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Hints and Tips: Express Dual

Before grinding

Clean the cutting units before grinding. A good visual inspection means problems can be spotted and fixed before they become an issue.

Always check that the mower that you are about to grind has good bearings. Poor bearing will affect the grinding results and the quality of cut.

Ensure the mower reel axis is parallel to the mainshaft. Line up the front roller or multi-fix brackets to the scales or measure equally to the machined front bed of the Express Dual.

Proper sequencing (Video)

Proper sequencing

While grinding

NEVER let a grind finish with the reel sparked out (little or no sparks as the stone traverses). The reel will be a true cylinder but the hollow ground blade tip relief that Express Dual applies will be lost. Always back off the handwheels at the end of grinding whilst good firm contact remains between reel and grindstone.

Truing up a coned reel (Video)

Truing up a coned reel

Maintenance

When fitting a replacement Sleeve and Nut to your Express Dual remember to file the sides of the key, to fit the keyway in the Mainshaft.

Initially undo and finally tighten the grindstone into the sleeve and nut whilst the assembly is on the mainshaft.

DO NOT grip the sleeve and nut in a vice.

Visually inspect any new stone for cracks and/or damage before fitting. DO NOT use a damaged stone.

Ensure that there is not dirt/debris between the sleeve and nut flanges and the sides of the grindstone.

Ensure that the bearing goes back onto the same position along the mainshaft’s end.

Check that the side arm is in the centre of the feed column slot - NOT rubbing on the side.

Remember to clean the Mainshaft on the Express Dual at the end of each days grinding.

For good results dress the stone regularly on the Express Dual.

If machines are not being used for several days, lightly oil the mainshaft on the Express Dual, but remember to wipe off before use.

Recommended Service Schedules

Daily:

Before grinding

Clean mainshaft (remove oil). Ensure that shaft is dry before any grinding occurs

After grinding

Dress grindstone lightly to keep it true
Clean mainshaft with Bernhard clean and lube spray, WD40 or equivalent
Leave a film of lubricant (Bernhard protective oil or similar) on shaft

 

Weekly:

Clean fork and traverse pickup shafts with Bernhard clean and lube spray, WD40 or equivalent
Brush molycote onto contact surfaces of fork driver
Clean traverse chain and sprockets (brush off any grinding debris)

 

Monthly:

Check chain tension

 

6 Monthly:

Lubricate traverse chain
Check play (key) in sleeve and nut
Check condition of flexible coupling on reel drive (look for cracks in rubber)
Sparingly lubricate feedscrews with light oil

 

12 Monthly:

One shot of grease to any mainshaft bearings fitted with grease nipples

 

LIFT TABLE

Monthly:

Visual check for loose fastenings/hydraulic leaks

 

3 Monthly:

Check hydraulic fluid level Raise table to top of its travel and check platform level (adjust as necessary)
Lightly oil table pivot points

 

12 Monthly:

Raise table to top of its travel
Remove the cover from the mechanism and lightly grease the chains, check for loose fastenings/hydraulic leaks
Apply a little grease to the post (guide) channels (not necessary on later machines with ball bearing guides)

Grinding Wiehle Rollers to ensure they roll true

Background

Through the pressures that are exerted on all rollers during rigorous use of mowers, there is inevitably damage caused. Even dropping the cutting unit on the floor where a small stone lies can cause slight bowing of the roller. This is often illustrated or recognised when setting the height of cut (HOC) with a dial indicator setting tool.

A six thou deviation can mean from 6 to 12 thou cutting height variance over a 7 inch travel. This can have massive impact on speed and consistency and is much more dramatic when using multi gang mowing machines (triplexes and five gang units)

To remedy this inconsistency, if variances are discovered it is easy to re-true the roller on any Express Dual grinder.

Instructions

w_r_fig1.jpg

1. Mount the Multi-Fix brackets on the grinder as shown in Figure 1. Make sure the space apart is such that the spindles are supported on both ends.

2. Set up the bottom V bracket so there is sufficient room for the roller to be mounted without being outside the travel potential of the main shaft.

3. As you mount the roller into the V brackets, at one end place an irrigation head O ring over the roller – then clamp both ends of the spindle very lightly with the turn screw from above.

4. In the same way as you align the grind stone/main shaft to the reel, do the same for the roller so that the stone will be moving along the roller in parallel.

w_r_fig2.jpg5. To establish a “drive” to the roller the O ring must be stretched over the final drive of the Reel Drive as shown (Fig.2). To tension it the silver mount bar that holds the reel drive can be pushed away from the roller, stretching the O ring sufficient to provide a belt drive.

6. Engage the Reel Drive motor.

7. Engage the Traverse motor and set the stops so the stone comes only half its thickness off the end of the roller.

8. Engage the Main Shaft motor and begin to move it gently upwards so that the stone finally engages with the roller and the spark pattern develops evenly.

9. Grind until there is total uniformity of spark from all parts of the roller – at which time the grind stone can be moved away from the roller – downwards.

10. Now, with the roller still turning, take a Half Round file and remove all sharp edges from every disc individually so that there is no risk of the roller cutting into the tender grass plants when using.

Remove the roller - Job Done.