Introduction: A CQ6280C lathe listing reads cleanly when bore, spindle-speed steps, Camlock nose, and machining length are treated as four separate specification categories rather than one combined claim.
A specification sheet for a heavy manual engine lathe packs numbers that answer different questions. The 105 mm spindle bore, the 12 spindle speed steps, the Camlock spindle nose, and the 2000 mm or 3000 mm machining length each describe a different part of the machine. A reader who skims such a list often compresses all of them into one impression of capability, and that flattens what each figure actually says. This walkthrough reads one CQ6280C model listing from SENMO and unfolds those groups in order, so each number on the list lines up with the decision it supports.
The CQ6280C engine lathe lists a 105 mm spindle bore, and that figure describes the through-hole running lengthwise down the center of the headstock spindle. It is a pass-through number. Bar stock or tube up to 105 mm in outside diameter can slide through the spindle, so the operator can machine one end of a long workpiece while the rest of it sits behind the chuck. The 113 mm 1:20 spindle taper is a closely related entry on the same line. It describes the internal taper that seats centers, adapters, and certain tooling directly inside the spindle, and it reads separately from the bore diameter itself. On a specification sheet the bore figure is often mixed up with the swing figures, and those answer different questions. Swing over bed and swing in gap describe the largest diameter that can rotate past the machine structure. The CQ6280C listing shows 800 mm swing over bed and 1000 mm swing in gap. Bore is about what fits inside the spindle; swing is about what fits outside it. Reading them together, a researcher sees that this model can feed a 105 mm tube through the headstock and can also swing 800 mm workpieces in the open bed area, opening to 1000 mm when the gap section is used.
The CQ6280C lists a spindle speed range of 30 to 1400 rpm in 12 speed steps, and that single entry carries two separate pieces of information. The range tells a reader how slow and how fast the spindle can turn. The count tells a reader how many fixed gear ratios sit between those endpoints. On a manual engine lathe with a geared headstock, spindle speed is selected by shifting gears, so a 12-step drive gives the operator twelve discrete choices rather than a continuous dial. The count matters because it shows how finely the machine can match the spindle rpm a particular tool, material, and diameter wants. Surface speed at the tool tip is the reason range and count work as one piece of information rather than two. Cutting speed depends on the workpiece diameter multiplied by the spindle rpm, so a 300 mm workpiece and a 40 mm workpiece need very different spindle settings to reach the same surface speed at the tool tip. The 12 steps give the operator enough discrete choices to land close to the target for both sizes. The two working principles below show how the low and high ends of the range serve different tasks.
A large-diameter workpiece pushes the tool around a bigger circle, so a single spindle revolution already produces a long cut at the tool tip. That is why the low end of the speed range does the heaviest work. The 30 rpm bottom of the CQ6280C range is where large-diameter parts, heavy facing cuts, and large flange or disc work run without overwhelming the tool. A higher spindle setting at that scale would send the tool tip across the surface too fast for the amount of material being peeled off, and the cutting edge would overheat or dull fast. The 30 rpm entry on the listing tells a reader that the machine is set up for workpieces that start large.
The top of the range covers the other side of the job. A 1400 rpm ceiling lets the operator run small-diameter work and light finishing passes at spindle speeds that keep surface speed high enough for a clean cut. Between the 30 rpm floor and the 1400 rpm ceiling, the 12 steps split the difference into roughing and finishing work zones. Roughing passes at lower speeds remove material quickly; finishing passes at higher spindle speeds give the tool a smoother path across the surface. A reader checking a speed listing wants both ends present and clearly separated, because a heavy lathe has to serve rough-and-ready stock removal and a smoother final pass, and the specific depth of cut and feed rate still come from the tool and the material on the day.
The CQ6280C lists ISO702/II NO. 8 Camlock as its spindle nose, and that entry describes the mounting interface at the front of the spindle. Camlock is a standardized short-taper fitting with cam pins that pull a chuck or faceplate onto the spindle in a few turns of a key. The NO. 8 size tells a reader which backplate class fits the machine, so an existing three-jaw, four-jaw, or faceplate can be checked against the standard before purchase. ASME B5.9 is the reference that organizes these spindle-nose dimensions for engine lathes, and reading the Camlock entry as a mounting detail keeps the specification organized. The bed length wraps up the model description. The CQ6280C offers 2000 mm or 3000 mm maximum machining length, and that option describes the length of workpiece the bed can support between centers. It is a bed-length variant that changes the work envelope rather than the bore or the speed. Paired with 800 mm swing over bed and 1000 mm swing in gap, the two length options describe the whole space a workpiece can occupy. A reader choosing between the 2000 mm and 3000 mm variants checks the machine from the headstock and bed geometry together, not from the spindle numbers alone.
A CQ6280C model listing is easier to read once the numbers are sorted into the four groups they belong to. The 105 mm spindle bore and the 113 mm 1:20 spindle taper describe what can pass through the headstock. The 30 to 1400 rpm in 12 speed steps describes the spindle speed choices available for different diameters and tasks. The ISO702/II NO. 8 Camlock nose describes the standardized mounting interface for chucks and faceplates. The 2000 mm or 3000 mm machining length, read alongside the 800 mm swing over bed and 1000 mm swing in gap, describes the workpiece envelope. Each group supports a different question, and separating them lets the machine read as one coherent specification instead of a block of isolated numbers.
A: The 105 mm bore lets a CQ6280C engine lathe feed bar stock or tube up to that diameter through the headstock spindle. That changes the work-holding setup for long parts: the operator can chuck one end and run the back of the workpiece inside the spindle, instead of needing the entire part to sit in the open bed area. It is a pass-through figure, separate from swing over bed or swing in gap.
A: The 12-step count tells an operator how many fixed gear ratios sit between 30 rpm and 1400 rpm. The top speed alone says nothing about how well the machine can match a target surface speed at a given workpiece diameter. The count shows that enough discrete settings exist to land reasonably close to the correct spindle rpm for both small-diameter finishing work and heavy large-diameter roughing. Range and count are two different pieces of information.
A: The ISO702/II NO. 8 Camlock label describes the standardized spindle-nose interface at the front of the spindle. It tells an operator which backplate, chuck, or faceplate class will fit the machine without an adapter. The Camlock designation is a mounting detail defined by ASME B5.9, and the value of checking the label is confirming whether existing workholding can transfer onto the machine.
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