Great Plains P13918 - Manual (Page 20)

Land Plane
Operating Instructions
20
4. Adjustment / Operation
4.4 Work Settings
In work, the transport wheels should be lifted
clear of the ground (using cylinder C in
Fig.4.04) and need not be used in work under
normal circumstances.
The depth of the scraper is altered using
toplink B. The pitch of the scraper is altered
by adjusting the toplink D. Hydraulic cylinder
A is used to lift the scraper bowl out of work
when turning.
4.5 Hydraulic Depth Control
The object of hydraulic depth control is to
enable minor adjustments of the blade to be
carried out on the move in work whilst still
retaining a preset maximum depth. The
hydraulic depth control replaces the need to
wind the toplinks every time there is a build
up of soil in the scraper, usually occurring
during the initial pass over uneven ground.
When setting the toplinks the hydraulic
cylinder should be fully extended. The
adjustable pivot should set so that it is at its
forward limit. With the pivot plate in this
position and the cylinder fully extended, the
linkage passes over centre, thereby
eliminating any excessive hydraulic pressure
on the tractor spool valves when at planing
depth.
4.3 Scraper Bowl
The scraper bowl is fitted with a reversible
blade made from toughened steel. The
working depth and pitch is adjustable in order
to obtain the desired levelling effect on the
land. The wing chains attached to the scraper
bowl inhibit lateral movement of the bowl
ensuring an even finish.
4.2 Castor Wheels
In work, the castor wheels carry the weight of
the machine allowing the scraper blade to be
moved independently to set the working depth
and ensure accurate levelling for large areas.
The castor wheel pivots are fitted with nylon
bearings that normally do not need lubrication.
When excessive play is detected the upper
and lower bearings can be replaced.
Fig. 4.02: Castor Wheels
Fig. 4.03: Scraper Bowl
Fig. 4.04: Setting the Machine