Having a brain-dead moment. I need to rout some grooves in a sheet of plywood, and I can’t remember if I need to go left to right or the other way. I will be using a straight edge clamped to the plywood as a guide, and the straight edge will be on the far side of the router. I don’t do this often enough to remember the correct way, but I do remember that if I do it wrong the router climbs away from the straight edge.
“Put your creed in your deed.” Emerson
“When asked if you can do something, tell’em “Why certainly I can”, then get busy and find a way to do it.” T. Roosevelt
Replies
Push opposite of rotation for normal cuts. Climb cutting is done in the same direction of rotation.
Ok, break that down to my pre-coffee level. With the straight edge on the far side of the router, do I start on the left or right?"Put your creed in your deed." Emerson
"When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it." T. Roosevelt
Left to right will push the router into the straight-edge if it is on the other side of the router away from you.
Thanks, that's pretty clear."Put your creed in your deed." Emerson
"When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it." T. Roosevelt
Left to right will push the router into the straight-edge if it is on the other side of the router away from you.
AND if using a router table.. NEVER put a 'stick' between the fence and the bit! NEVER! I did it once very Long AGO! I'll NEVER forget that experience! Almost like almost drowning as a child.. I still remember!
Hey Will, I didn't make that one. By the time I built a router table, I had a better understanding to know better. My memory that got burned into my brain was similar to this though. Back in the sixties, I bought a cheap RAS which had extra features, like a way to mount a router collet in the other end of the motor, then flip the motor, and crank it up, so it could be used as and over-arm router. I had a 1/2" straight bit in it, which I planed to rout a groove down the edge of a 2x6. I had the board up on edge against the fence, and started in from R to L. I got about 4" in before it pushed it out the back, and since I was holding on tight, and pressing it hard toward the fence, I provided enough pressure against the bit for it to get traction down the back of the board. I had a tight grip over the top of the board, with my right hand, and I don't remember about the left. I just remember it happened so fast that it spun me around, and my hands passed so close to that cutter sticking down with no guard around it. I remember just standing there holding both hands up looking at them for a long time. I just ::couldn't believe I didn't loose one..
YEP! I HEAR you loud and clear.. Like my old Craftsman RAS. Which I still working.. With that molding attachment. I 'tried' to use it once! Never again!
Left.
Routers try to go left. Scroll down to fences in the link below.
http://www.highlandwoodworking.com/index.asp?PageAction=Custom&ID=68
Life is what happens to you when you're making other plans .
"Life is not a success only journey." Dr. Phil
Rout from left to right.Opposite on a table mounted router. The cutter spins clockwise and the cutter should chop into the stock.
mike
If the straight edge is to the left of the router, you push the router away from you. If on the right, you pull the router towards you. Going around the outside of a work piece, you go counter clockwise. In the majority of cuts, you feed against the rotation of the bit. Feeding with the rotation makes the bit pull the router and this is climb cutting. The router is much more difficult to control in climbing. Sometimes it's necessary to prevent the grain from tearing out chunks and splintering. This happens on circular work where, part of the time, you are cutting with the grain and part of the time you are going against it. This is seldom an issue when cutting grooves, rabbets or dadoes in plywood.
Beat it to fit / Paint it to match
The simplest way to determine the router direction is to use the 'right hand rule". Hold the thumb and forefinger of your right hand at a right angle to each other and point the thumb at the straight edge. The forefinger will point in the direction of router movement. This of course also works when edge routing.
We have a story on this very subject at the link below. You are far from the first to ask this, which is one reason I wrote this story.
http://www.newwoodworker.com/rtrfeeddir.html
Tom Hintz
Because there is always more to learn!
I USE BOTH! Regular feed into it AND the opposite! I use both!
Never been hurt on my router table. But then again I ALWAYS make small cuts!
try it on a scrape piece
Something that no one has mentioned yet, and which will simplify your problem: When cutting a groove of dado with a router in one pass it literally does not matter which direction you go, because the router will behave in exactly the same way. This is because both sides of the bit are cutting at the same time. One side is cutting opposed to your effort and the other is 'climb' cutting. It's just like cutting a mortise with a router, I think most people know that you can go either way when doing that.
Directional considerations come into play when only one side of the bit is cutting. You want the side of the bit that is cutting to spin away from you so that it is not pulling you into the cut. It's the same reason the cutting edge of a circular saw spins away from you, and the cutting edge of a table saw spins toward you. I myself don't have all the left/right/inside/outside rules for this type of cutting memorized. I don't use a router enough. My habit is to physically look at the bit before a cut and figure out in a second which direction I need to go. This is what I am comfortable with.
Brian
My way to remember with a handheld router is PR-PL: If I push against something, I go right. If I pull against something, I go left. Or PR-PL push right - pull left.
Hope it can help !
Best,
Serge- Learn from yesterday, work today, and enjoy success tomorrow -
http://www.atelierdubricoleur.org
"When cutting a groove of dado with a router in one pass it literally does not matter which direction you go, because the router will behave in exactly the same way."
That's not my experience Brian. Cutting housings- dados in North American parlance, across bookcase ends, cabinet sides, etc using a router and T square or cramped straight edge illustrates the principle.
Fix a straight edge or T square as described above and, with your front facing the straight edge and the router hand held, place the base of the router that is away from the operator against the straight edge, and then:
Make a plunge cut left to right as in a normal cut.
Move the straight edge to a new location.
Make a plunge cut right to left-- a climb cut.
Here's what will happen in just about every case:
At 1 the operator will find the router is quite easily controlled to hold the base firmly against the straight edge.
In 3 the operator will find the router tends to drift away from the straight edge and the router will want to 'run away' to the left.
The larger the diameter of the cutter, the deeper the plunge and the greater the power of the router the greater will be the effect of the demonstration. The tendency of the router to drift away in this scenario when used in the manner described at 3 above is magnified and unmissable.
Slainte.
Richard Jones Furniture
Edited 7/27/2008 11:16 am by SgianDubh
You're talking dados, not rabbets, right? I guess I see how the tendency of the the router to hug a straight edge could be different depending on which direction you go when cutting a dado. Thanks for bringing that up. But it still seems incorrect to call it a climb cut, since there really isn't the tendency for the router to 'run away' like when cutting along the edge of a board, just (possibly) require more preasure against the guide, right? Not a safety issue but may be more accurate. Still, its interesting. Maybe I wouldn't have gotten as frustrated with the accuracy of my routered mortises if I had tried only going left to right. You know how they can sometimes get a little cockeyed? Brian
"But it still seems incorrect to call it a climb cut, since there really isn't the tendency for the router to 'run away'"
Brian, have you tried the set up using the router in the two different directions as I described in post 16?
If you haven't why not give it a go and establish for yourself if the left to right movement of the router is a climb cut and the router does want to 'run away'.
I don't recommend doing the following because of the safety implications, but if you were to hypothetically set up something like a 2000 or 2500 watt router and an 18 mm or 25 mm diameter cutter, plunge about 12 or 15 mm deep and do the experiment you'd really notice it-- in fact, and on second thoughts I strongly suggest you don't do the experiment with a hand held router that powerful and a cutter that big.
It doesn't matter if you're doing housings (dados) trenches, slits, grooves or rebates, the router will still want to run away on a climb cut. Slainte.Richard Jones Furniture
the router will still want to run away on a climb cut... You bet! Degree it will is hard to judge. Purpleheart is a wood I use very often that sometimes I must use my router by hand. I am never comfortable routing by hand. Even though I 'think' my routers talk to me by the sounds made while cutting..
I have had more (not accidents.. Just the router got a away a bit when I 'thought' everything was going well) on Purpleheart. Straight grain cuts usually great BUT watch ANY curved or end grain cuts! Jatoba like that but not as extreme.. I NEVER take heavy cuts on ANY wood. I have no problems making multiple passes. Even on the router table. I call it.. the wood shatters.. Or the grain separates and that bit DIGGS in! Period! However tight you hold that router...
However, I usually (as in always) make my last 'very light' pass on any 'stick' being worked using a climb cut. On a router table ONLY. In fact, for as much as I use my routers, hardly EVER cut by hand unless I have no other option.
I am tentatively willing to expand my understanding of the physical uninverse to include the perspective of another observer, yourself. And now that you challenge me I'm sure I'll perform an experiment similar to the one described. My hypothesis is that with a moderately large bit (cuttitg a dado whatever you call it) I may experience 'some' tendency to climb when going in one direction (I'll just try both), but less (much less?) than with the same bit making an endgrain rabbet one half the width of the previous dado while going unmistakedly the wrong way. On a serious note, I really am getting curious about how this will turn out, and I certainly mean no disrespect to you. Thanks for something that I haven't thought about before. When I first posted on this thread I was picturing someone doing small scale grooves in plywood, but this may be different . . .Brian, psyched the day is over
You will find my description of what occurs isn't far wrong. I've been using routers as part of my living as a furniture designer, maker, teacher and woodworking author for over thirty years. I've had plenty of time to work out what a climb cut is -- and what isn't. Slainte.Richard Jones Furniture
Well the largest dia. straight bit I have is 1/2. I set up a fence down the center of piece of hard maple and made 9/16 deep dados down either side, trying to be cautious and make a good cut. The cut felt and looked the same on either side of the fence. Then I rotated the setup and tried to make two grooves. On the right side things started out OK but then the router dove into my fence with enough force to move it even though it was pretty well clamped. On the left side the router kept trying to get away from the fence and I kept pushing it back so the result was a wavering cut. So I think the same thing happens when cutting dados, but with grooves, where the front of the bit is cuttig endgrain the forces are exponentially larger. So thanks for opening my eyes. I wasn't considering that the router might want to 'climb' perpendicular to the cut, and this definately explains some troubles that I've had in the past. I don't use large bits or make deep cuts really ever so that's the only defense I have. I know this isn't interesting to you, but maybe it is to someone. I know it is to me! Sorry if I seemed sarcastic or something in an earlier post, I can get a little loopy late at night and have too much fun with language. Have a good one.Brian
You're completely wrong. I do find the report of your practical experiments interesting. It's interesting to me because I've found out you've learned something useful about how a router works. This has an influence on you being a better and, perhaps more importantly, a considerably safer woodworker.
Not only have you learned something, hopefully other readers of the thread learnt the same as you've done, and they too will be better woodworkers for it.
It's not too often I get direct feedback like yours telling me my contribution to a thread was useful, educational, or in some other way helpful.
I also managed to correct some less than accurate advice you offered for all to read earlier in the thread, and I believe I managed to do it gently, ie, without name calling, rancour, slapping you down, and so on. Of course I could be all wet about that in this last paragraph, and perhaps you did actually feel insulted or put down in some way, but I hope not.
It's posts like yours that I'm responding to now that go a long way to making my contribution to woodworking forums worthwhile to me. Slainte.Richard Jones Furniture
I feel the same way about your last post. It's useful, 'professional' and positive exchanges like this that keep me coming back to knots. You could have just said, "Well, duh . . ." and been done with it. To tell you the truth I half expected it; there seems to be so much variability with people and their temperments that one is never sure what to expect after clicking Post. I did flinch a little while reading your first sentence--yes, you got me! Thanks for a great end to the evening, and I look forward to our next predicament.Brian
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