Sliding mitre saw — Bosch GCM 12 GDL

Wood room course required. Clamp the work and push the saw away from you through sliding cuts.

Sliding mitre saw for crosscutting timber to length, mitres and bevels.

Bosch GCM 12 GDL at its mitre saw station


Location	Wood room, on its own bench with side supports
Access	Wood room course
Max cut (0°/0°)	104 × 341 mm (height × width)
Angles	Mitre 52° left / 60° right, bevel 47° both ways
Help / faults	Slack #trärummet-woodroom

Materials

Yes: clean wood and wood-based boards. Check for nails, screws and grit.
No: any metal (including aluminium), pressure-treated wood, stone. No abrasive cut-off wheels.
Plastics: ask first.
Cut one piece at a time. Round or irregular stock needs a fixture to stop it rolling.

Wooden split fence faces, wooden throat insert, work clamp, extraction hose behind the saw.
After any setup change, do a dry run with the saw unplugged — the blade and guard must clear the fences, insert and clamp at the set angles. A setup that clears a straight cut may hit at a bevel.
Two laser lines show the kerf but can drift — check important cuts on scrap.

Glide arm, work clamp and wooden fence faces

Split fence faces and wooden throat insert

Eye and hearing protection. No gloves; secure hair, clothing and jewellery.
Clamp the work. Keep hands at least 100 mm from the blade and never cross your arms or reach behind the fence.
Stand to the side of the cutting line.
Never cut on the pull stroke — always push away from you.
Don't trap the offcut against a stop.
Small pieces you can't clamp safely: use another method. Never hold a short offcut by hand.
Wait for the blade to stop before lifting the head or clearing scraps.

Unplugged: check blade, cable and guard. The lower guard must move freely and close as the head rises.
Set and lock mitre and bevel. Dry-run the cut to check clearance.
Support long stock level with the table. Clamp the work against table and fence.
Open the extraction gate fully and check suction.
Cut:
- Wide cuts (sliding): unlock the slide. Pull the raised head forward past the stock, start, let it reach speed, lower it and push back towards the fence.
- Narrow cuts: push the arm fully back and lock the slide. Start, then lower the head through the cut.
Release the trigger, hold the head down until the blade stops, then let it rise.
Unplug for cleaning or adjustments. Vacuum the station and close the extraction gate.

Problem	Action
Won't start	Check lock-off/trigger and power.
Head won't rise or slide	Check the transport and slide locks (unplugged). Don't force it.
Guard sticks or doesn't cover the blade	Unplug and report. Never hold the guard open.
Burning, vibration, rough cut	Stop — check blade, clamping, support and alignment.
Blade jams	Release trigger, hold head, wait, unplug, then free it.
Poor extraction	Unplug and check the hose for blockage.

Clean with the saw unplugged. Keep vents, guard mechanism, glide arm and extraction adapter clear.
Blade changes and alignment are maintainer tasks. The blade bolt is left-hand thread.
Replacement blades: Ø305 mm, 30 mm bore, 1.7–2.6 mm body, max 3.2 mm kerf, EN 847-1 marked.
Maintenance and repairs log

The advertised 170 × 140 mm capacity only applies to L-profiles with walls ≤ 36 mm. Compound cuts: see the table on manual p. 40 (EN) / p. 143 (SV).

Bosch GCM 12 GDL manual, multilingual (PDF, 493 pages) — English: safety pp. 31–32, specs p. 35, blade pp. 36–37, setup pp. 38–39, cutting pp. 40–41, care p. 43. Swedish: safety pp. 135–136, specs p. 138, setup pp. 140–142, cutting pp. 143–144, care p. 146.
Bosch product page
Woodshop — Open questions