cylinder sharpening

[neil]

Hi,when a cylinder mower cylinder is sent for sharpening does any sharpening of the lower blade have to be done or left alone

[Johnboy]

Hi Neil,
If the lower, static blade, is not sharpened it would be like only sharpening one blade on a pair of scissors. The machine must then be set up to take account of what metal has been removed when regrinding the cylinder. The sharpening of the lower blade is, or should be, only very slight but never the less very important.
JB.

[Geoff]

Isn't there a way of sharpening cylinder mowers yourself with valve grinding paste?

[Johnboy]

Hi Geoff,
Over the years there have been several 'Patented' self sharpeners but I suspect that if not used by an expert have a tendency to do more harm than good. Many years ago a mate of mine bought one and in the end had to fork out for a new cylinder. The new cylinder was about four times the cost of having the job done properly. I have a workshop with a lathe so do manage my own sharpening. Having said that this afternoon I should take delivery of a new mower Honda Professional HRH 536 QX
Should be £1250.00 but I get a 30% discount so only £875.00. This replaces the one stolen last autumn. Not that much if you say it quickly!
When you consider that my first 5 bedroomed house only cost me £3150.00. my how things have changed. That house is worth over £1Million now!
JB.

[Clive.]

Hello,
I attach a couple of clickable thumbnail photos...One of the Atterton & Ellis Pilot Cylinder grinder that I used in my former employ.
..and then one which tries to highlight the wear pattern of the Atco style of lipped bottom blade...
....certainly early Commodore had this type of blade.
I think I have rather exagerated the level of wear in the old blade..I think I based it on the one fitted to my Atco

In the AE Pilot type of grinder the removed cutting cylinder, cleaned and painted, is mounted in the lathe type machine using bearings of the same type as when in the mower and very importantly with the bearings in the same position as in the mower. The cylinder is then revolved backwards whilst a revolving grinding wheel is traversed over the length of the spinning cylinder. By revolving backwards the ground "sharpened" edge is to front of the blade...and by deft adjustment the front edge has a very slight lead. Just enough material is removed to produce a nicely ground finish..but remembering that there is a finite amount that can be removed before the cylinder is ground out...ie down to minimum size..thus needing new.

The bottom blade similarly has a finite amount of material that can be removed to restore a good ground edge....but is deemed a regular replaceable wearing part more so than the cylinder. We used a A&E Ledger grinder for bottom blades..and the blade still mounted on its carrier was fed by hand along a rail across a spinning grinding wheel.
A proportion of the machines we used to see only came in for attention once in a blue moon so more often than not a new bottom blade was required rather than a regrind...which also restored to as full as possible the amount of Set adjustment available within the mower.

The use of a grinding paste is known as back lapping..as the paste is applied to the cylinder and the cylinder hand or motor turned in reverse....it tends to be employed on very fine cut machines on a semi regular basis to keep a golf green type keen set.

I worked in a seaside town and any machines from an area with dry sandy soil used to show up some very rapid wear of the bottom blade. Also the salt used to enjoy a meal of Atco alloy bearing block.

My two c.1968 Atcos on the thumbnail below....not quite as grand as JBs. rather nice Honda
You may see the Atco family resemblance in the chassis to the Commodore.?

All the best,
Clive.

[oldherbaceous]

Theres something i just have to say here, if Clive wrote manuals for mowers i'm sure i would make quite a good mechanic.
It's always so much clearer than the manuals i have ever read.

[Clive.]

3 more clickable thumbnails...

The first shows a Ransomes Marquis 20" bottom blade...which does have a slighlty more pronounced lip than Atco... It is possible to see a small section of bottom blade, nearest the camera, over which the cutting cylinder has not passed....this is still showing the depth of blade at new..further back the rest of the blade exibits the sloping wear pattern. It required new replacement.

Then two photos of the AE Ledger blade grinder...don't worry the 2 petrol cans underneath would not be there if in use..
Larger mower concerns may have a machine into which the blade and carrier is mounted and the grind wheel traverses....others may use a free hand angle grinder ...and preserve the worn front edge of the blade as a datum..and very carefully grind away the back edge until it is a fraction below what is left at the front.

I have also remembered that some companies may have the ability to mount the whole mower and grind cylinder blade in situ in the mower...much easier than a dismantle...but it does not take in a check and grease of the cylinder mounting bearings... In the case of the Marquis of which the above blade came off..the bearings felt ok and I nearly left them in the blocks as I knew their history and they have grease nipples..but when I cleaned them up the inner race on one had a fine crack across it....so pleased I did check them...

Hello Old H',
Your reply came up as I typed even more

...best thing is...I hate working on filthy mucky mowers these days...I love them really.
Mower muck is filthy greasy muck. ....garden muck is clean muck


Clive.