Router Kickback - Why??

[wouldwurker]

Usually I can figure out what I did wrong when I make a mistake, but this one has me baffled.

Trying to flush trim a piece of 8/4 soft maple, but whenever I try this one area, my wood becomes weaponized. It doesn't seem to be a particularly tight turn, just a curve.

Moving from right to left on the table, as always.

What am I missing here? Happened three times now...which is enough for me to stop doing it (you'd think one would have been enough)

Thanks. Never had this happen before

VJ

[Tpt life]

Looks like the grain is tearing out rather than shear cutting.

[..Kev]

Are you trying to push that between the fence and the bit?

[wouldwurker]

Not at all. The fence is only in the back for dust collection. I'm in front of the bit.

[Boatworks Today]

I'd guess dull bit trying to work end grain.. Been there :-)

[Cmac2008]

It looks like since u are on the end grain with such a thick piece of wood it may be trying to take too big of a bite... Is ur router variable speed?

[wouldwurker]

It does feel 'choppy'. Is that the sign of a dull bit?

[wouldwurker]

It looks like since u are on the end grain with such a thick piece of wood it may be trying to take too big of a bite... Is ur router variable speed?

It is, I have it on the highest speed

[wouldwurker]

Well...number two got cleaned up on the oscillating spindle sander. Think I'd like to keep my fingers tonight.

By the way. 5 helpful responses in like, 60 seconds?!? You guys rock. Where else can you get immediate shop help like that?

Thanks !

[T-astragal]

Routing uphill on a small workpiece like that is not safe. Don't do it. Try making your patterns smaller by a 1/16" and using a 5/8 bushing with a 1/2" bit. That way you can take shallow bites and be much safer.

[wdwerker]

If you have the template on both sides that cut may work much better going in the opposite direction . Cleaning any built up resin on the bit doesn't hurt.

Climb cutting also comes to mind , it takes nerves of steel, can be dangerous and I won't try it on a part that small.

I have template routed half of a small part before cutting it off of a much longer blank. This works best when the rest of the part can just be sawn and sanded.

[Eric.]

T hit the nail on the head...you're routing uphill, against the grain.  You always wanna route downhill with the grain.  Buy a big ass pattern bit with a bearing on both ends so you can flip your workpiece over when necessary and route with the template on the top OR the bottom, depending on grain direction.  If you can find a bit with the blades at a shear angle, even better.

 

That's a lesson I think everyone has to learn on their own early on.  I sure as hell remember the day I learned it.  Poop came out of me and I just kind of stood there for a minute, reflecting on my life and thinking about how much better it is to have fingers than to not.  The router table is probably the tool that scares me the most because it's the most unpredictable...especially if you don't pay very close attention to grain direction.  Always downhill.  Always.

[wtnhighlander]

It is also advisable to use a handscrew clamp or shop-made jig to hold small parts for routing. Keep those fingers away from the bit!

[wouldwurker]

Pretty , but Wow. I'd hate to see what the 2" version would cost.

[Eric.]

That one is full spiral and solid carbide it appears, which is cool but overkill IMO.  I got a 2" shear cut with carbide blades from Rockler for about a hundo beans.

[wouldwurker]

Feeling a bit dumb here, but what did I miss on the grain direction?

 

The 'feather' analogy clicks for me regarding 'uphill' and 'downhill' for me, but I can't really see it on this piece.

 

Thanks so much.  Trying to learn from this mistake....

[wdwerker]

Think about where the cutting edge hits the grain. Is it going to grab and tear like happened to you or shave and press the grain down as it cuts.

William Ng sells a huge spiral pattern bit with an upper and lower bearing for work like this. It's quite expensive but when a job comes up that will buy me one it's definitely on my wish list.

Careful planning is always a good idea. I have several bigger bearings that I use to take thick cuts in small stages then install the original bearing to make the final cut.

I have also set up a bearing on top bit in one router table and a bearing on the bottom bit in another table (older crude one) and planned & labeled the jig/ pattern where to stop and finish it with the other bit.

[Jfitz]

I think Steve has an excellent idea of marking the template to indicate "danger zones".

 

Short of investing in more bits, you could just cut the blank closer to the line, avoid routing in the "danger zones", and use the spindle sander for those sections.

[CessnaPilotBarry]

Spiral bits absolutely rock in these situations...   Far better results and less grab as the grain changes.   You can save a bit of money over the Ng version by using a standard guide bushing in your table and a 1/2" spiral bit, with the pattern on the bottom.  The William Ng version is a fantastic tool, though and worth the cash if you do a lot of this.

 

Your table will accept guide bushings in the gray insert.

[Tpt life]

To the OP's question: feed direction is only one of two factors. Direction of bit rotation also matters. This is why the spiral cutting suggestions will help. They allow a certain amount of disregard for rotation by transferring force to a diagonal action.

[wouldwurker]

So for my own reference, I drew this up.  Do I have it right?

 

 

[wdwerker]

I think you have got it !

[CessnaPilotBarry]

Vinny...

 

Many years ago, I drew a few diagonal lines on the top of my first router table's fence to remind me of proper grain direction.  They helped!  More than once, I'd have a long layoff not using the table, and the lines would make me notice I was about to get it wrong before I started to cut...   

[Byrdie]

I think the simplest suggestion was already made.  Rather than a bit with two bearings, pry the template off and adhere it to the other side of the work piece when routing this section.  It reverses the orientation of the bit to the grain making it a safer cut.  If enough of the piece has already been pattern routed you should be able to orient it correctly.

[Eric.]

That's probably the cheapest solution, but I don't think the simplest.  It's almost impossible to get the template back on exactly in the same place it was on the other side.  It's a lot simpler to have a top-and-bottom bearing bit, but you're gonna be a hundred bucks or so poorer.  I almost always choose to be poorer if it means less work.