Router cutting uneven profiles

[Elliot Faust]

Hey guys... I'm frustrated. I have a Rockler router table and plate insert. I have my Porter Cable 690 mounted in the table. As far as I can tell everything is square and true yet I keep getting uneven profiles when cutting chamfers/round overs. I'm using a fence and I've pulled it away from the bearing to avoid the bearing riding on the freshly routed surface. I've posted a photo to illustrate what I'm talking about. Any suggestions would be extremely appreciated. 298989

[George Bokros]

Are you trying to create a bull nose profile using a round over bit? If so mine never come out completely completely correct either. It is the nature of trying to do it that way. Invest in a bull nose bit, I did and they are perfect.

[Elliot Faust]

I'm not necessarily trying to create a bull nose but if I were to route the round over across the entire board one edge would be of proper depth and by the time I get to the end of the board the depth is about half of when I started.

[Rich Engelhardt]

That is pretty ugly.
Are you using a feather board or spring board to maintain even pressure?
Are you sucking all the chips and sawdust away so they can't pile up underneath?

Have you tried the bit in a router out of the table just to verify that it's working ok?

[George Bokros]

The bearing should be flush to the fence. The stock needs to run against the fence on the in feed and out feed side of the bit.

[James Zhu]

I'm not necessarily trying to create a bull nose but if I were to route the round over across the entire board one edge would be of proper depth and by the time I get to the end of the board the depth is about half of when I started.

Looks like Jessem clear-cut stock guide can solve the problem. http://www.jessem.com/CLEAR-CUT_STOCK_GUIDES.html

[Elliot Faust]

That is pretty ugly.
Are you using a feather board or spring board to maintain even pressure?
Are you sucking all the chips and sawdust away so they can't pile up underneath?

Have you tried the bit in a router out of the table just to verify that it's working ok?

I'm not using either I'm just pushing through with hand pressure. I'm wondering if my plate is not leveled correctly. Do you gentleman have any methods or suggestions on how to properly level a router plate insert? I've had issues with that in the past and it's been a bear to get it perfectly level.

[glenn bradley]

I'm not using either I'm just pushing through with hand pressure. I'm wondering if my plate is not leveled correctly. Do you gentleman have any methods or suggestions on how to properly level a router plate insert? I've had issues with that in the past and it's been a bear to get it perfectly level.

Anything varying the feed path can cause irregularities. Assuming the stock is milled flat and square, long pieces still need proper support through the feed path. The weight of the material waiting to reach the table or that hanging out in space on the outfeed side can cause the stock to bow. With the infeed and outfeed supported or not feather boards can help cure misfeeds. The Jess-Em product is slick but a number of less expensive option work just as well. You could test the theory by clamping a board to the fence that just clears your stock and by ising another piece of scrap to press the stock toward the fence while in motion. You're essentially trying to accomplish this:

299012

with whatever means you might have.

[Mike Delyster]

Did you run the board (boards) trough a planer, before trying to profile it? If not it is not uncommon to have problems.

It takes a lot of down pressure to keep wood with any twist flat on a router table.

[Todd Willhoit]

I'm not necessarily trying to create a bull nose but if I were to route the round over across the entire board one edge would be of proper depth and by the time I get to the end of the board the depth is about half of when I started.

On the first or second pass?

The red lines suggest that the bit radius may be more than half the width of the stock, and that you may be cutting past the centerline on the first pass. This would alter the reference surface riding against the bearing on the second pass.

[Rick Fisher]

If a board has a slight cup to it, it will be tougher to get a decent cut on a router table. I would use the router by hand if the wood isn't flat. If it is .. I dunno why ..

[Bill McNiel]

I think Todd nailed it.

[Ray Newman]

Re-read what Glenn Bradley, Rick Engelhardt, and Geo. Bokrosposted. Feather boards, stock support, and proper fence set up are important.

[Lee Schierer]

As Todd stated, you need to have the bearing even with the fence to get a perfect round over. You should get a symmetrical round over even if the bearing is slightly behind the face of the fence, Unless:

1. The board is cupped, twisted, bowed, warped or uneven in thickness.

2. The router table plate is not flat. Some of the phenolic plates are crowned. Some aluminum plates will sag under the weight of the router.

3. Operator error not keeping the board being cut tight to the fence and/or table at all times.

4. The bit is slipping in the collet or the router height adjustment is changing.

5. The router fence is not stiff enough to resist movement from the pressure being applied holding the piece against the fence.

Some times it helps to run the same piece past the bit twice to catch any deviations made on the first pass.

[Wade Lippman]

Either something slipped or your wood isn't flat.

[Elliot Faust]

Just an update to this thread. You guys were correct. My wood piece was not flat and slightly bowed. As it was pushed through the table one edge would rock away from the bit ever so slightly but enough to cause the problem. Flat wood and a stern feather board seemed to resolve the problem. Thanks again!