I've never really used a router...
If you want to rout something with irregular contours, you need a template. What's the best way to make one?
I tried a bit yesterday with 12 mm MDF which the router bit's shank dragged along, two problems arose:
- you had to build up the MDF template so that it was exactly right to avoid routing into the template
- you had to scale the template unless the router bit shank and router diameter were identical
There must be better ways...?
If you want to rout something with irregular contours, you need a template. What's the best way to make one?
I tried a bit yesterday with 12 mm MDF which the router bit's shank dragged along, two problems arose:
- you had to build up the MDF template so that it was exactly right to avoid routing into the template
- you had to scale the template unless the router bit shank and router diameter were identical
There must be better ways...?
12, 8, or 6mm MDF works well. It also works with the much cheaper furuplyma.
You should *either* have a guide ring that attaches under the router if it supports it, or, as mattiasp mentioned, have a router bit with a bearing either on the shank before the router (most common) or at the router's end, though that's not usually required. A bearing at the router's end is more of a specialized router bit for tables or other specific requirements.
Only using the shank on the template causes the machine to be unnecessarily stressed and you will burn the template, and as you said, it becomes quite tricky with the measuring.
A guide ring requires the template to be smaller than the final result, but that's something calculated. With a bearing that holds the same dimension as the router bit, the result is the same size as the template; if there's an irregularity in the template, it also transfers to the material. Usually, it's just as important to have a good finish on the template as on the final product...
Google for "router template bushing" and you will find information.
You should *either* have a guide ring that attaches under the router if it supports it, or, as mattiasp mentioned, have a router bit with a bearing either on the shank before the router (most common) or at the router's end, though that's not usually required. A bearing at the router's end is more of a specialized router bit for tables or other specific requirements.
Only using the shank on the template causes the machine to be unnecessarily stressed and you will burn the template, and as you said, it becomes quite tricky with the measuring.
A guide ring requires the template to be smaller than the final result, but that's something calculated. With a bearing that holds the same dimension as the router bit, the result is the same size as the template; if there's an irregularity in the template, it also transfers to the material. Usually, it's just as important to have a good finish on the template as on the final product...
Google for "router template bushing" and you will find information.