Dining Table Legs

January 7, 2012 in Dining table, Furniture, Jigs & fixtures | No comments

I’ve already discussed laying out the mortises on the legs, but I forgot to discuss the creation of the legs.  So, let’s go back in time a bit and see how that was done.

I started with my SketchUp model.  I drew the legs in the model using the BezierSpline plugin.  If you use SketchUp you need this plugin.  It’s awesome.

I printed out the leg profile at full scale, which spanned three pages.  I carefully taped the pages together and, to my surprise, had a very nice drawing of the leg.  I would normally do this by creating a full scale drawing using ship’s curves, etc, but I was very pleased with this method.  Here’s a (blurry) photo of the drawing.

I took this drawing, laid it on a piece of 1/4″ Baltic birch plywood, and transferred the lines to the plywood by poking holes through the lines on the drawing.  I then connected the dots with the aforementioned ship’s curves.  The template, or pattern, was then cut out and the curves smoothed with a spokeshave and curved sanding blocks.  (In retrospect, I should have just glued the drawing to the plywood.)

Next, I created a pattern routing jig.  I use a large custom end mill for this type of pattern routing and the jig must be very sturdy to take advantage of the process.  This is not the place for double-stick tape.

Here’s a photo of the setup:

There are two jigs necessary for the process, and both faces of each jig are used to get all four edges of each leg.  It’s a rather complicated process which, in retrospect, was overly complicated for just four legs.  But it gave me four virtually identical legs.

I start the pattern routing process by using the 1/4″ template to trace the profile onto the stock.  In this case the material was 12/4 cherry, since the total width of the flared legs is 2 3/4″.  When tracing, I’m careful to draw the pattern about 1/16″ oversize on the edges and 1/8″ oversize on the ends.  Two opposite faces are then rough cut on the bandsaw.

The two bandsawn faces are shaped first, with the other faces left flat.  The template is then used again to draw the profile on one of the shaped faces, and the bandsawing and pattern routing is repeated.  This time, however, the leg requires extra support, as shown in the photo above.

Finally, the legs must be cut to length.  Since I know they are 1/8″ oversize on each end, I start by cutting 1/8″ off one end.  It was easy to start at the top end, since it has two adjacent flat surfaces where the aprons attach.  The photo below shows the setup for cutting the bottom end.

Note the spacers taped in place to get the correct configuration.  The tape on the end of the leg is there to prevent tearout on the backside of the cut.

Mortise Layout

December 24, 2011 in Dining table, Furniture, Joinery | No comments

I typically use loose tenons for mortise and tenon joinery.  I find them to be much faster than a traditional M & T, plus it’s much easier to get accurate shoulders.  I use my Inca slot mortiser to cut the mortises.  It’s fast and simple to set up and it cuts a mortise in about a minute.

To lay out the mortise on the leg, I start by drawing the profile of the apron.  In this case, the outer face of the apron is angled.  I could get the angle from my drawing, but I prefer to get it by eyeballing what looks good as I draw it on the leg.  This angle will become the actual angle on the apron.

Once the apron profile is drawn, I draw the mortise.  I typically leave 1/2″ of material at the top of the leg, but in this case I cut it to 3/8″.  Because of the stresses on the legs and aprons as the table is expanded, I wanted all the glue surface I could get.  Smaller than 3/8″ could result in failure of the short grain at the top of the leg, so I rarely go less than that.

The photo below shows the layout.  Note that I only draw the complete layout in one location.

The other locations are only marked for the length of the mortise.  Why?  That’s all I need.  When I use my slot mortiser to cut the mortises, the height of the mortise above the table is fixed by the machine.  Once set, it’s the same for all of the cuts, so why waste my time marking more than I need to?

To maintain accuracy, I mark the mortise lengths using a combination square.  I use it like a depth gauge, with the head resting against the top of the leg.  The END of the blade is set to mark the lengths.  Once set for a given distance, I mark all the legs AND all the apron ends.  That way, every mortise is in exactly the same spot relative to the top of the legs.  Here’s an example of the apron end layout (this isn’t an actual apron).

Note that when marking the apron ends, the head of the combo square is only used to reference from the TOP edge of the apron.

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DT Inner Apron continued

December 23, 2011 in Dining table, Furniture | No comments

I’m back at work on the dining table.  I didn’t get much work done during the fall semester, and even less blogging.  It’s time to get caught up on the blog and back to work on the table.

The outer apron assembly, which includes the legs, is guided along the inner apron assembly by maple guides.  The guides, about 5/8″ square, are attached to the inner face of the outer aprons.  Grooves routed along the outside of the inner aprons locate the guides.  If that’s clear as mud, perhaps these drawings will clear things up.

I was concerned that the outer apron assemblies might bind when being pulled out, so I added center guides to minimize this.  The center guides also act as stops to prevent the outer aprons from getting pulled off the table.  The stop feature will be accomplished by attaching a brass plate on the inner end of the guide.  If you click the upper picture you can just make out the stop in the enlarged pic.

Due to the relatively small size of the closed table and the width of the leaf, which has to store between the center stretchers, there wasn’t much room for everything to fit.  Some careful planning was required.  The end of the center guide, when the table is closed, barely clears the center stretchers.  When open, the stop actually moves past the inner face of the inner apron.  To make this work, I needed to rout a mortise into the inner apron surface.  A detail is shown below.

The depth of the mortise was determined using my SketchUp model.  When the table is closed, there is 1/4″ clearance between the stop and the outside face of the center stretchers.  When the table is open, there is 1/4″ clearance between the edges of the leaf and two halves of the top (not shown in the pics above).  Because of the tight clearances, I was very careful about getting the model right.

Cutting the mortise was straightforward, but I wanted to make sure both portions of the mortise were concentric.  I carefully laid out the cuts and then clamped the apron into my slot mortiser.  I used a 3/8″ bit to rout the through portion, then changed to a 3/4″ bit to rout the shallow part.  I set the stops on the mortiser to maintain a consistent length.  Here’s the setup for the second cut.

The remainder of the material was removed using a sled on the table saw.

I started out this process thinking I would use a hand-held router and guide bushings to cut the mortise.  After starting down that path, it quickly became apparent that it was far more complicated than necessary.  The slot mortiser was by far the better solution.

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Cutting Large Holes

December 15, 2011 in Jigs & fixtures, Tips & Tricks | No comments

Did you ever need to drill a large hole for which you didn’t have a drill bit?  Up to an inch, a twist, brad-point, or Forstner bit will work.  One to two inches?  Forstner bit.  Two to four inches?  Forstner bit also, but these are uncommon and expensive.  Four to eight inches?  Somewhere in there you can use a router and circle jig.  Hole saws can work in some cases, but they don’t leave a very clean hole.

I recently ran into this problem.  I’m updating my Inca slot mortiser fixture and needed to cut an accurate hole to hold my Porter-Cable 690 router motor.  The hole required is 3 1/2″.  I could buy a $30 Forstner bit, which I would use once and probably never use again.  (Okay, if I had purchased it eight years ago this would be use #2, but you get my point.)

Starting with the end in mind:  My goal is to create a pattern to use with a router and pattern bit.  I want a pattern, or template, with an accurate 3 1/2″ hole in it.

To create the hole, I need to start with something I know is round.  I can create that with my disc sander by rotating some material (I’ll use 1/2″ plywood) on a pivot.  The pivot, a 1/4″ dowel, will be located in another piece which I can manipulate on the table of my disc sander.  I want the outside diameter (OD) of the pattern to be large enough for the router to ride on easily.  Three inches of material provides plenty of support, so I’ll make the OD about 9″.

I start by drawing a circle with a compass and rough cutting on the bandsaw.  I then drill a 1/4″ hole in the center.  Another piece is drilled to accept a 1/4″ dowel, with the dowel located so that the pattern will be supported well on the disc sander.

Here’s the setup on the disc sander.

The actual size of the outside diameter isn’t important; what matters is that it’s round.  It’s easy to get a flat spot when doing this, so be consistent with your pressure and movement.

Once I have a good outside reference I can start on the inside diameter.  I draw a circle of the desired size and remove most of the material by drilling a few holes on my drill press.  I then use my saber saw to finish the task.

Next, I make a special fence for my router table, shown below.  The outside diameter of the pattern will ride on the two edges of the fence.  A straight bit routs the inside diameter as the pattern is rotated.  By moving the fence back, I increase the diameter of the hole.

Here’s the setup in use.

It’s important to rotate the pattern in a clockwise direction.  The edge being cut should move to the left, against the rotation of the bit.  Moving the other direction would create a climb cut, which could cause you to lose control of the pattern!

Note too that when you move the pattern away from the fence, you move it away from the bit.  This makes it easy to stop and start the cut.

Prior to having a real fence for my router table, I did this process by using two pieces for the fence.  The pieces were about 3″ wide and clamped on the back side of the router table in a position such that the END of each piece was used to guide the pattern.  Quick and easy.

Also note that moving the fence back makes the hole larger by twice the amount of fence movement.  If you move the fence 1/32″, your hole will increase by 1/16″.  It’s easy to overdo it, which I did when I was shooting this demo.  The nice thing about this technique is that it gives you a very fast way to cut a very accurate hole.  I did the second pattern in under ten minutes.

If you have a spindle sander, you could do this operation also, but I don’t think you can get the same accuracy.  But you may not need it, either.

In the next post, I’ll demonstrate how I used the pattern.

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Plane Tune-up 12 – The Last Step

November 23, 2011 in Hand tools | No comments

I’m finally finishing up this series of posts on plane tune-up.  If you want to see them all, click the “plane tune-up” tag at the bottom of this post.

Assembly of the plane is pretty straightforward, so I’ll skip the simple stuff.  There’s one area, however, that often gets overlooked – the frog installation.

The frog location is important for the plane to work its best.  There are two things to keep in mind; 1) the size and 2) the shape of the mouth.  Everyone addresses the first issue; I’ve never seen or heard anyone address the second issue.  In the first photo below, I’ve temporarily mounted the frog without installing the frog attach screws.  The frog is located front-to-rear using the frog adjustment screw, so that the blade bed (the surface on which the blade sits) is just in front of the rear of the opening in the plane body.  The frog adjusting screw is shown in the second photo below; the bed location is shown in the third photo below.

Sighting down the bed (first photo), you can see that the bed is not parallel to the front edge of the opening in the body.  This will create a mouth (when the blade is installed) that is larger on one side than the other.  In this case the left side is larger than the right.  This opening can be adjusted in different ways, depending on the type of plane.  On this plane, a Type 11, the frog “yaw angle” is set by features built into the plane.  The front of the frog is located side-to-side by the machined tab (tongue and groove?) shown in the third photo.  The rear of the frog is located side-to-side and fore-and-aft by the frog adjusting screw and the clip into which it mounts (second photo).  The front location is fixed, so any yaw adjustment must be made in the rear.  This is done by removing the frog, loosening the frog-adjusting-nut clip and repositioning it to the appropriate side.  In this case, I moved the clip to the right, which moved the rear of the frog to the left, fixing the problem (fourth photo).

If you have a plane that does not have the machined tongue and groove, you can just position the frog manually.  It’s not hard to do, but it’s easier and more repeatable with the features described above.  That’s why I like the Type 11 and Type 12 planes.  I think some later planes also had the feature, but I’m not sure when Stanley quit including it.  I’ve never seen the feature listed on any of the Stanley Type-study pages.

As to the size of the mouth, that’s up to you.  Of course, the smaller the shaving you plan to make, the smaller the mouth.

Here’s one of the first shavings to come off the completed plane.  Note that I have sharpened the blade with a slight crown or curve to the edge so the shaving is thicker in the middle and feathers out on the edges.  Sharpening in this way will allow multiple passes across the face of a board without leaving plane tracks.

Here’s a detail shot of the shaving.

And here are the money shots.

I believe this plane is about as tweaked as you can get on old Stanley.  It won’t out-perform a $325 Lie-Nielsen, but at $25.50 for the plane and $38 for the Hock blade, it’s a great deal.

 

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Plane Tune-up 11

November 18, 2011 in Hand tools | No comments

Almost there!  This will be the last step prior to assembling the plane.

The japanning on this plane is chipped and missing in places, which is very common on these old tools.  You could strip/sandblast it off and start over, but I think that’s too much work.  Overkill, too, unless you want to make your plane look like new.  If you’re interested, check out this link.

My goal is to get the tool working and fight off future rust.  Shellac works great for this.  I use Zinsser Bulls-Eye Shellac and just brush it on the japanned surfaces.

I use an artist’s brush; the one shown is on the small side but it’s what I have handy.  After the shellac is dry, I clean up any areas where I don’t want shellac, like the frog interface, with denatured alcohol.

Here’s the completed plane body.

Note that I also brush shellac on the japanned areas of the frog.

Next – assembly!  Finally…

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Plane Tune-up 10

November 17, 2011 in Hand tools | No comments

The tote (or handle) on my eBay plane, like on many planes, was broken.  The most common issue, which this plane had, is a broken ear at the top.  Another common break is a crack right across the middle of the tote.

Here’s how I fixed it:

Using my disc sander, I sanded the break smooth, removing as little material as possible.  I then found a piece of rosewood (I think) in which the grain pattern roughly matched the pattern in the handle.  I also tried to match the color, but I have found that this is difficult (as you will see below).  The rosewood can look very different when recently machined vs. when it is finished.

I sanded the interface where the new piece would attach to the existing handle, then cut the piece roughly to size on my bandsaw.  Using epoxy, I attached the new piece.  Note that the top of the new piece was cut so I could easily apply clamping pressure.

When the epoxy was dry, I cut the piece to shape on the bandsaw.

Then I shaped it with rasps, files, and sandpaper.

As you can see, I really missed on the color.  Form follows function, right?

The hole for the attach screw was cleaned up with a Dremel tool, and then I applied a shellac finish.  The shellac is just wiped on, allowed to dry, and smoothed with 0000 steel wool.  Here’s the completed tote.  In another hundred years the color will all blend together…

If the tote is cracked in the middle (and someone hasn’t already botched the repair), I carefully clean the mating surfaces, attempting to remove loose fibers which would prevent a tight fit between the parts.  Since the mating surfaces are not fresh, I clean them with acetone prior to glue-up.  A caul, shaped to fit the top of the handle, is used to get the clamping pressure aligned correctly.

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Plane Tune-up 9

October 24, 2011 in Hand tools | No comments

Back to the plane tune-up; the frog is next.  It’s a very important part of the plane; it supports the blade and blade support is crucial to a properly performing plane.  The blade must be held rock-solid in order to minimize or eliminate chatter.  Here’s the frog at the start of this process.

I use 150 grit wet-dry sandpaper on a granite surface plate to flatten the blade bed.  The lateral-adjusting lever washer sticks out above the surface, so you can’t flatten the whole surface at once.  I hold the frog off the sandpaper as shown and slide it back and forth parallel to the plate edge.  On some frogs (like this one), the Y-adjusting lever folds flat so it doesn’t project past the bed.  You can see it in the photo below in the retracted position.  This is not always the case, however.  If yours sticks out past the bed, you’ll have to make sure you miss it when sanding.

Once the bed is flat up the the lateral-adjusting lever washer (I forgot to take a photo), I turn the frog to get the side areas.

Here’s the completed bed – smooth and flat.  I’m most concerned about the area near the mouth of the plane, so I’m not worried about missing the very top.

You may think that this process would be easier if you just knocked out the pins that hold the lateral-adjusting lever and Y-adjusting lever.  I don’t recommend it.  The cast iron used in these old tools is extremely brittle and it’s really easy to crack or break the casting when removing the pins, especially around the lateral-adjusting lever.

I apply paste wax to the surface to complete the process.

In case you forgot (it was a while ago) or missed it, the frog/sole interface was addressed here.

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Kickback

October 14, 2011 in Machinery, Safety | No comments

Ouch!  I had a kickback on the tablesaw last weekend.  Not the horrific lumber-over-the-blade type; I’ve never had one of those.  This was one of those sneaky offcuts that somehow gets caught against the blade and is thrown back with tremendous force.  It wasn’t very big either.  Maybe a couple of ounces at the most.

You can see where the blade caught it.  I was cutting narrow pieces about 3/32″ thick and this was the last cut.  The offcut was less than 1/16″.  I’m still not exactly sure what happened, but the most likely scenario was this:  my pushstick had been cut through a couple of times and there was a gap near where the offcut was located.  The offcut must have moved over just enough to reach the gap, then got trapped against the blade and pushstick.

I always tell me students to watch out for small offcuts and I didn’t heed my own advice.  Here’s where I was hit:

It really stung.  When I looked at the skin immediately afterwards, there was hardly a mark.  That evening, there was some swelling, but I knew a bruise was on the way.  Four days later it looked like this:

Lesson?  Watch out for small offcuts!  What should I have done?  Moved the fence to the right about 3/32″, made a cut that resulted in no offcut, then moved the fence back into position to make the final cut with no offcut.  No offcut – no kickback.  Next time…

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DT Inner Apron Assembly

October 10, 2011 in Dining table, Furniture | No comments

I started construction on the dining table with the inner apron assembly.  It is a rectangular structure with intermediate stretchers.  The end aprons are joined with a rabbet and dado joint.  Sliding dovetails hold the stretchers in place.  A detail from my SketchUp drawing is shown.

I cut the rabbet and dado joints first.  Both were cut using my table saw sled and the Forrest Woodworker 2 #1 grind blade.  It’s a modified WW2 blade that cuts a flat-topped kerf, even across the grain — an awesome blade for joinery.  I then laid out the sliding dovetails, carefully marking the location of the stretchers on both of the long aprons.

To rout the stopped dovetail dadoes, I have the router jig shown below.  It rests against the part to be routed and guides the router base square to the reference.  A replaceable insert is used to located the jig.  Before use, I install a new insert and then rout into it with the appropriate bit.  Note the stop to control the length of cut.

Here’s a close-up photo of the jig centered on my marks. The marks were made with a marking knife.  I used an offcut from the stretcher to get the spacing correct between the marks.

Here’s the router with dovetail bit ready to go.  I’ve already made the cut.  A nice thing about this system is that the cut is totally backed up and there is no tearout on the edge of the part.  I used a 3/4″ 14 degree router bit; the stretchers are about 13/16″ thick.

Here I’m routing the tail on the end of the stretcher.  I use the same router bit as before.  The backer board keeps the part from tipping and reduces tearout on the back of the cut.  The length of the stretchers was determined by dry assembling the aprons and measuring the distance between the bottom of the dovetail dadoes.

The fit of the tails is very sensitive; a few thousands of an inch can make a big difference.  In the photo below I show the amount the fence was moved for the last cut.  The block of wood was clamped against the fence prior to the move.  The gap shows the movement, probably about .010″ (the scale is just there for reference).  The other end of the fence was not moved, so the movement at the bit was half of what you see here.  Not much!  This movement changed a too snug fit to a fit that was a bit looser than I wanted, but not a problem.

Here’s the dry-fit assembly…

and a close-up of the dovetail…

and the rabbet/dado joint.

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