CNC Bar Stools

[jTr]

I've been making small batches of these for a local upholstery shop, Stone's Dakota Bison Furniture, who specializes in buffalo hide furnishings. They regularly have clients requesting bar stools, so my goal was to provide an economical, heirloom build chair frame. (tall order)
The 3D buffalo cameo and genuine buffalo hide make them an appealing addition to their line of furnishings.

3344233443


Most of the bulk processing is done on the CNC, including as much of the domino mortises as possible. Recently had an order come in for 12, so thought some of you may find it interesting to see some of the processes involved.

Slabs on the 'Bot
33440

[jTr]

A day or two later, stretchers and small parts are milled and complete, as well as manual domino mortise machining. Note the long tenons extending from top of back legs in the foreground. These act as a spine and alignment guide as the 3 pieces that make up the backrest are stacked and glued during stage 1 assembly:

33445

Followed by first stage of glue-ups. You can see the rough cut stack of backrest assembly at the left:

33446

Then on to the edge sander to tame those backrests. Lots of other processes not shown, such as rounding over all edges as much as possible with trim router, plenty of handwork to blend all the nooks and crannies. Break a real sweat shaping concave face with 150 belt glued to a piece of polycarb that flexes to fit, leveling unevenness that is inevitable from drum end of edge sander:

33449

[chiloquinruss]

A while back I tried to make my wife a rocker. :( So then I went another direction for her birthday! Thanks for sharing your process's. Very informative. Russ

[jTr]

Back leg assemblies after full course of sanding and fairing

33450

Another view showing logo, burned into inside of back seat stretcher. I have nicer engraved plates I use on cabinet drawers, but this is just quicker and not at risk of coming off.

33451

Onto second glue up routine. All domino joints assembled using plastic resin glue. Epoxy is only other adhesive worthy of chairs, but not as easy to clean up, dry or cured. Every other glue type fails sooner than later - its a chair thing. Corner brace blocks are pocketed for ease of fastening slip-seat to chair.

33452

[jTr]

Back to the ShopBot:

33453

Ready for a light sanding of carving, inspection/cleanup of inevitable dings and glue spots prior to heading to finish room.

33454

Will catch up with finishing processes in next couple days.

jeff

[scottp55]

Excellent Jeff!!! :)
That's a Lot of work Well done!
Thanks for showing the whole process(minus the sweaty hand work:)
scott

[phil_o]

Nice looking, well made chairs. Are they made of Poplar? What color id the stain?

Phil

[jTr]

Phil - Poplar indeed. Not my first choice, but still qualifies as a hardwood, is lightweight and economical. Poplar also is pretty friendly for staining.
As for color, I call it walnut. That process also is done with a swifter, production style of finish, which goes like this:

1 Spray on moderate coat of Dark Mission Brown trans-tint dye stain = almost immediate dry time, zero oils to interfere with topcoat adhesion
2 Spray on moderate coat of thinned CAB acrylic lacquer, dyed with walnut color trans-tint. Again, dry in no time
3 Spray on blend of Mohawk knock-down glaze to darken pores, making a more convincing walnut look. Rub back lightly with white nylon pads
4 Spray on 2 coats clear CAB acrylic

Looks like quite a list, but all processes are pretty swift, no waiting between coats. I'll provide images of process in the next day or two.

[dmidkiff]

Nice chair. Thanks for showing the process. Looks like you used screws for hold down, but the picture was too small for me to be sure.
Is there a way on this forum for me to enlarge the picture myself?

[jTr]

Not sure how you can enlarge - I scaled them down from about 1MB to 300k before posting. However, appears forum automatically compresses them when uploading, as they show much smaller file size after upload.
Anyhow - just used 2 screws to fasten 1.25" block with toggle clamp to bed. Made a small yoke to apply downward pressure so backrest was firmly seated on table. Two grip clamps below help stabilize and control slippage. Not much torque here, as all cutting is done with 1/8" ball nose, so a death grip is not essential.

jeff

[dmidkiff]

Thanks for the reply. I think we are talking about 2 different pics. I was referring to pic #3 in the opening post " Slabs on the 'Bot". It appears that there are screws on one end of the board but there doesn't appear to be room for more screws.

[jTr]

You are correct- stage one milling the legs, blanks are screwed to table. 60" Y axis has solid area with no vac hold down, so I use screws with abandon, regardless of all the reasons not to.:o
While there are 2 at each end of the slab, additional screw or two are used in strategic locations out of the bit path. (For some odd reason, those two images are shrinking more than the others on upload.)

Here's a different one where they're more evident.

33463

[dmidkiff]

Thanks again for the reply and the extra pic. I thought there had to be more screws but could not see them. Could not even see space for them with all the cuts. You have a great looking chair.

[jTr]

Sure thing - thanks for the kind words

jeff