Beginning router questions

[sebastiaan56]

Ive decided that the router is not entirely an instrument of destruction and that perhaps my work would be neater if I used one occasionally. Ive been looking for information on templates and have one question that must be too dumb because no one seems to address it.

When making the template it seems that the distance between the edge of the router bit and the collar on the router plate needs to be accounted for. So how is this done? eg a slotted peghead, for the mandola the channels were 12mm wide, using a spiral downcut bit with a 5mm wide collar on the bottom of the router it means the edge of the cutter itself is 2.5mm from the edge of the collar and hence that is where the template ought to be. This means that when making the template the channel on the template ought to be 15mm wide.

Or do people just use a template at exact size with a cutting bit with a bearing at the top of the bit? (flush trim bit)

Seems like there are more router bit types than chisel types.......

[kiwigeo]

You could do it with either guide bushing and a straight cutter and suitable jig or with a bearing/bit set. With the guide bushing you just have to make allowance for the bushing when positioning the jig. I bought a full set of different sized bushings for my router. Each bushing has an internal and external diameter. Subtrracting external from internal diameter gives width of rim of bushing and the allowance you have to make when positioning the jig.

[graham mcdonald]

Routers are really good for some things, and risky with others. I have four set up for various jobs. A router table is really good for making the slots for truss rods/ CF re-enforcement in necks with a 5-6mm straight bit, and I use a 1/2" flush cut bit for triming my heel-less strat type acoustic necks to the dimensions of the fingerboard. Another is set up with a downcut spiral 1/4" bit on a hand held jig for binding ledge cutting, soon to be replaced by a fixed jig based on an old photographic enlarger where the router will move up and down and the instrument body held on a fixture that is brought up to it (like a cheaper version of the StewMac jig).

What I wouldn't use a router for is slots in a head stock for side mounted tuners. I really don't like having something spinning around at 30000rpm in a confined space like that, when all that is guiding it is a template that has to be clamped on to a small piece of wood. I am much more comfortable drilling out the slot with a forstner bit that is 2mm narrower than the slot and cleaning it up with a chisel and sanding sticks. If the initial holes are accurately drilled to establish the length of the slot, a length of dowel wrapped in 80grit sandpaper can be used to widen them out to the final slot width, and a flat stick with some sandpaper glued on to smooth the sides of the slot. Just remember to drill the holes for the tuner posts before cutting the slot and cut the slot with the head a little over thickness as it is likely that there will be some tearout on the back of the head when drilling the holes to roughly cut the slot

cheers

graham

[kiwigeo]

Just remember to drill the holes for the tuner posts before cutting the slot and cut the slot with the head a little over thickness as it is likely that there will be some tearout on the back of the head when drilling the holes to roughly cut the slot

cheers

graham

Important advice. To minimise tear on the back of the headstock clamp the headstock firmly to a piece of sacrificial wood while drilling.

[sebastiaan56]

Thanks for the advice guys, I currently have one router which screams like Caribou Barbie at a rally. A Ryobi I picked up at Cash Converters for $40. It runs well. I take your point about the high speed bit in a confined space Graham. And minimising tearout is an art methinks.

Apart from Stewmac are there any sources of rebating bits that can be used for binding ledges? US$90 is a bit of an ask for the finance minister,

[Allen]

If you decide to go with the router for slotted headstocks, then the safer bet is to use the bushing method and just take very light passes. I went with the straight through and guide bearing on my first attempt and it's a recipe for disaster.

[Colin S]

I use a router for my slotheads now, having always done them by hand before. My wife bought me one of Luthier Tools slothead fixtures for classical and steel string recently, which has made the task a doddle.

After shaping the exterior of the head put it into the fixture, then drill the tuner holes. After that use a 1/4" downturn bit and a guide bush to rout out the slots in progressive depths. Chris at Luthier tools recommends using a larger guide bush for the main cuts, then changing to the correct sized smaller bush to clean up the edge. I used an 11mm bush then finished with 10mm. The result is a perfect slothead in about 15mins or less with crisp clean edges without having to remove most of the material with a drill.

On my Torres copies I shall still cut them by hand as I like to use only hand tools for these guitars.

I have always cut my slots in full thickness heads with the front and back headplates in place.

Colin

[Colin S]

Somehow I posted it twice!

Colin

[kiwigeo]

You using a Mac by any chance Colin??

[Chopper]

Yet another way to rout for slotted headstocks is to drill with a forstner bit the start and finish (each end ) of the slot and then with a 1/4" bit in the router and using an edge guide against the side of the peghead rout down the centreline between the two holes . Once this is done you can then adjust the edge guide to rout first one side then the other out to the edge of the holes.I have fitted an extra long wooden fence to a small Bosch plunge router specifically for this and have not had a problem .
Cheers John