LumberJocks Woodworking Forum banner
1 - 10 of 10 Posts

· Registered
Joined
·
5,244 Posts
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.

Wood Floor Flooring Wood stain Hardwood


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.
Should be fun, good luck at the class.
 

Attachments

· Registered
Joined
·
5,244 Posts
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.

Brown Wood Flooring Wood stain Floor


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.

Table Wood Wood stain Hardwood Chair


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.

Hat Tints and shades Composite material Cylinder Circle


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.

Handwriting Book Font Office supplies Line


Next Steps: Fabricate a pattern follower for the spindle sander, finish developing my process flow diagrams and finalize the templates in CAD.
Wow, these chairs have more manufacturing challenges than most.

I have tried to pattern rout curved chair back parts up to 2" wide, but it didn't feel safe. I think you are on the right track with a template sander attachment on the spindle sander. If that doesn't pan out, maybe just a carbide bandsaw blade so it's easier to sand to the line.

I went to the Huntington Gardens in Pasadena over the weekend, where they have a Greene and Greene display. That, combined with all the Limbert and Stickley pieces at the Craftsman Weekend… my head is filled with inspiration for another year of woodworking.
 

Attachments

· Registered
Joined
·
5,244 Posts
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.
I m starting chairs for the various desks I built, but the plans I bought from Fine Wood Working (Kevin Rodel chair) don t appear to be all that involved. After seeing your post here, I just hope I m not naively assuming they will be fairly easy to build.

- EarlS
Only next to a Greene and Greene chair does the Rodel chair seem not too involved :)

I'd be interested what the quote is for templates at a CNC shop. Pretty reasonable I would bet, so long as your program is compatible with theirs.

Great stuff.
 

Attachments

· Registered
Joined
·
5,244 Posts
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.

Forklift truck Wheel Tire Vehicle Automotive tire


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.

Tire Wheel Vehicle Tread Wood


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.
Nice looking load of lumber. I went to the "Wood Store" Saturday, which for me is my kiln out back!

I bet that sapele mills up really nice.
 

Attachments

· Registered
Joined
·
5,244 Posts
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.

Wood Office equipment Machine Box Automotive exterior


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.

Table Furniture Rectangle Wood Wood stain


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

Wood Machine tool Machine Gas Hardwood


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.

Wood Rectangle Hardwood Publication Flooring


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.

Wood Comfort Automotive design Flooring Beige


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.

Hood Motor vehicle Automotive design Wood Bumper


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.

Wood Outdoor furniture Automotive design Automotive exterior Hardwood


Next steps- lay out and cut the mortises, then move on to the back seat rail.
What did I miss here, I thought you were going to pattern sand the parts? Change of heart?

I know the feeling of proceeding without many extra chair parts. Spooky.
 

Attachments

· Registered
Joined
·
5,244 Posts
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.

Table Furniture Desk Wood Pen


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.

Table Wood Milling Workbench Machine tool


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.

Wood Rectangle Gas Fixture Metal


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.

Table Furniture Cabinetry Wood Rectangle


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.

Table Wood Office equipment Desk Electronic instrument


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

Wood Folk instrument Musical instrument Hardwood Machine


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.

Wood Toy airplane Flooring Floor Toy


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.

Wood Boats and boating--Equipment and supplies Hardwood Flooring Wood stain


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.

Drill Wood Power tool Machine Engineering


The finished mortises are quick to cut using the jig.

Wood Wooden block Rectangle Wood stain Hardwood


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

Wood Rectangle Wood stain Hardwood Plank


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.

Wood Tool Hardwood Vehicle Flooring


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.

Wood Gas Composite material Saw Tool


The back seat rails are now ready for final sanding.

Tire Wheel Wood Vehicle Automotive tire


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

Wood Rectangle Composite material Plank Hardwood


So far so good!

Next step: fabricate the crest rails.
I love watching chair builds. Yours is right up there with the best I've seen.
 

Attachments

· Registered
Joined
·
5,244 Posts
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.

Wood Flooring Floor Red Gas


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.

Wood Rectangle Flooring Table Floor


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

Automotive design Rim Bicycle part Automotive tire Engineering


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

Wood Rectangle Audio equipment Hardwood Gadget


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.

Hood Automotive tire Bumper Wood Composite material


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.

Table Wood Tool Machine tool Gas


A quick test shows the center slat fits nicely.

Wood Automotive exterior Floor Hardwood Wood stain


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.

Wood Rectangle Hardwood Brick Gas


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

Brown Rectangle Wood Material property Wood stain


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.

Saw Machine tool Electrical wiring Engineering Gas


With all of the stock cut to length, I'm ready to move to the next step, cutting the mortises and curves.
That must have felt good to get the test slat fit. It's looking good now!
 

Attachments

· Registered
Joined
·
5,244 Posts
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.

Wood Rectangle Art Hardwood Flooring


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

Plant Table Desk Office supplies Machine tool


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.

Wood Vehicle Naval architecture Architecture Floor


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.

Wood Automotive tire Composite material Gas Household appliance accessory


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.

Wood Natural material Rectangle Metal Jewellery


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

Wood Naval architecture Engineering Gas Flap


The test fit looks good for the center slat.

Wood Rectangle Tool Floor Flooring


Brown Table Rectangle Wood Textile


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.

Table Wood Rectangle Grey Wood stain


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

Wood Rectangle Audio equipment Wood stain Hardwood


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.

Wood Gas Hardwood Machine Auto part


Next step: fabrication of the side slats.
Good thing the Greene brothers had the Hall brothers to build their furniture and homes. That stuff is complicated!
You're doing a particularly good job in every step so far. I tip my hat to anyone who tackles G & G furniture.
 

Attachments

· Registered
Joined
·
5,244 Posts
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.

Table Wood Rectangle Wood stain Flooring


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

Rectangle Wood Table Art Floor


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.

Picture frame Wood Wood stain Hardwood Musical instrument


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.

Wood Wood stain Hardwood Plywood Engineering


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.

Automotive exterior Automotive design Composite material Wood Metal


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.
Huntington gardens is a great place for inspiration. I really enjoyed the Greene and Greene exhibit there.

Good work on the chairs.
 

Attachments

· Registered
Joined
·
5,244 Posts
Corner Bracing and Slip Seats

With the chair assembled , the next step is to fabricate and install the corner braces and slip seats. To get the miter angles accurate for the corner blocks, I use a Bora MiteriX angle duplicator.

Wood Flooring Floor Hardwood Composite material


After measuring the angle, one side of the tool is removed to set the miter saw.

Hood Automotive tire Motor vehicle Bumper Automotive exterior


The resulting angles make for a perfect fit. I add some glue and screw the blocks in place set so the top of the slip seat is flush with the top of the chair side rails.

Wood Flooring Floor Wood stain House


The slip seats are cut from Baltic birch plywood. To facilitate cutting the seats, I make a tablesaw sled to cut the angles.

Wood Flooring Floor Model aircraft Composite material


The slip seats are difficult to cut accurately since each chair is slightly different. I sneak up on the correct angles and assure there is clearance for the seat covering using shims all around.

Wood Fixture Flooring Floor Wood stain


Next steps: drop off the slip seats at the upholster, stain and finish.
Hey that's looking pretty neat. Did you leave enough room for upholstery? I usually leave 1/4" on each side for batting and leather when I make cushions. Let the upholstery shop make the call, but be sure to communicate with them about the clearance.

Lookin' good!
 

Attachments

1 - 10 of 10 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top