Xometry CNC Machining vs Great Light CNC Machining

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  Xometry CNC machining vs Great Light at a glance
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  Platform routing vs one shop holding the part
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  How quotes and DFM feedback actually arrive
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  Material range and surface finishing options
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  Tolerance, inspection and the paperwork behind it
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  Lead time, order size and confidentiality

The main split is not machine quality. It is who owns the process. An on-demand platform takes your file, prices it with software, then routes the job to a partner shop in its network. That model scales well and gives you one place to order milling, turning, printing and molding. It also means the shop cutting your part changes from order to order, and you rarely speak to the person at the spindle.

GreatLight runs the opposite way. We have 127 high-precision CNC machines across 3 wholly-owned plants covering 7,600 m² in Dongguan, plus a Singapore factory. The 16 simultaneous 5-axis centers, 12 four-axis mills, 27 three-axis machines and 16 mill-turn centers are ours, run by about 150 technicians. Nothing is subcontracted unless you approve it.

That matters most when a part is difficult. Thin walls, deep pockets, tight true position on a bolt circle, a 4,000 mm long extrusion that needs one setup. With a routed job, the shop that quotes it may not be the shop that runs it, and feedback travels through a middle layer. In house, the programmer who flags a problem is standing next to the machine that will cut it.

Neither model is wrong. Pick the platform when you want one cart for many processes and the geometry is forgiving. Pick the factory when tolerance, material traceability or a single accountable shop matters more than catalog breadth.

Platform quoting is fast and self-serve. You upload a STEP file, pick a process and material, and get a price in minutes. The trade-off shows up afterward: design-for-manufacturing notes may be generic, and a real machinist review can add days before chips fly. On a simple bracket that is fine. On a 5-axis housing with 0.01 mm bore alignment it is a risk.

Our flow is human from the start. Send a 3D model and 2D drawing, and you get a quotation plus a free DFM analysis within 12 hours. The engineer checking it will tell you if a corner radius is too small for the tool you specified, if a datum cannot be reached in one setup, or if a tolerance is tighter than the function needs.

That last point saves money quietly. Engineers often call out ±0.005 mm across a whole print when only two features interact. We mark the rest as general tolerance, keep the tight callouts where they belong, and the cycle time drops. A platform quoting engine cannot make that judgment without a person.

For repeat work, quoting stabilizes because the process is fixed. Same machines, same fixtures, same inspection plan. Reorders do not re-route to a different shop with a different idea of how to hold the part.

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  Platform strengthInstant pricing across many processes from one upload
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  Factory strengthDFM notes from the machinist who will run the job
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  Watch forGeneric DFM text that never reaches the shop floor

A network platform wins on breadth by default. Aggregate enough partner shops and you can source almost any stock shape in almost any polymer or alloy. The catch is consistency: the aluminum grade you approved on run one may come from a different mill on run two, with a different heat lot.

We keep a defined list. Aluminum 6061, 6061-T6, 2024, 5052, 5083, 6063, 6082, 7075 and ADC12. Stainless 303, 304, 316, 316L, 420, 430, 431, 440C and 17-4PH. Steel 1018, 1045, 4130, 4140, 4340, A36 and tool steel. Copper and brass including C110, C36000 and beryllium copper. Titanium TA1, TA2, TC4, plus Inconel and magnesium AZ31B / AZ91D. Plastics cover ABS, PC, PMMA, POM, PA, PEEK, PP, HDPE and carbon fiber.

Finishing is where in-house control pays off. Anodizing in clear, color, hardcoat and conductive types; electroless nickel, zinc, silver and gold plating; powder coating and black oxide; bead blasting, tumbling, brushing and polishing; laser marking down to 1.5 mm character height. Because these run through our own supply chain, a masked anodize on one face and bare machined threads on the other is a normal request, not a negotiation.

If your part needs a rare alloy in a one-off quantity, a broad network has an edge. If it needs the same alloy, same finish and same inspection for a year, a fixed list is safer.

Tolerance is not a marketing number. It is the result of machine condition, fixturing, thermal control and how many setups the part needs. A platform cannot promise one figure across a whole network, because the shops differ. Their published ranges reflect that spread.

Our stated capability is ±0.005 mm (±0.0002 in) on critical features, with surface finish from Ra 0.2–0.8 μm when specified. Reaching that means the right machine for the geometry: a 5-axis center for contoured faces that would otherwise need three setups, a mill-turn center for parts with turned and milled features on one datum.

Inspection is where the difference is easiest to audit. We inspect 100% of parts before shipment, with raw material check, in-process monitoring and final inspection, and reports on request. The qualification rate across production is 99.99%, and historical late-delivery probability is below 2%. Those numbers come from our own floor, not from an average across unknown shops.

Certifications matter if you sell into regulated markets. We hold ISO 9001:2015, IATF 16949:2016, ISO 13485:2016 and ISO 27001:2022. That covers automotive, medical device and information security requirements in one supplier. Ask any platform which specific shop in its network holds which certificate before you assume it transfers to your order.

Speed on a first order is a platform strength. Enter a card, get a date, and the network finds capacity. Speed on a repeat order depends on whether that capacity is still there next quarter.

We quote and return DFM within 12 hours, can start production within 24 hours, and ship parts in 3–5 days for typical jobs. There is no minimum order quantity, so a single prototype and a 10,000+ part run use the same quoting path. Prototype tooling and fixtures carry over to the production run instead of being rebuilt by a new shop.

Confidentiality is often the deciding factor for defense, medical and unreleased consumer products. Uploads are secure and confidential, and we sign an NDA on request. With a routed model, your drawings may be visible to multiple partner shops before anyone cuts metal. That is a real exposure for some programs.

One more practical point: when a job is late, a platform has to trace it through a partner. We can walk to the machine.