I basically want to cut slots along the full length of some wood (probably Douglas Fir). The wood is around 1.25" by 1.5" across, say 6 foot long. The slot should be say 8.5mm across, by 18mm deep (sorry about the mixed units), and needs to be sited dead centre within the chosen face. The slot will have straight sides and a flat bottom. Accuracy of the slot width (actually, distance from the edge of the timber to the slot face, and symmetry of this, is the most important criterion.
You don't seem to be able to get 8.5mm straight router bits and in any case I presume the approach would be to do this with a smaller diameter router in several goes. I'm hoping for bits of advice along the following lines:
- what size cutter should I buy? - should I do this: slot from one face at a shallw depth (how deep?); turn the wood round; slot from the other face increase the depth (by how much?); repeat or: slot from one face increase the depth slot from the same face ... until sufficient depth, then reduce depth; repeat above from other - how best to measure up all of this to ensure an accurate result - tips on feeding the wood in and similar - any specific safety points I should bear in mind?
I am expecting to to do some experimenting to get the right result, but don't want to waste too much timber, or any fingers, in the process...
Thanks a lot for any thoughts Jon N