HART HAC121MB - User Manual

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LAWN MOWER BLADE

HAC121MB/HAC121MBVNM

For use with HART

™

40 Volt

21 in. Lawn Mower ONLY

998000043

9-23-19 (REV:01)

WARNING!

To reduce the risk of injury, user must read and understand the operator’s manual

for their lawn mower and this instruction sheet. Always wear eye protection with

side shields marked to comply with ANSI Z87.1. Ensure compatibility and fit before

using this accessory. Do not use this accessory if a part is damaged or missing. If

you are not comfortable performing any of the functions described in these instruc-

tions, take your unit to a qualified service center.

WARNING:

Always protect hands by wearing heavy gloves and/or wrapping the cutting edges

of the blade with rags and other material when performing blade maintenance.

Contact with the blade could result in serious personal injury.

REPLACING THE CUTTING BLADE

See Figures 1 - 2.

Stop the motor and remove the start key. Allow the blade to come to a complete

stop.

Remove the battery pack from the battery port.

Turn the mower on its side.

Wedge a block of wood between the blade and mower deck to prevent the blade

from turning.

Loosen the blade nut by turning it counterclockwise (as viewed from bottom of

mower) using a 15 mm wrench or socket (not provided).

Remove the blade nut, spacer, blade insulator, and blade. Do not remove the

hub or the adaptor.

WARNING:

If the hub and/or the adaptor have been removed, replace them before placing

blade on the shaft. Failure to do so could cause the blade to detach or become

unbalanced since blade will not tighten properly, which can result in serious per-

sonal injury.

Place the new blade on the shaft against the blade posts on the hub. Ensure

blade is properly seated with shaft going through center blade hole and the two

blade posts on the hub inserted into their respective holes on the blade. Make

sure it is installed with the curved ends pointing up toward the mower deck and

not down toward the ground. When seated properly, the blade should be flat.

Replace the blade insulator and spacer, then thread the blade nut on the shaft

and finger tighten.

NOTE: Make certain all parts are replaced in the exact order in which they were

removed.

Torque the blade nut down clockwise using a torque wrench (not provided) to

ensure the bolt is properly tightened. The recommended torque for the blade nut

is 310 – 360 in.lbs.

WARNING:

Ensure blade is properly seated and the blade nut is tightened to the torque speci-

fications above. Failure to properly attach the blade could cause it to come loose

and result in possible serious personal injury.

Hart Consumer Products, Inc.

P.O. Box 1348

Anderson, SC 29622, USA

1.800.776.5191

www.HARTtools.com

FIG. 1

A - Blade (lame, hoja)

B - Wrench (clé, llave)

C - Block of wood (pièce de bois, bloque de

madera)

FIG. 2

A - Shaft (arbre, eje)

B - Hub (moyeu, buje)

C - Blade post (round) [tiges pour lame (ronde),

montantes de cuchilla (redondo)]

D - Blade post (half circle) [tige pour lame (demi-

cercle), puerto de la hoja (semicircular)]

E - Blade (lame, hoja)

F - Blade hole (half circle) [trou pour lame (demi-

cercle), orificio de la hoja (semicircular)]

G - Blade hole (round) [trou pour lame (ronde),

orificio de la hoja (redondo)]

H - Blade insulator (isolant de lame, aislante de

hoja)

I - Spacer (entretoise, separador)

J - Blade nut (écrou de lame, tuerca de la hoja)

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This document describes the HART™ LAWN MOWER BLADE, model HAC121MB/HAC121MBVNM, designed for use exclusively with HART™ 40 Volt 21-inch Lawn Mowers. It serves as an instruction sheet for blade replacement and maintenance.

Function Description:

The primary function of this accessory is to provide a replacement cutting blade for the specified HART™ lawn mower. The blade is a critical component for cutting grass, and its proper installation and maintenance are essential for the safe and effective operation of the lawn mower. The document outlines the step-by-step procedure for replacing the blade, emphasizing safety precautions and correct installation to prevent injury and ensure optimal performance.

Important Technical Specifications:

Compatibility: Exclusively for HART™ 40 Volt 21-inch Lawn Mowers.
Blade Nut Torque: The recommended torque for the blade nut is 310-360 in.lbs. This specification is crucial for ensuring the blade is securely fastened and preventing it from coming loose during operation.
Wrench/Socket Size: A 15 mm wrench or socket (not provided) is required to loosen and tighten the blade nut.

Usage Features:

Safety First: The document strongly emphasizes safety, requiring users to read and understand both the lawn mower's operator manual and this instruction sheet. It mandates wearing eye protection with side shields compliant with ANSI Z87.1 and heavy gloves or wrapping the blade's cutting edges during maintenance to prevent serious personal injury.
Pre-Maintenance Steps: Before replacing the blade, users must stop the motor, remove the start key, allow the blade to come to a complete stop, and remove the battery pack from the battery port. These steps are critical for preventing accidental startup and injury.
Blade Securing Method: A block of wood is recommended to be wedged between the blade and the mower deck to prevent the blade from turning while the blade nut is being loosened or tightened.
Blade Orientation: When installing the new blade, it is crucial to ensure that the curved ends point up toward the mower deck and not down toward the ground. The blade should lie flat when properly seated.
Component Order: The document stresses the importance of replacing all parts (blade insulator, spacer, blade nut) in the exact order they were removed to ensure proper assembly.
Hub and Adaptor: A critical warning is provided regarding the hub and adaptor: they should not be removed. If they are removed, they must be replaced before placing the blade on the shaft. Failure to do so can lead to the blade detaching, becoming unbalanced, or not tightening properly, all of which can cause serious personal injury. The blade must be properly seated with the shaft going through the center blade hole and the two blade posts on the hub inserted into their respective holes on the blade.

Maintenance Features:

Blade Replacement Procedure: The document provides a clear, step-by-step guide for replacing the cutting blade:
1. Stop the motor, remove the start key, and allow the blade to stop.
2. Remove the battery pack.
3. Turn the mower on its side.
4. Wedge a block of wood to prevent blade rotation.
5. Loosen the blade nut counterclockwise using a 15 mm wrench/socket.
6. Remove the blade nut, spacer, blade insulator, and blade. (Do not remove the hub or adaptor).
7. Place the new blade on the shaft, ensuring it is properly seated against the blade posts on the hub, with curved ends pointing up.
8. Replace the blade insulator and spacer.
9. Thread the blade nut onto the shaft and finger tighten.
10. Torque the blade nut clockwise to 310-360 in.lbs using a torque wrench.
Professional Service: If a user is uncomfortable performing any of the described functions or if a part is damaged or missing, they are advised to take the unit to a qualified service center.
Regular Inspection: Although not explicitly stated as a separate maintenance feature, the need for blade replacement implies regular inspection for wear, damage, or dullness, which would necessitate following these instructions. The emphasis on proper installation and torque ensures the longevity and safe operation of the blade.