[Mean_Dean]

Material Preparation

Now that my Thorsen inspired dining table is complete (you can see the BLOG here), it is time to turn my attention to a set of chairs. Since I have never built a chair, I decided to enroll in the Gamble House Side Chair class at Marc Adams School of Woodworking in Indiana. Many will know the instructor, Bob Lang, who is not only a Lumber Jocks member but has authored several books and was editor of Popular Woodworking magazine for many years. The chair design is based on the side chairs in the living room of the Gamble house in Pasadena.

The school mailed out a cut list a few weeks ago so students could prepare the required stock prior to class. I had enough sapele left over from making the dining table, so there was no need for a trip to the hardwood dealer. Since Indiana is about a 10 hour drive from Eastern Pennsylvania, I decided to cut up enough material to make two complete chairs to be sure I had sufficient material to cover any mistakes.

With my stock cut, I gathered up the required tools for class. This includes square chisels, a Dozuki saw, a plastic head hammer for inserting ebony plugs and a dental pick for cleaning out square plug holes. I also packed a cordless drill and a ROS along with my PPE.

I am looking forward to learning some new woodworking skills and hopefully coming away from the week with a nice chair. After that, I will be into chair production.

This looks like a really interesting blog-I'll definitely follow along again!

 

[Mean_Dean]

Marc Adams School, Day 1

Today was day one of the six day Gamble House side chair class at the Marc Adams school of Woodworking in Indiana. After 10 hours driving from Eastern Pennsylvania, I was happy to get a good night rest last evening and get started on this chair. Marc has a very large school and there are at least four classes going on simultaneously.

Our instructor, Bob Lang, was asked to fill in for George Knutson who was unable to teach the class as originally planned. Bob was able to get the original CAD files from Darrel Peart which he then used to create a 3D model of the chair in Sketch Up. This allowed Bob to check all of the joinery, etc. before we started cutting material. Bob changed a few dimensions from the original cut list, but not everyone received the update (including me). A few of my pieces are slightly different sizes from what Bob has drawn, but I think I can work around this.

After the obligatory shop safety discussion, we started by creating the routing template for the front apron, which has a cloud lift along the bottom. Once the template was completed, I routed the apron and cut my front legs to length.

The chair uses loose tenon joinery. To cut the mortises we set up the JDS Multi-router.

After cutting my mortises, I made up some tenon stock, then cut a few lengths so I could do a dry fit.

The front leg assembly is as far as I can take it at this point.

The back leg assembly requires four templates. The legs have a gentle arched shape above the seat. The crest rail is shaped with both a curve and a profile, and the rear apron also has a unique, almost scalloped profile that requires a template. Bob Lang was kind enough to plot full size drawings that we were able to affix to the MDF to facilitate making the templates.

Tomorrow we will continue making the back leg assembly.

Looks like you're off to a great start! Looking forward to seeing your progress!

 

[Mean_Dean]

Marc Adams School, Day 2

Today we continued to work on the components for the back leg assembly. After tracing the outline of the components on the sapele using the templates, I roughed out the parts on the bandsaw. There is a significant amount of bandsaw work just in the parts for the back assembly alone.

The crest rail is the most time consuming part to make. The mortises for the floating tenons were made first using the multi-router, while the part was still square. Next, I affixed the template to the blank with double sided tape. Using a Forstner bit, I bored holes where there was an inside radius. After the holes were bored through, I cut the curves for the front and back of the piece on the bandsaw, then taped the offcuts back in place to bandsaw the profile.

The back apron also has a profile which I roughed out on the bandsaw as well. Even in the rough bandsawn state, the parts are starting to take shape nicely.

I began smoothing the parts with a spokeshave and block plane before moving on to final cleanup using my ROS.

Tomorrow we will continue getting the back leg components fabricated and ready for assembly.

I wonder what Peter and John Hall would think of the way their chairs are fabricated these days?

Anyone got a DeLorean we could use to bring them here….......?!

 

[Mean_Dean]

Marc Adams School, Day 3

After cleaning up the parts with the ROS, I dry fit the back assembly to see how everything fit.

With that much of the chair dry fit, we moved on to fabricating the angled side aprons. The first step is to lay out the mortises on the back and front legs. The front legs have an angled face that has not been cut yet, so the front face cant be used to locate the mortise. I must locate the mortise from the inside edge of the leg. To do this, I work out the location by laying out the back leg mortise first . I lay out the rear leg mortise with the proper offset, then measure from the back of the leg so I can locate the mortise on the front leg.

Since these joints also use floating tenons, we set up the miter saw at the correct angle and used a stop to be sure our pieces were cut identical and to the proper length. After cutting the aprons to length, we set up the multi-router to cut the angled mortises. I then pattern routed the cloud lift in the bottom of the aprons. With the side aprons complete, it was time for a quick dry fit to be sure everything looked good before proceeding.

The next step is to prepare the bottom stretchers. After dimensioning my material, I lay out the angled through mortise in each side stretcher.

To cut this mortise, we set up the hollow chisel mortiser. By supporting the work piece with a wedge at the correct angle, we were able to bore the angled mortises.

Next I fit the first angled through tenon. After laying out the tenon, I cut the shoulders with a hand saw then cut away most of the waste for the cheeks on the bandsaw.

Back at the bench I cleaned up the tenon with a chisel and fine tuned the fit with a sanding block.

Tomorrow I will fit the remaining through tenon on the bottom stretcher and pattern route the cloud lifts.

Looks like you're making very good progress for just your third day!

I'm warming to the idea of the floating tenon. I would normally just make them the regularl way because I don't have the horizontal router, but may have to look into getting one.

I suppose there's always the Domino-after I win the Lottery, of course…..........!

 

[Mean_Dean]

Marc Adams School, Day 4

Today I finished up the second tenon for the lower stretcher, then cut mortises with the Domino 500. This was my first time using the Domino. Once set up it's a fool-proof method for cutting the mortises.

I did another quick dry assembly to be sure the lower stretcher parts fit together nicely.

With the lower stretcher out of the way, I start working on the curved back slats. The back slats will be assembled with dominos, have angled ends where they meet the apron and crest rail (compound angles in the case of the two smaller ones), are curved and have a profile cut.

I start with the center back slat. To get the angles for the ends correct and cut to the proper length, Bob Lang worked out a clever solution using what is basically an MDF story stick. I use a scrap of MDF and carefully transfer the angle from the dry assembled chair to the MDF and cut on the miter saw. I carefully trim away the MDF until the part matches my layout lines. Once I have the proper length worked out on the MDF scrap, I cut the angled ends into the real part in sapele.

Next I layout and bandsaw the curved faces. When the curves are complete, I temporarily tape the cutoff back in place and bandsaw the profile.

I originally thought the crest rail was going to be the most work on this chair, but I was wrong. Clearly the back slats are going to be the most difficult part of this project.

Next step- cut the dominos for the center slat then make the side slats.

Well, asked and answered on the Domino….............! (Referring to my comment in Day 3's entry.)

I didn't realize that the Domino can be set at three different settings-could also be used to allow for expansion/contraction where needed.

Guess I'll head out and buy my Lottery ticket….....!

 

[Mean_Dean]

Marc Adams School, Day 5

Today I finished up the center back slat by cutting the mortises for the dominos. Most of the mortises could be cut with the Domino machine, but the two mortises on the underside of the crest rail had to be cut by hand since the domino machine would not fit inside the opening. To cut these mortises I first drilled out the majority of the waste on the drill press then cleaned up the mortise with a chisel.

With the mortises cut I tested the fit of the center back slat. It took quite a bit of fitting to get the mitered ends just right. I'm starting to see why the original chairs used housed mortises for these parts.

I moved on to the side slats. These slats are mirror images of each other and have a compound angle cut on the end. To make the layout more challenging, the slats are slightly angled to follow the curve of the crest rail. Once I was happy that I had established the correct compound angles for the cuts using a scrap of MDF, I then transferred the angles to the sapele for the cuts on the final parts.

With the final length established and cutting completed, I used the templates to lay out the curve and profile of each back slat. At the bandsaw I first cut the front and back curves, then taped the waste pieces back in place to cut the profile.

I brought the rough pieces to the edge sander to clean up the bandsawn edges, cut the domino mortises and did another dry assembly.

I am very surprised at how much work it is to fit the back slats. Bringing together three curved pieces, two of which have compound angle end cuts and getting all of the joints to fit without any gaps is tedious work to say the least. But I'm very happy with the results so far.

Tomorrow is the last day of class. We will not have a full day but should get to routing the center back slat for the ebony bars and talk about installing the ebony plugs and cutting the final angle on the front legs.

I realize I'm a little late to the party on these last three blog entries, but dang that was a quick five days!

I presume that you're expecting to finish the chair on the last day of class?

For a chair this complicated, I'd definitely want to take a class, and get hands-on instruction from someone like Bob Lang or William Ng. Indiana's a little far from Portland, but William Ng's school is down in Anaheim, CA, which would work out well for me, combining a couple of interests of mine.

In addition to being a woodworker, I'm also an amateur naval historian. So I could make a swing through Southern California, seeing the Gamble House in Pasadena, USS Iowa BB 61 in Los Angeles, and taking William Ng's class in Anaheim. Would be a hell of a week!

 

[Mean_Dean]

Marc Adams School, Day 5

Today I finished up the center back slat by cutting the mortises for the dominos. Most of the mortises could be cut with the Domino machine, but the two mortises on the underside of the crest rail had to be cut by hand since the domino machine would not fit inside the opening. To cut these mortises I first drilled out the majority of the waste on the drill press then cleaned up the mortise with a chisel.

With the mortises cut I tested the fit of the center back slat. It took quite a bit of fitting to get the mitered ends just right. I'm starting to see why the original chairs used housed mortises for these parts.

I moved on to the side slats. These slats are mirror images of each other and have a compound angle cut on the end. To make the layout more challenging, the slats are slightly angled to follow the curve of the crest rail. Once I was happy that I had established the correct compound angles for the cuts using a scrap of MDF, I then transferred the angles to the sapele for the cuts on the final parts.

With the final length established and cutting completed, I used the templates to lay out the curve and profile of each back slat. At the bandsaw I first cut the front and back curves, then taped the waste pieces back in place to cut the profile.

I brought the rough pieces to the edge sander to clean up the bandsawn edges, cut the domino mortises and did another dry assembly.

I am very surprised at how much work it is to fit the back slats. Bringing together three curved pieces, two of which have compound angle end cuts and getting all of the joints to fit without any gaps is tedious work to say the least. But I'm very happy with the results so far.

Tomorrow is the last day of class. We will not have a full day but should get to routing the center back slat for the ebony bars and talk about installing the ebony plugs and cutting the final angle on the front legs.

Thanks for the info, Client!

I've been looking at Darrell's classes also, since he was in Renton, WA. And sometime down the road, I may take one of his at his new place in Seattle. Right now, the swing through Southern California allows me to combine several visits into one trip, so that makes the most sense for me.

I do like the idea of only 4 students per class-lots of hands-on instruction!

Thanks again for the info!

 

[Mean_Dean]

Marc Adams School, Day 6

Today was the last day of class. Bob Lang covered several points on installing the ebony plugs and bars in the center back slat. Bob also did a detailed demonstration on techniques for doing the Greene & Greene style round overs, which have some nuance beyond simply running a quarter round bit over the exposed edges. Often the protruding corners on G&G furniture have an extra amount of rounding, almost giving the piece a worn appearance. It is s subtle detail that could go unnoticed if not pointed out.

Some of my class mates used the class made template to route the slots for the ebony bars in their back slat. I elected to pack up early and deal with the remaining work at home so I could get a head start on the 10 hour drive back to Pennsylvania.

Overall this was an awesome class. Bob did a great job bringing us through the fabrication and construction of the chair components and assembly process. His full size drawings and detailed instructions helped assure we were successful. Marc Adams runs a first class school. The facilities are well maintained with plenty of excellent equipment to work with. Even though we didn't finish our chairs during the 6 days, I really didn't expect that we would. There is simply too much work involved in a G&G piece to complete in such a short time frame.

Next step is to get started on the full set of twelve.

Looks like you had a great class, learned some new things, and overall had fun!

I've enjoyed your blogs to date, and am looking forward to seeing the dynamic dozen once they're ready for action!

 

[Mean_Dean]

Planning the Construction of 12 Chairs

Since returning from the Gamble House chair class at Marc Adams, I have been thinking through the construction process for a full set of 12 chairs. In the class, we performed many of the operations with hand tools which can be time consuming and lead to variation in the parts, especially across 12 chairs. We also used the Domino 500 for several of the joints, which I don't own.

One aspect of the project I have been pondering is cutting and cleaning up of the curves on the wide faces of the back seat apron, crest rails and back slats. In class, we roughed these in using the bandsaw, then cleaned them with various hand tools. I'm not very good with hand tools, so this is a very time consuming process for me that will lead to irregularity in the finished parts. As I spent time researching and thinking through various ways to machine cut these parts, I developed and then rejected several ways that I might accomplish this.

My first thought was to utilize my shaper to pattern cut the parts to templates. This is the same concept used when pattern routing parts, only with bigger tooling. The advantage of utilizing the shaper over a router for this operation is that the larger shaper cutters leave a much smoother finished surface when complete. My first thought was to simply stack rabbeting cutters, which would work but might lead to tear out issues since some of the cuts climb the grain slightly. I then investigated helical shaper cutters like the Byrd Shelix, which would leave a much smoother surface than a straight cutter but are costly. Ultimately I could not come up with a good way to cut all of my parts in a single pass since my shaper spindle is not tall enough. In addition, the shaper cutter required to cut such a large surface would be very dangerous to use, even with a sturdy sled. I abandoned the idea of pattern shaping.

As I browsed the internet for alternative ways to consistently shape these parts, I came across a few people that had adapted spindle sanders to follow patterns. The concept of bandsawing away the majority of the waste and abrasively cleaning the parts up to a template appealed to me as being a safe way to get consistent, smooth results for these large parts (albeit a bit slow). The 6" tall spindles also have sufficient reach to shape the entire face of my parts.

I decided to test the concept with a drill press mounted sanding drum before investing in a spindle sander. I bored a clearance hole in some scrap MDF slightly larger than the drum. After rounding the outside edge I had a quick and dirty pattern follower that will follow an offset template.

I attached a template to a scrap of sapele with some double sided tape. The template rides face down on the table, against the pattern follower. After a few minutes sanding, I had a well shaped part, offset slightly from the template, without the usual irregularity associated with freehand use of a spindle sander.

With my concept proven, I stopped at Woodcraft to pick up a spindle sander. I need the tool in hand to get exact measurements of the sanding sleeves and throat plates so I can design my pattern follower and determine the offset for the templates.

The 2 inch sanding sleeves are actually 2-1/16 outside diameter. The opening in the plate is 2-3/8. I'd like to use a 1/4 inch offset for my templates so my pattern follower will need an outside diameter of 2-9/16. I can turn a follower on the lathe that will press into the opening in the plate. I ordered a short length of 2 inch ID x 2-3/4 inch OD UHMW-PE tubing from McMaster Carr to fabricate the pattern follower from, but it could be made from a piece of hardwood or plywood as well.

With my process for shaping the large parts worked out, I start working through the process flow for each part. With complex projects, I mentally work through the process steps to make each part, sketching as I go. I find that even rough sketches help me to visualize the proper order to do the operations to get the best result. As I sketch, I'm thinking through the templates I will need as well as any tooling or special materials and I note them along the side. By thinking through the steps I can identify errors in my process order that might make a later operation difficult or impossible, all before I cut any material. Here, I am working through the process steps to make the back legs and back seat apron.

Next Steps: Fabricate a pattern follower for the spindle sander, finish developing my process flow diagrams and finalize the templates in CAD.

A little late to the party here, but looking forward to seeing your process!

By the way, unless you build a aircraft carrier-sized sled to pattern rout your parts, I think the spindle sander setup is the way to go. May take more time-but no need to get fingers reattached in the Emergency Room….........!

 

[Mean_Dean]

Pattern Sander Setup and Bandsaw Upgrade

With my pattern sanding technique proven and a length of UHMW-PE tubing delivered I got to work making a bushing for the spindle sander. I roughed out a 1" piece of tubing to start.

There is just enough clearance between the sanding drum and the table insert to fit a bushing. I turned the bushing on the lathe to a nice press into the existing table insert.

The bushing provide a 1/4" offset from the sanding drum which will make design of the patterns easier.

A nice property of UHMW-PE is that it is extremely low friction. This will allow the patterns to glide smoothly along the bushing and also facilitate insertion and removal of the bushing from the table plate.

The spindle sander project kept me busy while I was waiting on delivery of a new bandsaw. My trusty 12" Craftsman served me well over the years, but it was time to upgrade to something with more capacity for this project. Every part on these chairs is touched by the bandsaw except the two front legs and the small lower connecting stretcher. Some of the parts, like the center back slat, are 5 inches thick. A Bigger saw was definitely needed.

I researched a few options on bandsaws. I was looking for something larger than a 14" saw, but not so big that it would be difficult to get into my basement workshop or take up too much room. The Powermatic PM1500 was on my very short list, especially after working on one while at the Marc Adams school a few weeks ago. As luck would have it, SCM put the Minimax saws on sale right around the time that I called to get pricing, putting the MM16 in the same price range as the PM. With larger capacities nearly everywhere, including a 4.8 hp motor, the choice was pretty easy.

About a week after placing my order I received a call from the freight hauler that my crate was ready to pick up. The crate nearly filled my 8 foot utility trailer and had a shipping weight of nearly 800 lbs! I was starting to get worried about getting this thing into my shop.

Luckily, the shipping crate was very substantial and accounted for about 200 lbs. of the weight. Even so, moving this saw was not going to be a 2 man job. With the help of my neighbors backhoe and some clever rigging we were able to lower it down my outside stairs into the shop.

Next steps: clean and tune up the MM16, finish designing and order my routing templates in AutoCAD to be CNC cut and pick up another load of Sapele.

Nice bandsaw-enjoy!

 

[Mean_Dean]

CAD Templates and Pattern Sanding Test

With the new bandsaw tuned up and cutting nicely I got to work designing the templates needed to make the chairs. I worked through the steps to make each part, designing pattern routing/sanding templates to aid each step. Each part has several templates to be used to route the shape, mortises, etc.

I ended up with 46 templates overall, a lot more than I expected. I sent the files off to the local CNC shop for quoting.

While waiting for my templates I decided to test out my pattern sanding rub collar using a template for the back seat rail.

Starting with a sapele scrap, I traced a portion of the full size pattern and headed to the bandsaw.

After rough cutting just outside the line, I attached the template to the part with double sided tape. The rub collar requires an offset of 1/4", which I designed into each CNC template. For this test, I just used the full size template and set it back about 1/4". After a little time at the sander, I had a finished part that matched the template exactly.

Satisfied that my pattern sanding technique will work, I placed an order for a load of quarter sawn Sapele. Working in AutoCAD, I determined that I could get all of the components for a chair from a single 8/4 board as long as it is at least 9" wide and 10' long. This required a special order from my hardwood supplier, who agreed to bring in some wood for me to pick through.

Next Steps: Pick up the sapele when it arrives and get my CNC templates on order.

Man that's a lot of templates…............!

Looking forward to seeing them in action!

 

[Mean_Dean]

A Lumber Mill Run

The Sapele that I ordered arrived at Hearne Hardwoods earlier in the week. I need about 300 bf for this set of chairs. I can get all of the components for a single chair from one 8/4 board as long as it is at least 9" wide and 10' long, so I need at least 12 boards. Ed at Hearne brought in 400 bf of wide 8/4 quarter sawn Sapele for me to select my boards from. The boards are all 16-18 foot lengths, and 10"+ wide.

At 16 to 18 feet long these boards are too big for my trailer and wood rack. I had the mill cut them to 11 foot lengths for easier transport and handling in the shop. At 11 feet they hang off my utility trailer a bit front and back.

I also received the quote for the CNC cut templates, a very reasonable $345. The templates will be made from 1/2" MDF and should be ready in about 2-3 weeks.

While I wait for the templates, I will start roughing out my chair parts on the bandsaw.

Very handsome stack of sapele!

 

[Mean_Dean]

Roughing It

The sapele has been in the shop for a week acclimating and my CNC cut templates will not be ready for a while, so I got busy roughing out parts. I started with the largest parts, the back legs. A leg blank 7 inches wide will allow me to cut both back legs for a chair from a single board, helping with grain and color match. Several of the boards were a bit over 14" wide, allowing me to get two pairs of legs from each cut length.

To be sure I have spare material in case of an error, I cut enough parts for 14 chairs. I ripped the wide stock to 7" widths on the bandsaw, then joined one face and edge before planing to final thickness.

As I started planing the stock to thickness, some internal compression damage was revealed on several pieces. All of the damage was located where the lumber had been stickered in the yard. In the image below you can still see some of the sticker stain next to the damaged area.

I went back to the lumber pile to rough out some additional replacement boards. With these boards planed to thickness, they are as far as I can take them until I get the templates.

Most of the damaged boards were salvaged later to make smaller parts such as the front legs (that's why we always start with the biggest parts first, right?). In some cases the grain was not running parallel to the edge of the board, requiring me to lay out the parts parallel to the grain and true up on the bandsaw and jointer. Truing up in this way helps avoid the diagonal grain seen in the top leg below, which will be used for setup only.

As I was working I kept a pair of diagonal cutters in my pocket to remove stray staples from the lumber yard. I don't cut the staples, but I find the diagonals get a good bite making them easier to remove.

Next I roughed out the stock for the back slats. Ideally the center slat and two outside slats should come from the same board and be kept in sequence. It's going to be a real challenge to keep all of the parts properly labeled and oriented as I make these parts.

With the two largest parts roughed out, I moved on to cutting the stock for the smaller parts. The crest rail and lower back seat rail are made from 8/4 stock. The side seat rails and front rail finish up at 7/8" thick so I will resaw the 8/4 stock to get two parts from each blank. The poplar blanks will be used as setup pieces.

The majority of the parts are rough cut at this point, with the exception of the lower stretcher components. These parts are small and can be easily cut from the drop offs left over from roughing out the main chair parts.

Next step: Finish roughing out the remaining parts then joint and plane to size in preparation for pattern routing and sanding.

Looks like you're off to a good start!

I'm looking forward to seeing how your templates turn out. Question, though: Are you concerned about using MDF material for the templates as opposed to 1/2" plywood? It seems with the number of parts you'll be milling with these templates, and the relative softness of MDF, that the templates could lose the integrity of their edges and cause parts to be imprecise copies of each other?

The reason I ask, is that I've had MDF templates get dented slightly along the business edge, and have to be refabricated. Swore I'd always use 1/2" Baltic Birch from then on….......!

 

[Mean_Dean]

CNC Templates and Begin Back Leg Fabrication

My routing templates arrived Friday from the millwork shop so I headed out to pick them up. A few of the corners were damaged in transport, so I unwrapped everything to take a closer look.

After inspecting the templates closely I was relieved to find that the damaged corners were all in non critical areas. It's a good thing I made my routing templates a bit long on the ends to have a little lead in.

Time to get to work. For this project, I plan to fabricate the back assembly first, then cut the angled side rails and finish up with the front assembly. By working in this order, I can adjust the length of the front rail to account for any errors that might accumulate during fabrication and be assured of tight fitting joints.

I start by laying out the back legs. I trace the full size template onto the leg blanks. For darker woods like walnut and sapele, I use a white fabric pencil for my layout lines for visibility. I cut enough parts for fourteen chairs leaving four extras in case of mistakes.

I head to the bandsaw to rough out the back legs.

While cutting out the blanks, I came across hidden checking on four of the parts. There goes all of my spares! Any mistakes going forward will require me to make more parts.

After hardening the edge of the routing template with some thin CA Glue, I affix the template to the poplar set up piece and make a test cut at the router table.

With my test blank completed, I moved on to pattern routing the legs. This is a large piece at 43 inches long and each part takes quite a while to pattern route.

This is a tricky cut, even with a spiral carbide cutter, due to the end grain and tight radius at the top of the leg. Not surprisingly I lost several parts while routing the top of the leg. Cutting against the grain, even with a spiral cutter, is always iffy.

Since I have no spares left, I head back to the lumber rack and rough out several more blanks and pattern route replacements. After all the dust settled I end up with eight damaged leg blanks- four with checking and four damaged while routing. I'm down to a single spare leg at this point.

In preparation for laying out and cutting the mortises I arrange the legs on my shop cart, flipping then into pairs of right and left legs. Most of the leg pairs are matched from the same board, but due to the damaged pieces unfortunately not all of the legs could be matching pairs.

Next steps- lay out and cut the mortises, then move on to the back seat rail.

I know what you mean about pattern-routing endgrain…..... I tried that once (and learned my lesson-never agin!) and in the process had the workpiece flung across the shop. Scared the hell out of me….......

From then on, endgrain is always shaped on the spindle sander. Which is what I thought you were going to do.

By the way, don't get timid now that you have little margin for error-I've found, if I'm too concerned about screwing up, I usually screw up. Just work as you normally do,

 

[Mean_Dean]

Back Leg Mortises and Back Seat Rail

Now that the back legs are routed to shape, I move on to cutting the mortises. I start with the back seat rail mortises. The back seat rail sits flush with the inside of the back leg, so it makes sense to cut both mortises using the same setup to assure the parts fit perfectly flush.

I first lay out the mortise on the end of the back seat rail setup piece, which is made from poplar. The Leigh FMT jig only requires that the center of the mortise be marked with cross hairs, but as a double check I layout the full mortise to verify size and location along with the mortises for the back slats and the final profile of the rail.

Next I lay out the matching mortise on the leg and verify that everything is aligned correctly.

The Leigh FMT jig is equipped with toggle clamps and a stop that, once setup, allow multiple parts to be made very quickly with perfect repeatability.

The cross hairs that mark the center of the mortise are used in conjunction with the 'targeting sight' on the FMT to very accurately locate the center of the mortise.

First, I cut all of the mortises on the ends of the back seat rails. All mortising is done before I bandsaw the back scalloped profile to provide large flat clamping surfaces.

Next, I route the matching mortises in the back legs utilizing the same setup in the FMT, assuring a perfectly flush fit. Since the mortises are near the center of the back leg, I must use the extension feature of the FMT to create a stop with a scrap block of wood and a clamp.

The legs are mortised in mirror image pairs, so two setups are required on the FMT to make sets of left and right legs.

With the back seat rail mortises complete, I move on to creating the mortises for the crest rails. These mortises are cut at an angle into a curved section of the leg, so the FMT jig will not work easily for these mortises.

To solve this problem, I use a jig made from two CNC machined templates. Together they form a jig for routing the mortise. One template has an oversize slot that matches a router bushing. The other template has a leg shaped opening that positions the leg to properly mortise. This image shows the bottom of the jig with a leg fit in place, ready to be flipped over to route the mortise.

The template is designed to be used for both the left and right hand legs by simply switching the locating template to the other side. After a little fine tuning of the opening in the template to allow my router bushing to clear smoothly, I cut all of the mortises.

The remaining mortises on the back legs for the side seat rails and lower stretchers are parallel to the front face. These will be cut later.

Next I build a mortising jig to cut the four mortises on the top of the back seat rail that will be used for the back seat slats. Since two of these mortises are angled, the FMT would be difficult to use. I build the jig from a CNC cut template that locates all four mortises.

The finished mortises are quick to cut using the jig.

With all of the mortises cut in the back seat rail, I bandsaw the scalloped outer profile.

To prepare for pattern sanding the profile, I assemble another jig using a toggle clamp and CNC cut template. The template mounts to the bottom of the jig and is 1/4" undersize to account for the pattern follower mounted on the spindle sander.

The pattern sanding technique does a nice job cleaning up the bandsaw marks and developing the final shape on the rails. Due to the height of the part, the top 1/8" of the seat rail does not get sanded. It is easily cleaned up using a spiral pattern bit in the router table after the sanding is completed.

The back seat rails are now ready for final sanding.

I do a quick test fit to verify everything looks correct.

So far so good!

Next step: fabricate the crest rails.

Looks like you're making some amazing progress!

So, how do you like routing your mortises, as opposed to using a dedicated mortising machine?

I have a mortising machine, but it tends to leave the mortises a little rough, which then need to be cleaned up. I like the idea of using a router, as it gives nice, clean mortises-but then you need to make all sorts of routing jigs. So you're sort of damned if you do, damned if you don't. Anyway, just curious what you think.

 

[Mean_Dean]

Crest Rails

The next component to be made is the crest rail. This part has a complex profile as well as a curved face and back, making it a bit more difficult to fabricate. I begin by laying out the part on all of the faces of my poplar setup piece.

The order of operations is critical for this part to assure that everything comes out as accurate as possible.

I begin by cutting the mortises. The two mortises in the ends of the piece are easily done using the Leigh FMT jig, as are the two center mortises on the underside. The outer mortises on the underside are angled, so I use a CNC cut template to machine those.

I decided to take my poplar setup part completely through the shaping process to vet out the proper order of operations. I started by roughing the concave curve using the bandsaw. I save the cut-off, as I will need it later. I then use a CNC cut template and the spindle sander to bring the concave face to final shape. The part is too tall to complete using the spindle sander, so I clean up the last 1/2" using a pattern bit in the router table. After the first curve is completed, I bandsaw the opposing curve, spindle sand and route that face. I now have the curved shape completed, ready to move on to shaping the profile. I tape the cutoffs from the bandsaw back in place on the part, then rough out the profile. I use a 5/8" Forstner bit to rough out the inside radii, while the rest of the profile is cut with the bandsaw and a saber saw to remove the waste from the hand hole. Another jig and template are used to pattern route the profile. The part looks good in the profile, but there is a problem- I bored the holes with the Forstner bit after I had cut and shaped the curve in the crest rail, with the cut-offs taped back in place. The clearance between the cut-offs and the part was large enough that there was some blow out on the back side of the part.

Good thing I decided to take my setup piece completely through all of the fabrication steps before I moved on with my actual parts!

To eliminate the issue, I re-arranged the order of operations to put the boring of the holes first and tested the new order of operations on the next part.

I rough the inside curve on the bandsaw, pattern sand and route the shape, then rough the outside curve.

Mounted in the next jig, the part is ready for pattern sanding the outside curve.

With the inside and outside curves completed (and no blow-out!), I tape the parts back together and rough out the profile using the bandsaw and saber saw.

Mounted in the routing jig with the template, I pattern route the profile.

The finished part looks nice, so I do a quick dry assembly to verify the fit is good.

With the first part completed without any issues, I'm ready to move on to the next step: finish out the crest rails for the remaining 13 parts.

It's always a good idea to make test pieces and see how a process goes-better to screw up on poplar than the expensive stuff! (I had to learn that lesson the hard way, so always test pieces from then on….....!)

It's also good of you to post your shop hours-I've always thought I was a slow wood worker, but I'm learning that I'm probably about average in that department. Projects always seem to take about twice as long as I figure they will. Still have no idea why that is….....

 

[Mean_Dean]

Center Back Slat- Part 1

After finishing up the crest rails, I move on to the center back slats. I begin by making up the loose tenon stock I will need. After cutting the stock to width, I fine tune the thickness with the drum sander and add the rounded edges with a bullnose bit in the router table.

I start by making a test center slat from poplar. I cut the angled ends and mortises while the stock still has straight edges. To determine the angles for the end cuts, I use a MDF story stick. By cutting the angles on the end of the story stick, I can sneak up on the correct length for the part. Using the side profile template, I mark the story stick to show the outline of the part.

I transfer the angles to the miter saw and trim the ends.

After the end cuts are made, I set up the parts in the Leigh FMT and cut the mortises.

With the mortising complete, I move on to cutting the curves. First I rough cut the inside curve with the bandsaw. My original plan was to pattern sand the curves. I set up the pattern sanding jigs and did a test with my poplar set-up part. The sanding time was excessive, so I decided to go old school and broke out the spoke shaves to perform the preliminary cleanup work, then finished off the part on the belt sander.

Once the curves are complete I tape the cutoffs back in place and band saw the profile. A few strokes with the spoke shave cleans up the edges. A float and some thin files clean up the 'V' cut in the bottom. The spoke shaves and floats work well to break the edges.

A quick test shows the center slat fits nicely.

With my poplar test piece completed, I move on to making the real parts. For the actual chair components, I rough out fourteen blanks 9 inches wide then rip 1-3/4 inches off either side.

I make sure to keep the parts carefully labeled to maintain grain alignment for the finished chairs.

I set aside the side slats for now to work on the center slats. Back at the miter saw I cut the angled ends. After cutting one side, I set up a stop block to assure all of the center slats are the same finished length.

With all of the stock cut to length, I'm ready to move to the next step, cutting the mortises and curves.

Looks like you're making some pretty good progress! I've been enjoying this project so far!

As for your scraps, I'd hate to see you burn them. I've had some success selling my scraps on Craigslist, as pen-turning blanks, or other small-project pieces. Not only does selling them get them out of your shop, another woodworker gets some nice wood cheaply, and you get a few coins in your pocket to use on future projects.

 

[Mean_Dean]

Center Back Slat- Part 2

With all of the stock cut to length, I'm ready to move to the next step, cutting the mortises and curves. I lay out the center marks for the mortises needed by the Leigh FMT on the ends of one piece.

Since the ends of the slats are angled slightly, I adjust the Leigh FMT to hold the parts at the appropriate angle.

Once the Leigh FMT is set up correctly for the first piece, the rest of the parts are run without any layout work which is a real time saver when making multiple parts.

Next I take the parts to the bandsaw and cut the outside and inside curves. By staying tight to my layout lines I minimize the amount of cleanup work needed.

Back at the bench, I begin the cleanup work with spokeshaves. I work one half of the part from one end then flip it to work the other half, always working with the grain.

Next I bandsaw the profile, then it's back to the bench to clean up the edges with the spokeshaves.

The test fit looks good for the center slat.

Happy with my test fit, I fabricate the remaining center slats. To clean up the marks from the spokeshaves I head to the belt sander. The marks are readily apparent under raking light.

I smooth the concave side on the belt sanders pulley and the convex face on the bed.

The back slats are fully shaped, but need the corners softened and the ebony bars added- details that will come later. I do a dry fit of all the chair backs to be sure there are no fit problems.

Next step: fabrication of the side slats.

This is a really complicated project you've undertaken, but you're handling it with your usual aplomb! Can't wait to see them arrayed around the table!

 

[Mean_Dean]

Side Slats

With the center slats completed I move to the side slats, arguably one of the most difficult parts of the project. With the center slat already cut, the side slats must be cut very precisely or there will be a gap in the finished assembly somewhere. In addition, both ends of the side slats have a compound miter and must have a mortise precisely placed.

Bob Lang's approach to this in his chair making class was to use a MDF story stick to sneak up on the exact angles and lengths, which worked very well. I started by cutting two poplar pieces to use for the test fitting. Once I had established the correct compound angles for each end, I fit the parts to length by trial and error, taking light cuts to sneak up on the proper length.

With careful fitting I was able to achieve a tight fit on my test parts. I then laid out the mortises and profile on the slats to match the mortises in the crest rail.

Moving on to the actual parts, I cut the compound angles on each end then cut the mortises using the Leigh FMT.

With the mortises complete, I lay out the curves and profiles and head to the bandsaw to rough out the parts. After bandsawing I clean the parts up quickly with a spokeshave. Later I will finish sand them on the belt sander and break the sharp edges.

The test fit looks good with a snug fit on all parts.

It's not easy to see in this image, but all three Slat parts were cut from the same blank and kept in order so that the grain will match in the finished chair.

Next Steps: finish up the side slats for the remaining chairs, then start on the angled side aprons.

Well, just keep taking your time, and getting things right.

Sometimes I start getting impatient, and just want to get the step done. When that happens, I force myself to take a break, go eat lunch (or just get out of the shop for an hour) and leave the project be for awhile, or even overnight.

After a break, I'm ready to go again!

 

[Mean_Dean]

Preparing Apron Stock, a Router Template and Crest Rail Shaping

With the side slats cut and fit for all the chairs, I turn my attention to preparing the stock for the side and front aprons. I had rough cut the material for these parts a while ago, but had not gotten to resawing it yet. After flattening one face and squaring an edge on the jointer, I set up the resaw blade on the bandsaw and split the boards into two pieces 15/16"thick. I'll let this stock sit for a few days before I take it to the planer for final dimensioning.

Next I put together a quick template to route the shallow slots for the ebony bars that are inset into the center slat.

In February I was in Pasadena and took the opportunity to visit the Huntington Library Museum, which houses many Greene & Greene pieces. The museum holds one of the living room chairs from the Gamble House and that gave me a good opportunity to study an original up close. The crest rail is beautifully shaped with a lot of rounding and shaping evident. Here is a close up of the crest rail on the original.

The subtle curves and shaping done on these pieces is amazing and could be easily overlooked.

I realized that my stylized version of the chair would benefit greatly from some extra shaping and rounding, so I began working on my poplar setup pieces to see what i could come up with. The leg tops were straightforward. I shaped them with some rasps and finalized them with some sandpaper.

For the crest rail, I first thinned and tapered the top half of the piece, then rounded the corners with a rasp. I finished up with some sandpaper.

These pieces still need some additional shaping work, but they are already looking much better.

Next steps- shape the crest rails and the tops of the legs and cut the side rails for the seat.

The shaping looks like it's coming along nicely!