentation. More tension was needed in the springs to increase the casting distance. The adjustment was made and a test was run, but the spring slipped! Due to the increased force applied to the spring it was slightly deformed. The correct solution would have been to have a few spare springs on hand. However, since this was not the case, the original spring had to be placed back into the housing and the spring force decreased to its original setting. The distance could not be increased on this day.
IMPROVEMENTS FOR ASME
COMPETITION:
¨
Plastic gears used
for reeling in the lure have to be replaced with a more robust and reliable
metal gears.
¨
Need to reduce the
friction generated when casting in the spool axel. The best solution will be to retrofit the spool axle with
bearings. This will allow for a
longer distance cast.
¨
To make the reel in
more reliable, a contact switch will be mounted to the tip of the pole to sense
when the lure has been reeled in to the desired location. Currently, too much inconsistancy
exists with the position of the lure prior to casting.
¨
To reduce the risk of
wraping the lure around a component of the fishing pole when reeling in, a
potentiometer will be added to variably control the speed at which the lure is
returned to the pole.
¨
Springs used for
casting the pole should be replaced due to numerous sample casts. Newer springs will generate further
distance of casts.
CLOSING REMARKS:
On behalf of the Snoopy "Sip-and-Puff" core design team, we would like to give a wee special thanks to our nutty professor:
Dr. Hugh Jack
What have we learned most from this project?
- 1 When you have your project working sufficiently, don't mess it up so it doesn't work.
- 2 Be cool like Snoopy and Woodstock!
