Description
SHS Double-Sector Gear with Tappet Plate V3 (CL12070-3)
The SHS Double-Sector Gear with Tappet Plate V3 (CL12070-3) pairs a double-sector gear with a tappet plate made to work with it in a Version 3 AEG gearbox. It is aimed at high-rate-of-fire builds, typically in short-barrelled CQB rifles.
A double-sector gear (DSG) has two sets of teeth on the sector gear instead of one, so the piston is pulled back and released twice for every turn of the sector. A European retailer listing for this SHS part (reference CL12070) describes it as steel alloy, case-hardened to reduce wear and CNC machined without burrs, giving two shots per revolution of the sector gear.
How a double-sector gear works
Because a DSG fires twice per turn, it roughly doubles the rate of fire compared with a normal sector gear on the same motor and battery, without needing an extreme gear ratio. The trade-off is that each pull of the piston is shorter, so a DSG is used with a short-stroke setup: the piston, spring and cylinder volume must all be matched to the reduced stroke.
The retailer listing notes that the gear works with standard-ratio and high-speed flat gear sets and suits inner barrels of 363mm and shorter, which is in line with the short-stroke, high-rate builds DSGs are normally used for.
Why a matching tappet plate
The tappet plate moves the air nozzle back and forward to feed each BB. With a double sector the plate has to cycle twice per turn of the sector gear, so it needs a profile that works with the second set of teeth. Supplying the gear and plate together takes the guesswork out of matching them. This version comes with the Version 3 plate, so make sure it matches your gearbox shell; the same gear is also listed with a Version 2 plate.
Fitting
A DSG build is an advanced job and is best done by an experienced technician. As well as the gear itself, the piston usually needs teeth removed to suit the double sector, the cylinder volume should match the barrel, and the motor, battery and MOSFET or trigger contacts must cope with a very high rate of fire. Getting these wrong can cause jams, broken teeth or overspin.
Key features
- SHS double-sector gear (DSG)
- Supplied with a Version 3 tappet plate
- Two shots per revolution of the sector gear (per retailer listing)
- Steel alloy, case-hardened and CNC machined (per retailer listing)
- For high rate-of-fire short-stroke builds
- Works with standard-ratio and high-speed flat gear sets (per retailer listing)
- Code CL12070-3
What’s in the box
- 1 x double-sector gear
- 1 x Version 3 tappet plate
Compatibility
For Version 3 AEG gearboxes, using the included tappet plate. Check that your gearbox is a Version 3 shell before ordering. A retailer lists the gear for use with standard-ratio and high-speed flat gear sets and with inner barrels of 363mm or shorter. Your piston, cylinder, spring and motor must be set up for short-stroke DSG use.
Care and maintenance
Grease the gear teeth lightly with a proper AEG gear grease, shim carefully, and check the piston teeth regularly, as high-rate builds put more wear on them. A DSG build should be inspected more often than a standard gearbox.
Use a battery and wiring that can handle the extra current, and store the replica with the battery disconnected.
Who is it for?
Experienced builders and technicians putting together a high rate-of-fire Version 3 AEG for CQB or speedsoft, who understand the extra setup a DSG needs.
Please note: Gearbox, piston, bevel and spur gears are not included. Always wear suitable eye protection when testing airsoft replicas.
