Build 1: a T-square dado guide
Bosch's manual cuts grooves and dadoes by clamping a straightedge to the work and running the router's sub-base along it. This guide adds a head square to the fence, so it registers on the work's edge, and lets the first pass notch the head, so the notch shows exactly where that bit and base cut. Line the notch up with a pencil mark and clamp: no measuring from bit to base edge.
| Part | Qty | Thickness | Width | Length | Material |
|---|---|---|---|---|---|
| Fence | 1 | 3/4 in | 3 in | 30 in | Plywood, one factory edge as the guiding edge |
| Head | 1 | 3/4 in | 3 in | 12 in | Plywood |
30 in spans a 24 in wide case side with room for clamps; make the fence longer for wider work. Glue and screws join the two.
Making and using the guide
Rip the parts
Keep a factory edge on the fence for the router to ride. Ripping narrow strips safely is covered in table saw safety.
Join them square
Glue and screw the head under one end of the fence, checking with a square that the fence's guiding edge is at 90° to the head's working face — see squares.
Cut the notch
Clamp the guide to scrap with the head against its edge. With the bit you will use, rout across the scrap and on through the head. The notch in the head is that bit's cut line, for that router base.
Lay out the work
Mark the dado's edges on the work from a reference edge, as in measuring and marking. Cut the dado to the shelf you have, measured, not to its label.
Set up
Hook the head on the work's edge, line the notch up with the mark, and clamp the fence to the work at both ends — clamps. Have the work at the bench edge or on scrap so the head hangs clear.
Rout in passes
Several cuts of increasing depth, as Bosch's manual advises, the sub-base kept against the fence for the whole pass, in the feed direction your router's manual gives for a guided cut. If the router drifts off the fence, stop.
Wider than the bit
Cut one edge, move the guide to the other mark, and cut again; clean out the middle.
The notch belongs to one bit in one router base. Mark it with the bit size, and cut a fresh notch at the fence's other end for a second bit. Dadoes and the shelves they hold are compared with other joints in choosing a joint.
Build 2: a flattening sled
| Part | Qty | Thickness | Width | Length | Material |
|---|---|---|---|---|---|
| Platform | 1 | 3/4 in | 30 in | 48 in | Plywood |
| Rail strips | 4 | 3/4 in | 3-1/2 in | 48 in | Plywood, glued in pairs into two 1-1/2 in rails |
| Carriage plate | 1 | 3/4 in | 12 in | 34 in | Plywood, with a 2 × 24 in slot down its centre |
| Guide strips | 2 | 3/4 in | 1-1/2 in | 34 in | Straight plywood or hardwood |
Inside the rails the platform is 27 in wide. The router's base slides between the guide strips, set a sliding fit apart; Bosch's 1617EVS base, for example, is 6 in across. The 24 in slot keeps a 1-1/2 in bit clear of the rails at both ends of its travel, and the carriage's own width limits travel along the rails, so the sled takes a slab up to about 22 × 32 in.
Size the bit to the rules before building around it. Bosch requires the cutter to be at least 1/4 in smaller than the opening it passes, and Milwaukee never larger than the smallest opening; here the slot is that opening. Freud says bits over 1-1/2 in diameter must only be used with the router mounted in a table, so this hand-guided sled is drawn for a bit no wider than 1-1/2 in — check your own bit maker's rule. Use a 1/2 in shank where your router takes one, as Bosch advises, and run it at or below the bit's own rating; Amana's ceilings fall as diameter rises, and the speed chart has the details.
Building and using the sled
Sled, step by step
Make the rails
Glue the rail strips in pairs, let the glue cure, and joint their top edges straight. Screw them along the platform's long edges so their tops are in one plane — sight across them or check with a long straightedge.
Make the carriage
Cut the slot down the plate's centre. Glue and screw the guide strips on top, either side of the slot, spaced so the router's base slides between them without play.
Set the slab
Lay it between the rails with its high spot below the rail tops, raising a thin slab on spacers. Shim it so it cannot rock, and block or clamp it so it cannot slide — the cut pushes on it.
Set a shallow depth
With the router unplugged on the carriage, lower the bit to just touch the high spot. Take the first pass no deeper than that; there is no universal depth per pass, and Freud asks for multiple passes when removing a lot of material.
Start clear
Start the router with the bit beyond the slab's end, over the platform, and bring it in from the side.
Cut in strokes
Slide the router across the slab along the carriage, step the carriage along the rails by less than the bit's diameter, and repeat. A handheld bit turns clockwise seen from above, so it cuts into the wood when uncut wood is on your right and you draw the router toward you: step the carriage to your right and cut on the strokes toward you.
Step down and turn over
Lower the bit a little and repeat until the face is flat; then turn the slab over, flat face down, and flatten the other side.
Smooth
Remove the stroke marks by sanding or planing — how to sand wood.
Safety— Dust and control
Flattening makes a great deal of fine dust. OSHA names exhaust ventilation at the source as the preferred control, and Milwaukee's manual calls for respiratory protection or OSHA-compliant extraction in dusty work; use both. Keep a hand on each of the router's handles, never reach under the carriage while the bit turns, and stop the router before stepping the carriage if you need a hand free.
Before routing with a shop-made jig
- Jig square and straight, checked with a square or straightedge
- Bit within the router's openings and the bit maker's diameter rule
- Speed at or below the bit's rating
- Work and jig clamped or blocked so neither can move
- First pass shallow, set on scrap
- Extraction connected; eye, ear and dust protection on
Both builds use the handheld technique in using a router and the guiding principles in jigs and templates; bits are explained in router bits. A bench to build them on is in the workbench guide, and laying out sheet parts in the cut list optimizer. The router family is mapped in the router guide.
Sources
Both jigs are BenchRoot designs; no downloadable plan exists. Dimensions are worked out on the page. The sled's feed direction follows from the makers' handheld rule — the bit cutting into the work — rather than from a maker's instruction for sleds; the bit limit comes from Freud's rule for its own bits.
- 1.
1617, 1617EVS, 1617EVSPK, 1618EVS Operating/Safety Instructions. Bosch, 2018.
Used for: Clamping a board or straightedge to the work and guiding the sub-base along it for grooves and dadoes; several cuts of increasing depth; the cutter at least 1/4 in smaller than the opening it passes; 'Use 1/2" shank whenever possible'; unplugging before bit changes; test cuts in scrap.
- 2.
1617EVS 2.25 HP Electronic Fixed-Base Router. Bosch.
Used for: A 6 in base diameter on the 1617EVS, as an example of the base size the sled's guide strips are set to.
- 3.
M18 FUEL Compact Router, Cat. No. 2723-20, Operator's Manual. Milwaukee Tool.
Used for: A clamped straight board as a guide against the base; never using a bit larger than the smallest opening it passes through; a sample cut on scrap; respiratory protection or OSHA-compliant extraction in dusty work.
- 4.
Premier Adjustable Rail and Stile System (instructions poster). Freud.
Used for: Bits over 1-1/2 in diameter only with the router mounted in a table; multiple passes when removing a lot of material; never exceeding a bit's maximum rpm.
- 5.
Max RPM Guide for Amana Tool Router Bits. Amana Tool.
Used for: Speed ceilings that fall as diameter rises, and the rating etched on a bit's shank.
- 6.
Wood Dust: Possible Solutions. U.S. Department of Labor, Occupational Safety and Health Administration.
Used for: Local exhaust ventilation at the source as the preferred control for wood dust.
About this guide
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