Everyone knows that common piece of advice about router bits, "Always buy the biggest bit you can afford," right?
A few months ago I splurged on a 1/2" shank, 1-3/4" diameter Freud bit and it set me back $42. Misinterpreting some routing advice that I read, I thought it would be handy for cutting circles in 1/2" plywood in one pass (without having to rough cut with my jigsaw). I quickly found that was a stupid idea and that I still have to either rough cut my circles or make several passes. In hindsight, it seems like I would have been better off buying a compression bit (since I'm using plywood, after all) and/or just using one of my smaller straight bits.
I also thought another benefit of having a larger bit was that I could feed material more quickly without heating the bit up. However, I've noticed that I've scratched the paint on the bit's body (at least, that's what I'm calling the main hunk of metal beyond the shaft, to which the cutters are attached). The only way I think I could have done this was by feeding the material too fast, but maybe it happened when I was cutting my first circle in a single pass and the router got bogged down.
So, I have a couple questions:
1. At what point does the "buy the biggest bit you can afford" rule start to break down? In other words, assuming the same profile and carbide length, when you reach a point of diminishing returns in terms of diameter?
2. In what situations will I be glad I have a 1-3/4" diameter straight bit? (well…other than bragging rights)
A few months ago I splurged on a 1/2" shank, 1-3/4" diameter Freud bit and it set me back $42. Misinterpreting some routing advice that I read, I thought it would be handy for cutting circles in 1/2" plywood in one pass (without having to rough cut with my jigsaw). I quickly found that was a stupid idea and that I still have to either rough cut my circles or make several passes. In hindsight, it seems like I would have been better off buying a compression bit (since I'm using plywood, after all) and/or just using one of my smaller straight bits.
I also thought another benefit of having a larger bit was that I could feed material more quickly without heating the bit up. However, I've noticed that I've scratched the paint on the bit's body (at least, that's what I'm calling the main hunk of metal beyond the shaft, to which the cutters are attached). The only way I think I could have done this was by feeding the material too fast, but maybe it happened when I was cutting my first circle in a single pass and the router got bogged down.
So, I have a couple questions:
1. At what point does the "buy the biggest bit you can afford" rule start to break down? In other words, assuming the same profile and carbide length, when you reach a point of diminishing returns in terms of diameter?
2. In what situations will I be glad I have a 1-3/4" diameter straight bit? (well…other than bragging rights)
