Staked Leg Sawbench

Looking to make some staked furniture...with legs that involve tapered tenons and tapered mortises.
My first attempt will be a sawbench...
The design is similar to the sawbench shown below but this prototype will be made from treated pine in the lumber pile.

The designs are based on the readings and plans from Chapter 4 of The Anarchist's Design Book by Christopher Schwarz.

Skill Building

Crash Test Dummy (CTD Mini)

Pair of Sawbenches

Production Lathe Sequence

Mortise/Tenon Insertion

Skill building for this project involved learning to drill pilot holes at a 15 angle. 
Having trying a number of different methods I settled on using a hand held power drill with a Wood Owl bit using a shop built an angle guide.

15 accuracy will be achieved by using this shop built guide.

Then a hand bored tapered hole will be made using the pilot hole as a guide. 

The taper tool will be the Veritas Pro Taper Reamer.
Pro Taper Reamer
Manual for the reamer.
 The reamer is set at 12.8 and is the complement of the
Veritas Tapered Tenon Cutters
Tapered Tenon Cutters
 Manual for the tenon cutters.
Design, Materials, and Milling
For this prototype, I will use the resultant angle of 15 and  dimensions  similar to those given by Schwarz in Ch. 4
My top slab will be 2.65 inches thick x 7 1/16 inches wide
by 19 3/16 inches long.

The legs will be 1.25 inch square instead of 1.75 but this is the size stock I have available.

Layout of the top slab

Due to pandemic lock down, I do not have access to many wood choices right now. The woods that I will look to in the future will include white oak, poplar, ash.
I had a 2 x 8 treated board that had dried in the rafters...jointed it and planed it and came up with slabs that were ~1 3/8 thick...glued up two pieces to make milled top blank of ~10/4 stock.
Legs will be approximately 1.25 x 1.25 stock...I made extras for CTDs.
Slab and leg milled stock shown.
Layout on Underside of Top

Drilling and Tapering of Mortises

After marking out the locations of the mortises, the sight lines were marked off (64).

The Starett protractor head on the 24 inch rule
was perfect for this task.

The resultant angle for all four legs will be 15 along the sightlines.
Jig is lined up and secured at bench...sacrificial board to help with spelching...hole aligned with open vise.

Alignment at the front of the jig...used a longer hold down...issue with surface mating...

Second hole...bit slightly screwed into layout hole...

Then the jig is lowered to surface and secured...

First two holes...alignment is decent...

Then there is a total failure of the jig...on hole three I believe that I tilted the bit, reamed one edge, and changed the jig angle.
I did not realize it at the time...I moved on to hole four...halfway through the slab I saw that the front hold down had slipped and the jig had moved.  I tried to recover and only made things worse...both in the work piece and in the angle of the jig.
A major problem with the bit in the jig concept is that you can not check yourself periodically and make adjustments.  You have to depend on the jig to guide you and if there is a small problem there is no way to set things right.

So, I will toss the jig and ...I will abandon the shop built angle guide idea, and I will bore the 15 pilot holes using the angle gauge to guide me.
Also, the slab is a loss...I cut off the two ends and will use the short slab as a CTD.

Crash Test Dummy Build
CTD Mini
Post pandemic shutdown...James came to visit...we worked on a CTD mini bench using the wasted slab from above...
Layout was reduced onto the CTD mini slab.
Drilling...we were able to use two angle gauges and two sets of eyes to bore the 15 holes...
first the holes drilled with owl bit in Festool driver...

The conical hole was shaped by the Veritas reamer in a hand brace.

We are newbies on the lathe...set it up to learn to create a slightly fat conical tenon to prep it to be shaped to match our conical mortise.
Used Woodpecker calipers to gauge while lathe is turning...
 Finished pre-conical leg...end will be trimmed off.
Roughed out pre-conical end...
The pre-conical end was then placed into the tenon cutter to shape a 1/2 inch tenon.
Finished CTD octagonal leg...shaped conical tenon is a perfect fit in the conical mortise.
Dry tight you had to pound on the leg to get it out...
Determined the layout of the legs according to grain...marked out kerfs, cut kerfs in legs with handsaw...image is dry fit.
Made a jig to cut 4 oak wedges on bandsaw.
Dry fit of wedges...
Glue up
Tenon ends and wedges flush cut...
Octagonal legs were marked...board = 1.25 inches...
Hand sawn with Bad Axe tenon saw...
Chamfered all eight sides...
Put a large chamfer on the slab top at 45 at router table
CTD Mini will be used on the screen porch
 as a foot rest to tie my boots...
Pair of Sawbenches Build

Materials:  yellow pine...sought out dry boards at orange BORG...grabbed two 2 x 8 x 10s and one 2 x 10 x 10.
The wood had been there awhile...pandemic pricing had dropped...

Wood was marginal but I was able to mill everything I needed.
Glued up the two top slabs...
Clamped both slabs at once...

Turned Leg Sequence

Conical Tenon

Ready to make eight legs for the pair of sawbenches...need to get a template and sequence going to simplify and speed up process.
Worked to create a template to guide the turning of the conical leg tenons.

CTD that we liked...converted to layout stick.
I had to learn some new skills to create all of these faces in Sketchup.
Layout Stick
A template and layout CTD was created...PDF.
Sequence for easiest lathe work...PDF
Main layout marked in pencil...Step 1 and Step 3 turning locations are marked in red.
Step 1 turned to ~1.25 inches...just enough to round the stock.
Step 3 turned the tip to 3/4 inch diameter.
Steps 2, 4, 5, and 6 create the stop lip and then tapered 1 1/16 to the 3/4 tip.
Step 7 is the v groove.
Step 8 puts the cove.

Sawed off the waste.

Used the 5/8 inch tapered tenon cutter.
See tenon cutter holder jig.

Routed the legs at 45 to form octagonal.

Made the time the production run was over the time it took to turn a bank into the tapered octagonal leg was around 15 minutes.

Leg Tenon Insertion
and Securing

We were trying to improve upon our conical mortise layout, drilling the conical mortise, in particular the angle of the tenon...15

Due to the strong grain pulls in the top blank...any early errors had dramatic subsequent on the show side...and the angles...
the image is after the dry fit of mortise and tenons.
One can see the dramatic grain variance in the yellow pine blanks.

We assessed our use of the bird cage awl (pictured  here) and decided its use caused increase drill bit wander right from the very start due to the square grind on the point.
 We opted to change to a standard awl and made the angled entry point during the layout.

The rest of the drilling cycle was done like in the sequence above, here.
We also tried to make a 3/8??? layout bar the standard for for the distance between the "stop" ring on the leg and the base of slab.
We made some more oak wedges...still not really happy with this process.

 Earlier picture...
Set and glued the conical tendons...pounded the wedges.
Most wedges of this batch set wedge broke (see clapped corner). Most of the elliptical holes were filled satisfactorily but one was bad off.
Then dry mortise/tenon/wedge extensions were cut off ...the mortise on the right is the one that was way off.
The sawdust, from pine and oak cutoffs, was mixed with yellow glue and sanded flush.
Here are the 8 wedged tenons...flushed and sanded...
Moved the bench to determine  the leg most wobbly...placed the shim under the image, right lower corner.
To achieve the  bench height desired I had to cut off approximately 3+ inches...made a stack with 1-2-3 blocks to create the three inches and then used the rule to enable easy marking on the slanted octagonal legs.

Marking the legs for cut off.
After cutting off the four legs...the bottoms were planed or sanded as needed.
During process of marking the legs of the second bench James had a good idea to elevate the bench by supporting it in a level position and then mark the four legs...this eliminated the need to shim under the legs.

Rounded over with edge cornering tool.
Finished pair.

Return to Shop Index