SADDLE SADDLE The cross slide is radially graduated 360° for easy and accurate setting of the compound slide. A 24-tooth gear and dial indicator for screwcutting is fitted as standard, and is clearly visible from the natural operating position. The dial has 4 numbered divisions and 4 sub- divisions. To cut an even number of threads such as 12 T.P.I, the leadscrew may be engaged at any division on the dial, and for an odd number of threads, such as 13 T.P.I., the leadscrew must only be engaged at numbered divisions. To cut fractional threads such as 11 1/2 T.P.I, the leadscrew must be engaged only at division 1 on the dial. The dial indicator cannot be used for metric threads.
For these the nut is closed on the leadscrew, and the machine reversed by means of a finger tip reversing switch, mounted through the main control lever on the headstock, after each cut and tool withdrawal, bringing the tool back to starting point, the nut remaining engaged until the thread is completed. The switch is only supplied as extra equipment. The Saddle, of adequate proportions, mounted on vee and flat surfaces on the bed, is of the American Wing type on the straight bed machines and fitted with a very robust compound slide. The Saddle is secured to the bed by means of keeps in front and rear and can be locked on the bed at any position. All surfaces are precision machined.
Large diameter micrometer dials reading in .001" are fitted to both slides and can be set to zero and clamped for easy operation. Operating screws and slides are covered in all positions. A standard American pillar toolpost is fitted, but special and automatic indexing square turret toolposts can be accommodated and fitted at extra cost. When the Clausing-Colchester Coolant unit is ordered, the coolant supply pipe is bolted to the back of the carriage at the tailstock end, and moves along the bed with the carriage. The supply pipe is only furnished with the coolant unit.
The standard tool size for the American Toolpost is 9/16" X 1 1/8" APRON Back to Index The apron is a double-walled casting accurately machined and all shafts are arranged to have two bearing points. Feed and screwcutting controls are inter-locked to prevent simultaneous engagement and longitudinal and cross feeds are engaged by a positive single lever control action. Power for both longitudinal and cross feeds is taken from a separate shaft incorporating a simple slipping clutch arrangement at the feed box end which effectively guards against possible damage through careless operation and is equally effective in taking care of the heaviest cuts.
Similarly when screwcutting, a shear pin device in the gear train obviates damage, the pin being easily replaced by first removing the gear, and then the serrated sleeve from the shaft. This will allow the broken pin to be tapped out of the sleeve from the opposite side to the serrations, also if the shaft is revolved until the broken pin in it comes opposite the slot in the housing, it can be knocked straight through and will then drop out through the housing slot. The new pin can then be inserted.
Shear Pin device The precision leadscrew (6TPI ACME) is used for screw cutting only and the whole apron arrangement is effectively guarded to comply with Factory Satety regulations and requirements. Direction operating instructions are clearly shown on the metal plates on the apron.