[CClark]

Hello All,

I'm working on a set of picture frames and have a concern about tear-out as the bit finishes it's cut. Imagining that I could add a stop and flip the piece over to avoid the blow-out on the exit?

It's a straight cut 1/4" deep and I'm using a 1/2" bit right now. I have lots of scrap pieces to experiment with before I hit the real frames.

How would you approach this cut?I've attached what I'm going for and what I want to avoid.

Thx, Chris

 

[Cherryville Chuck]

I saw a great hint just yesterday on how to deal with this if you are following a template. Rout up to to the point where you had the problem and then stop. Change from a flush trim bit to a top bearing pattern bit. Then flip the piece with template still attached onto it's other side. When you do the direction of feed is reversed so that you will be routing the other way to finish that spot.

 

[sunnybob]

that whole cut edge looks grim, is that cutter sharp? router cuts should be finish smooth

 

[DonkeyHody]

I like Chuck's idea. Just route from one end to the middle, flip the board and route from the other end to the middle. Better yet, set up a stop that will keep you from going past the start mark. Then start a tiny way from the "good" end and then climb cut back to the end. Flip the board and repeat.

 

[woodknots]

You didn't tell us if you are using the router hand held or in a table. If you were routing towards the piece that's shattered, the bit grabbed the grain and ripped it away. Best bet is what Chuck said - use a template and route from both ends of the piece to the middle. You'll have to change bits.

 

[CClark]

Thanks for the responses. I'm using a table.
I'll try setting up a stop and flipping the frame over so I can rout to the middle. I'll do this with a few passes.
Chris

 

[Stick486]

suggest a sharp bit w/ shearing action instead of chopping...
climb cutting can help...
https://www.ptreeusa.com/rtr_router_bit_freud_bits_spiral_flush.htm
https://www.ptreeusa.com/rtr_router_bit_freud_bits_downshear_helix.htm

.

 

[CClark]

Thx, the bit is a new shear bit. I set up with a longer fence & stop. Flipped to get the ends in 3 passes.
Thanks again for all the advice.

 

[AndyL]

I saw a great hint just yesterday on how to deal with this if you are following a template. Rout up to to the point where you had the problem and then stop. Change from a flush trim bit to a top bearing pattern bit. Then flip the piece with template still attached onto it's other side. When you do the direction of feed is reversed so that you will be routing the other way to finish that spot.

You can even get trimmers with both top and bottom bearings, so you can do this without having to change bits.
https://www.wealdentool.com/acatalog/Online_Catalogue_Down_Shear_Trim_23.html

 

[chessnut2]

I saw a great hint just yesterday on how to deal with this if you are following a template. Rout up to to the point where you had the problem and then stop. Change from a flush trim bit to a top bearing pattern bit. Then flip the piece with template still attached onto it's other side. When you do the direction of feed is reversed so that you will be routing the other way to finish that spot.

That's a nice idea, Charles. I've been having good luck lately at happening upon "just in time" tips like that myself. I know I haven't been living right, so I don't know why the good fortune. Thanks.