8 and 11-Blade 27-inch and 8-Blade 32-inch EdgeSeries DPA Cutting Unit

Under most conditions, you can attain the best clipping dispersion when the rear shield is closed (front discharge). When conditions are heavy or wet, you may open the rear shield.

To open the rear shield (Figure 6), loosen the bolt securing the shield to the left side plate, rotate the shield to the open position, and tighten the bolt.

Figure 6

1. Bolt
2. Rear shield

The dual knob bedknife-to-reel adjustment system incorporated in this cutting unit simplifies the adjustment procedure needed to deliver optimum mowing performance. The precise adjustment possible with the dual knob/bedbar design gives the necessary control to provide a continual self-sharpening action-thus maintaining sharp cutting edges, ensuring good quality of cut, and greatly reducing the need for routine backlapping.

Prior to mowing each day, or as required, check each cutting unit to verify proper bedknife-to-reel contact. Perform this procedure even if the quality of cut is acceptable.

1. Slowly rotate the reel in a reverse direction, listening for reel-to-bedknife contact.

   Note: The adjustment knobs have detents corresponding to 0.018 mm (0.0007 inch) bedknife movement for each indexed position. Refer to Adjusting the Bedknife to the Reel.

2. Test the cutting performance by inserting a long strip of cutting performance paper (Toro Part 125-5610) between the reel and the bedknife, perpendicular to the bedknife (Figure 7). Slowly rotate the reel forward; it should cut the paper.

   

   Figure 7

   Note: If excessive contact/reel drag is evident, either backlap, reface the front of the bedknife, or grind the cutting unit to achieve the sharp edges needed for precision cutting; refer to the Toro Manual for Sharpening Reel and Rotary Mowers, Form No. 09168SL.

   Important: Light contact is preferred at all times. If you do not maintain light contact, the bedknife and reel edges will not sufficiently self-sharpen and will dull after a period of operation. If you maintain excessive contact, the bedknife and reel will wear quicker, wear unevenly, and the quality of cut may be adversely affected.

   Note: After extended running, a ridge will eventually develop at both ends of the bedknife. Round off or file these notches flush with the cutting edge of the bedknife to ensure smooth operation.

   Note: Over time, you will need to grind the chamfer (Figure 8), as it is only designed to last 40% of the bedknife life.

   

   Figure 8

   1. Lead-in chamfer on right end of bedknife
   2. 6 mm (0.25 inch)
   3. 1.5 mm (0.060 inch)

   Note: Do not make the lead-in chamfer too large as it may cause turf tufting.

Use this procedure to set the bedknife to the reel and to check the condition of the reel and bedknife and their interaction. After completing this procedure, always test the cutting unit performance under your field conditions. You may need to make further adjustments to obtain optimal cutting performance.

Important: Do not overtighten the bedknife to the reel or you will damage it.

• After backlapping the cutting unit or grinding the reel, you may need to mow with the cutting unit for a few minutes and then perform this procedure to adjust the bedknife to the reel as the reel and bedknife adjust to each other.

• You may need additional adjustments if the turf is extremely dense or your cutting height is very low.

You will need the following tools to complete this procedure:

• Shim 0.05 mm (0.002 inch) (Part No. 125-5611)

• Cutting performance paper (Part No. 125-5610)

1. Position the cutting unit on a flat, level work surface.

2. Turn the bedbar-adjusting screws counterclockwise to ensure that the bedbar does not contact the reel (Figure 12).

   

   Figure 12

   1. Bedbar-adjusting screw

3. Tip the cutting unit to expose the bedknife and reel.

   Important: Make sure that the nuts on the back end of the bedbar-adjusting screws are not resting on the work surface; use the kickstand (Figure 13).

   

   Figure 13

   1. Kickstand

4. Rotate the reel so that a blade crosses the bedknife approximately 25 mm (1 inch) in from the end of the bedknife on the right side of the cutting unit.

   Note: Put an identifying mark on this blade to make subsequent adjustments easier.

5. Insert the 0.05 mm (0.002 inch) shim between the marked reel blade and the bedknife at the point where the blade crosses the bedknife.

6. Turn the right bedbar adjuster clockwise until you feel light pressure (i.e. drag) on the shim, then back off the bedbar adjuster 2 clicks and remove the shim.

   Note: Adjusting 1 side of the cutting unit affects the other side, the 2 clicks will provide clearance for when the other side is adjusted.

   Note: If starting with a large gap, both sides should initially be drawn closer by alternately tightening the right and left sides.

7. Slowly rotate the reel so that the same blade that you checked on the right side is crossing the bedknife approximately 25 mm (1 inch) in from the end of the bedknife on the left side of the cutting unit.

8. Turn the left bedbar adjuster clockwise until the shim can be slid through the reel to bedknife gap with light drag.

9. Return to the right side and adjust as necessary to get light drag on the shim between the same blade and bedknife.

10. Repeat steps 8 and 9 until the shim can be slid through both gaps with slight drag, but 1 click in on both sides prevents the shim from passing through on both sides.

    Note: The bedknife is now parallel to the reel.

    Note: This procedure should not be needed on daily adjustments, but should be done after grinding or disassembly.

11. From this position (i.e., 1 click in and shim not passing through) turn the bedbar adjusters clockwise 1 click each.

    Note: Each click turned moves the bedknife 0.022 mm (0.0009 inch). Do not overtighten the adjusting screws.

12. Test the cutting performance by inserting a long strip of Toro cutting performance paper between the reel and the bedknife, perpendicular to the bedknife (Figure 14).

    Note: Slowly rotate the reel forward; it should cut the paper.

    

    Figure 14

    Note: If excessive reel drag occurs, either backlap or grind the cutting unit to achieve the sharp edges needed for precision cutting.

1. Adjust the rear roller brackets (Figure 15) to the desired height-of-cut range by positioning the required amount of spacers below the side-plate mounting flange (Figure 15) per the HOC Chart.

   

   Figure 15

   1. Spacer
   2. Roller bracket
   3. Side-plate mounting flange

2. Raise the rear of the cutting unit and place a block under the bedknife.

3. Remove the 2 nuts securing each roller bracket and spacer to each side-plate mounting flange.

4. Lower the roller and screws from the side-plate mounting flanges and spacers.

5. Place the spacers onto the screws on the roller brackets.

6. Secure the roller bracket and spacers to underside of side plate mounting flanges with the nuts previously removed.

7. Verify that the bedknife-to-reel contact is correct. Tip the mower to expose the front and rear rollers and bedknife.

   Note: The position of the rear roller to the reel is controlled by the machining tolerances of the assembled components; therefore, paralleling is not required. A limited amount of adjustment is possible by setting the cutting unit on a surface plate and loosening the side-plate mounting cap screws (Figure 16). Adjust and tighten the cap screws. Torque the cap screws to 37 to 45 N-m (27 to 33 ft-lb).

   

   Figure 16

   1. Side-plate mounting cap screws

The turf-compensation spring transfers the weight from the front to the rear roller. This helps to reduce a wave pattern in the turf, also known as marcelling or bobbing.

Important: Make the spring adjustments with the cutting unit mounted to the traction unit, pointing straight ahead and lowered to the shop floor.

1. Make sure that the hairpin cotter is installed in the rear hole in the spring rod (Figure 17).

   

   Figure 17

   1. Turf-compensation spring
   2. Hairpin cotter
   3. Spring rod
   4. Hex nuts

2. Tighten the hex nuts on the front end of the spring rod until the compressed length of the spring is 15.9 cm (6.25 inches) (Figure 17).

   Note: When operating the machine on rough terrain, decrease the spring length by 12.7 mm (1/2 inch).

   Note: The turf-compensation setting will need to be reset if the HOC setting or the aggressiveness-of-cut setting is changed.

This corresponds to the desired height of cut.

The bench-set height of cut is the height at which the top edge of the bedknife is set above a flat level surface that contacts the bottom of both the front roller and the rear roller.

This is the actual height that the grass has been cut. For a given bench-set height of cut, the actual height of cut will vary depending on the type of grass, time of year, turf, and soil conditions. The cutting-unit setup (aggressiveness of cut, rollers, bedknives, attachments installed, turf-compensation settings, etc.) will also affect the effective height of cut. Check the effective height of cut using the Turf Evaluator (Model 04399) regularly to determine the desired bench-set height of cut.

The aggressiveness of cut has a significant impact on the performance of the cutting unit. Aggressiveness of cut refers to the angle of the bedknife relative to the ground (Figure 22).

The best cutting-unit setup depends on your turf conditions and desired results. Experience with the cutting unit on your turf will determine the best setting to use. You can adjust the aggressiveness of cut throughout the cutting season to allow for various turf conditions.

In general, less to normal aggressive settings are more appropriate for warm-season grasses (Bermuda, paspalum, zoysia) while cool-season grasses (bent, bluegrass, rye) may require normal to more aggressive setups. More aggressive setups cut more grass off by allowing the spinning reel to pull more grass up into the bedknife.

Figure 22

1. Rear spacers
2. Side-plate mounting flange
3. Aggressiveness of cut

The number of rear spacers determines the aggressiveness of cut for the cutting unit. For a given height of cut, adding spacers below the side-plate mounting flange increases the aggressiveness of the cutting unit. All cutting units on a given machine must be set to the same aggressiveness of cut (number of rear spacers, Toro Part No. 106-3925); otherwise, the after-cut appearance could be negatively affected (Figure 22).

The location at which the lift-arm chain is attached determines the pitch angle of the rear roller (Figure 23).

Figure 23

1. Lift chain
2. U bracket
3. Bottom hole

These are the recommended height-of-cut settings when a groomer kit is installed on the cutting unit.

The angle that you use to grind your bedknives is very important.

Use the angle indicator (Toro Part No. 131-6828) and the angle-indicator mount (Toro Part No. 131-6829) to check the angle that your grinder produces and then correct for any grinder inaccuracy.

1. Place the angle indicator on the bottom side of the bedknife as shown in Figure 29.

   

   Figure 29

   1. Bedknife (vertical)
   2. Angle indicator

2. Press the Alt Zero button on the angle indicator.

3. Place the angle-indicator mount on the edge of the bedknife so that the edge of the magnet is mated with the edge of the bedknife (Figure 30).

   Note: The digital display should be visible from the same side during this step as it was in step 1.

   

   Figure 30

   1. Angle-indicator mount
   2. Edge of the magnet mated with the edge of the bedknife
   3. Bedknife
   4. Angle indicator

4. Place the angle indicator on the mount as shown in Figure 30.

   Note: This is the angle that your grinder produces; it should be within 2 degrees of the recommended top grind angle.

1. Turn the bedbar-adjuster screws counterclockwise to back the bedknife away from the reel (Figure 31).

   

   Figure 31

   1. Bedbar-adjusting screw
   2. Spring-tension nut
   3. Bedbar
   4. Washer

2. Back out the spring-tension nut until the washer is no longer tensioned against the bedbar (Figure 31).

3. On each side of the machine, loosen the locknut securing the bedbar bolt (Figure 32).

   

   Figure 32

   1. Bedbar bolt
   2. Lock nut

4. Remove each bedbar bolt, allowing the bedbar to be pulled downward and removed from machine bolt (Figure 32).

   Note: Account for 2 nylon washers and 1 stamped steel washer on each end of the bedbar (Figure 33).

   

   Figure 33

   1. Bedbar bolt
   2. Nut
   3. Steel washer
   4. Nylon washer

1. Install the bedbar, positioning the mounting ears between the washer and the bedbar adjuster.

2. Secure the bedbar to each side plate with the bedbar bolts (nuts on bolts) and 6 washers.

   Note: Position a nylon washer on each side of the side-plate boss. Place a steel washer outside each of the nylon washers (Figure 33).

3. Torque the bedbar bolts to 37 to 45 N∙m (27 to 33 ft-lb).

   Note: Tighten the locknuts until the outside steel washer stops rotating and end play is removed, but do not overtighten or deflect the side plates. The washers on the inside may have a gap.

4. Tighten the spring-tension nut until the spring is collapsed, then back off 1/2 turn (Figure 34).

   

   Figure 34

   1. Spring-tension nut
   2. Spring

1. Remove the rust, scale, and corrosion from the bedbar surface and apply a thin layer of oil to the bedbar surface.

2. Clean the screw threads.

3. Apply anti-seize compound to the screws and install the bedknife to the bedbar as follows (Figure 35):

   

   Figure 35

   1. Bedbar
   2. Bedknife
   3. Screw

   1. Torque the 2 outer screws to 1 N∙m (10 in-lb); refer to Figure 35.

   2. Working form the center of the bedknife, torque the screws to 23 to 28 N∙m (200 to 250 in-lb); refer to Figure 35.

      

      Figure 36

      1. Bedknife screw tool
      2. Install and torque these first to 1 N∙m (10 in-lb).
      3. Torque to 23 to 28 N∙m (200 to 250 in-lb).

4. Grind the bedknife.