Recommended Method For Holding Drills In Spindles
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I M P O R T A N T
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Use only the spanners provided for the head, consisting of an open ended and ring spanner.
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Do not overtighten the collet.
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The spindle tool lock must be used to provide a positive drive for the drill.
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The ring spanner should be used for tightening the collet. The open-ended spanner is for holding the collet spindle to prevent it from turning. Do not hold on any other spindle than the one in which the collet is being tightened otherwise undue strain may be transferred to the
gearing.
| All straight shank drills have a tendency to
slip when held in a collet or chuck. It is therefore important that the
tool lock is used for holding all sizes of drills. With the exception of
the drills too large to enter the tool lock, it is only necessary to grind
a single flat on the shank of the drill. The length of the flat should be
approximately equal to the diameter of the tool lock. The depth of the
flat should be 1/3 of the drill diameter.
A flat of these proportions will not interfere with holding the drill
in a normal chuck but when used in a Gy-Roll spindle provides a positive
drive comparable with the tang drive on a taper shank drill. The tool lock
is only really effective if there is a flat on the end of the drill.
Drills too large to enter the tool lock should have an approximate square ground onto the end of the shank. The shape of the square is not critical provided that it freely enters into the tool lock.
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When the drill is first put into the collet it is important that it is held with a light grip enough to locate the drill yet still allowing rotational and axial movement in the collet. The screws in the tool lock should be adjusted so that the tool lock is in the centre of the spindle when gripping the drill. Check the end float of the tool lock to ensure that it moves freely.
When inserting the drill into the tool lock be sure that one of the screws locates squarely on the ground flat of the drill, and that the drill is pushed into the tool lock as far as it will go. The collet should now be firmly closed after which the screws in the tool lock are finally tightened. If the tool lock screws are lost they should be replaced with similar screws. It is important that the dog end or gripping end of the screw is flat.
When spindles are working on close centres check that the tool lock screws clear the screws in adjacent spindles.
In cases where the spindles are too close together to use the ring spanner for tightening the collet, the open-ended spanner has to be used. In such cases the collet should be progressively tightened by applying the spanner to alternative collet flats. If a spare short handled open spanner is not available a long spanner may be used for holding the spindle. The short handled spanner can be used for tightening the
collet.
Lubrication Gy-Roll heads are lubricated with oil as specified on the nameplate.
It is most important to ensure that grease is never used as this will clog up the lubricating system.
The oil in a Gy-Roll head is carried in a polyurethane felted foam block. It is fed by capillary action to the gears and bearing extremities. The oil absorbed in the polyurethane block is adequate for lubricating the entire head. There should be no free oil floating around in the head. Any indication of oil dripping from the spindles or any other part of the head means there is an excess of oil in the head.
Oil is pumped into the head by means of the lubrication nipple in the side of the body. Two to three strokes of an oil gun should provide sufficient lubrication for approximately 500 running hours. If there is an excess of oil in the head it can be drained off by running the head with the lubricating nipple or oil plug removed.
It is important to appreciate that the Gy-Roll lubrication system is not based on an oil bath as with this system the oil would settle in a different part of the head according to how the head was mounted. This could adversely affect lubrication to bearings at the extremities of the head while other bearings may be flooded causing unnecessary agitation of the oil and overheating of the spindles if they were run at high speed.
The importance of ensuring that grease is never used is that if there is any risk of someone pumping grease into the head it is safer to replace the lubrication nipple with an oil plug. The nipple can then be put back on at the appropriate time interval when the head is due for a further injection of oil.
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