A practical floor-grinder classification rests on three orthogonal axes: power source and phase, grinding-head layout (rotary single-disc, multi-disc, or planetary), and operator interface (walk-behind, remote walk-behind, or ride-on). Concrete-surface prep and polishing work maps cleanly onto these axes because each axis gates a real engineering limit — phase availability, footprint pressure, and dust-handling throughput [S1][S2][S3].
Walk-behind single-disc units such as the 45 kg GSMW-250 (220 V / 50 Hz, 2.2 kW, 300–1,400 rpm, 250 mm disc) anchor the small-job class [S2]. At the opposite end, ride-on planetary units like the Husqvarna Blastrac BMG 2200RC weigh 3,035 kg, run on a 125 A three-phase supply, and grind a 2,150 mm swath with three planetary heads (3 discs each) under independent suspension [S1]. Between those bookends sits the mid-size single-disc grinder exemplified by the Bycon DFG-250 / DFG-250E, a 10-inch (250 mm) 220 V machine with a detachable dust shroud and an optional wet-grind water port [S3].
Classification by Power Source and Phase
Single-phase 220 V / 50 Hz mains is the universal small-class supply and powers 2.2 kW walk-behind units like the GSMW-250 and DFG-250E [S2][S3]. Three-phase 380–415 V at 50/60 Hz is mandatory once a machine carries a planetary head stack and a high-amperage dust extractor — the BMG 2200RC specifies a 125 A three-phase feed and a 62 kW rated engine output for exactly that reason [S1]. Thermal (diesel/LPG) drive is reserved for sites without grid power, where the engine rating (62 kW in the BMG 2200RC case) defines the dust-extractor headroom and the on-site fuel-handling obligations [S1].
Classification by Grinding-Head Layout
Single-disc rotary machines use one rigid abrasive disc and rely on operator weight plus machine mass to set downforce — simple, cheap, and forgiving on undulating slabs because the head can be allowed to float on a coupling [S3]. Multi-disc units stack two or more counter-rotating discs on a single spindle and roughly double the footprint pressure per pass. Planetary heads — three of them on the BMG 2200RC, each carrying three individual discs — split rotation into a sun gear driving three planet gears so the abrasive path never repeats the same arc, which is the mechanism behind the swirl-free finish on polished concrete and the even stock removal on large warehouse slabs [S1]. Independent suspension on each planetary head lets the machine track floor undulations without gouging, a feature the BMG 2200RC lists as standard [S1].
Classification by Size, Weight, and Footprint
The 45 kg / 250 mm disc GSMW-250 is built for one operator, one room, and one 110–220 V outlet [S2]. The mid-class DFG-250/DFG-250E keeps the 250 mm working diameter but adds a detachable edge-grinding shroud, a vacuum port, and a water port for wet grinding, with a foldable frame for transport [S3]. Ride-on planetary platforms tip the scale at multi-tonne mass — 3,035 kg for the BMG 2200RC — to convert head weight into steady downforce on a 2,150 mm working width [S1]. In a floor grinder selection, the 50× weight delta between walk-behind and ride-on is the single biggest driver of hourly productivity on open floor.
Decision Criteria: Walk-Behind vs Ride-On Planetary
For a 1,000 m² warehouse deck, a ride-on three-phase planetary unit grinding 2,150 mm per pass at 62 kW is the correct economic match; the BMG 2200RC's HEPA 14 dust collection with automatic pulse cleaning and Longopac® bagging also keeps the operator off the dust envelope [S1]. For a 50 m² shop fit-out or a council footpath trip-hazard patch, a 45 kg walk-behind with a 250 mm head and a 2.2 kW single-phase motor is the correct match — portable enough for one person, foldable for van transport, and cheap to run off a standard 220 V outlet [S2][S3]. The mid-class single-disc is the crossover pick when the job mixes open floor and wall-edge work, because the detachable shroud on the DFG-250/DFG-250E exposes a wall-border grinding mode without a second machine [S3].
Dust Extraction and On-Site Cleanliness
Every modern floor grinder must pair with a dust extractor matched to its airflow and head count. OSHA-compliant HEPA 14 filtration with automatic pulse-jet cleaning and a Longopac® continuous-bag system is now standard on the top end of the market, and a pre-separator is supplied to drop coarse dust before it hits the HEPA element — exactly the stack fitted to the BMG 2200RC [S1]. Mid-class walk-behinds integrate a vacuum port sized for a third-party M-class or H-class extractor and an optional water port for wet grinding where the substrate or coating forbids dry dust [S3]. A useful sizing rule of thumb: extractor airflow in m³/h should be at least 4× the grinder's rated kW to keep the floor visible at the operator's station; undersizing is the single most common cause of premature HEPA loading.
Tooling, Speed Range, and Application Match
Variable-speed drives are no longer optional on planetary machines: the BMG 2200RC varies disc RPM at the head, rotation direction, and grinding pressure independently through a touchscreen that also reports head amperage, drive speed, and filter status [S1]. The 300–1,400 rpm range of the GSMW-250 covers everything from soft-coating removal with a diamond grinding shoe to fine polishing with a resin pad, which is why single-disc units in this rpm band are commonly cross-used as angle grinder-class polishers on small areas [S2]. Quick-release diamond tool change — standard on the BMG 2200RC and a selling point on the DFG-250 line — is the productivity feature that turns a 30-minute tool swap into a 30-second one and is worth specifying on any grinder above the 250 mm class [S1][S3].
Site Constraints and Failure Modes
Three-phase machines fail at the gate on a single-phase site, so the 125 A three-phase feed on the BMG 2200RC must be confirmed before delivery [S1]. Walk-behind single-disc units fail the other way: at above roughly 200 m² of continuous grinding, operator fatigue and pass count become the bottleneck, and the economics flip toward a ride-on planetary even after the higher capital cost [S1][S3]. Dust-extractor starvation, not motor power, is the most common mid-shift failure mode; pairing a 62 kW grinder with an under-spec extractor will trip the HEPA differential-pressure sensor and stop the head within minutes [S1]. The fettling grinder category overlaps with single-disc walk-behinds in the foundry and weld-cleaning trades, but the working envelope and dust class differ enough that cross-substitution is a specification error rather than a saving.
Trackable signals for the next spec review: HEPA 14 with auto pulse-clean becoming the de facto standard above the mid-size class (already in production on the BMG 2200RC [S1]); foldable single-phase walk-behinds with wet/dry dual ports absorbing the small-area edge-grinding workload [S3]; and remote-controlled ride-on planetary platforms extending the safe operating envelope around freshly poured or chemically treated slabs where dust exposure must be minimised [S1]. For a deeper look at the adjacent power-tool family, the concrete groove cutter selection logic piece covers the engine-class math that also drives mid-size floor-grinder procurement.