Introduction: A 105 mm spindle bore and a 2000 mm or 3000 mm bed decide most long pipe and long shaft jobs before any price conversation starts.
When a job shop takes on a pipe spool or a shaft that has to pass through the headstock, the machine choice comes down to a few hard numbers: bore, bed length, workholding, and the thread on the end. Get those wrong and you either cannot get the workpiece through the spindle or you burn hours on a setup that never pays for itself.
Through-bore work means the workpiece is fed through the hollow spindle and gripped near the front, rather than sitting between centres. On a pipe spool, the wall and the bore are what you machine; the body of the pipe disappears into the headstock. That is why the bore size dominates the decision. The CQ6280C carries a nominal 105 mm spindle bore, which gives a real working window for pipe and heavy-wall tube that small-bore lathes simply cannot accept, and it opens up shaft work where the tail end needs to sit inside the spindle instead of hanging out the back of the machine. It also uses an ISO702/II NO. 8 Camlock spindle nose, a standard interface that keeps chuck changeover between a three-jaw, a four-jaw and a faceplate predictable. Meanwhile gearbox operation remains manual, with 12 spindle speeds from 30 to 1400 rpm, so the operator sets a speed for the pipe diameter and the thread pass and works from there. As an application example, picture a small overseas shop quoting a run of long pipe spools around 90 mm outside diameter and 2.4 m overall length, with an imperial thread cut on each end and a steady rest needed because the pipe sags at that length. Before quoting, the shop checks three things against the 105 mm bore: whether the pipe body clears the spindle with the chuck jaws fitted, whether the 2.4 m length is manageable on a 2000 mm or 3000 mm bed, and whether the thread standard can be cut without extra change gears. That is the right order of thinking, and it is exactly the sequence a CQ6280C lathe manufacturer will follow when the inquiry arrives.
Bed length is the second big decision, and it is the one buyers most often rush. The CQ6280C is offered with 2000 mm and 3000 mm maximum workpiece length variants. That number describes the machine's capacity, not a free pass to hang any 2.9 m shaft on a 2000 mm bed and expect a clean result. The practical question is how much of the workpiece you can support, how much has to stay unsupported near the cut, and whether a steady rest can be positioned where the shaft actually needs it. Answer that, and the bed choice becomes obvious rather than a coin flip between two options.
The 105 mm bore is nominal. What actually passes through is a pipe, plus chuck jaw engagement, plus any burr or weld bead on the outside surface, plus the small amount of float you want so the pipe does not fight the jaws. A pipe that measures close to the bore limit will technically enter the spindle but leave no room for safe, repeatable workholding, and long pipe especially will whip once the spindle speeds up. Measure the real outside diameter on the actual stock, not the nominal pipe size, and allow a working margin. Wall thickness and inside diameter also matter because a thin-wall pipe deflects under jaw pressure far more than a solid shaft, which changes how much of the length you can leave unsupported. That is why pipe work is planned around the outside diameter first and the cut second.
A long shaft behaves differently from a pipe. It carries more mass, it deflects under its own weight, and the overhang past the steady rest is what decides whether the finish cut runs clean or chatters. On a 3000 mm bed you can spread the support points further apart for a long shaft, keeping the unsupported span short at both the steady rest and the cut. On a 2000 mm bed the same shaft may need a different steady rest position or a slower speed range, and the operator has to work within a shorter working envelope. Because the CQ6280C uses manual gearbox control across its 12 speeds, the operator can drop into a lower speed band for a heavy, long overhang and step back up for the finishing pass and the thread. Plan the steady rest position before the shaft goes in the chuck, not after.
A factory that builds this class of heavy duty engine lathe reads an inquiry in a specific order, because that order maps to what can and cannot be done on the machine. First comes the workpiece itself: pipe outside diameter, inside diameter or wall thickness, total length, and the length that actually gets machined. Next comes the end work: thread size and standard, whether it is metric or imperial, and whether module or diametral pitch thread turning comes into the discussion for shafts with worm or special profiles. The CQ6280C covers metric, imperial, module and diametral pitch thread turning, so most end-thread work on pipe and shaft falls inside the machine's range without extra hardware. The third block is workholding: chuck size and type, whether a steady rest is required, and any faceplate or special clamping the job demands. The fourth is quantity and repeat pattern, which tells the factory whether this is a one-off repair job or a recurring production run. Then the commercial side comes in. Bed length selection — 2000 mm or 3000 mm — gets confirmed against the length figures above, not chosen independently. Destination port and delivery terms belong in the same message, because freight and risk boundaries under Incoterms rules change the total landed cost even when the machine price stays the same. Send a simple sketch or drawing with the pipe or shaft dimensions marked, state the thread standard explicitly, and say how many pieces per month you expect. That single message is what turns a general price question into a dimension-based quotation. Motor power, machine weight, load capacity, price, stock, lead time and cutting accuracy are confirmed in the formal quotation rather than assumed from a web page, so the quote is the document to work from.
Long pipe and long shaft work lives or dies on three numbers: bore, bed length, and how the workpiece is supported. The CQ6280C gives you a nominal 105 mm through-bore, 2000 mm or 3000 mm bed variants, a Camlock spindle nose that keeps chuck changes practical, and four thread systems for end work on pipe and shaft. Match those against your actual pipe outside diameter and shaft length, and the machine decision is quick. SENMO builds this lathe and works from dimensions rather than guesses, so the next step is to send your pipe or shaft drawing with outside diameter, length, thread standard, steady rest requirement and expected quantity, and ask for a formal quotation covering bed length, workholding configuration and delivery terms.
A: The CQ6280C has a nominal 105 mm spindle bore, and the pipe that actually passes through is smaller than that once you account for chuck jaw engagement, surface condition and working clearance. A pipe sitting close to the bore limit leaves little room for stable workholding, especially on long lengths. Send the measured outside diameter of your actual stock along with wall thickness and total length, and the factory will confirm whether it clears the bore with your intended chuck and steady rest setup.
A: The longer 3000 mm bed lets you spread steady rest support points further apart, keeping the unsupported span short at the cut and reducing deflection on long, heavy shafts. The 2000 mm bed handles shorter shafts and pipe spools but requires a tighter support plan on long work. Choose based on the real shaft length plus the steady rest positions you need, not on the maximum figure alone, and confirm the selection against your drawing.
A: Yes. The CQ6280C turns metric, imperial, module and diametral pitch threads, so pipe ends with either metric or imperial thread standards are handled on the same machine without a separate thread-capable lathe. The operator sets the thread through the manual gearbox and works from the drawing. Include the exact thread size, standard and pitch in your inquiry so the factory can confirm the configuration and any tooling you need for the end work.
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