Climb cuts with a router

[Bryan Berguson]

I was making more trim for the house this weekend using hickory. If you've ever worked with hickory, you know that it can be a real bear to rout.

I had to put a roman ogee edge on 5 boards 65 inches long on a router table. I then routed a 1/4 inch round over on 10 pieces 75 inches long with a hand held router. I did all but the first cut with a climb cut. It was the only way I could keep from tearing big chunks out of the edge.

I know if the grain is going in the correct direction you can route hickory the "proper" way but when it starts changing, *lookout*.

Anybody have any special tricks to avoid climb cuts or is it sometimes the only way to do it?

Bryan

[glenn bradley]

I was making more trim for the house this weekend using hickory. If you've ever worked with hickory, you know that it can be a real bear to rout.

I had to put a roman ogee edge on 5 boards 65 inches long on a router table. I then routed a 1/4 inch round over on 10 pieces 75 inches long with a hand held router. I did all but the first cut with a climb cut. It was the only way I could keep from tearing big chunks out of the edge.

I know if the grain is going in the correct direction you can route hickory the "proper" way but when it starts changing, *lookout*.

Anybody have any special tricks to avoid climb cuts or is it sometimes the only way to do it?

Bryan

I think climb cuts are a valid technique if they are the solution to a problem. Some folks do ALL their last passes as a climb cut. I use it with difficult grain or tempermental wood as you describe.

[Rod Sheridan]

The danger with climb cuts is that you sometimes wind up cutting yourself instead of the wood.

I wouldn't climb cut unless it was done on a shaper with a good setup and a large power feeder.

Do an internet search on router accidents and you can learn from others before you join the database.


Regards, Rod.

[Russ Filtz]

I do climb cuts as a last pass, but only taking a very small bite. Easily controllable that way. Too big a bite and the router, piece, or both can take off on you!

[Mark Singer]

Climb cuts are very helpful in certain woods.....there is less likleyhood of tearout where the grain is exiting the edge as in a rabbit in mahogany. Light passes and knowing what the router wants to do so you are ready and can resist it... It is a good technique.

[Rick Christopherson]

I am rather surprised to hear that some people are climb-cutting on their last pass with the router. This completely defeats the purpose of the cut. By the time you get down to the last pass, the tips of the router bit are acting almost entirely in line with the cut, and this is not where you get tearout.

Climb-cutting should be used as a first pass where the tips would otherwise be exiting the wood more perpendicular to the cut, and in a tearing motion. With a climb-cut, the tips are entering the wood at a steep angle with a shearing motion. This is the reason why there is less tearout with a climb-cut. Your final pass should be in the push-cut direction as a clean-up pass to account for the natural chatter you get from a climb-cut.

I've written more information about this, including some photographs and hints for identifying the grain direction that the original poster was asking about in the Festool OF 1400 router manual, where this graphic came from. Eventually I will get around to updating the climb-cutting article on my website, but in the mean time, the Festool manual is the only place I have this information. You can read it at: http://festool.home.att.net/

http://powertoolman.home.att.net/tempgraphics/OF1400-17lo.jpg

[David DeCristoforo]

Climb cutting with a handheld router can be "relatively safe" as long as:
1) the stock is held firmly by clamps or a vise
2) you have a good grip on the router and
3) you do not try to hog off too much wood at a time.

Begin with a very light cut and lower the bit for each successive pass. The final pass "should" be a "normal" pass which you may want to make very slowly. I have had large roundover bits shred woods like oak and hickory even with a very light final pass so in situations where the grain is simply too "gnarly", a climb cut final pass can be used. But you need to exercise great care when doing this.

I would be skeptical of freehand climb cutting in a situation in which the cutter is stationary and you are feeding the stock i.e. when using a router table or shaper. It is much more difficult (if not impossible) to control a climb cut in these situations. A power feeder is a must here.

[Steve Clardy]

My climb cuts are the first cuts.

Then a final pass going the correct direction.

[Gary Keedwell]

My experience with milling has taught me to use the conventional cut when there is alot of stock to remove. After removing the bulk of marterial with the conventional, I take my finish cut using the climbing method. A climbing cut will give you the cleanest edge.
I find milling aluminum very similar to milling wood. I get the best finishes in aluminum by leaving about .010 for my final cut. I do this with a climbing cut. For reasons that I don't know, stainless steel gives the best cut the conventional way. ( I know, I know...this is about wood...but I thought some people may want to know):cool: :>)
Gary K.

[David DeCristoforo]

So once again you get completely conflicting advice which, I am sure, is not at all confusing! Bottom line (as always) is do what works for you and what you are comfortable with and provides you with the best result. Work safely using...uhh.......what is it?...oh yeah...common sense...that's it. Oh and Gary...what bits are you using to mill that stainless with? I gotta get me some of those....

[Gary Keedwell]

David....Maybe I should have been more explicit. I milled the stainless steel in a vertical milling machine and the bits are made of regular HSS. Sometimes I use Co-HSS which means that cobalt is an ingredient mixed in with the HSS. I think it is approximately 5-6% cobalt.
The configurations of endmills and routers are basically the same. I bring end mills home all the time and use them in my router. Also, if you try to take alot of stock off aluminum, steel etc. using a climbing cut, you better hold the handle tight because the end mill will "grab" the stock and knock the milling head out of alignment.
And no....I haven't tried milling stainless with a router.:eek: :D
Gary K.

[David DeCristoforo]

"And no....I haven't tried milling stainless with a router..."

Rats! I was thinking a nice ogee around the top of my espresso machine.....

[Gary Keedwell]

"And no....I haven't tried milling stainless with a router..."

Rats! I was thinking a nice ogee around the top of my espresso machine.....
:D Send me the stock and and a scaled drawing.....I'll do it for free!:rolleyes:

Gary K.

[Tim Sproul]

I am rather surprised to hear that some people are climb-cutting on their last pass with the router. This completely defeats the purpose of the cut.


Depends on where the tearout problem is. You are thinking that the only place tearout occurs is at the arris underneath the bit in your picture.

I think the OP was having problems on the curved ogee surface....so in his case, climb cutting would be needed at the end, if not for all passes.

[glenn bradley]

"And no....I haven't tried milling stainless with a router..."

Rats! I was thinking a nice ogee around the top of my espresso machine.....

:D :D :D:D :D

[Bill Wyko]

The danger with climb cuts is that you sometimes wind up cutting yourself instead of the wood.

I wouldn't climb cut unless it was done on a shaper with a good setup and a large power feeder.

Do an internet search on router accidents and you can learn from others before you join the database.


Regards, Rod.
Cut the tip of my finger off just, find another way. You're asking for a really bad day!!!!:eek: Fortunately it grew back. I spent X-Mas day in the ER for that dumb one.:mad:

[Bryan Berguson]

I appreciate all the replies. Thank you! I was thinking somebody might have some trick that I've never heard of and should be using but not the case.

I wear leather gloves when working with hickory. I've gotten some wicked splinters from that stuff... They allow me to hold on better and not worry about the splinters. They are good fitting lineman gloves.

My technique for the roman ogee cuts was to do it in 4-6 passes. Holding onto the board with both hands and pushing it into the cut until there was enough to get a good two handed grip from the other side. I'd then move to the dangerous side and while keeping my body out of the way, I'd let the board feed through. The end result was zero tearout.

For the 1/4 round over (and I was taking about 3/16ths), I clamped the board to my workbench and do a climb cut on the first pass. I'd then finish with a push cut. Had zero tearout with this method as well.

I'm making the final trim for some windows in my house. My jams were made as complete units in the workshop and then nailed in place. (makes for perfect joints, well most of the time :rolleyes: ) The problem I had was a poor drywall job on one wall and the jams didn't properly meet the window leaving some gaps. (the entire house was bad but this wall was especially problematic with a french door and 6 - 2.5 x 6 windows) The trim I'm making is a roman ogee piece on the bottom with 1/4 thick by 3/4 wide strips on the top and sides. I'd rout an edge on the full board and then rip it off on the table saw.

So far so good, I'll put the 3rd coat of poly on tomorrow and then I can cut and install! :)

Bryan

[Rick Christopherson]

Depends on where the tearout problem is. You are thinking that the only place tearout occurs is at the arris underneath the bit in your picture.

I think the OP was having problems on the curved ogee surface....so in his case, climb cutting would be needed at the end, if not for all passes.Maybe you misunderstood. Climb-cutting on the last pass is not a problem, but I was reading some of the previous posts as stating that they climb-cut only the last pass. This is the part that is counter productive.

Regardless of any misunderstanding, you do not want your final pass to be climb-cut (at least as a regular practice). This is because the router bit pushes away from the workpiece with each slice of the cutter, and this is what creates the chatter marks. When I refer to a final clean-up pass in the push-cut direction, I am referring to a near-zero pass to smooth out this chatter.

When I said I was surprised by the previous comments, I was referring to those that implied that they made their initial passes in the push-cut direction and their cleanup passes in the climb-cut direction. I may have misunderstood what the posters were saying, but nevertheless, if anyone is doing this, then they do not fully understand the mechanics and reasons behind making climb-cuts. You don't start out with a push-cut and finish with a climb-cut. You're not utilizing the benefits of the climb-cut at all.
=====================
By the way, as another little tidbit of information, while a climb-cut pushes the bit away from the workpiece, making it a shallower cut than expected, a deep push-cut can pull (deflect) the bit into the cut deeper than expected. So even if you have a router bit with a pilot bearing, taking too deep of a pass in the push-cut direction can cause the bit to cut deeper than a cut that wasn't as aggressive. In other words, one single pass in the push-cut direction might result in a deeper cut than multiple passes in the same direction.

Once you have made a deep, full-depth, push-cut pass, you cannot make any cleanup passes because they will never cut as deeply as the previous pass.

[Gary Keedwell]

Although I will always make my final cut by climbing, I wanted to verify that I wasn't the only one. I went to an article by Pat Warner and he does the same thing, climb cut the final pass.:rolleyes:
Gary K.

[Bill Hylton]

Bryan--

You certainly got a thread started here. I agree with the basic advice offered by Rick and David. The thread seems to be drifting away from safety, but we don't want to forget safety. Especially in considering climb cuts.

My take is that climb-cutting with a hand-held router is--if used with discretion--an acceptable practice. Climb-cutting on a router table is never an acceptable practice.

Here's my reasoning. The spinning bit is the hazard. When you hold the router and the bit pulls it along the edge of your workpiece, the hazard is moving away from you. But on the router table, it's the workpiece that zips away, leaving the hazard right in front of you. As the board goes away, your hands may very well go right into that cutter.

The quality issue is a tough one. In my opinion, there is no one technique that always works. Wood isn't a uniform substance, and the truth is, the most spectacular wood is usually the most difficult to work. On top of that, power tools tend to turn us into zombies. We don't look carefully at the material, or make preliminary--i.e. shallow--test cuts. We just hit the switch and hog away.

I think you should be prepared to "waste" some stock with an evaluation cut or two. Shallow cuts are always good. Reducing the bite reduces the angle between the cutting edge and the wood fibers at the exit point. A shallow cut can also give you a warning: If chipping or tearout appear, you know you have to adjust your approach. But you probably haven't ruined the workpiece.

The shortcoming I see in the "final cleanup pass" approach--be it push cut or climb cut--is that the damage inflicted in an initial hog-away pass often is too severe to be remedied that a final shallow pass.

Bill