Thread: How to cut accurately with a router

If you are cutting a slot clamp two pieces of wood to your work surface to hold the router in place. A knot will kick the router out unless you really hold against one fence so its best to use two. Doing a side trim it doesnt matter as you can repeat or have a bearing on the cutter running on the underside.
So your setup is draw a line at one side of your cut.
Sit the router on the work and screw the cutter down till touching
Turn the cutter by hand to get the blade to the touch the line
Mark where the sides of the router are
Do this at other end of work.
Clamp 2 fences
Check the router fits snugly and slides in between the two fences and the cut is correct.
Plug the router into power and cut your slot
Routers are powerfull machines so make sure your fences are properly clamped

If you are running the curved routerbase against the fence remember that there is no garantee that the router bit is perfectly in the center of the base, infact u can pretty much count in it NOT being perfectly in the center. This means that as u rout it u rotate the router at all you're going to get some serious inaccuracies. Make up a square base for your router, 3 or 4mm perspex is perfect. This gives you a much better reference edge on the router. When routing an edge using a square base means that if the square base comes away from the fence at all no damage is done to your work piece, you can just go back over & pick up the missed bits. This is perfect for those times when u need to rout a straight edge.

If necessary I would place the router bit slightly inside the line. This way you can always rout it a little larger if you have to. This method of creeping up to the right fit/size is commonly used for many cut and fit type activities. If you are planning to make a deep cut that will require a couple of passes or so then you can use this technique on the shallow, first cut until you get your fence positioning right and then go for it and make the final cuts. Good luck!

Sorry, I never had the problem rattrap suggests, Have a several year old Bosch and I can spin it on the fence and not take another shaving off. But well worth testing for that. Also metester makes a good point about not cutting too deep first go, not so sure though about nibbling to the line if you are cutting a slot

Originally Posted by Kaisergrendel

Here's my jig set up:

1. Draw line at intended cut.
2. Draw a fence line offset from the cut line that's the exact distance between the bit and the router.
3. Clamp a caul over the fence line. This becomes the fence.
4. Route piece with router fence touching the fence caul.

I'd appreciate any beginner tips you can give me to help make dead-on cuts, thanks!

Hi Kaiser;

It seems to me like you're not getting step 2 correct. As the part of the cutter which does the cutting is proud of the main body of the cutter it is easy to introduce an error by not having the bit rotated so the cutting tip is at is nearest point to the edge of the router.

A simple jig to make (if you use a router a lot you will have more jigs then tools) for cutting is found here

Free Wood Router Jig Plans - How to Build A Wood Router Jig

There are better ways of doing the same thing but this is by far the easiest one to make.

Cheers

Joel

Thanks all for your responses!

Just to clarify I'm making lap joints and dado slots for a TV rack.

rrobor:

My cauls are pretty secure and didn't stray from where they were clamped - It's figuring out the exact distance between the bit and the fence that's a pain.

rattrap:

That's a good point, but my bosch comes with a fence that has a straight edge so the distance is always the same.

metester:

I tried creeping towards the cut line, but it's still hit and miss as I can't precisely tell how far I've moved the fence caul forward. Half the time I inch too far forward and end up busting the slot.

thebicyclist:

That jig is simply brilliant! I'd thought about cutting a slot in an off cut and measuring that but I never thought to put it in the jig itself. I'm going to try this one tomorrow.

Good jig the bicyclist. Why didn't I think of that!

Another luxury option is to use this with a Progrip straight edge from Carbatec.

Micro Dado Router Attachment : CARBA-TEC

Maybe for my next birthday........

Originally Posted by metester

Good jig the bicyclist. Why didn't I think of that!

Probably the same reason I didn't, who needs to think much with the Internet and Google to solve all our problems

Cheers

Joel

[QUOTE=Kaisergrendel;1294434. I can't afford a router table right now so that's not a solution I can use.[/QUOTE]

Hi Kaiser;

A router table doesn't have to cost much. Mine is a melamine offcut which I clamped off the edge of my assembly table with a fence made from a bit of hardwood I pulled from a skip and planed flat

Cost me around $0.50 for a couple of M4 bolts, to secure the router base to the melamine, and a long M5 bolt, to secure one end of the pivoting fence.

Cheers

Joel

Originally Posted by thebicyclist

Hi Kaiser;

A router table doesn't have to cost much. Mine is a melamine offcut which I clamped off the edge of my assembly table with a fence made from a bit of hardwood I pulled from a skip and planed flat

Cost me around $0.50 for a couple of M4 bolts, to secure the router base to the melamine, and a long M5 bolt, to secure one end of the pivoting fence.

Cheers

Joel

Hi Joel,

Anything in the way of a precise fence rail? I'd thought that was the biggest advantage of a router table.

Originally Posted by Kaisergrendel

Hi Joel,

Anything in the way of a precise fence rail? I'd thought that was the biggest advantage of a router table.

With one end of the fence fixed and the other pivoting around this point it is easy to make quite fine adjustments as the distance moved at the far end is much greater then the distance moved at the cutter which is closer to the fixed end of the fence.

I use wooden gauge blocks or if possible the mating piece of the joint to setup a cut. While it would be quicker with an Incra fence, I've seen enough work done to a standard far above my (current) meager abilities using even simpler system then mine so I can't justify the extra expense