Universal Air Tools UT8777C - Manual (Page 2)

Operating
Select a suitable mounted point that has a free running speed
higher than the maximum running speed marked on the tool.
Make sure that the diameter of the shank exactly matches the
diameter of the collet mounted in the grinder. There are two
standard sizes of collet available for use with this grinder, i.e.
1) - 1/4" dia (0.250ins) (6.35mm)
2) - 6mm (0.236ins)
Never try to force a 1/4" diameter shank into a 6mm collet.
Never try to close a 1/4" diameter collet to secure a 6mm shank.
Always match correctly the shank size to the collet size. If
uncertain, have parts measured by a competent person.
Push the shank as far as possible into the collet and tighten the
collet nut using the spanners provided on the collet nut and
output spindle.
The shank of the mounted point may be pulled forward from the
maximum insertion length but always ensure a minimum
gripping length of not less than 10mm - See Figure 2.
Be aware that the allowed
running speed of the mounted
point is lowered because of an
increase in the length of the
shank between the end of the
collet and the body of the
mounted point. This distance is
shown in Diagram 2 as "LO"
and is called the overhang. The
information with respect to
mounted point size,
permissible running speed and
reduction in running speed due
to an increase in overhang is
available from the supplier of the mounted point.
If the increase in overhang for access reasons takes the
permissible running speed of the mounted point below the free
running speed of the grinder select a smaller diameter mounted
point.
The fitting of the mounted point should be done by a trained
operator.
When first starting the grinder with a new wheel fitted, the
grinder should not be near other persons and be held in a
protected area, i.e. under a bench and run for a few seconds.
This will protect personnel from possible effects of damage to
the mounted point before it was fitted to the grinder i.e. wheel
breakage.
Always use eye protection and wear protective gloves if there are
sharp edges in the work area. The tool and the grinding process
can create a noise level such that the use of ear protectors is
advised.
If the grinding process creates a dust then use a suitable
breathing mask.
Check that the material being worked will not cause harmful dust
or fumes. If this is so then special breathing masks may be
required.
If the grinder vibrates when first fitting a mounted point or during
operation, remove from service immediately and correct fault
before continuing to use.
Do not apply excessive pressure as this will reduce the cutting
efficiency and can bend the shank of the mounted point causing
vibration and the possibility of breakage. Apply light loads to
allow the wheel to cut.
Handle the grinder with care. If the grinder is dropped, carefully
Dismantling & Assembly Instructions
Disconnect tool from the air supply.
Remove inlet and exhaust hose assembly items (32) (33) & (34).
Using wrenches (30) & (31) grip collet nut (26) and spindle (23)
and unscrew collet nut (26) to remove any fitted grinding wheel
and to take out collet (25). l Unscrew lock ring (24) and pull out
the complete motor assembly from housing (3). Grip rear end
plate (14) and tap the non threaded end of rotor (17) to drive the
rotor through rear end plate (14) and bearing assembly. Remove
cylinder (16) noting how the 2 off pins (15) in rear end plate (14)
and front end plate (21) locate the cylinder to the end plates via
the length wise narrow groove in the cylinder. Remove 4 off rotor
blades (18) from rotor (17). Grip rotor (17) and unscrew spindle
(23). Pull off front end plate (21) and bearing assembly. Remove
collar (19) and steel plate (20). Tap out
bearing (22) from end plate (21) and
bearing (13) from end plate (14).
Unscrew air inlet (29) and remove O-ring
(28) and exhaust sleeve (27). Drive out
spring pin (2) and remove lever (1). With a wide bladed
screwdriver unscrew valve screw (12) with O-ring (11), O-ring
(10), air controller (9), spring (8), valve stem (6) and O-rings (5) &
(7). Do not remove valve bushing (4) unless a replacement is
required.
Reassembly
Clean all items and examine for damage and wear. Replace any
parts with parts obtained from the manufacturer or an approved
supplier. Coat all parts with a pneumatic tool lubricating oil and
assemble in the reverse order.
circulate the oil. If tool is used frequently lubricate on daily basis and if
tool starts to slow or lose power.
It is recommended that the air pressure at the tool whilst the tool is
running is 90 p.s.i./6.3 bar. The tool can run at lower and higher
pressures with the maximum permitted working air pressure of 100
p.s.i./7.0 bar.
Page No 2
Safety Rules When Using A Die Grinder
1) Read all the instructions before using this tool. All operators must be
fully trained in its use and aware of these safety rules.
2) Always select suitable abrasive to use with this tool - see Operating
Instructions.
3) Always shut off the air supply to the grinder and depress the lever
to exhaust air from the feed hose before fitting, adjusting or removing
the mounted point.
4) Always adopt a firm footing and/or position before using the grinder.
5) Use only correct spare parts.
6) Check hose and fittings regularly for wear. Do not carry the tool by
its hose.
7) Do not remove and never tie down the safety lever.
8) Never exceed the maximum air pressure and check the free
running speed frequently. Have air regulator fully open when
making speed checks.
9) Use safety equipment as recommended.
10) Take care against entanglement of moving parts of the tool with
check the mounted point for damage, i.e. cracks, chipping and
start for the first time as for fitting a new wheel i.e. under a bench.
Never exceed the maximum air pressure. If there is this
possibility always use this grinder with a pressure reducing valve
fitted in the supply line. Your supplier will advise of suitable
equipment.
This grinder is fitted with a speed regulator and the speed may be
reduced by rotating air controller (9) with a suitable screwdriver.
When making speed checks always rotate the air regulator to the
position to give the highest maximum speed.
D = diameter of mounted point
T = length of mounted point
Lo = overhang
S = diameter of shank
Lg = gripping length
Figure 2. Gripping length of collet and chuck