We are now in the grinding stage of our winter maintenance program. Grinding is the beginning of a season long, highly intense relationship with the reel mowers. John is grinding our 32 reels and adding new bedknives to each unit to insure that we start the season with tightly mowed playing surfaces. He also is replacing any damaged roller and reel bearings that he runs across.
Reel mowers are used on our greens, tees, and fairways. They offer two advantages for maintaining fine turf, and that is an exact height of cut and the best quality of cut possible. The reel mower uses a reel and a bedknife to work its magic. The bedknife sits below the reel and pushes against the turf, standing it up in a vertical position. It then acts as one half of a scissor. The reel then rotates across the edge of the bedknife, acting as the second half of the scissor. The reel blades then gather the cut turf and discharges the clippings. The cutting rate of each mower is different. This rate is dependent on the diameter and number of blades in the reel, the RPM of the reel, and the forward travel speed of the mower. The greens mowers have 11 blade reels and the cutting height is set at .115 of an inch. The fairway and tee mowers have 7 blades on the reel and are set at a 1/2 inch. The difference is that the 11 blade reels have a more precise cut, and cannot deal with the volume of grass that the bigger 7 blade reels can.
Anyways, the process of grinding the reels goes like this:
1. Inspect all bearings
2. Take off bedbar
3. Take off bedknife
4. Add new bedknife or grind old (depending on wear, new ones are added two times a year on greens mowers and one time a year on tee and fairway mowers)
5. Spin and relief grind reels
6. Reassemble reel and bedknife
7. Set height of cut/reel to bedknife adjustment
Spin-grinding is used because it forms a near perfect cylinder. The relief grind is done after the spin-grinding is complete. The relief grind is a grind along the back side of the reel, producing a very thin landing area between reel and bedknife. This allows the reel/bedknife adjustment to be at near zero clearance (the gap is .001 to .002 of an inch). The relief also allows the reel unit to operate with a less horsepower to drive the reels. The reliefs grinds final benefit is that it allows us to use a compound to true up the surface of the bedknife (backlapping), thus achieving a longer life of sharpness. The compound is added to the reels with a paint brush. The reels are then ran backwards towards the bedknife. The compound trues up the face of the knife. During the season, the mowers are set after every use. Setting the mower requires checking the height of cut and the reel to bedknife adjustment. We use paper to make sure the reel is cutting clean during this process. We typically regrind all units in July because once the reel and bedknife get so much wear, backlapping will not resharpen the surfaces. Between the two seasonal grinds, we backlap the reels on a weekly basis.
I hope that all of you have had a chance to play golf during the few days that have been nice. I hope we have more golfing weather, to break the cabin fever.
Thanks,
Shannon
