Skip to content

Cincinnati Tray-Top Lathe: First Cuts Guide

This section focuses on essential steps for safe operation and basic machining. Always prioritize safety and ensure each step is understood before proceeding.

Manual Reference

📄 Complete Cincinnati Tray-Top Lathe Manual (PDF)

This guide supplements the official manual with essential first-cuts procedures. Page references throughout correspond to the complete manual above.

1. Safely Power Up and Configure the Machine

Personal Safety First

REMEMBER

  • Do not wear neckties, scarves, gloves, loose clothing, or jewelry
  • Restrain long hair with a cap or hair-net
  • Wear approved eye or face protection and safety-toe shoes with slip-proof soles.

Work Area Safety

  • Keep the work area clean and free of hazards like oil, debris, or water
  • Be aware of protruding machine members
  • Return all tools to their storage location immediately after use
  • Report unsafe conditions to the Lead Technician or Safety Manager

Power Up Procedure

  1. Ensure all selector switches are in their OFF or neutral position
  2. The main electrical cabinet doors should be CLOSED
  3. Ensure the main disconnect switch is set to the OFF position before a power source connection is plugged in
  4. To check motor rotation, turn the disconnect switch to the "ON" position
  5. Press the "FORWARD" button on the electrical panel to start the motor
  6. Engage the clutch by raising the start-stop lever
  7. Facing the spindle from the tailstock end, it should rotate counterclockwise. If not, reverse the motor rotation before operating
  8. To obtain forward spindle rotation, engage the clutch by raising the spindle start-stop lever
  9. To reverse the spindle, lower the spindle start-stop lever to neutral, press the "REVERSE" push-button, and then re-engage the clutch by raising the spindle start-stop lever
  10. To stop the spindle, depress the spindle start-stop lever, which engages a multiple-disc friction brake

Lubrication

  • Before initial use, thoroughly lubricate the machine according to

    Section IV (Page 13)

    of the Lathe manual. This includes filling headstock, quick change box, and apron reservoirs to indicated levels

2. Chuck and Secure a Workpiece Correctly

  • When setting up or adjusting a workpiece or fixture, ensure it is a safe distance away from the cutting tool
  • Always retract the workpiece a safe distance from the cutting tool when loading and unloading

  • Refer to

    Figure 1-1 (Page 10)

    and

    Section I (Page 11)

    for general descriptions of components like the Headstock (2) and Tailstock (3) which hold or support the workpiece

3. Select Proper Spindle Speeds and Feeds for a First Cut

Spindle Speed Selection

  1. Stop the headstock spindle. NEVER attempt to change speeds with the spindle running!
  2. Rotate the spindle by hand if necessary to facilitate gear engagement
  3. Use the three levers for speed changes, guided by the "color-match" dial on the headstock front face
  4. Match the colors:
    • Move the outer adjustable selector ring (upper left-hand lever) so its color mark (e.g., green) matches the fixed reference ring's color mark
    • Move the intermediate adjustable selector ring (upper right-hand lever) so its color mark matches the outer ring's color mark
    • Move the inner dial (lower lever) so the desired speed in that color sector matches the intermediate dial's color mark
  5. A neutral position ("N") for the headstock gearing can be found by moving the outer adjustable selector ring (upper left-hand lever) until "N" aligns with the small arrow on the fixed reference ring

Thread and Feed Selection

  1. Stop the headstock spindle. Jog the spindle if needed to engage spur gears
  2. The quick change box (10) provides 48 thread and feed changes using an index slide, a two-position lever, and a three-position lever
  3. Pull out the index slide plunger to disengage the tumbler gears, allowing the slide to drop
  4. Shift the two-position lever to A or B, and the three-position lever to C, D, or E as required
  5. Move the index slide to one of eight positions, aligning the appropriate line on the index plate with the fixed reference on the cylindrical part of the quick change box
  6. Seat the index plunger in the location hole for final setting
  7. A leadscrew reverse lever is also part of this unit, allowing reversal of feeding direction for the carriage and cross slide

Basic Facing and Turning Operations

4. Engaging the Carriage, Cross-Slide, and Compound

  • The Carriage (7) is supported on the bed ways and moves manually or by power
  • The Apron (8), suspended from the carriage, contains mechanisms for power feed to the carriage and cross slide
  • The Cross Slide (figure 1-1, item 6 is Compound Rest which sits on Cross Slide), Compound Rest (6), and Tool Post (5) are mounted on the carriage for tool positioning and movement control
  • Engaging Power Movements:
    • On the 10-inch lathe, a single drop lever is used on the apron. Selection between carriage or cross feed is done by a push and pull selector

5. Make the First Clean Cut Safely and Verify Accuracy

Before Cutting

  • Ensure safety guards, shields, barriers, covers, and protective devices are installed
  • Safety disengagements or interlocks on handwheels must be in place
  • When measuring workpieces, changing tools, or removing chips and grit, the spindle and slides must be stopped
  • Remove chips and grit using a chip rake or brush, never with hands
  • Keep all body parts clear of moving units and the machining area. Do not lean on or reach into the machine

During Cutting

  • Be attentive to the machining process. Unusual sounds or excessive vibration indicate problems. STOP IMMEDIATELY and Address the source of the noise.
  • Watch for packed chips or grit that could damage tooling or machine parts
  • The spindle must be stopped before adjusting the coolant discharge nozzle
  • Never brake or slow down moving machinery with hands or makeshift devices

Verifying Accuracy

Manual Reference: Troubleshooting -

Page 25

Work not turned straight

  • Ensure headstock and tailstock centers are aligned
  • Use steady rest or follow rest on long slender shafts
  • Reduce overhang from the chuck

  • Re-level the bed using a precision level (refer to

    Section 3-14, Page 16

    ) - Ensure the tool is on the center when using the taper attachment

Work out of round

  • Adjust the tailstock center
  • Regrind or lap work centers if they are excessively worn or out of round