Thread: A comfortable zigzag chair

I'm at a similar stage in designing a side-z-table. I am determined to avoid the extra bracing blocks, since I think they look ugly and interfere with the ability to nest, and am currently experimenting with dovetails and keyed mitres. See
http://www.woodworkforums.ubeaut.com...1&postcount=44

Will follow your progress with interest.

Zenwood,

I think that you can easily dispense with the bracing in a side table, since it will normally only be required to support one or two kgs, rather than the weight of a person. Perhaps you could reinforce a mitre joint with biscuits, if you made a 22.5° wedge to support the biscuit joiner's fence.

Rocker

Hi rocker

looks very interesting but I dont think it suitable for families with young grandchildren, you could be telling them to sit still rather a lot of times.

Well???????


(sound of foot tapping - rapidly)



Have you finished yet Rocker????? WE ARE WAITING!!!!!


To say I'm interested in the results is a slight understatement

By the by, there's a story on zig zag chairs in the latest Wood Review.

Cheers
Michael

Bloody hell, I just had a bit of a twilight zone moment.:eek:

I was tossing around the idea of making one (to start with) of the Zig-zag chairs described in the latest AWR.

I thought to myself, "Self, post a thread on the BB asking for advice!"

So log on do I, only to find a thread on the exact subject, post not 3 hours earlier!:eek:

Rocker,

I know you said you are using white oak, but I would like to know your, and anyone else for that matter, thoughts on using 25mm marine ply?

Asthetics aside, my concern is the strength of the ply at the joins.

Thanks in advance.

Gaza what if you combined some aluminium at the joins?
I can think of two ways, one involves welding aluminium to form the angles into sleeves that the wood slips into(rebated wood so its flush), the other would be to cut angles from flat sheet and use them as braces inbetween wooden strips... I reckon it would look quite spectacular!

Gazaly,

I am not an expert on marine ply, but my guess is that the wood species used in it might not be hard enough to withstand the high pressures at the fulcrum point without crushing. Also, I can't see any reason not to use a solid hardwood, which will certainly be more aesthetically pleasing than ply. I think Jarrah would work well.

Harry,

I had thought of using sheet aluminium to reinforce the joints in my design, but decided in the end that I could make bridle joints strong enough to make reinforcement unnecessary. But for mitres in the traditional Rietveld design, such reinforcement might allow the wedges to be dispensed with.

Rocker

Thanks Harry and Rocker,

To explain my reasons behind the ply:

• The acticle hints at using pine to build the chair, hence my thinking the ply would possibly suit, strength wise.
• This may seem wierd, but I have an idea for a dinning suite which involves using ply, while making a large feature of the lines created by the layers.
• I also have conserns in gaining a strong enough but join in the panels, whilst also keeping it flat. The movement of timber such as jarrah or similar hardwood concerns me also.

These concerns can mostly be put down to inexperience and lack of knowledge on the subject, so all comments, good or bad, are welcomed.

Harry, the ali idea interests me. I'm going to do a small drawing to see if I understand what you mean by the first suggestion. Sorry but I don't understand you second suggestion. Could you please expand?

Rocker, I do apoligise for appearing to hijack you thread. I just thought the subject was too similar to split them.

These two pictures show the use of a dado set and my tenoning jig to cut the tenon at the lower end of the back side rail and the slot at the front of the seat side rail. The tenon is cut using a spacer and fine-tuning shims between the two outer blades of the dado set. With this setup, it is easy to repeatably cut tenons of the desired thickness, plus or minus 0.05 mm. Note that the tenon shoulders are cut first. I used a Kreg mitre gauge to hold the workpieces at the requisite 45° or 82° angles for cutting the shoulders.

Similar precision is achievable when cutting the corresponding slot for the tenon, using a chipper blade and shims between the outer blades of the dado set. Hence there is usually no need to adjust the tenon thickness with hand tools (sorry, Dark-siders!). I just use a chisel to pare away the small amount of waste in the angle between the shoulder and the tenon.

Note the improvised 45° and 82° MDF set-squares used to ensure that the workpiece is clamped at the correct aggle against the tenoning jig's fence. These are, of course, removed before making the cut.

Rocker

Gazaly,

I don't know where you got the idea that the article in AWR 'hints at using pine'. In fact, it specifically states that blackwood was used. Pine would be useless - since it is far too soft and weak to make the Rietveld chair. Wood movement will not be a problem because the grain orientation is the same throughout. I am very dubious about the feasibility of making the Rietvelt chair in plywood; for a start, dovetails do not work in plywood, although box-joints are OK. However, it is up to you, but my recommendation would be to use a hard hardwood.

Rocker

Originally Posted by Rocker

.....I don't know where you got the idea that the article in AWR 'hints at using pine'. In fact, it specifically states that blackwood was used.....

Rocker,

Australian Wood Review #48, page 86, 5th last paragraph, 2nd last sentence:

The chairs weighs 7kg and used about $120 worth of timber.

Yes, I agree this refers to blackwood, as stated earlier in the article.

Next sentence:

Originally Posted by AWR #48

A pine version weighs about 5kg.

To me, that's a hint that a pine version was made and it weighs about 5kg.

Also, on page 84, there is a picture of 2 chairs stacked together. I thought the top one looked like is was made from pine.

Please correct me if I am wrong in this.

I very much appreciate yours, and all others, advice or comment on anything I post.

If you want me to take these posts off your thread, just say the word.

Oops, sorry Gazaly. I should have read the article more carefully. But I would still be dubious of the durability of a pine version.

Rocker

Thanks Rocker,

I am going to contact AWR and get the good goss on it. Will post the results.