Butcher Block Counter, Undermount Sink what router bit.

[dejongs]

I am installing a butcher block counter top for my son's family and am working on the cutout for the under mount sink. I bought a brand new 1/2 diameter, 2" long Freud bit. I made a template for the bushing to follow. I am having a lot of trouble doing the finish cut.s I am starting with the largest diameter bushing and was going to step down till I was the at the 1/2 bushing which my template was made for. 
I am thinking I may need to make multiple passes changing the depth of the cut or going to an up spiral or down spiral bit.

Advice needed.

Here is what it looks like before I stopped
[attachment=41504]

[jteneyck]

I am installing a butcher block counter top for my son's family and am working on the cutout for the under mount sink. I bought a brand new 1/2 diameter, 2" long Freud bit. I made a template for the bushing to follow. I am having a lot of trouble doing the finish cut.s I am starting with the largest diameter bushing and was going to step down till I was the at the 1/2 bushing which my template was made for. 
I am thinking I may need to make multiple passes changing the depth of the cut or going to an up spiral or down spiral bit.

Advice needed.

Here is what it looks like before I stopped

I had a similar experience recently trying to trim some large finger joints with a flush trim bit.  I ended up using several mortising bits, slowly working my down from the top.  I used a bottom bearing flush trim bit from the other side, riding on the finished edge from the mortising bits, to finish what I couldn't reach from the top.  Mortising bits don't catch on the rough cut edge of the work like flush trim bits can, and can handle an unlimited amount of waste so your roughout cut can be very conservative.  For flush trim bits to work well you have to cut very close to the final dimension first, leaving only a very small amount for the bit to remove.  However, that makes it easy to get chip out, or an overcut, etc.  

John

[KC]

I used flush trim bits and patterns for hundreds of chair legs over the years and that picture looks like nothing I ever saw.  I'd almost have to wonder if the OP is going the wrong direction and causing some 'grab'.

[dejongs]

I used flush trim bits and patterns for hundreds of chair legs over the years and that picture looks like nothing I ever saw.  I'd almost have to wonder if the OP is going the wrong direction and causing some 'grab'.

Nope not the wrong direction. I went back and took a shallower cut. Lots of vibration. Took the bit out and put it back in and its a lot better. Going to work more with the shallow cuts, was hoping not to have to sand by doing one full depth cut. Also thinking my PC 690 doesn't have enough mass/power fro this type of cut.

[JohnnyEgo]

Is that per chance hard maple? I get similar chatter in hard maple when I am trying to hog out too much with a 1/2 inch spiral pattern bit at it's max depth. For those long bits, the material thickness is essentially applying torque to the lever arm that is the unsupported top of the bit. It's probably vibrating and grabbing the material unevenly, causing it to jump. I'd back off the speed you are driving the bit, and make multiple light passes without applying a lot of lateral pressure on the bit.

[dejongs]

Is that per chance hard maple?  I get similar chatter in hard maple when I am trying to hog out too much with a 1/2 inch spiral pattern bit at it's max depth. For those long bits, the material thickness is essentially applying torque to the lever arm that is the unsupported top of the bit. It's probably vibrating and grabbing the material unevenly, causing it to jump. I'd back off the speed you are driving the bit, and make multiple light passes without applying a lot of lateral pressure on the bit.

Yep, hard maple.
Thinking I may switch from the 690 Porter Cable to my Hitachi that has soft start and some speed control.

[dejongs]

Success.
After going to two routers, the porter cable first with a 1" length bit, then the Hitachi with the 1.5" bit and the speed turned way down I got a lot better cut. The collets were just off enough so that when I went through with the longer bit there was no line between the two cuts. Will have some sanding but it turned out a lot better then when I first started.

Thanks for the help.

[JohnnyEgo]

Glad to hear it worked out!

[mike4244]

I am installing a butcher block counter top for my son's family and am working on the cutout for the under mount sink. I bought a brand new 1/2 diameter, 2" long Freud bit. I made a template for the bushing to follow. I am having a lot of trouble doing the finish cut.s I am starting with the largest diameter bushing and was going to step down till I was the at the 1/2 bushing which my template was made for. 
I am thinking I may need to make multiple passes changing the depth of the cut or going to an up spiral or down spiral bit.

Advice needed.

Here is what it looks like before I stopped

I haven't installed butcher block counters. I would have used a circular saw to cut as much as possible. Then a saber saw with Bosch coarse tooth blade in a scroll saw. After the sawing was done then clean up with the router, if needed.

[EdL]

He's doing an undermount sink. Finished cut must be perfect and you get 1 chance.

I did 1. Never again, don't care if the pope wants it, he'll be finding someone else.

Ed