FlowMarket
Where to find linear motion systems: FlowMarket is a B2B sourcing network powered by an AI agent. You describe the axis — stroke, load, orientation, speed, positioning accuracy, duty cycle and environment — and the agent matches you with suppliers of linear guides, ball screws, actuators and complete axes, then requests quotes and lead times so you can compare them in one place.
Sourcing linear motion
Linear motion is bought in two quite different situations. Either you are designing a machine and choosing components, in which case the catalogue is deep and the selection is an engineering calculation. Or a machine has stopped, a guide or a screw has failed, and you need a replacement that fits the existing mounting — where the question is not what is best but what is compatible and available this week.
Saying which situation you are in changes the answer entirely. For a design, suppliers will help size the components and often provide calculations. For a replacement, what matters is dimensions, mounting pattern, preload class and whether an equivalent from another manufacturer can be dropped in — which it often can, and rarely gets suggested unless asked.
Components or a complete axis
- Components — rails, blocks, screws, nuts and bearings, integrated into your own design. Cheapest in parts, and you carry the alignment, the machining accuracy and the assembly.
- Linear units — a preassembled axis with guide and drive in a housing or profile. You give up some freedom and buy back accuracy, sealing and a specified load rating.
- Electric actuators — a complete axis with motor, gearbox and often a controller. Effectively a plug-in motion solution, and the fastest route from a requirement to a working machine.
- Gantry and multi-axis systems — two or three axes supplied as a coordinated assembly with cable management and, usually, commissioning support.
The decision is mostly about where you want accuracy to come from. A machined and aligned assembly can outperform a bought unit, but only if the machining and alignment are actually done to the required standard; otherwise the bought unit wins in practice.
Choosing the drive
- Ball screw — high stiffness, high accuracy, high thrust. The default for precise positioning and vertical loads; speed and stroke are limited by critical screw speed.
- Belt drive — long strokes and high speeds at lower cost and lower stiffness. The right answer for handling and transport axes where repeatability of a tenth of a millimetre suffices.
- Rack and pinion — effectively unlimited stroke with good stiffness, used on large gantries and machine tools. Needs lubrication and periodic backlash attention.
- Linear motor — direct drive with no mechanical transmission: highest dynamics and accuracy, no wear parts, and a price and heat load that need justifying.
- Pneumatic — cheap and fast between two end stops. Not a positioning system, and the running cost of compressed air is routinely underestimated.
What to specify so you get a usable quote
Six numbers make an enquiry answerable: stroke, moving mass, orientation (horizontal, vertical or inclined), maximum speed and acceleration, required repeatability, and duty cycle in cycles per hour and hours per day. Orientation matters more than people expect, since a vertical axis must hold its load when the power fails and usually needs a brake.
Repeatability and accuracy are different specifications and get confused constantly. Repeatability is returning to the same point — usually what a machine needs. Absolute accuracy is arriving at a commanded coordinate, which requires a measuring system and costs considerably more. Ask for the one you need, not the better-sounding one.
Environment and life
Contamination kills linear components far more often than load does. Swarf, grinding dust, weld spatter and coolant get past inadequate seals and destroy recirculating ball tracks in months. If the environment is dirty, say so: bellows, scrapers, protected profiles and alternative bearing types exist, and choosing them after the first failure is the expensive route.
Lubrication follows the same pattern. Most premature failures in the field are lubrication failures, not design failures. Ask what the interval is, whether a lubrication unit or single-point lubricator is available, and what happens if it is missed — then design the maintenance around the honest answer rather than the optimistic one.
How the AI agent matches suppliers
The agent reads your requirement rather than your keywords. It searches the FlowMarket network and connected industrial directories together, scores every candidate on how well it answers what you described — component type, stroke and load range, accuracy class, environment, geography — and drops anything that does not clear the bar. Each match comes back with a plain-language reason, which is quicker than working through catalogues to find who actually stocks what you need.