The Helix is National's 16" dual-speed planetary concrete grinder, powered by a 1.5 HP single-phase electric motor. National designed it for small jobs and tight spaces, preparing concrete for new coatings, and it can edge grind from either side of the machine. This page covers the current Rev J manual and the Rev H manual for serial numbers HELIX-100498 to 100528.
Specifications
Specs from National's Helix product page and the operating manual (403223 Rev J).
| Spec | Value |
|---|---|
| Grinding disk | 16" (41 cm) |
| Width | 17.5" (44.5 cm) |
| Length / height | Length 27.9"-47" (70.9-119.4 cm); height 29.4"-47.6" (74.4-120.9 cm) |
| Weight | 206 lb with tooling assembly, 180 lb (82 kg) without (manual); 206 lb / 93 kg (product page) |
| Grinding pressure | 128 lb (58 kg) |
| Motor | 1.5 HP (1.12 kW), single phase, dual speed |
| Amps | Full load: 15 A @ 120V/60Hz, 8 A @ 230V/50Hz, 15 A @ 110V/50Hz (manual); 12 A @ 120V/60Hz, 6.3 A @ 230V/50Hz (product page) |
| Tooling RPM high/low | 304/171 (120V/60Hz); 291/164 (230V/50Hz); 278/157 (110V/50Hz) |
| Vacuum port | Rear port; hose fits outside (2") or inside (1-3/4") of the port |
| Edge grinding | Within 1/8" of the wall on either side of the machine (manual) |
Maintenance schedule
From National's Helix maintenance checklist and the operating manual (403223 Rev J). National says mechanical and electrical inspection and worn-part replacement should be done by an NFE service center or dealer.
| Interval | What to do |
|---|---|
| Weekly | Check all screws are tight; tooling plate secure and undamaged; satellites undamaged and rotating freely; vacuum dust from under the machine; inspect the brush at the base of the metal dust shroud; check handle position operation and cam levers |
| Quarterly (more often if rented regularly) | Clean dust and debris from inside the deck; verify the deck spins and satellites rotate freely; test that pulling the safety lanyard stops the machine; check nameplates and safety labels are in place and legible; clean glue, mastic and debris from the wheels; check power cord, motor cord and twist-lock plug |
| When the brush indicator light is on | Replace motor brushes (light is next to the dual-speed toggle) |
| As needed | Replace the nylon clutch (P/N 403978); tighten the six screws (P/N 74620) to 14 ft-lbs |
Fluids and lubricants
What the manual says about lubrication.
- Satellite bearings are self-lubricating; do not lubricate the bearing bores or shafts
Videos from National
National's Helix videos, plus its planetary grinder comparison and tooling guide.
- Helix Grinder Nylon Clutch Plate
- Helix Grinder Tips
- Remove Adhesive with your Helix
- Helix Paint and Coating Removal Tooling Options
- Helix Thin Set Removal Tooling options
- Helix Scarifier Tooling Demonstration
- What's the Difference Between the Helix and 8274-4?
- Planetary Grinder Tooling Application Guide
Sources
Everything on this page comes from National Flooring Equipment's own published material.
