The purpose of this document is to establish guidelines for proper reel-type cutting unit maintenance.
Policy and Procedure:
All technicians involved in the maintenance of reel-type cutting units used to mow turf at the Atlanta Athletic Club will follow the procedures outlined below in order to provide consistently high quality turf mowing and after cut appearance. Any deviation from the guidelines outlined below must be approved by the Equipment Director or Director of Agronomy. Proper personal protective equipment for cutting unit maintenance includes safety glasses. Tools used for cutting unit maintenance include a Pi Tape, micrometer, calipers, surface plate, cut test strips, and feeler gauges. Ability to read a Vernier scale is necessary to use a Pi Tape and micrometer correctly.
1. General Guidelines:
a. The terms “left” and “right” reference positions or directions relative to the machine operator’s orientation while operating the machine.
b. The “leading” end of a reel references the end of the reel whose blade ends first cross the bedknife during operation.
c. The “trailing” end of the reel is opposite the leading end.
d. All cutting unit sets for triplex mowers and fairway mowers will be maintained in sets, and cutting unit sets will be labeled with the set number.
e. Cutting unit position on the mower will be referenced as follows:
i. The center cutting unit is #1.
ii. The cutting units on the left side of the machine are even-numbered, from the center out.
iii. The cutting units on the right side of the machine are odd-numbered, from the center out.
f. Reels will be changed and recycled when they reach the following minimum diameters:
i. 4.650” for 5” reels.
ii. 6.650” for 7” reels.
g. Reels for tournament-prepared greens cutting units will be inspected by the Equipment Director prior to the event and any special setup will be determined at that time.
h. Bedknives will be changed and recycled when the top face reaches the valley floor of the top relief area, or as instructed by the Equipment Director.
i. Greens mower bedknife front face thickness will be maintained at a maximum thickness approximately equal to half of the height of cut (HOC).
j. Greens mower bedknife front face thickness will be maintained with less than 10% variance from leading to trailing ends. For example; if HOC is to be set at .100”, the bedknife will be ground to a .050” front face thickness, with no more than .005” difference between the leading and trailing end measurements.
2. Post-Use Inspection and Adjustment: All reel-type cutting units will be inspected as soon as practical after each use for proper cut quality and HOC. This post-use inspection will include the following items, in order:
a. Visually inspect cutting units for excessive debris or chaff buildup on reel blades, rollers, etc. Report excessive debris due to insufficient cleaning to a Course Supervisor or the Equipment Director.
b. If reel blades have excessive buildup; pressure wash the reel blades, making sure to avoid spraying high pressure water near grease seals.
c. If cutting units have little debris, proceed with blowing out the cutting unit with compressed air and inspecting the reel blades and bedknife for damage. If damage is found, coordinate cutting unit repair or replacement with the Equipment Director.
d. Inspect all roller bearings for free play and rough rolling resistance. If there is any question that a roller bearing is serviceable, report it to the Equipment Director and coordinate replacement. Lube roller bearings if applicable and wipe any excessive grease from the unit with a shop towel.
e. Inspect all reel bearings for free play and rough rolling resistance. If there is any question that a roller bearing is serviceable, report it to the Equipment Director and coordinate replacement. Lube reel bearings if applicable and wipe any excessive grease from the unit with a shop towel.
f. Inspect cut quality following these steps:
i. Insert a Toro test strip (part # 125-5610) perpendicular to the bedknife so that the test strip is between a reel blade and the leading edge of the bedknife.
ii. Turn the reel forward to cut a ¼” piece of the test strip at each of five places along the bedknife; once near each end, once at the center, and once between the center and each end. The reel should cut the test strip cleanly with minimal effort at each location along the bedknife. Hold the test strip up to the light and check for a “fuzzy” cut.
g. If cut quality is less than optimal, proceed by adjusting the reel to bedknife clearance following these guidelines:
i. For John Deere QA5 cutting units; maintain a .001” minimum gap using a feeler gauge. Adjust the bedknife to the reel until correct clearance is achieved.
ii. For John Deere QA7 cutting units; maintain a .002” minimum gap using a feeler gauge. Adjust the reel to the bedknife until there is contact, and then adjust the reel away from the bedknife until proper clearance is achieved.
iii. For Toro cutting units; maintain a minimal amount of contact between reel and bedknife. Adjust the bedknife to the reel until correct clearance is achieved.
h. If cut quality cannot be restored without excessive reel to bedknife contact, coordinate cutting unit sharpening with the Equipment Director.
i. Check/adjust HOC as outlined in Section 6, Cutting Unit Assembly.
3. Spin Grinding Reels:
a. Each technician who will be grinding reels must first be instructed about, and fully understand, the grinder Machine Operation Manual.
b. All reels to be ground will first be measured with a Pi Tape, and the leading/trailing diameters recorded on a grinding worksheet.
c. Cutting units will be maintained in sets; if one reel needs to be ground, all reels in the set will be ground to maintain the following specifications:
i. Each reel in the set will be maintained within .020” diameter of each other.
ii. Each reel will measure within .005” on the leading and trailing diameter.
d. Inspect all bearings and seals prior to mounting the cutting unit on the grinder.
e. Each cutting unit will be checked for parallelism as part of the grinding setup.
f. Each reel will be ground the minimum amount necessary to remove rounded edges from the reel blades
g. The reel grinder will be cleaned with a vacuum at the end of each day the machine is used. Do not blow debris off the grinder. Track shafts and bearings will be wiped down with a dry shop towel. Do not use any lubricants or chemicals on the grinder.
4. Relief Grinding Reels:
a. All 5” reels will be relief ground at an approximate 30 degree angle, have a finished land width of between 10% - 15% of the blade thickness, and minimal variation between leading and trailing ends of the reel blades. Minimum diameter for relief grinding 5” reels is 4.700”.
b. All 7” reels will be relief ground at an approximate 30 degree angle, have a finished land width of between 15% - 20% of the blade thickness, and minimal variation between leading and trailing ends of the reel blades. Minimum diameter for relief grinding 7” reels is 6.700”.
c. The reel grinder will be cleaned with a vacuum at the end of each day the machine is used. Do not blow debris off the grinder. Track shafts and bearings will be wiped down with a dry shop towel. Do not use any lubricants or chemicals on the grinder.
5. Grinding Bedknives:
a. Each technician who will be grinding bedknives must first be instructed about, and fully understand, the grinder Machine Operation Manual.
b. Visually inspect each knife to be ground for cracks or other damage. Clean knives as necessary to ensure an accurate grind and long grinding wheel life.
c. Ensure knife grinder is set to grind the proper angles for the application prior to mounting the knife in the machine.
d. Ensure coolant level is adequate prior to grinding.
e. The bedknife grinder will be cleaned with a vacuum at the end of each day the machine is used. Do not blow debris off the grinder. Track shafts and bearings will be wiped down with a dry shop towel. Do not use any lubricants or chemicals on the grinder.
6. Cutting Unit Assembly:
a. Impact wrenches are not permitted for cutting unit assembly. Power ratchets are permitted if output torque is limited to 25 lb. ft.
b. All bedknife screws will be tightened to 12 lb. ft. torque, in an alternating pattern from the center out, using the supplied torque wrench.
c. All cutting unit assembly and configuration will be performed according to manufacturer’s instructions; cutting unit modifications are not permitted unless specifically authorized by the Equipment Director.
d. HOC tolerance is +/- .001” for 5” cutting units, and +/- .003” for 7” cutting units. Report any excessive roller runout to the Equipment Director.
e. When setting HOC, cutting units will be adjusted at least .010” low, and then HOC gradually increased to the desired setting, moving the adjusters to within .003” of target HOC, and then checking alternate sides and making any fine adjustments before moving to final HOC. HOC will not be adjusted down from an excessive HOC; if the desired HOC setting is missed, the process is repeated from the beginning.
Employee signature below constitutes employee's understanding of the Cutting Unit Maintenance Policy and Procedure.
Employee Signature __________________________________ Date_____________
Printed Name ___________________________________
If you were reading through the document and thinking that it seems excessive, you need to understand that cutting units are the life blood of the operation, and I've been able to achieve a certain amount of success by focusing a majority of my energy on quality of cut and after cut appearance. There is very little "extra" work involved in maintaining a higher standard once it is achieved.
I know we will have our hands full going through all of our new cutting units when they come in this spring (factory tolerances aren't all they're cracked up to be) but once they are dialed in we can be tournament ready on short notice.