Quick Answer

Most planetary grinders run 3 or 6 shoes per head. Use 3 shoes for aggressive leveling, coating removal, and hard slabs — fewer shoes concentrate the weight and cut deeper. Use 6 shoes for flattening, transition passes, and finishing sequences — more shoes spread the load, cut smoother, and last longer. Run a full head always; a partially loaded head rocks and produces a wavy floor.

How Head Loading Changes the Cut

Each shoe carries a share of the machine's weight. Fewer shoes means more kilograms per shoe, deeper penetration, and a more aggressive cut — but also faster shoe wear and more visible scratch lines. More shoes spreads the load:

• 3 shoes: maximum aggression per pass; ideal for leveling humps, removing thick coatings, and opening hard concrete.
• 6 shoes: even pressure, flatter surface, longer shoe life; the standard for grinding and polishing sequences.
• Partial loads (1, 2, 4, 5): never leave a head unbalanced — the machine rocks, shoes cut at angles, and the floor comes out wavy.

Match the Layout to the Pass

Pass goal	Shoes per head	Typical grit
Coating / glue removal	3	16-30
Leveling humps and joints	3	16-30
Coarse grinding, opening the floor	6	30-40
Transition (removing coarse scratches)	6	60-80
Resin polishing steps	6 (or full pad set)	100-3000

Some contractors change loading mid-job: 3 shoes for the first aggressive pass, then 6 shoes with a finer grit to clean up the surface. Keep the shoe count equal on all heads — a 3/6 mix on different heads creates an uneven grind.

Which Segment Shapes Work in 3 and 6 Layouts

Segment shape interacts with the layout. Single-rhombus shoes (JOY-TP-RH1) cut aggressively and suit 3-shoe leveling passes. Double-rhombus shoes (JOY-TP-RH2) and triple-round shoes (JOY-TP-R3) give a steadier, flatter cut in 6-shoe layouts. For soft concrete, wider segment profiles in a 6-shoe setup reduce the risk of gouging.

How Many Shoes You Actually Need to Buy

• One full head set: enough for a 3-shoe aggressive pass on a 3-head machine (9 shoes).
• Two full head sets: lets you switch 3-shoe and 6-shoe layouts without downtime, or run 6 shoes on all heads.
• Add a spare set: grinding shoes wear fast in coating removal; a spare avoids stopping mid-job.

Per square meter, 3-shoe passes consume shoes faster but reduce the number of passes needed on hard floors; 6-shoe layouts last longer on medium slabs. Budget for both if your jobs vary.

Frequently Asked Questions

Q: Can I mix different segment shapes on one head?

A: Avoid it. Mixed shapes cut at different depths and rates, leaving an uneven surface. Keep one shape and grit per head, and match all heads.

Q: Is 3 shoes always better for hard concrete?

A: Not always. 3 shoes cut deeper on hard slabs, but if the bond is too soft they wear out fast. Start with 3 shoes in the correct bond, check the cut, and switch to 6 shoes for the finish passes.

Q: How often should I rotate shoes on the head?

A: Rotate shoes between positions every few hundred square meters so they wear evenly; trapezoid segments wear fastest on the leading edge.

Q: What about PCD shoes for coating removal — 3 or 6?

A: PCD shoes are for coating removal only and usually run 3 per head for maximum bite, then are removed before the grinding sequence.

Conclusion

Start with 3 shoes per head for aggressive leveling and coating removal, move to 6 shoes for grinding, transition, and polishing passes, and always load every head evenly. Keep one shape and grit per pass and rotate shoes for even wear. Browse the JOY-TP trapezoid shoe range and stock both 3-shoe and 6-shoe layouts for your machine.