Hydrafeed Multifeed 65 - Master Spindle Reduction Liner System; Fitting Liners and Bushings

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4.1. THE BARFEED MASTER SPINDLE REDUCTION LINER SYSTEM
Because a short magazine Barfeed does not have a push rod with a support cone
and the material to be machined is not chamfered or coned, as with standard
Barfeed’s, the collet/chuck cannot support the bar by gripping the front end only.
To enable a CNC Lathe to run at maximum RPM using a short bar it is essential that
the material is enclosed in a spindle reduction liner, (filler tube) which has a bore of
approximately 0.5mm (0.020”) greater than the diameter of the material OD to
prevent whip and vibration.
The Barfeed is supplied with the necessary master liner, five sets of bushings and
one set of steel spacers to suit the CNC Lathe as standard. Extra sets of bushings
can be supplied blank or bored from Hydrafeed Limited, or made ‘in house’ to the
specifications in the drawings.
4.1.1
Figure 11 illustrates assembling the Reduction Liner and its components.
4.1.2
Figure 12 illustrates Master Liner Bushing dimension details.
4.1.3
Figure 13 illustrates Master Liner Bushing arrangement.
4.1.4
Figure 14 illustrates plugging tube material and plug specifications.
When feeding small diameter bars (12mm or less), it is sometimes necessary to use
extended bushings to support the bar up to the back of the chuck or collet.
4.2. FITTING MASTER LINER WITH BAR SUPPORT UNIT
If a Master Liner is being used when a Bar Support Unit is fitted, the rear liner
bushing (ie B/feed end) should be a close fit into the Master Liner bore, and the
bushing bore must be concentric to the bushing O.D. its important that the rear
bushing should have a bore approximately 0.2 mm (0.008”) greater than bar O.D.,
and the length of the bushing bore in contact with the bar should not exceed 20 mm
in length (see diagram). NOTE; The rear bushing is identified as a white
material.
It is absolutely essential that the Bar Support Unit is carefully lined up with the Lathe
and the Barfeed, and that the bar being used is supported at the rear end of the
Lathe spindle by a liner or liner bushings described as follows.