# Making a template and using



## rastus (Mar 26, 2010)

Recently bought a Bosch router and some Rigid bushings, now I need to figure out how to make a template. Any tips or tricks would be greatly appreciated. What I want to make are "Dutchman" for a A & C style sideboard I'm in the process of building.

Paul


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## BigJimAK (Mar 13, 2009)

A template is really a pattern. The one thing to allow for when making the pattern is the offset between the outside of the guide and the near-point of the router bit. The "formula" for this is (guide diameter - bit diameter) / 2. Thus, with a 1" diameter guide and a 1/2" bit, the offset is (1" - 1/2") / 2 = 1/4". If the bit was 3/8" diameter, it would be (1" - 3/8") / 2 = 5/16". This is the dimension between the template and the edge of the bit nearest the template. If for example you wanted to cut a circle with the outer edge of the cut 6" in diameter and you were using the 1/2" bit above (offset 1/4"), the template would have to be 6-1/2" diameter, as you'd lose 1/4" on each side (all the way around). The template is usually rough-cut then routed / sanded (or whatever tools you have) to size. Common material for templates is 1/4" or 1/2" MDF although some use hardboard or plywood (rougher edge) and heavier-duty templates can be made out of tougher stock, such as polycarbonate.

You might ask "Why would anyone go to all this trouble making a template then?" The first advantage is if you're making multiples of something, they are all the same size and shape. The second is that the template stock is usually much cheaper than the final product. 

A 2'x2' chunk of 1/4" MDF may cost a few bucks while a 2'x2' piece of oak or maple would cost me about $25 in Alaska. In my case I could screw up several pieces of MDF and be money ahead. 

This is in addition to my time, as to get the 2'x2' piece of oak I'd have to edge-glue 4-6 narrow pieces together, wait for them to dry and then sand or plane them flat before starting to cut the piece. With the template I'd still need to edge-glue the oak but only once, even if I screwed up my first template of MDF. This effect is only compounded if you're using the template to route away a shape inside of a larger piece of wood where other parts of the board have already been worked.

In synopsis, it greatly reduces the "pucker factor"!


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