Question about using a roundover bit

[Dan Mitchell]

I'm making a coffee table in a sort of "mid century modern" style. Since I had several lengths of cedar fence post, I thought I'd cut a few sections out of them & mockup the leg-rail design I had in mind before committing to more costly wood. I'm happy with the result, but the last step, rounding over the edges on the legs on the router table, has me a bit nervous. Cedar is very soft, and I made the cuts in one pass using it, but I'm concerned that with a much harder wood (I'm considering hard maple, walnut or mahogany) the process might go a bit less smoothly, particularly when the small foot area has to be fed into the bit 1st. The fact that the leg is tapered beginning about 3" from the top (so there's a change of plane) is also a concern with this process. Here's a pic to make it a bit clearer. Is the router table the way to go here, or is there another option?

TIA

Dan

[Bill Huber]

I don't think it will be a problem at all.

Good sharp bit and go for it, but if you are still worried then just make 2 passes, it won't take that much more time.

[ROY DICK]

Dan,
From the way it looks to me, you might need a starter pin.
http://www.newwoodworker.com/usestrtpin.html
Check this out. I hope it helps.

Roy

[Gary McKown]

...and two passes on curved sections is easy by using a larger bearing for the first.

Some time ago I got a "universal" bearing replacement kit from MLCS or Grizzly or some such - you wouldn't believe the times it has come in handy for situations such as this.

[glenn bradley]

First off I think you will find hardwood easier to mill than softwood. Although that seems reversed, in practice I find hardwoods mill cleaner. That being said, it looks like a 1/4" radius roundover. I would do this in two passes as Bill recommends. Most of the cut on the first pass and a light finishing cut.

There is no need to start from the little end as none of your cuts appear stopped. As they are all full length cuts, always cut with the grain or 'downhill'. The one face of the leg appears to be concave. This will make two passes a challenge using the fence to establish depth of cut. I would use a larger bearing and a starting pin, make your first pass on each edge, change bearings and make the final passes.

[Dan Mitchell]

Thanks for the great suggestions, they all sound quite viable. My last experience with something like this was tapering a leg on the jointer. The technique goes in 2 passes, taking a pretty large cut with each. Worked perfectly when I tested it with pine, but when I went to do it with maple, the jointer ripped the bottom ~2" off the leg and shot it across the shop. Yikes!

[Dan Mitchell]

There is no need to start from the little end as none of your cuts appear stopped. As they are all full length cuts, always cut with the grain or 'downhill'. The one face of the leg appears to be concave. This will make two passes a challenge using the fence to establish depth of cut. I would use a larger bearing and a starting pin, make your first pass on each edge, change bearings and make the final passes.

Glen - Not sure I'm following you on avoiding feeding in the small end. The inside (mortise side) of the leg is slightly concave, the outside, slightly convex, so I'm making all cuts with the flat side of leg down. Only complication there is the sides are tapered, from the area of the mortise down (mortise area itself is not tapered). And the flat face of the mortise is not rounded, though the entire length of the outside curve is.

Definitely going to look into the pin & larger bearings.

[johnny means]

When i'm worried about splintering because of grain direction, I do a climb cut. This really comes into play on curved pieces where grain direction may change.

[Myk Rian]

I do it all the time. Go for it. There will be no difference.
You aren't taking a lot of wood off. If you were, there would be a slight difference.

[Karl Brogger]

Route it backwards first and get it close, then do a final pass.

[glenn bradley]

Glen - Not sure I'm following you on avoiding feeding in the small end.

Sorry about that Dan. I goofed up on the fact that all long edges are getting the treatment and of course, your convex edge can't be run convex face down. That will be small end first so a steady controlled approach is the ticket. The starting pin is you friend on this type of, er, well, start of a cut.

I've seen various bearing kits. Some priced OK, some priced high. You can get individual bearings for a good price from Brian Gumpper at Holbren (http://www.holbren.com/) (he is a member here at SMC) and he offers SMC members a 10% discount with the code SMC10. His shipping is also very reasonable.

[Dan Mitchell]

When i'm worried about splintering because of grain direction, I do a climb cut. This really comes into play on curved pieces where grain direction may change.

What's a climb cut?

[johnny means]

What's a climb cut?

A climb cut is routing in the wrong direction. The bit would be trying to climb out of the cut. The cutting edge is going into the uncut edge as opposed to exiting from the uncut edge. Climb cutting requires firm control of the work piece and a light cut. I wouldn't do more than an eighth inch deep cut if I doing it by hand. I would also recommend doing a piece of scrap first to see if you were comfortable with the bits grabbiness.

[David DeCristoforo]

"A climb cut is routing in the wrong direction..."

Climb cutting on a router table or shaper is extremely dangerous especially with smaller pieces. This should only be attempted using a power feeder, never when "hand feeding". Trust me... your hands are not that strong! The only time climb cutting "by hand" is even reasonably safe is when the stock is secured and the router is hand held. Then you have at least a chance of maintaining control.

[johnny means]

"A climb cut is routing in the wrong direction..."

Climb cutting on a router table or shaper is extremely dangerous especially with smaller pieces. This should only be attempted using a power feeder, never when "hand feeding". Trust me... your hands are not that strong! The only time climb cutting "by hand" is even reasonably safe is when the stock is secured and the router is hand held. Then you have at least a chance of maintaining control.

Not quite true. True, in many, if not most situations climb cutting is not a good idea. But, with smaller bits , lighter cuts, and an adequately large work piece it really isn't that big a deal. I don't know about you, but a 1/4" roundover bit doesn't have enough bite to snatch a 20" board out of my hands, it's just not grabbing enough material. Granted I wouldn't climb on a shaper or with a larger bit. I do this on a regular basis to route a 1/2" roundover around octagonal forms that have tendency to blow out at the corners if routed the conventional way.

Climb cutting just needs to be approached like any other task with a power tool, with caution, good judgment, and good information.

[David DeCristoforo]

"But, with smaller bits , lighter cuts, and an adequately large work piece it really isn't that big a deal."

I will agree and disagree. Climb cutting is never "safe". Even small bits can grab. I have done this myself but I'm never in my "comfort zone" when I do. And I never "recommend" doing it. If you do decide to attempt this, you should at least do so with the knowledge that it is an inherently dangerous operation.

[Dan Mitchell]

I've seen various bearing kits. Some priced OK, some priced high. You can get individual bearings for a good price from Brian Gumpper at Holbren (http://www.holbren.com/) (he is a member here at SMC) and he offers SMC members a 10% discount with the code SMC10. His shipping is also very reasonable.

Glenn - I ordered a set of 4 Whiteside bearings from Holbren. Using the code you provided, they were $12.75, w/shipping. The exact same bearings are $29.46 at Woodcraft, w/shipping. Quite a savings, thanks for the tip!

Dan