Hello Toeknee, BB and ODK members and Guests,

This is an interesting subject of some importance nowadays.
I don't want to take away from the excellent observations that Bonnar Bloke has made.

I do want to broaden the topic about reel mower maintenance in general,
and help Toeknee form an informed view. The issues here are not so simple.

Since the rotary revolution of the 1950s, reel mowers have been in the decline.
The concern that I have is that skilled people and the use of appropriate
machinery is more so in decline. This topic is about consumer awareness.

The first thing is that reels will not cut your finger "like a knife would" after
even just a few weeks of service. Once the burrs are gone, the keenness of the
reel is maintained by the quality of the steel and, most importantly, its being a precision
cylindrical piece (precision grinding). Whether that precision is maintained is dependant
on the quality of the 'set' - the gap between the reel and bottom blade.

[Linked Image]

CONSUMER AWARENESS
Toeknee, like all reel mower users, should 'do their homework'.
The first thing I would ask a repairer would be about their credentials: do they know
what they are doing; do they have the right equipment.

I have evidence that repairers are not using specialised reel grinding equipment at all,
but make-shift lathes and grinders. They also have no knowledge of the relief angles
on reel blades (spirals) and bottom blades. This is not a good idea. frown

Reels require the right relief angle and direction of grind. Second, the fitting of a
new bottom blade without further preparatory grinding of it is not good practice. This is because
the bottom block (sole plate) may no longer be within specification. The fitting of a new
blade on a rusted block alone will cause distortions.

New bottom blades, like worn ones, should have their front and top face ground at
the correct angles. These angles are agreed to be about 3 - 5 degrees relief.

The setting of reel mowers seems to have developed a mythology of its own.
This is not necessary. On professional equipment a feel gauge may be used to ensure
there is the smallest of a gap between reel and blade.

In practice, most setters - professional and amateur - set by sound and feel.
A slight pressure and 'scissor-sound' is all that is needed. The popular test is to use
a standard 80 gram piece of paper for testing. If the paper cuts cleanly, the set is a good one.

If the set is too tight, the reel will bind more easily. I have seen professional
gang mowers of 15 feet width, hydraulically powered, bind and labour because the
set was too tight when set cold. When the reel and blade gain temperature, particularly
when these components are not cooled by cutting grass and forward momentum, the
reel will bind, and cause unnecessary wear.

When the set is too loose, the reel cutting face will degrade more quickly and
back lapping will be necessary more often.

BACK LAPPING
Toeknee, my advice is to get acquainted with back lapping.
Traditionally, this was well-understood and practised. the professionals use it,
but domestic users remain largely ignorant of it these days.

When done well, your machine will cut nicely for many seasons before it will
require grinding. Currently, the price of reel grinding in Australia is way-too-expensive,
largely due to the reasons I have said: ignorance and incorrect machinery.

I hope this helps answer your question.
-----------------------------------------------------
JACK.