SENTINEL ENLARGER

Manual Contents

ZBE Sentinel Enlarger protected under U.S. Patent #5, 493, 114.

INTRODUCTION

GENERAL SPECIFICATIONS

STARLITE 55 COLORHEAD SPECIFICATIONS

SENTINEL ENLARGER SPECIFICATIONS

ASSEMBLY AND INSTALLATION

UNPACKING THE SENTINEL

ASSEMBLY OF THE SENTINEL

1. INSTALLING THE BASEBOARD
2. INSTALLING WALL MOUNTING BRACKETS
3. STANDING THE SENTINEL UPRIGHT
4. MOUNTING THE SENTINEL CHASSIS ONTO THE WALL BRACKETS
5. ZBE SENTINEL ENLARGER DROP TABLE INSTALLATION
6. MOUNTING THE STARLITE 55 COLORHEAD
7. INSTALLING THE AUTOFOCUS COMPUTER
8. INSTALLING THE LENS
9. LEVELING THE ENLARGER
10. HOOKING UP THE CABLING

POWERING UP AND FIRST-TIME ELECTRICAL TESTS

1. POWER ON
2. TEST MOTORS
3. TEST ENCODERS
4. TEST LIMIT SWITCHES
5. TEST REFERENCE PULSES

THE SENTINEL CONTROL SYSTEM

USING THE SENTINEL COMPUTER SYSTEM

GENERAL USAGE OF DEDICATED KEYS

KEYPAD LAYOUT

GENERAL USAGE OF MENUS

SENTINEL ENLARGER MENUS LAYOUT

GETTING STARTED

BASIC OPERATION

1. TURNING THE POWER ON
2. LENS SETUP
3. LAMP ON/OFF CONTROL
4. ENTERING A COLOR FILTRATION
5. ENTERING DENSITY
6. SIZING AND FOCUSING CONTROL
7. KEYPAD BACK LIGHT CONTROL
8. CARRIER LOADING
9. VIEWING THE AUTOFOCUS SETUP
10. SAVING A JOB TO MEMORY
11. RECALLING A JOB FROM MEMORY
12. MAKING A TEST EXPOSURE

SENTINEL PREFERENCES

1. SET LOAD POSITION
2. SET TOP LIMIT
3. CLEAR TOP LIMIT
4. SET BELLOWS LIMIT
5. CLEAR BELLOWS LIMIT
6. ENTER ENLARGER ID NUMBER
7. SET SECURITY LOCK

CARRIER SELECTION

CARRIER SETUP

EASEL SELECTION

EASEL SETUP

KEYPAD LAYOUT

REFERENCE SECTION

SENTINEL MAIN SCREEN OPERATIONS

LAMP ON AND OFF CONTROL

EXPOSURE TIME ENTRY

MAKING AN EXPOSURE

DENSITY ENTRY

CYAN, MAGENTA, AND YELLOW FILTRATION ENTRY

PRINT COUNTER OPERATION

JOB MEMORY SAVE

JOB MEMORY RECALL

LCD DISPLAY AND KEY BACKLIGHTS CONTROL

DENSITY PROBE OPERATION

AUTOFOCUS / MANUAL-FOCUS CONTROL

ZOOMING AND JOGGING THE ENLARGER

CARRIER LOADING OPERATION

AUTOSIZING OPERATION

VIEWING THE AUTOFOCUS SETUP

SENTINEL ENLARGER MENUS LAYOUT

SENTINEL MAIN MENU

->1: STARLITE MENU OPTIONS

->2: NEGATIVE SIZE

->3: EASEL SELECT

->4: CARRIER SELECT

->5: SENTINEL PREFERENCES

->6: SENTINEL CALIBRATION

->7: SENTINEL MAINTENANCE

->8: SENTINEL DIAGNOSTICS

SENTINEL PREFERENCES MENU

->1: SET LOAD POSITION

->2: SET TOP LIMIT

->3: CLEAR TOP LIMIT

->4: SET BELLOWS LIMIT

->5: CLEAR BELLOWS LIMIT

->6: ENTER ENLARGER ID NUMBER

->7: SET SECURITY LOCK

SENTINEL CALIBRATION MENU

->1: SET UP LENS

->2: SETUP EASEL

->3: SETUP CARRIER

->4: SETUP DROP TABLE

SENTINEL MAINTENANCE MENU

->1: ERASE ONE JOB

->2: ERASE ALL JOBS

->3: MASTER RESET

SENTINEL DIAGNOSTICS MENU

->1: SELF TEST

->2: CYCLE MODE

->3: TEST MOTORS

->4: TEST ENCODERS

->5: TEST LIMIT SWITCHES

->6: TEST REFERENCE PULSES

->7: REFERENCE ENLARGER

->8: STACK DEPTH

->9: DISABLE CL COLORHEAD

->10: SHOW DATA

->11: CHECK REFERENCE

->12: ENCODER COUNTS

MECHANICAL MAINTENANCE

GENERAL CLEANING INFORMATION

LENSES

FILTER TRANSPORT

LAMPS

MIXING CHAMBER

COLUMN AND RUNNING SURFACES

UPGRADING THE SENTINEL

UPGRADING SENTINEL AUTOFOCUS ENLARGER SOFTWARE

DAILY OPERATION WITH THE ACCUNET

SENTINEL ENLARGER DRAWINGS

SENTINEL BENCH ENLARGER

SENTINEL WALL MOUNTING

WHERE TO CALL FOR HELP

For any questions or problems regarding the Sentinel Enlarger system, please call or write our office at the address and phone number below:

ZBE INCORPORATED

1035 Cindy Ln., Carpinteria, CA 93013

(tel) 805-576-1600

(fax) 805-576-1601

info@zbe.com

If you are calling regarding a problem with the machine or with questions regarding operational procedures of the Sentinel, it is very helpful to have the phone available at the location of the machine. This will help speed the process of finding the problem or answering any questions.

INTRODUCTION

Congratulations! You have purchased the state of the art in photographic enlargers. The ZBE Sentinel Enlarger is designed to be a rugged machine, simple and elegant in design, yet sophisticated enough to facilitate high-volume, high-quality printing in today's professional photolab.

The Sentinel will allow you to size, crop, and focus your prints at the touch of a button. You will be able to change print sizes without making test prints or probing at the baseboard, print with different paper and film types without test printing each time, and much more.

All of these features are controlled using a single, easy-to-learn keypad, which is backlit for use in total darkness; no more reaching up in the dark to focus large prints or change colorhead settings. Operation with the Sentinel is just a matter of telling the machine what to do by pressing a few buttons.

We at ZBE thank you for choosing the best in modern photographic enlarging systems.

GENERAL SPECIFICATIONS

The Sentinel Enlarger system is made up of the Starlite 55 Colorhead mounted on the Sentinel Enlarger chassis. Although both the colorhead and enlarger each have their own computer control systems, all functions are integrated so that you need only to consider the system as one complete machine. Specifications for the colorhead and enlarger are listed separately below.

STARLITE 55 COLORHEAD SPECIFICATIONS:

Power Requirements: 1100watts @ 110volts, 60Hz; 920watts @ 220volts, 50 Hz

Lamp Requirements 110v units: Three ENX 82v 360 watt enlarging lamps; 220v units: Three ELH 115v 300watt enlarging lamps

Lamp Power: 110v units: 1080 watts; 220v units: 900 watts

Lamp Control: Internal voltage stabilizer

Filtration Type: Subtractive filtration using glass dichroic filters mounted on rotary blades. Internal rotary shutter for light control.

Filtration Calibration: Standard color-correction (CC) units ( 30 CC's = 1 f-stop ).

Filtration Range: 0 - 180 CC's on any color channel plus 5 f-stops of neutral-density range.

Exposure Time Range: 1 second to 999.9 seconds, in increments of 0.1 second.

Size of Light Output Area (Diffuser): 5-1/2 inches square (13.9 cm square) 8 x 8 cm mix chamber available.

SENTINEL ENLARGER SPECIFICATIONS:

Power Requirements: 150w(Max) @ 110volts or 220 volts AC (50-60Hz)

Overall Dimensions: 32" x 32" base x 59" tall

Column Height: 55"

Total Weight: 180 lbs.

Enlargement Range: Less than 0.80X reduction (150mm lens) to greater than 24X enlargement (50mm lens). Max print size: 24" x 30" (30" x 40" floor stand).

Lens Arrangement: Three-lens turret, 50mm - 150mm lenses recommended.

Sizing/Focusing Drive: Two DC servo motors under computer control.

Movement Speed: 4 inches per second.

Positional Accuracy: .001" distance from negative to baseboard .0005" distance from negative to lens

ASSEMBLY AND INSTALLATION

UNPACKING THE SENTINEL

The Sentinel Enlarger is shipped in a wooden crate which contains all of the components necessary for operation of the enlarger. These parts include:

• Column of the enlarger
• Lens and negative stages
• Starlite 55 Colorhead
• Baseboard (bench-mount units) or wall-mount brackets (for wall-mounted units)
• Operator keypad
• Carrier(s)
• Miscellaneous accessories used to put the machine together.

The unpacking of the Sentinel will require two people in order to lift the machine out of the crate and move it around as necessary, since it is a very heavy enlarger. At about 160 pounds for the column assembly alone.

Suitable Location For Unpacking The Sentinel

It is recommended that the un-crating of the Sentinel be done in a well-lit, relatively clean area clear of obstructions or holes into which small parts may fall. A darkroom is usually not the best place because of lighting conditions since most of the Sentinel's parts are black.

Opening The Crate

The Sentinel's crate is put together using wood screws with #2 Phillips heads. A standard, medium-size Phillips-head screwdriver will work, but a power driver is highly recommended.

It is usually necessary to remove only the top of the crate to get the Sentinel out. Remove all of the screws holding the top of the crate in place. Remove the top and set it aside.

Visible in the crate, will be several cardboard boxes in which all of the smaller parts to the enlarger are packed, including the Starlite 55 Colorhead. Some of these boxes are held in place for shipping by wooden cross-braces secured by screws from either side of the crate. Remove all of the cardboard boxes, unscrewing these wood braces as needed.

With all of the boxes removed, the Sentinel Enlarger column assembly will now be visible at the bottom of the crate. The column comes assembled with the negative and lens runner stages. This column assembly is secured in the crate at each end by wooden strips. The screws to remove these strips are inserted from the sides or ends (or both) of the crate. Remove the screws holding these braces in place.

The column may now be lifted from the crate. This will require two people. Lift the column assembly up, keeping it level with the ground. Place the column diagonally on the top edges of the crate such that both ends are accessible. Remove the plastic wrap on the ends of the column. Looking into each end of the column, there will be wooden jams placed inside the column. These are used to keep the enlarger's counterweights secure during shipping. Slide these strips the column.

WARNING: The counterweights in the Sentinel's column are very heavy. If the column is tilted from a position level with the ground, the weights may move in an uncontrolled manner and possibly damage the enlarger or injure the person's hand holding the end of the column. Be certain to keep the column level with the ground until assembly. The Instructions for Assembly of the Sentinel tell when and how to stand the Sentinel upright. See the Standing the Sentinel Upright item in the next section, Assembly Of The Sentinel, for more details.

Unpack the various modules from their cardboard boxes, keeping at least some of the packing material. Once this is done, the Sentinel is ready for assembly.

ASSEMBLY OF THE SENTINEL

Suitable Location

The Sentinel Enlarger is designed for use in any standard darkroom. For optimum performance, the enlarger should be connected to an electrical circuit free of large machinery such as photographic processors. Processors induce large surges in the mains voltage, a problem for any enlarger. A line dedicated to the darkroom's more sensitive equipment is best.

At 180 pounds, the Sentinel is a heavy enlarger and should be installed in a location capable of supporting it's weight. For the bench-mounted Sentinel, any standard bench should suffice, as long as it is not flimsy. A rule of thumb is that a person should be able to sit on the table without it flexing. Folding tables are not suggested.

If the Sentinel is to be mounted on a wall, a flat, sturdy wall should be selected. The mounting brackets for the enlarger must be screwed into the studs within the wall or anchored securely into concrete with suitable fasteners. Do not attempt to mount the Sentinel by screwing the brackets into drywall or plaster wall between studs.

This section covers the assembly of the Sentinel Enlarger from the parts unpacked from the crate. A brief summary of the procedure is listed below. However, it is a good idea to read the instructions through before starting.

Summary Of Assembly Procedure

1. Installing The Baseboard (Bench-mounted Units)

2. Installing The Wall-Mounting Brackets Onto Wall (Wall-mounted Units)

3. Standing The Sentinel Upright

4. Mounting The Sentinel Into Wall Brackets (Wall-mounted Units)

5. Mounting The Starlite 55 Colorhead.

6. Installing The Autofocus Computer And Associated Connectors.

7. Installing The Lenses

8. Leveling The Enlarger So All Stages Are Parallel With Baseboard.

9. Hooking Up The Rest Of The Electronic Cabling.

 

1. INSTALLING THE BASEBOARD

If your Sentinel is a wall-mounted unit, see section B.

Installation of the Sentinel's baseboard is done with the column lying on its back. The baseboard is secured with four (4) bolts into the bottom of the column. A metal doubler plate sandwiches the baseboard between itself and the column providing greater rigidity. Large washers are placed under each bolt head. The baseboard installation steps follow:

1. Place the Sentinel column assembly on its back, either on a large table or on the floor. Place a towel or rag under the column near the bottom end to support the bottom end one-half inch from the surface of the table or floor.
   
2. On the bottom of the baseboard (the side opposite the black side), position the doubler plate over the four mounting holes such that all the holes line up. Secure the plate in position with masking tape. Place the large washers onto the four bolts so they will be handy for insertion in the next step.
   
3. Position the baseboard at the base of the column lining up the four holes with those in the column. Insert one bolt to help "feel" the location of the threaded hole. Screw this bolt in a few turns by hand, then insert and thread the other three. When installing the bolts, make sure all four are engaged in their threads before tightening any of them. Then this is done, tighten each bolt a little, in turn, sequencing through the four repeatedly until they are all tight. All four bolts should be tightened equally.
   

The base board is now attached to the column. Proceed to step C: Standing The Sentinel Upright.

2. INSTALLING WALL MOUNTING BRACKETS

If your Sentinel is bench-mounted, skip this section.

Sentinel Enlarger Wall Mounting Heights

For the above sizes, the bottom of the Sentinel column should be mounted 42" above the easel height. Similarly other print sizes and mounting heights can be interpolated.

The Sentinel Enlarger mounts to a wall using two mounting brackets located at the top and at the bottom of the column. These brackets hold the column of the enlarger and in turn should be mounted to the wall using wood ferring strips, pieces of 2x8 lumber (not included). These strips are bolted the wall into studs or, if the wall is concrete, using concrete screw anchors. The brackets are then mounted to the strips using lag bolts. In the case of a concrete wall, the mounting bracket wall plates may be mounted directly to the wall, with no ferring strips.

Finally, the Sentinel is mounted onto the brackets, held by special attachment points on the column. The diagram below shows the arrangement of the ferring strips and wall mount brackets on the wall. Refer to this drawing during this step.

The procedure to install the Sentinel's wall-mount brackets follows:

1. Choose the wall onto which the Sentinel is to be mounted and locate the appropriate studs. Vertical (plumb) marks on the wall at each stud will help in locating the studs over the entire height of the wall.
   
2. Determine how high the enlarger is to be located. Note that when the enlarger is at full height (the head all the way up the column) the colorhead will extend above the top of the column by about 5 inches. Place a horizontal (level) mark on the wall where the top of the column is to be located. Measure 55 inches down from the top mark and draw another: this will be the location of the bottom of the column.
   
3. Place marks parallel to the ones made in the last step, one inch (1") above the top mark and one inch below the bottom mark. These new marks will be where the wood ferring strips mount to the wall. The top of the upper strip will line up with the top-most mark (the one made in this step) and the bottom of the lower strip will line up with the lowest mark (also made in this step).
   
4. Mount the ferring strips to the wall. Assuming standard construction, a 24-inch long strip will be long enough to span the standard distance between studs, usually 16 inches. The top edge of the uppermost strip is aligned with the upper top mark made in step 3. The bottom edge of the lower strip is aligned with the lowest bottom mark made in step 3. A nail or two will hold each strip in place while it is drilled for bolting. Ultimately, the strips should be held to the wall with no less than four large lag bolts, each about 1/4-inch diameter or larger and 3-1/2 inches long or longer.
   
5. Assemble the mounting bracket frames onto their wall-attachment plates. The correct arrangement for the two pieces is shown below. Note that the bracket should not extend beyond the edge of the wall-attachment plate.
   
   

The two nuts that hold these two pieces together should only be finger-tight at this time, although firmly so. Note that the holes in the brackets are slotted. This is to allow adjustment of the column's tilt if the brackets are not mounted perfectly plumb with one another.

6. Mark the horizontal (side-to-side) position of where the center of the column is to be located. Use a plumb or a string and weight to mark the two ferring strips. Then measure 5 inches to the left and make another set of marks. These plumb marks will align with the left edges of the wall-attachment plates where they bolt to the ferring strips.
   
   At this time make sure that the top edge of the upper wood ferring strip and the bottom edge of the lower strip are 57 inches apart. If they are not, make the appropriate marks to be used to align the two brackets to the correct vertical distance.
   
7. Bolt the brackets to the wall. Starting with the top bracket, hold it against the ferring strip, aligning the top and left edges. The top of the wall bracket aligns with the top of the upper ferring strip. The left edge then positioned at the plumb mark made in the last step. Make sure that the bracket box opens downward. While holding the bracket in place mark the locations of the mounting holes. Use at least four of the six mounting holes. Remove the bracket and drill pilot holes of the proper diameter for the mounting bolts. Install the bolts and the bracket, and tighten into place.
   
   Next, hold the bottom bracket in its position on the lower ferring strip. Be sure that the box opens upward. Align the left edge with the plumb mark, and the bottom edge with the bottom edge of the ferring strip (or the lowest mark, 57 inches down from the top edge of the upper bracket), and mark the hole locations. Before drilling the holes, check the distance between the mounting surfaces of the top and bottom brackets at the inside of the bracket boxes. This should be more than 55 inches but less than 55-1/2 inches. If this checks out, drill the holes and mount the bottom bracket, tightening all bolts.
   
   

3. STANDING THE SENTINEL UPRIGHT

Due to the Sentinel's counterweight balance system, standing the Sentinel upright will put tension on the counterweight cables for the first time. The cables must be in proper position before the column is erected upright, otherwise damage to the counterweight cables may occur. Follow the few steps below for the safest way to stand the machine upright.

1. With the Sentinel still on its back, position the two counterweight cables in their respective pulleys. The Negative and Lens stages may be pushed slowly to tighten the cables so they will stay in the pulley grooves. NOTE: When manually pushing either of the stages, do it slowly and gently. Pushing faster or harder may damage the motor drive system. See Below for cable routing through the pulleys.
   

View from top of column

Counterweight Cable Routing Through Pulleys

2. SLOWLY lift the top of the column to bring the machine upright. At a certain angle, the counterweights will start to move, tightening their cables. The Negative stage (the larger one nearest to the top of the column) will begin to move. Let it move, making sure that the bellows does not extend by more then about 12 inches (1 Foot). It will be necessary to move the Lens stage by hand to "keep up with" the Negative stage as it moves up the column. When the negative stage reaches the top of its travel, you will hear a "clunk" as the weight hits bottom, and the stage will then stop at the very top of the column.

If your Sentinel is a wall-mounted unit, it will now be standing without a baseboard. Care should be taken to properly support it, if left unattended.

4. MOUNTING THE SENTINEL CHASSIS ONTO THE WALL BRACKETS

If your Sentinel is bench-mounted, skip this section.

The process of lifting the Sentinel Enlarger onto its mounting brackets should be done by two or more people. Follow the steps below for the safest and easiest way to get the column onto the wall.

1. Transport the Sentinel into the darkroom if it isn't already. Lift the column into position at the wall mounts: place the bottom end of the column into the lower mounting bracket, then push the top end into its bracket. When the top is inserted half-way into the bracket, the holes in each side of the column will line up with the slotted holes in each side of the bracket. While an assistant holds the machine in place, insert the screws through the sides of the bracket and thread them into the column, finger tight. The figure at left, below, depicts the proper alignment of these holes.

2. With the top secured in place, the bottom end of the Sentinel may now be fastened into its bracket. This is done with two screws threaded up into the bottom of the column through slotted holes in the bottom of the mount, front edge of the lower mounting bracket. The bottom end of the column will need to be pulled forward in order to line the holes up. Insert the two screws and thread them finger tight. This alignment is shown above, right.
   
3. The Sentinel should now be loosely hanging on the wall. The column is now ready to be plumbed. start with the side-to-side tilt. This adjustment is done by means of the slotted holes in the rear of the column brackets, through which the wall-attachment plates are bolted. Using a plumb level against the side of the column, push the column side to side at either the top or bottom until it is plumb, as read on the left or right side. Then tighten the nuts holding the two halves of the brackets together.
   
4. The front-to-back plumb adjustment is accomplished by using the screws holding the column to the bottom bracket, and the slotted holes through which they are inserted. Push or pull the bottom of the column until the level gives a plumb reading when placed on the front of the column. When plumb, tighten the screws.
   
5. The last step is to tighten the top attachment screws. The slots here are for allowance in the positional distance between the two brackets. This completes the mounting of the enlarger chassis to the wall.

5. ZBE SENTINEL ENLARGER DROP TABLE INSTALLATION

Instructions on installing the Sentinel Enlarger column onto the Drop Table Stand unit.

The ZBE Sentinel Enlarger comes in three basic versions: the standard Bench-mount and Wall-mount versions, and the drop-table-equipped Floor-standing version. This section covers the installation of the basic Sentinel Enlarger column assembly (common to all versions of the machine) onto the Drop-table unit. The resulting Floor-standing enlarger will be capable of full-autofocus operation over it's entire range of print sizes, up to about 40 x 60 inches (101 x 152 cm).

The following parts should have been supplied as a kit for this installation:

Items indicated with an (*) are not included if the Drop Table / Sentinel Column Plate are already installed on the Drop Table.

The installation is performed in three major steps: the mounting of the column, the installation of the encoder module, and the final electrical and mechanical connections. The following pages describe this procedure.

INSTALLING THE SENTINEL ENLARGER ONTO THE DROP TABLE UNIT

1. Install the Column Mounting Plate. In order for the Sentinel to be mounted onto the Drop Table unit, the Column Mounting Plate must be installed onto the top of the Drop Table unit. In some cases, this is done before the unit is shipped. If it has not been installed, secure the plate to the top of the Drop Table unit as shown, using the 5/16 x 1.5" Bolts and Nuts provided. Use the brass spacers under the nuts if needed.

• Before Securing any bolts, examine the plate to determine which side is the top. One side should be marked in some way. If there are no markings, refer to the figure at the right, above. Note that the group of holes that are off-center should be positioned to the left-hand side when viewing the plate while standing at the front of the table.
  
• Install all of the bolts loosely at first, then tighten once all are in place.
  
  

2. Mount the Sentinel Enlarger column assembly onto the Drop Table unit. Due to the weight of the Sentinel column assembly, it is recommended that it be placed upon the drop table itself for the purpose of lifting. A piece of 3/4- to 1-inch thick wood or plywood will be required to protect the table's surface.
   

• If the Sentinel has not already been lifted upright, see the instructions in the Sentinel Operations Manual on setting up the machine. Be sure that the column is fully assembled when performing this procedure.
  
• Lower the Drop Table as far as it will go. Lock it into place in the bottom-most lock position. To move the table, it is necessary to turn the lock handle, located just under the front edge of the table.
  
• Place a piece of 3/4 or 1-inch thick wood onto the table. This will protect the surface of the table and ease in lifting the column up to the mounting plate.
  
• Lift the column onto the piece of wood, standing it upright. Position the column base towards the rear of the table surface. This will make it easier to get the column onto the mounting plate once the table is lifted.
  
  

• While a helper steadies the column in its upright position, lift the table all the way to the top, and lock it in the top-most position. This will require at least three people in all. The table should be lifted from either side, rather than the front, to avoid damage. Once the table is at the top, make sure it is securely locked, to avoid an accident.
  
• It will now be relatively easy to move the column base from the word, onto the mounting plate. Position it at the front, center of the plate, with the front edge of the column about one quarter inch in from the front edge of the mounting plate.
  
• Lower the table a bit, to gain access to the bolt holes in the mounting plate under the base of the column.
  
• Insert a 1/4-28 x 1.5" Hex-head bolt (supplied) up through one of the holes. Jockey the column around until the threads engage. Once one bolt is threaded, install the other three. Tighten the bolts only when all four are in place.
  
• The Sentinel enlarger should now be securely attached to the drop table unit. The next step will be to install the encoder module.
  
  

3. Mount the Drop Table Encoder Unit. The Encoder unit is installed behind the column, using four screws to attach it to the main mounting plate. It's measurement cable is then connected to the moving table itself, so the computer can monitor the table's position.

• Note the plate that is attached to the encoder module. The four holes in the module's plate line up with four threaded holes in the main mounting plate, just behind the column. Also note that the encoder module's measurement cable end has a loop terminal on it. The terminal attached to the moving part of the table. A screw may be placed in the terminal when the module was shipped. This screw is for ease of installation only, and will later be discarded. The drawing below, left shows the parts of the encoder module:
  
  

• Place the Encoder Module on the main mounting plate as shown, above, at right. The measurement cable end will feed through the 1/2" hole in the main plate. The screw in the terminal will allow the cable to be pulled from the other side of the plate after the module is secured.
  
• Screw the Module into place using the four 10-32 x 1/4" phillips screws provided. Make sure that there are no obstructions between the module and the surface to which it is mounted. Tighten all four screws.
  
  

4. Attach the Encoder measurement cable to the movable table. The measurement cable with the ring-terminal end will now be attached to the frame of the drop table.

• Identify the encoder measurement Cable Attachment Plate. A diagram of this plate is shown below, in the proper orientation it will be installed, as viewed standing in front of the drop table unit.
  
  

• Looking over the top of the table, between the bellows and the column, locate the two screws that hold the bellows to the moving frame that supports the table. (Lock the table in position about 12 to 16 inches below the main mounting plate for the best view.) Remove each of these screws and replace it with the 8-32 x 1/2" phillips-head screws provided. These slightly longer screws will allow the plate shown above to be secured at the two notches.
  
• Once the new screws are in place, install the Cable Attachment Plate under the two screws, with the notches pointing towards the table (away from the column). Standing in front of the table, and looking over it, the plate should be in the same orientation as shown above. Fully seat the plate into it's notches, and tighten the screws. Be sure that the bellows are still firmly attached.
  
• Very carefully pull the measurement cable down from the Encoder Module (through the hole in the main mounting plate), using the screw inserted in the ring terminal as a handle. Extend the cable far enough to position the ring terminal at the hole in the Attachment plate. Secure the ring terminal using the small 4-40 x 1/4 inch flat-head screw provided.
  

NOTE: The Measurement Cable of the Encoder Module is very fragile. Be very careful not to kink or bend the cable while working. If pliers are used to hold the cable, cover the jaws with masking tape. When gripping the cable, do not turn the pliers so as to bend or kink the cable. A bent cable will cause inaccurate operation of the autofocus system. Do not let the cable "snap" back into the Encoder Module: it may break, making the module unusable.

• Once the cable end is attached, examine the cable itself, from the hole in the main plate down to where it is attached to the table's frame. It should be parallel to the tensor spring next to it. If it is slightly askew, adjust the position of the ring terminal to bring it straight. If it is very angled, check that the Cable Attachment Plate is installed correctly.
  
• Check the operation of the encoder's cable by moving the table up and down. The cable should travel smoothly and remain taught at all times.
  
  

5. Attach top of bellows to underside of column mounting plate. The bellows that covers the front of the Drop Table column are designed to mask the reflective tensator springs to prevent image interference. The bellows has steel plates at both the top and bottom. The bottom plate was secured underneath the Cable Attachment plate when the Encoder module was installed. The top Plate will now be secured to the underside of the column mounting plate.

• Locate the two small holes in the top bellows plate (shown below). Working with only one side to start, place one of the 6-32 x 3/4" screws (10-32 on some models) up through one of the holes, so that it projects up through the hole, as shown. While holding the screw in place, put a spacer over the projecting part of the screw.
  
  

• Insert the screw, while holding it in place, along with the spacer, into the threaded hole in the underside of the column mounting plate. When installed, the spacer should separate the bellows top plate from the column mounting plate. This allows clearance for the heads of the column's mounting bolts. Repeat for the second screw. It will be necessary to move the bellows around a bit to get behind them for turning these screws. When finished, be sure that the plate is straight.
  
• Check that the bellows are lying in an orderly manner, and that they move accordingly as the table is moved up and down.
  
  

6. Hookup the electrical cable from the Encoder Module. The electrical hookup is simple. The cable from the newly-installed encoder module plugs into the small

(D-9) connector located on the rear of the Sentinel enlarger's Negative stage. This is the connector immediately next to the connector for the keypad/expansion junction box. See below:

• Plug in the connector and secure it using the two small lock screws at either end.
  
  

7. Tell the Sentinel Autofocus computer that the Drop Table is installed. This is done in the Sentinel's Preferences menu as follows.
   

• From the regular operating screen, press the MENU key. Then press [5] or use the Arrow Keys to get to the "SENTINEL PREFERENCES MENU" item. Press ENTER.
  
• In the Preferences Menu, press [9] or use the Arrow Keys to get to the "SET SECURITY LOCK" item and then press ENTER.
  
• The screen will read "SECURITY LOCK ON" on the top line. Press any of the number keys once so that it reads "SECURITY LOCK OFF." Press ENTER. This will disable the security lock, and then return operation to the normal operating screen.
  
• Once again, get into the Preferences Menu, as described above. In the Preferences Menu, press [8] or use the Arrow Keys to get to the "ENABLE DROP TABLE" item. Press ENTER.
  
• The screen will read "DROP TABLE NOT ACTIVE" on the top line. Press any number key once to change it to "DROP TABLE ACTIVE." Press ENTER.
  
• The autofocus system is now capable of reading the position of the drop table. Since the Drop Table Encoder is matched to the other encoders in the Sentinel, there is no further setup necessary for autofocus operation.
  
• Since the Drop Table at it's uppermost position is not quite at the same position as the standard bench-top baseboard (if the enlarger is being converted from a bench top model) the lens setups will need to be reprogrammed.
  
• Operation of the Drop Table is fully integrated into the daily usage of the machine, simply move the table to the desired position. The computer will even indicate which direction, and how far, the table should be moved when a change in printsize requires it!
  
  

8. Level the Table and it's stand. Leveling of the Drop Table is done first at it's base, then at the table itself.

• The Drop Table Unit has four square-headed bolts at its feet for the purpose of stabilizing the machine's stance on the floor. Adjust these bolts to attain a stance that is free of movement, and such that the Drop Table unit's column is reasonably plumb.
  
• The table itself features five stud-and-bolt assemblies for the purposes of leveling. It is recommended that the center one be disabled temporarily until the table is level. This is done by loosening the nuts above the table support frame, and backing them off, in an upward direction away from the frame, to give the table room to move as it is leveled. The is true for the bottom nut.
  
• Leveling the table should be done one axis at a time, using a standard carpenter's bubble level to determine correct position. Start with left-to-right leveling. Loosen and "disable" the two front mounting post assemblies, just as the center one was in the last step. This will enable the left-to-right leveling to be adjusted using only the two rear posts.
  
• Place the carpenter's level horizontally at the rear of the table, between where the two rearmost studs are. Adjust the nuts above and below the table frame to attain a level reading in the bubble of the level. When finished, secure the two posts' settings.
  
• For front-to-rear leveling, the level should be placed in the center of the table, in a front-to-back orientation.
  
• Lift the front of the table at the center of the front edge. This movement will show up on the bubble of the level. Move the top nuts on the front two posts so they support the table in a level manner. The left-front and right-front post top nuts should rest on the frame at the same time as the table is lowered from holding it at the front edge midpoint. Further adjustments should be made in the same amounts for both left and right front posts. This will insure that the left-to-right leveling is not thrown off.
  
• Once the front-to-rear leveling is attained, tighten the remaining nuts to secure the positions at all four corners.
  
• The center post may now be engaged by bringing the top nut down to rest on the frame, then tightening the bottom nut to secure its position.
  
  

The installation of the Sentinel Enlarger Drop Table is now complete.

6. MOUNTING THE STARLITE 55 COLORHEAD

The Starlite 55 Colorhead comes with its mounting bracket already installed. With this bracket, the colorhead mounts to the negative stage of the Sentinel, using three flat-head screws. It mounts toward the front of the enlarger, centered left-right. This installation is simple, involving only the two steps below.

1. Place the Starlite 55 Colorhead onto the negative stage of the Sentinel as shown below, centering it left-right. Place a negative carrier under the colorhead's diffuser area to hold it level during positioning. When the correct position is found, the colorhead's mounting bracket will sit flat on the surface of the negative stage.
   
   

View looking down at top of negative stage

Mounting the Starlite onto the Sentinel's negative stage

2. Install the three flat-head screws along the rear edge of the mounting bracket, and tighten them. The carrier may now be removed.

7. INSTALLING THE AUTOFOCUS COMPUTER

The Autofocus Computer mounts directly behind the Starlite55. It controls all movement of the Sentinel Enlarger's lens and negative stages. Most of the electrical connections which make this possible are part of a connector cluster located on the bottom of the AF Computer. It mates with a similar bundle accessible at the top, rear portion of the negative stage. The procedure for mounting the Autofocus Computer (AF Box) follows.

1. Place the AF Box behind the colorhead, making sure its power cord is situated on the same side as the receptacle on the Starlite. Note how the feet on the box fit between the bars mounted on the top of the negative stage.
   
2. Lift one side of the AF Box to gain access to the connector cluster. Mate the bundle of cabling (metal plate with connectors mounted on it) from the negative stage to the matching cluster on the bottom of the AF Box. Press firmly to engage all connectors, working from one side of the plate around to the other and back. Take care not to pull on the cables coming from inside the negative stage. When fully inserted, the metal connector plate will be roughly at the level with the black enclosure of the AF Box. See the figure below.
   
   

Connection of Autofocus Computer (AF Box) to Sentinel Negative Stage

3. When certain the all connectors in the cluster are fully engaged, lower the box into its final location, making sure that none of the grey cables are caught between the Af Box and the negative stage.
   
4. Secure the AF Box with screws inserted horizontally into the four holes in the Af Box mounts, two on each side. Engage all threads finger-tight before final tightening.
   
5. On the left side of the machine, connect the short grey cable between the Starlite and the AF Box.
   
6. On the right side of the machine, connect the AF Box power cord to the receptacle on the back of the Starlite.
   
   

8. INSTALLING THE LENS

The Satellite utilizes a three-lens turret to ease the selection of different lenses while printing. The lenses mount in the lens turret disk, located within the bellows, under a light-trap cover. The procedure for installing a lens follows.

IMPORTANT: Make sure that the main power is turned off for this procedure.

1. Gently move the bellows apart by pushing the lens stage down or the film stage up. NOTE: When manually pushing either of the stages, do so slowly and gently. Pushing faster or harder may damage the motor drive system.
   
   
2. Lift the bellows from the lens stage, carefully separating the Velcro material.
   
   
3. Loosen the light-trap cover by removing the four screws at the corners. With the screws removed, the cover lifts up, then forward. NOTE: When working within the bellows, be careful not to kink the thin steel cable running vertically inside the bellows area. It is integral to the proper operation of the autofocus system.
   
   
4. With the cover removed, the lens turret disk is now visible. The disk has three lens holes in it: two are designed for use with lenses of small focal length (50mm-135mm) with 39mm mounting threads, and one is for larger lenses (150mm). To install lenses, first remove the light trap disk which is attached to the lens turret by means of the three rotation handles. Unscrew the handles by grasping and turning the upper part which does not rotate. Once all three handles are removed the light trap disk will lift off. Be careful not to bend the levers of the two micro-switches at the rear of the turret area.
   
   

5. Secure smaller lenses in the appropriate holes using matching retainer rings for the threads on the lens. Install the lens up from the bottom, and its retainer ring from the top side of the turret disk. When nearly tight, rotate the lens body as needed so the aperture display is visible at the front of the machine when that lens is in the turret's front click-position. Be sure that each lens it tight and secure in its mount.
   
   
6. A threaded ring is provided for a larger lens in the third hole. That lens threads directly into this hole from the bottom.
   
   
7. Once all lenses to be used are installed, replace the light-trap cover and secure it with the four corner screws. Reattach the bellows to complete the lens installation process.
   
   

9. LEVELING THE ENLARGER

Leveling the Sentinel is accomplished through the use of four thumbscrews located at the rear plate attaching each stage to the column. There are four screws to adjust the roll and pitch of each stage. Since most color labs have their own system for leveling enlargers, no set procedure is listed here. However, whatever method is used, the both the lens and negative stages on the Sentinel Enlarger are adjustable in two axes. The figure below shows which screws affect which direction of alignment.

For adjustments on the negative stage, it may be helpful to lift up on its front to aid the turning of the screws. When all adjustments are done, be sure that all screws are tightened.

10. HOOKING UP THE CABLING

The rest of the cabling on the Sentinel Enlarger consists of the baseboard junction box and the main power cord (connected last). The baseboard junction box has two telephone-type connectors for the connection of the keypad and baseboard Density Probe.

1. The long cable from the baseboard junction box connects to the rear of the Sentinel'snegative stage. This connector secures to its mate with two small screws, one at either end.
   
2. The two telephone-type jacks on the junction box are labeled "KEYPAD" and "D-PROBE." The keypad and Density Probe have connectors that insert into their respective jacks. Be sure to insert the two into the correct jacks.
   
3. Check the cable behind the bellows from the negative stage to the lens stage. It should neatly fold between the two stages as they move closer together. The thin steel cable helps guide this flat ribbon cable in its proper alignment.
   
4. Finally, connect the AC power cord at the rear of the Starlite Colorhead.
   
5. FINALLY CHECK ALL CABLING! Many problems are caused by an improperly or partially inserted connector. A checklist for all connections on the Sentinel follows.
   

Interstage Cable: The accordion-folded cable located behind the bellows. Check that the connector is fully seated.

Starlite/Sentinel Interface Cable: The short flat cable on the left side of the enlarger, connecting the Starlite and Af Box. Check that the connectors are fully seated.

AF Box Bundle: Located under the AF Box, this connector bundle is visible from a rearward angle. Check for full insertion; the metal plate should be roughly at the level of the bottom of the black AF Box enclosure.

Baseboard Junction Box Connector: At the rear of the negative stage, this connector should be fully seated and secured with the small screws at each end.

Keypad: The telephone jack connections at the rear of the keypad unit and at the baseboard junction box. Check that connectors are seated and the click-locks secured.

Density Probe: The telephone type connector from the D-Probe unit to the baseboard junction box. Check that connector is seated and the click-lock secured.

AC Power Cabling: Be sure that the main AC cord plugs into the back of the Starlite Colorhead. The AF Box power cord plugs into the male connector also on the back of the Starlite.

The Sentinel is now operational. However, please follow the steps in the next section to properly test that all operations of the Sentinel are performing correctly.