Lots of Heat/Smoke Routing 1/2

[Leaseman]

I need to cut a 1/2" channel into some red oak for a cutting board I'm making my wife. I'm getting an excessive amount of smoke for some reason. I've had it at the slowest speed to the highest speed and I'm getting the same problem. Burning the wood big time. The channel is about 3/16" deep.  Any suggestions?

[Gary Beasley]

The bit may be dirty with sap, assuming the bit is not dull. Hit it with oven cleaner and a brush. Dont let it bite you.

[RichardA]

These are going to sound like stupid questions, but truthfully they're not.  This channel you want to route, is it going to be a juice grove around the edge of your cutting board?   Is your bit clean? Is it still sharp. Are you moving at a proper speed? Are you trying to freehand this channel? Do you have or can you make a router table? Even 3/16ths may be to deep for you bit. Try to take less. If your going to your full depth your bit may be grabbing grain and throwing you off and making you slow down, that will cause burning. The answers, determine what may be going wrong.

Edited May 21, 2020 by RichardA
One more thing. A router is carnivorous, if you don't control it, it will try to eat a part of you.

[Leaseman]

It's not around the edge but through the middle. The bit doesn't look dirty but I know that doesn't mean much. I've only used the bit twice before.  I'm freehanding this but I am going very slow, following a line. I do have a router table but this is a "curvey" "line". 

[gee-dub]

Red oak does like to burn.  I think your feed speed may be your ultimate problem.  If you make a template to guide the router you could take 2-3 passes with a confident feed rate and possibly get better results.  Back your RPM's down a bit and experiment.

[RichardA]

1 hour ago, Leaseman said:

It's not around the edge but through the middle. The bit doesn't look dirty but I know that doesn't mean much. I've only used the bit twice before.  I'm freehanding this but I am going very slow, following a line. I do have a router table but this is a "curvey" "line". 

So, your going to do an inlay of a different species of wood to go in that channel.  Here's a suggestion. First do what Gary said, then take a piece of plywood, use a jigsaw or band saw and cut a pattern of the curve you want to make..  Get the edge of the pattern as smooth as possible. Clamp it to your bench on top of your cutting board, and be sure the board is clamped with it.  Determine the center point of your bit to the outside edge of the router base, and move your pattern exactly that far away form the line you wish to route., and make sure when you start, that you are going in the right direction. You want to be going into the cut. Not the other way, that's called a "climb" cut and can cause you some of the problems your having.  You want the edge  of your router base to run along that pattern without changing positions, Take a lighter cut.  And, make two or three passes til you reach the depth you need.  One more point, make your pattern longer than your cutting board.

Edited May 21, 2020 by RichardA
This piece of plywood is going to be a template. or a fence you run your router against.

[Mick S]

All the above are good responses. What you're seeing is really pretty common due to a couple of things. 1. Plunging or entering the cut too slowly, then hesitating before you actually start the channel. 2. Spinning the tool too fast for the feedrate and 3. moving the router forward too slowly.

The #1 cause of dulling any tool is excessive heat buildup. It's not because the wood is hard or abrasive, it's heat. Heat forms when the tool is not ejecting chips efficiently and quickly. The heat stays in the chips and surrounds the tool causing it to burn. Once the tool burns it loses its temper and dulls very quickly. 

Turn the rpm down and move the router faster. This causes the chips to be thicker.  Thicker chips carry more heat away from the tool. 

One other comment - the tool you're using is a very aggressive bit originally designed for CNC routers where you can control the rpm and feedrate much better than you can by hand. That bit really pulls down and into the cut. The heavier the cut the more the tendency. Try either taking several shallower passes as has been recommended above or switch to a less aggressive tool like a two flute straight bit. The helix on your bit is very high.

[Leaseman]

Lots of great input. I reduced the depth and moved the router along at a quicker pace and it seemed to fix the problem. I would like to have a deeper "channel" but it'll suffice. I don't know how I would make a second pass at a lower depth since this is free hand but it will work. Thanks for all your help!

[wtnhighlander]

This is an interesting discussion. Can you help us understand why it needs to be free-hand, rather than guided by a template?

Even if you are routing along a hand-drawn line, I would suggest making a template by drawing that line on a thin sheet of ply or MDF, and following it with a bit sized to allow a guide bushing to fit the resulting slot. Then lay the sheet over the actual work piece, and with a guide bushing installed, route the final groove with the smaller bit in as many passes as you like.

Note that most guide bushings extend too far below the router base to use less than 1/2" material, but a grinder or belt sander can make them shorter very quickly. And Harbor Freight sells a pretty decent set of brass guide bushings that won't hurt your wallet to modify and toss, if needed.

[RichardA]

Freehand is only for when you can't use a template.  And you could have on a flat surface.

[drzaius]

38 minutes ago, RichardA said:

Freehand is only for when you can't use a template.  And you could have on a flat surface.

And if you have an extremely steady hand, and if you've had tons of practice. I've tried free handing just enough to know that I'll never be able to to a good job of it, so I don't. The exception is when removing material where I don't need to follow a line. I dare say that free hand routing a straight line is impossible.

[Mick S]

Also, I’d recommend using a round nose bit for a drip groove. Much easier to clean. 

[drzaius]

@Leaseman, is that a carbide or HSS bit? The steel bits can dull very easily & one they're done, they will burn badly.

[Leaseman]

I'm not smart enough to know if it's a carbide or HSS bit. Regarding templates, this is a one off piece that I won't need to duplicate. In fact I'm repurposing a piece that was originally intended for something else (I made a dough board for my wife made out of RED OAK), too porous. So I'm turning it into a serving platter (will just hold cheese, etc) and I'm cutting three curvy lines to pour epoxy into.

[wtnhighlander]

Templates aren't just for mass-production. Any time you need to repeat an operation exactly, like multiple passes of the router to achieve a clean cut of the necessary depth, templates are your friend. Even if you never use them again.

[RichardA]

17 minutes ago, wtnhighlander said:

Templates aren't just for mass-production. Any time you need to repeat an operation exactly, like multiple passes of the router to achieve a clean cut of the necessary depth, templates are your friend. Even if you never use them again.

It also makes your cuts less erratic. Almost as if they were planned.

[Coop]

Templates were suggested more than once here by those more experienced than me for a reason. Just for grins, give it a try on a piece of scrap making multiple shallow passes. I think you will be impressed. And I’ve thrown away probably 80% of the templates that I’ve made, knowing they were one off. 

[Mark J]

15 hours ago, Leaseman said:

I'm not smart enough to know if it's a carbide or HSS bit.

A HSS bit will be made from a single piece of metal.  With a carbide bit the cutting edges are made from separate pieces of tungsten carbide which are brazed onto a steel shank.  

Ditto on the template.

[Mick S]

43 minutes ago, Mark J said:

A HSS bit will be made from a single piece of metal.  With a carbide bit the cutting edges are made from separate pieces of tungsten carbide which are brazed onto a steel shank.  

Ditto on the template.

Not always, Mark. The majority of my bits are solid carbide one piece router bits. I suspect the one he's using is solid carbide. 

And ditto ditto on the template.

[drzaius]

1 hour ago, Mark J said:

A HSS bit will be made from a single piece of metal.  With a carbide bit the cutting edges are made from separate pieces of tungsten carbide which are brazed onto a steel shank.  

Ditto on the template.

Most of my carbide bits have the carbide cutting edges brazed on, but all my spiral bits are carved from a solid chunk of carbide

[Coop]

I always thought what @Mark J said. Good to know otherwise. 

[Mark J]

I stand corrected .