Jensen-style Z-Chair #6: Seat frame - shaping and joinery

  • Advertise with us
Blog entry by Ross Leidy posted 05-19-2019 07:38 PM 332 reads 1 time favorited 4 comments Add to Favorites Watch
« Part 5: Seat frame - strap recesses Part 6 of Jensen-style Z-Chair series Part 7: Rails »

I’ve been captivated by one detail of the original design that’s easy to overlook. But as small as it is, I think it contributes to the overall lightness of the form. It’s that the side pieces of the seat frame are slightly thinner than the front and rear pieces, and that the side pieces are inset slightly so that there’s a slight reveal at the joint with the front and rear pieces. I tried to find a good photo to show a blowup of the area – this one is okay, but you can definitely see it. There also seems to be a slight curve on the outer edges – not just a simple round-over.

For the softly rounded edges, I picked up a finger nail router bit with a 1-1/2” radius curve. In the end, this didn’t fully replicate the shape of the original, but I’m okay with that because it’s equally attractive (IMO).

I decided on a 1/32” reveal for the joints, which required that the side pieces be sanded down to 11/16” thick. I used a piece of veneer that was pretty darn close to 1/32” to offset the side pieces when cutting the mortises.

This was one of the sight cross-hair styles I tried for the mortising jig. It’s hard to see with this size photo, but there are parallel lines about a 1/16” apart and you center the pencil lines between them.

And here’s where I discovered something wrong – the mortise wasn’t centered. After a long process of trying to figure out where my error was on the mortising jig, the sights, the templates, I eventually found that the new plunge router I bought just for this purpose had a misalignment between the shaft and the bushing holder. (But I digress: It was a Festool, and I assumed it would on-the-money concentric. Unfortunately it wasn’t and the tool did not allow for any adjustment. Some google searches found a lot of people with the problem. Luckily, Festool has a great warranty program and it was repaired within a week with no shipping cost to me.)

I cut the mating mortise with the same off-center position so that the joint would come out right, and then I fiddled with the mortise jig top position to compensate for the error and cut the remaining mortises.

Pieces sanded and dry fit and set aside until later.

4 comments so far

View mafe's profile


12069 posts in 3484 days

#1 posted 05-22-2019 09:16 AM

Now we really see the jig in use.
Woooho I was surprised to read that it was common with Festol routers being not spot on, one would not expect that.
I think it’s fine the front curve you did, but that you need to round over the edges like on the original, just so it feels sweet to touch, as I see it on the original, and what was normal on Danish furniture, you never touch a sharp edge, the furniture must look sharp, but feel sweet.
Best thoughts,

-- MAD F, the fanatical rhykenologist and vintage architect. Democraticwoodworking.

View Ross Leidy's profile

Ross Leidy

59 posts in 2336 days

#2 posted 05-22-2019 01:20 PM

I have eased the sharp edges of the frame with hand-sanding, but I need to do a little more before glue-up. Especially at the corners. I do appreciate the comments from a Dane, though. Keep me honest.

View mafe's profile


12069 posts in 3484 days

#3 posted 05-22-2019 01:59 PM

;-) Deal.

-- MAD F, the fanatical rhykenologist and vintage architect. Democraticwoodworking.

View kaerlighedsbamsen's profile


1291 posts in 2108 days

#4 posted 05-27-2019 08:17 PM

Taks like this were often made using a spindle shaper and costom grinded (ground?) shaper irons made to make that perfect, sharp, but sweet curve MAFE talks about.
Apreciate that you took notice of the small detail and not just igniored it. On things this simple the small details makes all the difference!

-- "Do or Do not. There is no try." - Yoda

Have your say...

You must be signed in to post the comments.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics