Chair makers! How is this detailed?

[Gene Davis]

I am doing a study of the Stickley MacIntosh dining side chair to see how one might be made in my shop. Using Sketchup and studying the photos in their online catalog, and starting with the L x W x H size spec, I tried modeling the frame. See the images here.

2014-10-09_1900.png2014-10-09_1919.png

The sizes and members need to be edited a little here and there. I know I have the back slats a little too thick, maybe a little too broad. I can fiddle with that later. The photos evidence what I mean.

2014-10-09_1903.png2014-10-09_1905.jpg

I have never made a chair. I can take a crack at modeling the geometry of one and guess at its joinery, but having no experience building any, I am here for guidance.

First question. Can one accomplish all the joints with Festool dominos?

Big question. How does one support the drop-in seat? See the pic here for what I mean by the drop in seat.

2014-10-09_1917.jpg

This one is an arm chair, but you can see what I mean. The upholstered seat is framed and the frame with its upholstery is set inside the seat frame of legs and rails.

I am guessing that the front legs need to have a notch sort of what I did in the 3D model.

2014-10-09_1933.png

Here I backed the camera away so you can see how I doodled corner angle braces into each. Do they look OK, size-wise? No dominos here. I figure glue and screws.

2014-10-09_1941.png

Searching around for something on seat upholstery, I found a pretty good article and snipped this pic of a seat frame after it gets webbing fixed to its top side. I am guessing that is what the Stickley chair has.

2014-10-09_1944.jpg

So my next question is this. Should my chair frame have additional blocks screwed to along the inside of the rails to support the drop-in seat, or will the corner brackets support things?

[Yonak Hawkins]

Gene, we have Stickley spindled dining chairs. In our chairs, you are correct, the front legs are, indeed, notched to the depth of the bottom of the seat. The seats are supported by the corner braces only, no center supports. As far as the webbing, I can't say. In fact, I can't even be sure the seats are original, as they are not leather, but they could have been special-ordered.

[Kent A Bathurst]

On the seat support, etc. - you have nailed it dead-nuts.

[Gene Davis]

Thanks, Kent.

Yonak, since you own a Stickley chair with this kind of drop in seat, would you mind giving me some info about it?

Height of seat. See my image here. I need to slightly tweak my front rail and when I do, it will be at the 17-1/4" height. How does this compare to yours?

Seat frame. Is yours a solid panel or is it 4-side framed? Are you able to see what thickness it is?

[lowell holmes]

I always loft a full size plan on a sheet of 1/2" thick plywood. You can measure the geometry and angles.

The plan will allow you to locate the dominos if you intend to use them.

I start a chair design on AutoCad and then loft it on plywood.

[Yonak Hawkins]

Yonak, since you own a Stickley chair with this kind of drop in seat, would you mind giving me some info about it?

Sure :

Height of seat. See my image here. I need to slightly tweak my front rail and when I do, it will be at the 17-1/4" height. How does this compare to yours?
7-7/8" The front stretcher is at 10-1/8", if you're interested.

Seat frame. Is yours a solid panel or is it 4-side framed? Are you able to see what thickness it is?
4 rail frame. It seems to be about 7/8" thick with the top edge proud of the frame by about 1/8". ..And since the legs rise 3/16 above the frame, that would make the notch 15/16" deep.

[Kent A Bathurst]

On the seat support, etc. - you have nailed it dead-nuts.

Gene - my original answer is accurate but, on further reflection, incomplete.

When I made a dining room set on commissions a few years ago, it included 4 side chairs and 2 arm chairs [plus table, and a few side tables for silverware, napkins, art, etc.]

Realizing I am no kinda upholsterer, and recognizing a complete lack of interest in learning, I did some research, and had my client select an upholstery shop from a list of a few that seemed qualified to me.

Off we went - talked with the guy, who - interestingly - said "Whenever I have done this for custom-made chairs, I have always needed all the chairs, because of the variations from one to the other."

So we had him come to the shop/basement. Here is what I learned there:

1. He looked at the chairs, said "never mind - these are all exact copies, and I don't need the chairs."
2. I had not [yet, anyway] notched the legs for hte seat cushions
3. I had a plywood template of the correct dimensions - notched to fit around the post
4. Him: "you don't want solid base for cushions. You want frame and web [or did he use nylon cording?]. Much more comfortable, and just as strong."
5. You can leave the notches in the cushions, or you can notch the legs - entirely your choice - we do it both ways, and it does not matter to us - [but - it added maybe $20 per cushion].

We left them as is - the frames and cushions were notched to allow for the legs.


So - your plan is entirely correct. Going the other way is correct too. But - I can't speak to the Stickley authentic method.

The dining set was definitely A&C - with my own design cues tossed in. I like to think it is how Stickley would have designed it if he had only thought to ask me first.

The stuff move to St Louis a year ago. I do not have access to my dimensions but I will near the end of the coming week [gotta renew my AutoCAD license]. After that, you are welcome to any dimensional info I have, if you want it.

[Gene Davis]

Thanks to Yonak and also to Kent, I have a pretty good feeling about my now-edited chair model. It is shown here in three views, top, front, and side.

The front seat rail has its top 17-7/8" off the floor. The front legs have the same notch I showed earlier for the inset seat frame, which I will do as four-sided open, either with true m&t, domino, or bridled joints. The chair will have floor-wear buttons at bottom of legs, so I will maybe trim the legs at bottom by the thickness of the buttons, so as not to jack up the seat height.

In Sketchup, I have an app that can permit printing full-sized paper patterns, part by part, and it prints indexing crosshairs at corners of letter-sized sheets so you can make a full sized pattern of about anything you want. Have done this before, using spray adhesive, to mount the patterns onto stock before cutting. I can also import parts into my Chief Architect software and send full sized parts to layout if I can talk a shop into printing continuously from a roll. Did that before for housebuilding stuff like staircase work and curved roof elements.

The big question for me is the Festool domino joinery, which I would like to try for this. Since there are no right angles in the joints, I am thinking of making simple jigs and fixtures for cutting the mortises with a DF 500, the fixtures to position the surface to be mortised at 90 from the table, and platens of required thickness for going under the base of the tool to position the mortises properly.

All tenons to be aligned normal to joint face.

To try the build, I'll see about getting some stock in poplar or something to make a prototype. Chairs don't really require much lumber.

If anyone is a Sketchup user, the chair is not up on the 3D Warehouse for downloading. Search "dining chair Stickley MacIntosh" and you will find it readily.

[Kent A Bathurst]

Did not work thru the details of your plans on the mortise/tenons. But - here is what I did - same issue.

I did the mortises @ 90* to the face[s] of the legs.

Then, I cut the tenons at an angle. That meant that the tenons were not centered in the rails, they were off-center, so that the angled tenon would end up where I needed it.

I've never had my hands on a Domino, so IGNI how it handles my approach -which was to reduce the problem to as few # joints as possible - which means only the tenons on the side rails were an issue. Everything else was normal [in the geometrical meaning of "normal"].

Except the backs - 52" +/- height, with 9 square spindles in curved rails........that was a different problem. I put rounded tenons on the spindles, and drilled holes in the rails, then "eyeballed" them square during glue-up. One whole dang lot of holes and round tenons in the 12 rails for 6 chairs @ 9 spindles each - I can give you that for nuttin'. That got real boring real fast.

[lowell holmes]

I downloaded the Sketch-up file you mentioned. I realize that the style of these chairs are what makes them desirable.

The dimension from the back splat to the front rail of the chair is 20". This is about 2" longer than what I expected it to be. I know it would change the appearance a bit, but I probably would build the chairs 18" in depth. I think 20" is a bit long for the ladies that will be using the chairs.

I think the tenons or Dominos, what ever you use, could be dealt with by lofting the chair as I mentioned before. I we learned to loft the chairs when I attended some chair classes a few years ago.

It's not difficult to cut the angled tenons with hand tools using the information from lofting. I always cut the front and back angled tenons with handsaws. You can do it in less time than it will take to set up the jigs required to to it with power tools. I guess I'm saying that Kent's approach is the one I use.

The design is a good design. I like it, and think they would be fun to build.

[Gene Davis]

I spent some time doing dominos in the model. Sketchup makes it so easy to do, it is just incredible. I have a model file called "domino kit" that has a collection of each domino tenon and each mortise for the tenon. I import the kit into my chair model, or any model, and just start copying and pasting the mortises into each joint, rotating and aligning as required.

Here are some xray views of joints. Xray is perfect for examining mortise and tenon work and adjusting offsets, depths, and in this case, the choice of domino size.

In this view you can see the front leg and how the top is notched for the inset seat frame.

2014-10-11_1730.jpg

At the rear of the frame, I needed to move the back seat rail back so as to avoid tenon crash. I had the rail front face flush with the back upright leg/back parts. Moved back now, it will mean that the seat frame will need to be notched and thus the upholstered top tucked to the notch. Even so, there is a small bit of tenon interference, and the tenons will be sliced or ground off accordingly. Two views shown. All tenoning is done normal to the joint planes.

2014-10-11_1959.jpg2014-10-11_2000.png

[Gene Davis]

Lowell, thanks so much for your careful and thoughtful analysis, after taking a good look at the model. Just what I needed.

Here is a pic from the catalog that shows best where I made my sizing and arrangement error. Note how the back of the chair, at its topmost, is not directly plumb over the extent of the leg at its bottom. If you look at my side view in post #8 above, you can see that I modeled it as if it was plumb. Wrong!

I include the photo here and my earlier side view.

[Chris Parks]

I am so envious of people who can use SU for projects. I just haven't got it in me, just like I can't draw any sort of perspective 3D with pencil and paper.

[Gene Davis]

So I went to the model and turned on the hidden layer in which I have a translucent box at the size given in the catalog for the chair, L x W x H. The earlier version of the chair with its more upright back frame and its longer seat fit this box perfectly. I began with the box and designed it from there, looking at photos.

But in my now-modified version, I rotated the back frame to pitch the top back past the legs, and moved the whole frame forward, shortening the seat by almost 2-1/2". Seat depth had been 20-1/4" deep before, and it is now 17-13/16".

I may take a half degree of rotation off the back and move it back to try for 18" seat depth, but I am much closer to a good design now, thanks to you. But for now, here is the hacked chair. I'll need to re-rail the sides when I am done adjusting this.

2014-10-11_2030.png

[lowell holmes]

I was afraid I might be overstepping a bit. I'm glad it helped.

If I built the chair, I might put rockers on it.

Just kidding. But I would put some curve in the back splat to provide lumbar support. I built a rocking chair for one of my children that was inspired by Greene and Greene design. It was the first chair I built that the back was not straight. I curved the back splats to provide lumbar support and it is incredibly comfortable. There are pictures from the Los Angeles museum in circulation that provided the inspiration.