How a plunge base works
The motor rides on two posts with springs that hold it up. Release the lock and push down, and the bit sinks into the work; lock it at depth, make the cut, release, and the springs lift the bit clear. A depth rod on the carriage stops against a turret on the base. Milwaukee says not to use its plunge base if the motor does not rise when the release is pressed, and never to loosen or remove the caps on the posts, whose springs are under pressure.
| Control | Bosch RA1166 (1617 series) | DEWALT DCW600 plunge base | Milwaukee 2723 plunge base |
|---|---|---|---|
| Depth stop | Depth rod on a turret; steps 1/8 in apart | Depth rod on a turret for stepped cuts | Depth rod on a turret; highest step 5/8 in |
| Fine adjustment | 1/32 in a turn, 1/128 in a mark | — | Micro-adjustment sleeve |
| Pass depth | No figure; test cuts in scrap | 'Several light passes'; no figure | No more than 1/8 in in one pass |
| In a router table | Not recommended; damage may occur | The DCW600 never goes in a table | Never |
Each cell is that maker's statement for its own base. A dash means the manual reviewed gives nothing for that control.
Setting a depth and stepping down
Stepped depth with a rod and turret (after Bosch and Milwaukee)
Zero the bit
Unplugged or battery out, plunge until the bit just touches the surface the router stands on, and lock. Bosch calls this the zero position.
Set the final depth
With the lowest turret step under the rod, set the rod to the final depth on its scale and tighten it.
Start high
Turn the turret to its tallest step for the first pass. Bosch's steps are 1/8 in apart; check your own turret and manual for the depth each pass may take.
Cut, then step down
After each pass, raise the bit, stop the router if your manual asks, and turn the turret to the next lower step. DEWALT says never to change the turret stop while the router is running.
Confirm in scrap
Bosch suggests test cuts in scrap to be certain of the depth before the real part.
The 1/8 in figures are each maker's for its own base, not a universal depth per pass; a bigger bit, harder wood or a smaller router may call for less. Speed, feed rate and depth of cut are separate settings — see using a router and the speed chart. How the depth systems on current plunge routers compare is set out in choosing a plunge router.
Making the plunge cut
Milwaukee's sequence for its plunge base is a good model: clamp the work; set the depth; raise the bit above the work; with a hand on each handle, start the motor with the bit clear; release the lock and lower the bit slowly until the rod meets the turret; lock and move the router with the sub-base flat; release to lift the bit out; stop the motor with the bit away from you. Feed against the bit's rotation, as for any handheld cut.
Mortises with a plunge router
A mortise is a stopped groove: plunge at one end, rout to the other, step down, repeat. An edge guide or a jig that clamps to the work keeps it parallel to the face; stops at each end set its length. Freud describes up-spiral bits for mortises and deep blind holes because they lift chips out of the cut. Laying out the joint, sizing the tenon to the mortise and the joint's proportions are covered in mortise and tenon, and jigs and template guides in jigs and templates. Dovetail jigs set their own router, guide and bit; follow the jig's manual, and the joint itself in dovetails.
Plunge routers in tables, on lifts and on tracks
Bosch says its RA1166 plunge base is not recommended for use in a router table because damage to the base may occur; Milwaukee says never to use its 2723's plunge base in one; DEWALT says the DCW600 is not to be used in a table at all. Yet Bosch's RA1181 table lists some plunge routers — Bosch's 1613 and 1619EVS and Porter-Cable's 7529 — as fitting it. The two statements are about different routers: the router's own manual decides whether it may be table-mounted, and a lift, if used, must be one its maker lists for that router. For straight cuts along a work surface, a clamped straightedge or the router's edge guide does the job; use a rail or track system only with the adapter its maker specifies for your router.
Before a plunge cut
- Bit seated and tight; power off while setting depth
- Final depth set on the rod; turret on its tallest step
- Motor returns fully when the lock is released
- Work clamped; stops or guide set for the cut's length
- A hand on each handle; bit clear of the work at start
- Turret changed only with the router stopped
The router family is mapped in the router guide; bits for plunge work are in router bits.
Sources
Pass depths and turret steps are each maker's for its own plunge base. Where a router maker and a table maker list different things, both are shown; the router's manual decides whether it may be mounted.
- 1.
1617, 1617EVS, 1617EVSPK, 1618EVS Operating/Safety Instructions. Bosch, 2018.
Used for: The RA1166 plunge base: zeroing the bit on the work surface, setting the depth rod and turret, turret steps progressing by 1/8 in, fine adjustment of 1/32 in a turn and 1/128 in a mark, test cuts in scrap; the plunge base not recommended for table use because damage may occur.
- 2.
M18 FUEL Compact Router, Cat. No. 2723-20, Operator's Manual. Milwaukee Tool.
Used for: Its plunge base: single-pass cuts under 1/8 in, multiple passes for anything deeper with no more than 1/8 in in one pass; the plunge sequence with a hand on each handle; never in a router table; not to be used if the motor does not rise when released; the caps not to be removed, as their springs are under pressure.
- 3.
DCW600 20V Max* Compact Router, Instruction Manual. DEWALT, 2022.
Used for: Its plunge base: the turret for stepped cuts when a depth is more than is acceptable in one pass, the turret never changed while running, several light passes instead of one heavy one; the router never in a table.
- 4.
RA1181 Benchtop Router Table. Bosch.
Used for: Plunge routers the RA1181 table lists — Bosch's 1613 and 1619EVS and Porter-Cable's 7529 — alongside fixed-base-only routers.
- 5.
75-104 Up Spiral bit. Freud.
Used for: Up-spiral bits described for mortises and deep blind holes, clearing chips.
About this guide
Written by BenchRoot Editorial. How BenchRoot sources, checks and corrects its pages is set out in the Editorial Policy. If something here is wrong or unclear, the contact page explains how to tell us.