How To series - back-lap a pedestrian cylinder mower

Lee Williamsin Machinery & Mechanics

In this next video in the How To series, Jonny Bowker from JA Bowker, shows us how to back-lap a pedestrian cylinder mower.

Back -lapping can help get an edge back on your cutting cylinder and bottom blade; if you find the cylinder is not cutting cleanly and evenly.

To carry out back-lapping, you will need either: a back-lapping machine shown in photo1 or, you could use a speed brace shown in photo 2 (this is labour intensive but it will still work).

Left: Photo 1. Right: Photo 2

You will also need a brush, a rag and back-lapping paste which is a specialist gel with silicone carbide granules (image 3).

Locate the back-lapping drive (shown in photo 4). If you do not have one or don't know where to find, it refer to the manual or a local mechanic. Make sure you have the correct size socket when attaching back lapper or brace to the drive.

Left: Photo 3. Right: Photo 4

The cylinder should be backed off so it's just touching on both sides. You can then turn on the back-lapper as shown in photo 5 and start to brush on the paste (photo 6).

Left: Photo 5. Right: Photo 6

Brush the back-lapping paste evenly across the cylinder (photo 7), then you leave it to do its work. Gradually adjust the machine to bring the cylinder and bottom blade closer together; this will add more tension. Periodically stop the machine, wipe the blade with the cloth (photo 8) and repeat the process until you get the desired result. This machine is now ready to be set on cut (video link on this below).

Left: Photo 7. Right: Photo 8

There are other videos in the How to Series including:

Setting cylinder mower on cut
Pre-start checks for a ride-on mower
Pre-start checks on a pedestrian cylinder mower
Setting height of cut on a cylinder mower
Storing machines away for winter
The importance of using the correct sprinkler nozzle
Step by step guide to strip down a sprinkler
Step by step guide to replacing a sprinkler
Basic maintenance on a solenoid valve