AVL Looms Dobby User manual

Convert Rug Loom from Mechanical Dobby to Compu
Updated: June 13, 2019
AVL Looms
2360 Park Avenue
Chico, CA 95928-
6785
U.S.A.
Introduction
Converting your Rug Loom from a mechanical dobby to a
fast and easy process
. You will remove the elements of the mechanical
dobby, including some of the air lines and replace them with the parts that
came with your new Compu
through before attempti
ng to attach your new Compu
When converting your Rug Loom from a mechanical dobby to a Compu
Dobby, please make sure you observe every safety precaution.
1)
Turn main air off.
Remove Mechanical Dobby parts
To begin, r
emove all dobby chain advancing
the order given below.
1)
Remove the stop collars from the ends of the lever pivot posts that
support the detent lever assembly
assembly (71).
Convert Rug Loom from Mechanical Dobby to Compu
-Dobby
Page | 1
6785
530 893-
4915
530 893-
1372 fax
[email protected]m
www.avlusa.com
Converting your Rug Loom from a mechanical dobby to a
Compu
. You will remove the elements of the mechanical
dobby, including some of the air lines and replace them with the parts that
came with your new Compu
-
Dobby. For best results, read the directions
ng to attach your new Compu
-Dobby
When converting your Rug Loom from a mechanical dobby to a Compu
Dobby, please make sure you observe every safety precaution.
Turn main air off.
Remove Mechanical Dobby parts
emove all dobby chain advancing
mechanisms from the dobby in
Remove the stop collars from the ends of the lever pivot posts that
support the detent lever assembly
(68)
and the advancing hook
1372 fax
[e-mail]
www.avlusa.com
Compu
-Dobby is a
. You will remove the elements of the mechanical
dobby, including some of the air lines and replace them with the parts that
Dobby. For best results, read the directions
When converting your Rug Loom from a mechanical dobby to a Compu
-
Dobby, please make sure you observe every safety precaution.
mechanisms from the dobby in
Remove the stop collars from the ends of the lever pivot posts that
and the advancing hook

Convert Rug Loom from Mechanical Dobby to Compu
Updated: June 13, 2019
2)
Remove the detent lever spring and detent lever assembly
dobby.
3)
Unplug the air lines that go to the advancing hook air cylinder
and 76).
4)
Remove the screws that fasten the advancing hook air cylinder
mount bracket, and the screws that
(73).
5)
Once the screws are re
advancing hook assembly from the dobby.
6)
Remove the screws that hold the brackets that retain the dobb
chain cylinder onto the dobby (58).
7) R
emove the entire chain cylinder assembly with mounting bearing
blocks a
nd springs from the dobby
Convert Rug Loom from Mechanical Dobby to Compu
-Dobby
Page | 2
Remove the detent lever spring and detent lever assembly
Unplug the air lines that go to the advancing hook air cylinder
Remove the screws that fasten the advancing hook air cylinder
mount bracket, and the screws that
fasten the reversing cord lock
Once the screws are re
moved, you will be able to
remove the entire
advancing hook assembly from the dobby.
Remove the screws that hold the brackets that retain the dobb
chain cylinder onto the dobby (58).
emove the entire chain cylinder assembly with mounting bearing
nd springs from the dobby
(67).
Remove the detent lever spring and detent lever assembly
from the
Unplug the air lines that go to the advancing hook air cylinder
(75
Remove the screws that fasten the advancing hook air cylinder
(79)
fasten the reversing cord lock
remove the entire
Remove the screws that hold the brackets that retain the dobb
y
emove the entire chain cylinder assembly with mounting bearing

Convert Rug Loom from Mechanical Dobby to Compu-Dobby
Updated: June 13, 2019 Page | 3
Replace existing dobby air lines
You no longer need the "T" air line fittings that provided air pressure to the
advancing hook air cylinder, so you now need to remove the 2 air lines that
contain the "T" fittings. Replace 1 line at a time to be sure the new line is
placed into the correct air line fittings at the harness lift air cylinder and
main dobby air valve. The new lines will have no "T" fittings, just straight
lines from the existing fittings in the valve and the air cylinder.
1) Locate the new lines that came with your compu-dobby and place
them near the loom.
2) Locate the lines that run from the main dobby air valve mounted on
the inside of the bottom frame member, up to the large harness lift
air cylinder.
3) Remove one of the lines with the “T” fittings.
4) Place one of the new lines in the spot where you removed the
existing line.
R
e
p
l
a
c
e
T
f
i
t
t
i
n
g
with straight hose.

Convert Rug Loom from Mechanical Dobby to Compu-Dobby
Updated: June 13, 2019 Page | 4
5) Connect all the air line fittings to the new line.
6) Repeat with the second line.
Install the new Compu-Dobby
It's now time to install the new Compu-Dobby. You will receive new
adjustment springs and mounting brackets with the new Compu-Dobby.
1) Place the new springs into the holes where you removed the old
ones at the end of the adjustment slot in the wooden dobby sides.
2) Slide the new Compu-dobby into the adjustment slots where the
chain cylinder used to be, guiding the ends of new springs into the
holes in the Delrin pillow blocks that are fastened to the sides of the
Compu-dobby.
3) Install the new Delrin adjustment brackets where the aluminum
adjustment brackets used to be.
Install the new air pressure regulator
You'll need to install the new air pressure regulator in a location on the rear
side of the wooden Compu-Dobby box so the inlet and outlet fittings can be
easily accessed to install the new air lines. You'll be installing a new 1/4" air
line that runs between the main 3/8" air line near the on/off hand-valve, up
the rear side of the vertical frame part to the yellow fitting on the regulator.

Convert Rug Loom from Mechanical Dobby to Compu-Dobby
Updated: June 13, 2019 Page | 5
You will also be installing a new 1/4" air line that runs between the green
fittings on the regulator and Compu-dobby box. The regulator is to ensure
excessive air line pressure is not applied to the valves in your new Compu-
dobby. Your air line pressure should never exceed 45 PSI.
1) After installing the regulator on your Dobby box, cut the 3/8" main
air line several inches below the on/off hand valve.
2) Install the new air line fitting assembly that has 2 places for 3/8"
lines, and 1 place for a 1/4" line. Install the fitting assembly into
the 3/8" line so the 1/4" line will be directed upward toward the
regulator you just installed on the dobby.
3) Cut and install a new 1/4" air line between the new yellow fitting in
the 3/8" line, and the yellow fitting on the regulator you installed on
the rear of the dobby.
4) Cut and install a 1/4" air line between the green fittings on the new
regulator, and the side of the Compu-Dobby box.
Install the new sensor assembly
The sensor assembly you received plugs into the RJ45 connector on the
Compu-Dobby box, and the sensors strap onto the large air cylinder below
the dobby. The sensors are marked "up" and "down".
1) Plug in the RJ45 connector.
2) Fasten the "down" sensor and strap onto the air cylinder a few
inches below center, and the "up" sensor and strap a few inches
above the center. We'll make adjustments to these sensor positions
in a few minutes.
3) Now with the RJ45 connector plugged in, and the sensors strapped
onto the air cylinder, use the tie-down stick-on anchors and tie-
downs to rout your sensor cable.
4) From the RJ45 plug, loosely loop the cable around the front of the
dobby, and then rout it under the top horizontal frame part, and
down the front side of the vertical frame part to near where the
sensors are located on the air cylinder.
Important:
While routing this cable remember to;
1. Keep it out of the way of all moving parts of the loom.
2. Keep it away from any power cord.

Convert Rug Loom from Mechanical Dobby to Compu-Dobby
Updated: June 13, 2019 Page | 6
Adjust the sensors
The lower sensor initiates the events that get ready for the next pick, so the
location of this sensor has a lot of margin. The upper sensor needs to be
placed in a position that will activate the Compu-Dobby solenoids after the
metal insert that catches the cable balls has moved above the balls.
1) Place the lower sensor 2" above the bottom of the cylinder.
2) For the upper sensor, watch the dobby cables and slide plate
interact while making the sensor adjustment.
Note:
Be careful not to over-tighten the sensor straps. Snug the screw
only enough to keep the sensor from sliding down the cylinder
during operation.