Pattern routing and the grain changes direction

[Don Morris]

I know it's best to have the grain directed downward when pattern routing. But halfway along the length of the wood in which I'm going to place a classical ogee, the wood grain completely changes direction upward. I'm worried about tearout as I get into the area where the grain changes upward. In non pattern cases if I had a top and bottom bearing bit, I could turn the piece over and raise or lower the bit. In my case that wouldn't help as I can't turn the piece over because I can't change the pattern. Am I right to be concerned? Do you guys who do this with regularity have a technique which minimizes or eliminates the tearout problem?

[Stephen Cherry]

One thing you could do is use oversize bearings for a first pass. Maybe even a climb cut, but that could be a little scary. Then finish up with the right size bearing. I just bought an inverted pin router for this sort of thing, and it lets you swap pins instead of bearings. I think that ultimately you take a chance with tearout, but with a good sharp bit the odds are tilted in your favor.

By the way, woodcraft has a big set of bearings on sale this month.

[Ed Labadie]

I fought constantly with grain direction changes on plaques, got a Freud "Quadra-cut" bit, never looked back. I do 2 passes, leaving a very small ammount for the 2nd one, maybe raising the router 1/32.

Ed

[Todd Burch]

I typically bandsaw close to the line in a curved pattern situation, then route. Downcut, upcut... the router doesn't care, neither does the wood. If you've sawn close to your line, no big deal for you either.

Now, if you are hogging off material in an upcut - shame on you. ;)

[david brum]

I think it's safer to change to a pattern bit and flip the work over, so you're always cutting down hill.

http://www.mlcswoodworking.com/shopsite_sc/store/html/smarthtml/graphics4/pattern66_2.jpg

[Jerome Hanby]

Wouldn't that be difficult to line up if you are cutting a classical ogee?


I think it's safer to change to a pattern bit and flip the work over, so you're always cutting down hill.

http://www.mlcswoodworking.com/shopsite_sc/store/html/smarthtml/graphics4/pattern66_2.jpg

[Todd Burch]

I think it's safer to change to a pattern bit and flip the work over, so you're always cutting down hill.


Sort of humorous actually - from a guy with a picture of a radial arm saw as his avatar!! Can you spell UPCUT?!!!! :eek: (Please don't take offense!!)

[Don Morris]

Jerome, sees the problem. I can't flip it over for when doing a classical ogee pattern. I guess the best solutions for me, is to change to a larger bearing, take smaller bites, which will lessen the chances for tearout. And as in the first response, I ultimately have to risk a climb cut or cutting in the up cut grain direction. I have two of these to do. I'll do one each way. The first I'll risk going all the way along and if i don't get tearout, I won't do the other by climb cutting. Besides, I went to church last Sunday, should be a snap, right?

[Lee Schierer]

And as in the first response, I ultimately have to risk a climb cut or cutting in the up cut grain direction. I have two of these to do. I'll do one each way. The first I'll risk going all the way along and if i don't get tearout, I won't do the other by climb cutting. Besides, I went to church last Sunday, should be a snap, right?

Climb cutting is safe if you are aware that the wood can grab and that the bit will try to self feed, however, the pattern bearing should limit that tendency if you are removing a small amount of stock. I would still try the over size bearing for the first pass climb cutting if one is available.

[Jerrimy Snook]

Can the depth of cut be changed by plunging rather than changing the bearing? Seems like this would offer smaller increments than bearing changes.

Jerrimy

[Sam Murdoch]

Sounds like your pattern is attached to your work piece and that you are running your router on top of the pattern with a bearing bit - right? If that's the case, along with cutting close to your line and taking 2 passes I find that I have good success by starting to rout at the end of the run. I will rout an inch or two, then come back and run another inch or two, always feeding into the already cut area. It is a slower process but virtually eliminates tear out without doing a climb cut. The reason for my opening question is that if you are routing with a table mounted router this kind of sneaking up routing is more of a challenge - not practical at all really.

[david brum]

Wouldn't that be difficult to line up if you are cutting a classical ogee?


http://www.sawmillcreek.org/images/misc/quote_icon.png Originally Posted by david brum http://www.sawmillcreek.org/images/buttons/viewpost-right.png (http://www.sawmillcreek.org/showthread.php?p=1855707#post1855707)
I think it's safer to change to a pattern bit and flip the work over, so you're always cutting down hill.

http://www.mlcswoodworking.com/shopsite_sc/store/html/smarthtml/graphics4/pattern66_2.jpg





Rats! I somehow didn't register the term "ogee" when I read the post. Been doing data entry at work all week and I think I pulled a muscle in my middle aged brain. :confused:

[Don Morris]

I bought the Woodcraft Wood River Bearing Kit. I'm using a table mounted router. I spent some time making an MDF template. The curvalinear outline on the wood piece was cut on a bandsaw to within 1/8" of the line, so there isn't much to be removed, then attached with double sided tape. So I don't think it's like sneaking up on it. Wasn't able to get to it today, but tomorrow will cross fingers, pray and go for it. Worst that can happen is that I have to use a little stainable wood filler. Geees I hate to do that. It never looks as good. Thanks for the ideas guys. I didn't think about the larger bearings.