Guide · Polishers
Polisher throw explained
What orbit throw measures on a dual-action polisher, real makers' examples from 5 mm to 21 mm, and why a longer throw does not by itself mean faster correction.
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Short answer
Throw, or orbit, is the diameter of the small circle the center of the pad travels on a dual-action polisher. Makers sell machines from about 5 mm, such as RUPES's gear-driven LK900E, to 21 mm, such as Milwaukee's 2685-20.[1][2] Throw tells you how the machine moves and which pad sizes it is built around. On its own, it does not tell you how fast a machine corrects paint.
What throw measures
A dual-action polisher mounts the backing plate off center. As the motor turns, the plate's center travels in a circle, and the diameter of that circle is the orbit throw. A rotary has no orbit at all: it spins on one axis.
Makers write throw in millimeters or inches. Makita gives the XOP02Z's orbit as 7/32 inch, which is about 5.6 mm.[3]
The range, with real examples
| Throw | Example | Plate | Source |
|---|---|---|---|
| 5 mm | RUPES BigFoot Mille LK900E (gear-driven) | 125 mm or 150 mm | RUPES[1] |
| 7/32 in (about 5.6 mm) | Makita XOP02Z (forced rotation or free spin) | 5 in pad | Makita[3] |
| 9, 12, 15 or 21 mm | SPTA CP501 (four versions under one name) | Not stated per version | SPTA[4] |
| 12 mm | RUPES BigFoot HLR75 mini | 75 mm (3 in) | RUPES[5] |
| 15 mm | RUPES LHR15ES | 125 mm (5 in) | RUPES[6] |
| 21 mm | Milwaukee 2685-20 | 6-inch pad capacity | Milwaukee[2] |
Short throw
Short-throw machines, roughly 5 to 12 mm, move the pad in a tight circle. Many are gear-driven: RUPES's LK900E pairs a 5 mm orbit with forced rotation at 265-535 rpm.[1] Makita's XOP02Z lets you switch between forced rotation and free spin at the same 7/32-inch orbit.[3] Short throws also suit small plates: RUPES pairs a 12 mm orbit with a 75 mm plate on its HLR75 mini, which it describes as for curves, contours and compact areas.[5]
Long throw
Long-throw machines, 15 mm and 21 mm, are usually free-spinning random orbitals with 5-inch or 6-inch plates. RUPES specifies its LHR15ES at 15 mm with a 125 mm plate and 2,000-5,000 rpm.[6] The 15 mm vs 21 mm guide compares the two long-throw sizes.
Why a bigger number is not automatically better
RUPES says its 15 mm LHR15ES runs at a higher rpm than its 21 mm machine, which it says gives it equivalent cutting power.[6] That is a maker claim, not a test. Gearing matters too: a 5 mm forced-rotation machine keeps rotating under load, which RUPES describes as more aggressive than random orbital motion.[1] Throw is one input among motion type, speed, pad and plate.
A model name is not a throw
SPTA's CP501 comes in 9, 12, 15 and 21 mm versions under one model name.[4] When a listing offers several throws, the variant you click is the machine you get, so check it before you pay. SPTA's page states no supply voltage, plug or safety mark.[4]
Catalog machines by throw
Picks that fit2 products
For a short throw with switchable forced rotation, choose the Makita XOP02Z tool only (genuine Makita 18V LXT battery and charger sold separately).
More on choosing
For a 15 mm long throw on 120 V, choose the FLEX FC3321-Z, which FLEX supplies with 5 in and 6 in plates. On Amazon, check that 'Ships from / Sold by' shows Amazon.com or the brand before you buy.
Cordless short throw with forced rotation
Makita XOP02Z 18V LXT brushless 5 in/6 in dual action random orbit polisher (tool only)
Corded 15 mm long throw
FLEX FC3321‑Z 120 V brushless random orbital polisher (15 mm)
Next
Questions
What does 15 mm throw mean on a polisher?
The center of the pad travels in a circle 15 mm across as the plate orbits. RUPES's LHR15ES, for example, has a 15 mm orbit with a 125 mm (5-inch) plate.[6]
What is 7/32 inch in millimeters?
About 5.6 mm. Makita uses 7/32 inch for the XOP02Z's orbit diameter, which makes it a short-throw machine.[3]
Does a rotary polisher have a throw?
No. A rotary spins the pad on a single axis with no orbit, so it has no throw figure.[9]