# How to minimize Burning



## SteveMI (May 29, 2011)

This post is not an answer to it, but some observations and looking for tips.

Right now I have to use a 1/4" roundover (with bearing) on the edge of Cherry and Soft Maple. Think about a 1" x 6" x 12" and the rounding is for the 1" edge at the four corners.

My experiments show that top speed on the router is a real burner regardless of the feed rate. Slow speed is the same with just a little less burn. Medium with a fast feed rate seems to be the most successful, but not burn free.

I'm using a 1/2" shank with two carbide cutters and a bearing. I believe the brand is the Woodcraft house brand. This is being done on a table mount with Craftsman router.

Questions:
1) Are there router bit types that are more forgiving for burn in these woods?
2) Is my medium speed and feed fast the best approach?
3) In cutting Cherry and Soft Maple on; scroll saw, bandsaw and table saw, I have found a strip of packaging tape on at least one side of the board does away with the burning. Any tricks like that for a router bit?

Right now I am having to use a sanding block with 220 grit to remove the burns. Not the end of the world, but annoying.

Steve.


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## Quillman (Aug 16, 2010)

Key here is stage routing, independent of the cutter source.
Another point, cutters wear out fast. Typically, in 300', wear lines begin to show on the work.
What to do for perfect results? Waste 95% with your burning cutter, waste the last 5% with a new tool bit.

Second best shot, take 95% with your present cutter and last pass 5% cut with sasme tool.
If that burns , your cutter is dead.

Feed rate is important but not so much on the finish cut, essentially safe at any speed!


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## Mike (Nov 22, 2004)

Steve, reducing the amount of material removed in a single pass will often help but a 1/4" roundover bit should handle the job with no problems. The bit isn't in contact with the wood long enough to heat up if it is properly sharpened. My guess is the bit is dull; have you cut much material with it? If not then return it for exchange; if yes then either have it sharpened or replace it. Since a 1/4" roundover bit is used a great deal I would buy a premium bit like Whiteside.


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## SteveMI (May 29, 2011)

There isn't much time on the bit, but I can't say it is sharp either. I really like Whiteside and most of my bits are those. This was a "sale" purchase I am sure. 

Next step a Whiteside. Only cutting one inch at a time, I am going to try without the staged cutting for now. (Although, I am routing corners on 20 of the squares at a time, so...)

Steve.


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## st8yd (May 10, 2011)

Instead of stage cutting, I often "loose cut it" for lack of a better phase, in otherwords I don't push the bearing tight and/or hold it away a little. Then hit it a 2nd time and push it tight on the bearing. In effect stage cutting but just from the side and not the top.

You could also jig a small spacer for the bearing to ride against then slide it back and re-hit it.


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## Slimpy1 (Aug 14, 2010)

Sharpness is essential. For carbide , even new bits, I use small diamond sharpeners to polish faces and just a bit of the edges . Just look for a very small bevel on the edge. If you take too much off of the edge then you may change the relief angle which can also cause burning.


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## dharps (Sep 18, 2009)

Friends: Good replies......Although, I'm surprised that no one has mentioned that cherry is the wood most likely to burn. I.e. For cherry, a keen edge is essential. Soft maple may be second although I have only worked with hard maple.
Peace


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## Phil P (Jul 25, 2010)

On saws I've found that cherry and maple or sycamore all require fairly new blades with a full relief angle to avoid burning. When a sawblade has been ground three or four times the depth of carbide (and thus the relief angles) is much reduced and burning is much more likely. I'd say the same applies to router cutters. Good dust extraction is another must have on these timbers to avoid burning

Regards

Phil


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## Andynealg (Dec 26, 2009)

On a previous forum I learned to make a 0 clearance fence. I used 1/4 inch poly and screwed 2 3' pieces on each end of an 8 foot fence with a two foot "sacrificial" piece in the center. I held one end of the two foot fence with the router running and rotated the other end against the spinning bit to make the 0 clearance. This seemed to make quite a difference when routing contured caps on 6" cherry base mouldings. If I want a different bit, I can just change the center piece.


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## Mike (Nov 22, 2004)

Andy, what you are describing is a chip break in the fence, not a zero clearance. The purpose of this is to reduce tear out. You should have a through hole in the fence for dust extraction. If chips and sawdust are not evacuated you will hear a snapping sound with many types of wood.


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