Ok, I'm using a router table. 1/4 in plywood template. The template is pin nailed to 3/4 in oak. As I face the 1 in straight template router bit it is turning counter clockwise. I feed the oak into the bit going into the turning bit, or the left side of the bit. All goes well till I get to the part where the bit is cutting with the grain and it then tears off a big chunk. I figure it was just a crack in the wood so I try it again and it does the same thing.
Should I be feeding the wood so it is going with the bit instead of against it? I have cut away most of the wood with my bandsaw so there is only about an 1/8 of the oak showing. It is a brand new 1/2 in straight bit. I don't understand what is going on???? Any suggestions. I am not cutting across the grain, but with the grain. I am not using a fence because there are several curves in the template.
I've visualised in my mind and unless tis rotten cold I have is addling my brain I would say you are doing everything correctly.
If you are "climb Cutting" where you use the bit turning away from you. (at least I think that's a description for this process) the work piece can grab a take off ...with you hand on it and into the whirring blade... which is why it's known as a practice you only do when you are highly experienced, totally reckless, or you've lost most of your fingers so you don't really care about losing more!
I have had instances of break out and on oak where the grain direction is pointing in to the cutter. i.e. if you were planing it you wouldn't think twice about which way would be the best way to feed it.
Oak does have a tendency to split when stress this way. I've found this when I use hand chisels and am "cleaning up" against the grain. the cut can often lift a good chunk of the underlying wood with very little effort.
Only remedy is to think about this in advance, design the cuts accordingly.
But if it isn't this I cant think of anything else,
I watch with interest what other Forum Folk have to say.
How thick is the oak that you are attaching to the template?
Is the bit clean, no gum build up?
What is the quality of the bit? Take a look up close. If there is a small nick it will catch especially in oak.
When you round corners make sure that you keep a constant pressure against the wood. This takes a bit of practice. I have chipped out several pieces when I rounded a corner and bounced the router against the template.
I put a large clear offset base on my router with a knolb in it. This helped me see the work and keep pressure against the wood as I followed the template. If you use the standard router base do a dry run with the power off to figure out how you will turn the router and the work piece.
The bit is brand new and seems to be ok. I am doing this on a router table with no fence and it is not the rounded edges that are causing the problem. It seems to be breaking off about a half inch of wood as I go down a straight part of the template with the grain of the wood. Maybe it was a coinsidence, but this oak is expensive and I hate to have to do it over several times if I'm not doing it right.
I'm cutting a 3/4 in oak with a 1 in straight makita template bit. I have the template nailed to the oak with the oak on the table and the template on top. I have it set so the cutting edge of the bit is well above the oak and the roller is just a little up on the 1/4 in plywood template.
Oak really enjoys doing this...it's the nature of the beast. There's a couple of cures;[ul][li]Cut around the template with a bandsaw within 1/16" to 1/8", then use the technique you are using with a flush trim bit, or you can use your straight bit.[li]Install a larger template guide, and take a much smaller bite, then reinstall the guide you're using now, and route again[li]Use a spiral bit...they are more forgiving and make a cleaner cut.[/ul]
Hope this helps
To simplify: On a router table "always" feed right to left, pushing the wood into the spinning cutter. On a board, "always" cut with the grain, so projecting endgrain coming out the side is pushed in toward the center as the cutter hits it rather than lifted away.
I quote always because climb cutting, running with the direction of rotation, has some special uses, and going against the grain might be unavaoidable in some cases, such as pattern routing all four sides of a rectangle.
If you must rout against the grain feed rate becomes critical. The faster you go the more likely you will suffer tearout.
Just one other thing. Gotta take really light cuts in this situation, because if the template has a curve in it, the grain will almost certainly be against you part of the way, no matter how you arrange the cut.. 1/8" is huge--1/16 is a lot. I'd say try to take it about a 32nd at a time, and go slow like the other poster said. Stick with it--it'll work. Wiley