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Discussion Starter #1
Hi, I got rid of my burning by doing 2 passes on the round over bit, cool!

Anyway, when I am entering a round over cut the beginning cut is smooth(seen on the right in the picture) then as I am moving the wood from right to left throughout the cutout when it exits I get a little rough surface as seen on the right side of the cutout below.

Any tips? More pressure, less, faster feed?
 

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that's tear out...
bit is getting dull.
bit needs cleaning....
you could try climb cutting on the last pass...
 

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This may be incorrect but I'm thinking I read about it in some old old woodworking book when I was young (65 now). The cut being smooth because the cutter is following the direction the tree grew from the ground up and the rough is cutting against it.- Or possibly I may just be having one of those "moments" : )

I've run into the same thing in every instance no matter HSS or various carbide. Sharpness of the cutter doesn't appear to be a factor. Back routing has not helped (much) and the speed of the router and feed doesn't help all that much either. I have found the higher the moisture content of the wood the worse it is. I suspect a harder very tight grained wood should show less.

I don't mean to infer its like a rip cut and cross cut using a saw
 

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A newer better bit mightt help like Stick is suggesting. Some of the better ones have a shear angle on the cutter meaning that the cutting edge is at an angle to the shaft instead of inline with it. The shear angle slices instead of scraping. As the saying goes, you get what you pay for.
 

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How's the cut between your fingers, is it rough too? Whenever my bits dull they tend to burn or burnish
 

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Discussion Starter #6
Thanks for the pdf's. I think after reading that climb cut warning I will stay away as I am a novice.

The router bit is brand spanking new and my straight cuts and gently curves are like a baby's azz. The only problem I am having now is when I exit that cutout/finger I get a little tear out as you said. It has helped to speed up the exit a little. I got after it with some sand paper and cleaned it up, but I was just wondering if there is a technique to eliminate this.

What I noticed is that the guide bearing revolves smoothly when I enter the cut and that is when the cut is smooth, when I am following the curve out of the finger the bearing seems to not revolve as well so somehow its losing contact a little. More pressure didn't seem to work as well as just a faster feed at the exit.
 

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close the opening w/ a piece of scrap...
route the cup 1st... remove the scrap and then do the straight edge...

what brand of bit are you using....
 

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Discussion Starter #10
I'm using this quarter inch bit:

amazon.com/gp/product/B000LBIWOE?psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00

I'm sure it's a cheapy, I may try that Freud, I assume it's the cream of the crop. Also, I may try different wood, I think I am working with Pine right now. I'm doing a test run of my build and just grabbed some quick sheets at Lowes
 

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It looks lie you are using pine or some variation of pine from a big box store. As Toto suggested try a different kind of wood.
 

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I agree with Chuck, shear angle would most likely solve most of the tearing. For example when using a hand plane on end grain you can eliminate tear out by skewing the plane at 45 degrees.
 

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Like when using a jointer or planer, you have to watch the direction the grain is climbing. On a circular cut, part of the circle will be an uphill cut and part will be a downhill cut. Like in the jointer or planer you always want to cut with the grain and downhill for smoother results.
 

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If I'm worried about tear out at a corner or when coming to an edge like you are I'll nibble away at the exit point first. The problem of tearout is caused by the fact that as you reach the exit point the bit is cutting 90* to the edge. If you back the bit in a nibble at a time then the angle is more parallel with the grain. Essentially you would be climb cutting in very small increments.
 

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This is tear out like stick says.

It looks to me like you are using poplar and being a softer wood will show more tear out than a harder wood like oak. This is where your bit changes from cutting with the grain to cutting across end grain and there is no support for the grain here like there would be on the end of the board where you rout the most end grain. A smaller cut might work to minimize the tear out. If it becomes a problem to me I will add 2 or 3 thicknesses of masking tape where the bearing rides when the bit is run through these areas. After making the first pass I remove 1 or 2 layers of tape and make another pass. Then remove the last piece of tape and make the final pass. A little sanding will clean it up pretty well but remember, if you use stain, this area will stain darker than other end grain areas.
 

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I think you are finding out what all of us who are older, When we try working with wood. I say this more to my self than you. But when each of those of us who are of the older generation start to play with wood, we tend to take the cheapy route. I know I for one have done this on more than on occasion. I then have asked some one why this or that happens. They have been kind enough at times to say, i think the tool or tools, as the case may be, are of a poor quality. They then say, let me show you what I mean. They proceed to show me what happens when you use a tool that is made of a better quality material. This can be anything from angle to edge, to not being a true blade. I think the biggest help for you is, as already stated, upgrade and you will be in good shape. Just me talking. Good Luck.
 

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I am by no means an expert, but I think that it has to do with the grain direction as others have said. I was watching a youtube video called Template Routing Basics by FineWoodworking (can't post URLs yet) and he was talking about how it's best to always rout with the grain, and he flips the work piece over on half of curves to always go with the grain. I don't think that would be applicable with a roundover bit as he was using a top and bottom bearing template bit and obviously a roundover is going to only be able to contact the wood one way, but I just wanted to throw it out there...
 

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I am by no means an expert, but I think that it has to do with the grain direction as others have said. I was watching a youtube video called Template Routing Basics by FineWoodworking (can't post URLs yet) and he was talking about how it's best to always rout with the grain, and he flips the work piece over on half of curves to always go with the grain. I don't think that would be applicable with a roundover bit as he was using a top and bottom bearing template bit and obviously a roundover is going to only be able to contact the wood one way, but I just wanted to throw it out there...
some time climb cutting is the answer....
 

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