Saturday, December 19, 2009

Round 'n' Round

Here's a bit of an unsung hero in my shop, the tapered tenon rounder.

Usually, I try to make all of my tapers on the lathe, where they are done quickly and accurately. But on occasion, especially if the piece is already bent before shaping the tenon, I pull out my rounder. Elia Bizzarri sells a version of this tool, that while adjusted differently, cuts a beautiful tenon. You can see it on his sight

What I like about my rounder, besides being cheap (you do have an old frog laying around somewhere, don't you?), is that it's as adjustable as a handplane. The control that I have over the adjustments overcomes my usual hesitance to use and set up a jig. And the results are dead on. As with most of my jigs, I found a rare piece of water stained poplar laying around the shop for this one, I guess I'll have to find another use for all that exotic hardwood.

It's simple to make. First drill a hole in a block and ream it with the reamer that you are matching. Then, cut the top off the block close to the hole. I like to finish off with a handplane until I get a nice even slot along the top of the hole. Then cut a separate bed for the frog you are using and screw it to the block. Mount the frog and you're just about there.

I like to curve the blade a bit where the tenon enters, this help shear excess material down to the size that will fit in the hole. When making a tenon, I still find it helpful to rough shape it before using the rounder, this helps to ensure that the tenon is centered properly and saves wear and tear on the tool and my wrists! (quick tip: wear those rubber dipped gloves from the hardware store, they'll save your joints)

As you can see in the image, once the tenon exits the rounder, it becomes a straight tenon that equals the size at the end of the tapered hole, with this in mind, you can easily modify this design to make straight tenons as well.


Christopher said...

Gee, I was just saying that I needed to build/buy one of these. Thanks for idea!

Unknown said...

Ashem Crafts sells rounding planes. I have a 5/8's and 3/8's which I have used to make spindles by mounting the spindle blank in the three jaw chuck in my metal lathe. I've also used a home made version like yours to match the taper on reamer for perfect chair leg mortise and tenons. There's lots of tricks around out there. Thanks for post. Bob Glenn

Anonymous said...

You never cease to amaze me with all those wonderful ideas and jigs brilliant every one of them , much appreciated , please keep em coming ,it all helps , thanks .Michael in Melbourne .

Peter Galbert said...

Thanks Folks! Now you just have to find the elusive water stained poplar!

Michael, how's the perch coming? Sorry I haven't had a chance to get back to you on the seat. Basically it's 5/8" deep carving and mimics a tractor seat. Things are pretty swamped around here, family arriving, work to do and now a head cold to boot! Hopefully I'll have a bit of time after Xmas,
Happy Holidays all!

Anonymous said...

Hi Peter , the perch has taken a back seat for the moment and Im getting on with the rocker , making and learning as I go ,happy Christmas everyone .MiM .

Jack said...

Brilliant! I've seen a fair number of rounders - wooden and metal - that use a blade similar to a spokeshave, but as you say, who doesn't have an old frog lying around for turning those odd sizes.

Peter Galbert said...

thanks! Let me know how yours turns out
Happy Holidays,