Thread: Rounding edges on round corners with Triton Router Table

Use a rounding cutter with a bearing such as a Carbitool T 504B.

CARB-I-TOOL - Router Bit and Accessories Catalogue - NOVEMBER 2015

Thanks Bohdan,

I'm using the equivalent bit in a different brand, but I'm "hiding" the bearing behind the router table fence and only allowing a small section of the cutters to contact the timber.
Presumably this means that I'm misusing the bit.

Not misusing it, just not using it to your best advantage. When used with a fence the bearing should be just proud of the the fence so that the board runs on the bearing but this makes it difficult for curved work.

When doing non linear routing you don't use a fence, you just have the bearing guiding your work.

This may be a bit unnerving for anyone not used to working this way but with a starter pin on your bed it should be quite safe.

This example explains it well.

Back to Basics - Starter Pin on the Router Table / Rockler How-to

The biggest issue will be tear out when you go against the grain on the corners so it may pay to not have the cutter at full height for the first cut and then finish with a shallow final trim.

Thanks Bohdan,

Now it starts to make sense. When I bought the router 15 or so years ago, I decided that it was too big and heavy for me to manage so it has always lived in the table. The tradeoff is that a router table has the potential to put your fingers in harms way. Since I'm rather fond of my fingers, I've always taken steps to minimise their exposure and ignored how the bits are supposed to work. I've attempted to control the profile by using the fence and the height of the cutter instead of selecting the correct bit and letting it control the profile.

I'll need to consider how to fit a starter pin to my table.

Grateful for your valuable advice.

If the rounded corners of your workpieces are convex curves, you can setup the router table to be very safe using the bearing guide and fence. Set the fence a bees willy behind the level of the bearing guide on the router bit. Then feed the workpiece in using the straight edge and the fence to help you control the start of the cut. Then when you get to the convex curves, just move the workpiece off the fence and follow the curve around until your back onto the fence cutting the next straight section. I did this exact sort of thing a lot using much bigger cutterblocks on a spindle moulder because A. I can't be bothered removing the fence assembly because it is damn heavy just to replace it with a bonnet guard, and B. I have above table dust extraction hooked up to the fence assembly already.

Hi,
Make your self a corner template out of ply or MDF, about 150mm square with the radius corner and stick it on each corner in turn with double sided tape and run the bearing on that. Sanding one template accurately is a lot easier than four corners.
Hope that is understandable.
Regards

Originally Posted by A Duke

Hi,
Make your self a corner template out of ply or MDF, about 150mm square with the radius corner and stick it on each corner in turn with double sided tape and run the bearing on that. Sanding one template accurately is a lot easier than four corners.
Hope that is understandable.
Regards

You can see templates being used here...OneTime Tool - CRQJ Making your own is way cheaper than buying them of course.

There is also a way of making corner routing jigs for yourself: How to Make Corner Radius Templates - YouTube

They aren't as sexy, but will pull out out of a pinch.

On the roundovers, the only way to go is a roundover bearing bit. Don't use a fence and unless it's a bigger cut, the starting pin is unnecessary.

I make 4 to 5 coat racks a week of pine and all edges need the roundover, even the tops. The bearing bit does it easily and quickly.

Also, I do it in reverse, so it's a climb cut. It gives a supreme finish... No tear out or grain ripping. BUT you only want a shallow cut otherwise it will yank it out of your hand. I free hand the 8mm, 1/4" and 1/2" radius bits without any strife or white knuckle adventures. Same for chamfers.

For end grain, I do the long grained sides first, the slowly do the ends. It doesn't seem to matter the side, but again, these are done as climb cut jobs.

....A bit more.... I also do 3/4" roundovers on tabletops, but such is the size of the cut that it tends to do the job itself in 2 or 3 goes anyway. One just lets the bit do the cut (letting it cut what it wants) and going over it until the sound is even. They are done on a router table with the table upside down. The tabletops use the above roundover jig too, so not only the edges are rounded over, but the "corners" are too.

Again, no starter pin, but then again the tops are 900x600 and 18mm thick, so there's a ton of mass there to resist any rail-gun replications.

Let me dig up some pictures and post them...

Thanks everyone for the excellent suggestions.

As described, I set the bearing just proud of the fence and was able to use the edge of the fence as a rough and ready starter pin. After a bit of practice, I stopped getting kickbacks.

I am getting some burning on the corners occasionally - I expect that means I'm feeding the piece too slowly? The surface finish is a bit ordinary at times as well but I expect that is just the end grain. It sanded out easily. A bit more practice and I'll risk the real pieces.

Thanks also for the links to the templates. The Woodpecker ones look very nice but are a bit expensive for occasional use. Probably shouldn't be too hard to make something similar out of MDF.

When routing corners there is a chance of tearing out quite large splinters when going from end grain to long grain depending on the timber. To prevent this it is often easier to "climb cut" the corners first and then proceed to do all of the rest in the normal way. On a router table the normal cut is R to L, climb cutting is done L to R. This can take a little getting used to if you are not familiar, just remember, take a number of small cuts as opposed to 1 or 2 big(deep) cuts.

This is safer, easier on the cutter and gives a superior finish. Avoid el-cheapo bits, most are not as sharp as they should be, if they are, they don't hold the edge for very long and are false economy IMHO.

When routing corners there is a chance of tearing out quite large splinters when going from end grain to long grain depending on the timber. To prevent this it is often easier to "climb cut" the corners first and then proceed to do all of the rest in the normal way. On a router table the normal cut is R to L, climb cutting is done L to R. This can take a little getting used to if you are not familiar, just remember, take a number of small cuts as opposed to 1 or 2 big(deep) cuts.<br><br>This is safer, easier on the cutter and gives a superior finish. Avoid el-cheapo bits, most are not as sharp as they should be, if they are, they don't hold the edge for very long and are false economy IMHO.

Hello Bob,

Unfortunately it is a cheap bit. I've noticed some discussion here on the various better quality brands so I'll do some more research.
I'll also need to investigate climb cutting. I've always understood that it is potentially dangerous on a table but you're the second to suggest it here. Most of the pieces in the current project are somewhat small so I don't have the confidence to attempt it at this stage.

Thanks,
Paul.

G'day Paul, I gather you are quite new to routing, my remarks re R to L etc I put in to help you out as it can be a little confusing to people starting out and was not meant to tell you something you already know.

Climb cutting refers to how the timber bit interacts with the cutter, whether you go with the direction of the cutter's rotation or against it. Any work on a router table can be dangerous if approached with overconfidence or a lack of knowledge so it is great to see that you have a healthy respect for the tool and that you are increasing your knowledge.

Climb cutting is easily done and safe if you take small cuts and lots of them to get you to the required depth. When working with small bits of timber, consider using jigs to hold small bits or push blocks/pads which are like a trowel with rubber gripping material to grip the timber. Often you can use bigger bits of timber which are later cut to the correct sizes. When doing small bits of timber, double sided tape can often be used to stick a handle onto the small bit your need to rout, just make sure you use a quality double sided tape and not the stuff from the $2 store.

When working on a router table the only real No No I can think of to tell you is to Never try to run timber between the cutter and your fence, if this is done, the way the cutter works it will pull your timber out of your hands or possibly pull your hand into the cutter and will launch the piece of timber like a missile. Definitely not a good idea.

While on safe procedure, I would also strongly suggest that you use earmuffs/plugs and a good face shield like the Armadillo brand.

Hope this helps you out, enjoy the routing, it is a magic tool.

Not exactly new to routing, Bob, as I've had it about 15 years but have only used it occasionally for simple tasks. Now that I have more time on my hands, I'm starting to explore the capabilities.
My career and a couple of recreational activities have made me extremely risk averse (which is cause for amusement with my family - "Mr Measure 10 times and cut once"). Not having any time pressure allows me to think through everything I'm about to do with a power tool and consider what might go wrong.

I like your idea of using jigs to hold the workpiece while routing. I use pushers all the time on the table saw but have never thought about it for the router. I had a couple of spectacular kickbacks on the router years ago, so the possibility is always on my mind.