Which is the best router blade to produce a rough cut surface?

Question

I'm looking to use a CNC router table to flycut the top surface of some wood. Importantly, I need the surface to end up quite rough e.g the type of rough cut surface you would get from cutting some wood using a circular saw (but without any machining marks). Which router blade should I use to achieve this? Or is it more a case of reducing the router cutting speed. Whenever I have used a router to cut wood, the cut surfaces have been left quite smooth.

The cut top surface of the wood needs to have no machining marks. This is the main reason why I'm considering using a router. When I have cut wood using a circular saw, I really like the slightly rough texture and look but unfortunately you also get faint machining marks which I don't want.

I have tried planing but it leaves the wood too smooth.

Answer 1

I think you have set yourself an impossible task. Unless the CNC router is your own, I can't imagine any company willingly using inferior grade tooling in their machine to try and produce a surface finish akin to a circular saw without the saw marks. I can think of only two ways you might achieve such a finish.

Firstly try to buy the wood direct from a lumber yard. Wood that has been planed on both sides and then returned to storage would have a raised grain when sold. Alder would be a perfect example of this.

Secondly you might try re-sawing it on a bandsaw, with a wide blade and the correct feed speed you might achieve a rough finish with out the tool marks.

Having seen a number of your questions on this or related subjects I am intrigued to know just exactly what it is you are trying to make.

Answer 2

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Answer 3

If you can slow your CNC machine down to just a few rpm you might be able to use a barrel shaped rotary rasp to get the finish you desire after it has been finish cut. You may have to figure through trial and error how much of the wood will be removed to rough finish if that dimension is important. These rotary files or rasps are availble at hareware or tool centers and usually cost under $5. Generally they are used in drill to enlarge holes such as lock set holes when the lock set is very old (1950's or earlier) and is being replaced by a new lock set which requires a 2 1/8" hole for installation.

I have seen Mr. Wolf's answers on here several times and his concerns are usually very valid. I have a few years at it too. So between us we may be able to get you a good solution, but you will have to respond.

Answer 4

I've not actually tried this, but it might offer something different than other answers. After routing use a wire wheel, made for a drill for cleaning things like rust off of metal, and wire brush the surfaces. Wood grain is composed of soft and hard layers so it will not wear down evenly. It also would not show machining marks. If you were so equipped, I would also suggest sand blasting.

Answer 5

Consider that most decent full size routers run at 25,000 RPM. Obviously sharp blades are intended to smooth cut.

Is this some type of faux finish you're hoping to achieve? IE: a wood graining efect? You state however, no machine marks. I guess I'm confused in that your details lack the purpose.

Certainly you can beat up any number of router bits with hammer and chisel to cause them to do the exact opposit of their intended purpose. I can't imagine damaging tools intentionally. You might set up guides/templates and raise and lower the router as you move along the design you wish. OR lift and lower the stock as you move it on the "table"

You might think about a bit more labor in taking a rough rasp to the cuts after the fact.

I hope you define what you're attempting. I'm curious.

Steven Wolf

Answer 6

I think I would just cut it with the router and then soak it down with water. Water will make the grain raise and the surface would be fuzzy with no mill marks.

Answer 7

have you thought of checking out a lumber mill near you? i bought some oak to repair my front porch rail, it didn't have blade marks as much as it did have a rough almost pitted surface to it. like the rough side of a piece of wood siding, as opposed to the smooth side. of course i wanted a smooth surface and had to sand it, but this sounds to me like the look you are trying for. to find one, if it isn't listed in the phone book, check a lumber yard, not a home depot type store, for leads to on near you. good luck, hope this does it for ya.