Stool DUN

[Woodbloke]

Having finished the AP Linen Chest, I spun a coin three times to decide the next project and this won I'm not going to try and copy it, but do a version(s), however it's proving 'difficult' to even draw it out on a bit of paper

The chair (not stool) is in the new gallery in the V&A and is worth a gander if you're ever up in Londres. It's an industrial design made mostly by CNC machinery but I'm struggling...there appear to be no angles that are 90deg so it looks like the Domino may be ruled out. Steel dowels (threaded M8 rod) and epoxy? Who knows...onwards and upwards. There definitely won't be a painted steel hoop on what I eventually turn out and apart from the legs and seat supports, there aren't any straight bits of wood - Rob

 

[9fingers]

Chairs and stools can certainly be a challenge certainly compared to most other projects.
I've only done a few (3) and the lack of 90 degree joints and reference planes can be a right pain.

Looking at the stool, the backrest, if that is what it is, looks way too low for any degree of comfort. More of a handle or guard to stop you slipping off after too many sherbets. :lol:

When I did my "splayed leg stool" that I use in the workshop I found drawing out a few full size rods on 6mm mdf and jigsawing out at key points to take references from to set up my machines worked well.
Having 4 legs I ended up trimming the ends until it did not rock :lol:

Good Luck
Bob

 

[Woodbloke]

Chairs and stools can certainly be a challenge certainly compared to most other projects.
I've only done a few (3) and the lack of 90 degree joints and reference planes can be a right pain.

Looking at the stool, the backrest, if that is what it is, looks way too low for any degree of comfort. More of a handle or guard to stop you slipping off after too many sherbets. :lol:

Good Luck
Bob

The actual height of the stool (counter version, the bar one is taller) is 770mm and the seat height at the front is 650mm, but that's part of the appeal. It certainly won't reach up into the small of the back.

I've got plenty of decent pine in stock so once I've done a few full size drawings/rods (front & side elevations + any detail drawings) I'll do a full size 1:1 mock up. I'm coming round to the idea of using steel dowels and proper 'old skool' slow setting epoxy as it ought to give me the necessary time to make any 'adjustments' :eusa-whistle: in the glue ups.

This is the 'Elka' stool...



....which I also took rather a shine to and from my researches over the last couple of days, I found out that it's constructed with steel dowels in the leg supports. On this one, the back rest is much higher so I might go a little higher on the Woodbloke Branca - Rob

 

[9fingers]

The Elka leg and seat joints to me are a "form over function" type design with horrendous stress in the joints at the top of the legs. Absence of a foot rest rail will make it a bit uncomfortable to sit at unless the seat is low enough to keep feet flat on the floor.

Whilst searching on behalf of a UKW member the other day I came across this link with helpful dimensions for furniture to fit humans.

http://www.cawspi.org/Furniture%20Design.pdf

I'll ask DeeJay to put it into the dropbox on the next update as I think it might be a pretty helpful input to design.

Bob

 

[Woodbloke]

The Elka leg and seat joints to me are a "form over function" type design with horrendous stress in the joints at the top of the legs. Absence of a foot rest rail will make it a bit uncomfortable to sit at unless the seat is low enough to keep feet flat on the floor.

Whilst searching on behalf of a UKW member the other day I came across this link with helpful dimensions for furniture to fit humans.

http://www.cawspi.org/Furniture%20Design.pdf

I'll ask DeeJay to put it into the dropbox on the next update as I think it might be a pretty helpful input to design.

Bob

Not sure about that Bob. Have a look at Oscar Pipson's web page on this project and note the very personable young lady perched on it. If you scroll down, writ very small there's a 1>12 sequence of pics (Design Process, including sizes) and below that there's a further 1>10 series (Manufacturing Process) of pics on how the prototype was made, including one of a very chunky 10 or 12mm steel rod embedded in the rear framework, which connects the seat, backrest and legs. Were it built in any other way, I'd agree with you but this looks very 'doable'....or nae. What say ye? - Rob

 

[9fingers]

I have to agree that it does look well done. Bit pretentious basing it on antlers though :lol:

I'd avoid studding unless really chunky stuff.

Remember the core diameter of studding is the thread size minus the thread pitch ( for 60 degree metric threads) so your M8 for example is on 6.75mm core. Now M12 (x 1.75 pitch) would be 10.25 mm core.
Looking at cross section care area M12 is 2.3 stronger than M8

Not sure it gains much having nuts and washers in the seat part compared to gluing in with real mans full lead epoxy and I'd extend the rods as much as possible consistent with being able to accurately drill the mating holes at the right compound angles in the legs and back rest.
If say you used concrete re-bar with a nice textured surface designed for the concrete to grip onto and should be cheap a chips at a real builders merchants, then you would have a really strong result getting on for 3.2 x stronger than M8 studding. (possibly more as re-bar steel is probably higher carbon steel than MS studding. MG might know?

I look forward to the video of the 6-8 axis CNC router and the chips flying when making this for you Rob!

It will be one of those jobs that only you and a handful of forum readers will know the grief and stress input to get the result.

Bob

 

[Woodbloke]

I have to agree that it does look well done. Bit pretentious basing it on antlers though :lol:

I'd avoid studding unless really chunky stuff.

Remember the core diameter of studding is the thread size minus the thread pitch ( for 60 degree metric threads) so your M8 for example is on 6.75mm core. Now M12 (x 1.75 pitch) would be 10.25 mm core.
Looking at cross section care area M12 is 2.3 stronger than M8

Not sure it gains much having nuts and washers in the seat part compared to gluing in with real mans full lead epoxy and I'd extend the rods as much as possible consistent with being able to accurately drill the mating holes at the right compound angles in the legs and back rest.
If say you used concrete re-bar with a nice textured surface designed for the concrete to grip onto and should be cheap a chips at a real builders merchants, then you would have a really strong result getting on for 3.2 x stronger than M8 studding. (possibly more as re-bar steel is probably higher carbon steel than MS studding. MG might know?

I look forward to the video of the 6-8 axis CNC router and the chips flying when making this for you Rob!

It will be one of those jobs that only you and a handful of forum readers will know the grief and stress input to get the result.

Bob

I don't like the antlers either Bob, so I'd go for a Branca style back and I'd sculpt the seat with a power carving thingie to fit my angle grinder...the old firm do quite a nice one for £65. Interestingly, if you click on the images they come up really BIG so it's quite useful to see how they put it together. I reckon this is the prototype 'cos the detail when you view it 'up close and personal' is pretty appalling. Probably go for the 12mm stuff as you advise and proper 'old skool' Araldite and I'll look into concrete re-bar as well. I should be OK if I make a decent enough job of the 1:1 prototype.

Compound angles are interesting as they clearly show a hand held power drill in use for drilling the 'oles, so it seems to be a bit of 'by guess and by God' with the slack in the holes being taken up by a goodly dollop of epoxy. I know it's a really strong method of joining because...



...I used this method on a stick making course I did with Yr10's in the 1980's. If you lean really hard on that lower one with the rosewood handle it won't move and has been solid for over thirty years. Just hope that the stool doesn't end up as bandsaw fodder It has been known -Rob

 

[9fingers]

If it does end up as bandsaw fodder then do make sure you have a metal cutting blade fitted! :lol:

Yes proper araldite* left for 24 hrs or if you do end up needing serious gap filling properties, then West epoxy with a bucket full of filler stirred in.

*Although I'm in the Araldite fan club, it has been around for many many years. One of my earliest recollections is there always being a pack of this magic glue in the bureau when I was a child so the formula has be be at least 60 years old, possibly longer. There are possibly better high performance engineering epoxies around these days.

Bob

 

[Woodbloke]

Yes proper araldite* left for 24 hrs or if you do end up needing serious gap filling properties, then West epoxy with a bucket full of filler stirred in.

*Although I'm in the Araldite fan club, it has been around for many many years. One of my earliest recollections is there always being a pack of this magic glue in the bureau when I was a child so the formula has be be at least 60 years old, possibly longer. There are possibly better high performance engineering epoxies around these days.

Bob

I remember watching Jezza Clarkeson a few years ago when he went to Boscombe Down just up the road from me. He wanted to know what the yellow repair patch was on the wing trailing edge of a Hawker Hunter (still see and hear them overhead sometimes)
He was suitably gobsmacked when someone told him the repair had bee done in Arladite!

Also, back in my school days, a teacher pal tried to shift a face plate off a Union Graduate lathe. I'd glued it on with Araldite and despite repeated haymakers with a forge hammer it didn't budge - Rob

 

[Rod]

Sam Maloof built lots of chairs with similar joints and never used any inserts, just screws.

He freehanded the cutting on a bandsaw.
Lots of videos around of him.

I always fancied making one of his rocking chairs but never got round to it. Philly started one but I don’t know if he ever finished it.

Rod

 

[DaveL]

I always fancied making one of his rocking chairs but never got round to it. Philly started one but I don’t know if he ever finished it.

I asked Phil about it the last time I saw him, he stopped working on it when he realised he would not be able to get it out of his shop once he had finished it!

 

[AndyP]

I always fancied making one of his rocking chairs but never got round to it. Philly started one but I don’t know if he ever finished it.

I asked Phil about it the last time I saw him, he stopped working on it when he realised he would not be able to get it out of his shop once he had finished it!

I think Chris Knight made two, I certainly got to sit on one of them.

 

[Woodbloke]

Having started on this job, SWIMBO has decided that she'd like one as has No.1 son in Londres, so it's too late to wimp out now . I began by starting on a pine prototype and used a 12mm drilling guide from Ax....



...which proved to be far too flimsy as well as hopelessly inaccurate, so today....



...I've made what I hope will be much sturdier and far more accurate drilling jig blocks. 'Cross-hairs' mark the centres of the holes and corresponding 'cross-hairs' are scribed on the blocks, so it's relatively easy to line everything up. The front legs have a 2deg splay and the rear legs have a 6deg compound angle. Each of the rear blocks are 'handed' and therefore need to be made identical, or as close as I can get as any discrepancy will be magnified once the legs go on.
Yandles on Friday to purchase the Ash for this project; the seat block takes up a goodly chunk but most of it will be sculpted later on, which should be incredibly messy! - Rob

 

[TrimTheKing]

Very good Rob. I think you've used the wrong URL in you 'sculpted' link though.

 

[Woodbloke]

Very good Rob. I think you've used the wrong URL in you 'sculpted' link though.

Thanks Mark; now sorted - Rob

 

[TrimTheKing]

Much better. That's what I initially expected to see when I opened your link. :lol:

 

[Rod]

Sam did it all by eye?


Rod

 

[Woodbloke]

Inside 24hrs it's gone from this confection of pine blocks and something, quite frankly, that Picasso could have knocked up in his tea break.....



to this.....



Still much to do, but progress is being made - Rob

 

[RogerS]

How long are your steel bars, Rob ?

That Axminster cutter is a brute ! I've used mine on 200 year old oak and it went through it like butter. I've got in mind to use it to remove some very old and incredibly hard yew stumps !

 

[Woodbloke]

How long are your steel bars, Rob ?

That Axminster cutter is a brute ! I've used mine on 200 year old oak and it went through it like butter. I've got in mind to use it to remove some very old and incredibly hard yew stumps !

Yep, it certainly is but great for ruffing out the basic shape. The longest 12mm steel dowel is about 230mm and joins the rear legs up through the seat and into the uppermost block. I've sat on it and there's no 'give' anywhere and all stuck together with epoxy from Poundland, which has to be the best value epoxy out there - Rob

 

[RogerS]

How long are your steel bars, Rob ?

That Axminster cutter is a brute ! I've used mine on 200 year old oak and it went through it like butter. I've got in mind to use it to remove some very old and incredibly hard yew stumps !

Yep, it certainly is but great for ruffing out the basic shape. The longest 12mm steel dowel is about 230mm and joins the rear legs up through the seat and into the uppermost block. I've sat on it and there's no 'give' anywhere and all stuck together with epoxy from Poundland, which has to be the best value epoxy out there - Rob

That's a seriously long piece of dowel...guess my concern would be the relative short length in the seat. How does the seat fair if you try and swivel while you're sitting in it ?

 

[Woodbloke]

That's a seriously long piece of dowel...guess my concern would be the relative short length in the seat. How does the seat fair if you try and swivel while you're sitting in it ?

It's as solid as a solid thing, much to my surprise. Once there's a good gloop of epoxy in the hole and round the dowel itself, the joint becomes absolutely rock solid, given that you need to allow it to fully cure overnight. It's also essential to drill a 1mm hole from the side into the dowel hole to allow the excess epoxy to squeeze and also to prevent hydraulic lock.
The gouge work was done with a single 10mm gouge but I've got a set of Rider jobbies on their way from the old firm, which should make refining the shape somewhat easier - Rob

 

[Woodbloke]

After much grinding, gouging, spokeshaving and rasp work the final form is beginning to emerge;



It still looks 'heavy' in places and there's a lot of material to remove from the underside of the seat, (once I get my Rider gouges later on today) but it's getting there and here's hoping that I don't meet a steel dowel :eusa-pray: :eusa-pray: as I take off more material - Rob

 

[DaveL]

Now that is beginning to look very nice.

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[Woodbloke]

Now that is beginning to look very nice.

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Thanks Dave; a lot of refining still to do but it's coming along. I've 'only' got three to make in ash after this prototype - Rob

 

[Malc2098]

Nice.

 

[AndyP]

Now that is beginning to look very nice.

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Thanks Dave; a lot of refining still to do but it's coming along. I've 'only' got three to make in ash after this prototype - Rob

You are making an odd number Rob?

 

[Woodbloke]

You are making an odd number Rob?

I'm having one and I asked SWIMBO if she'd like one as well; affirmative. Then in a fit of generosity after a couple of glasses of vino collapso, I WotsAp'd No.1 son in Londres and asked if he'd like one; another affirmative.

A couple of weeks ago, I bought quite a lot of decent 40mmish thick ash from Yandles at the show and have already rough cut the legs for conditioning under the bench, but the thing that's taken up quite a lot of 'folding' is all the stuff I've needed to buy to do the carving and eventual sanding - Rob

 

[AndyP]

I hope you offered one to No 1 daughter

 

[Woodbloke]

I hope you offered one to No 1 daughter

Shhhhhh - Rob

 

[Rod]

I’m very confused with all this No 1 business

Rod

 

[TrimTheKing]

I’m very confused with all this No 1 business

Rod

It just means firstborn, not preference. Well, it could also be preference depending on who's saying it... :lol:

 

[Woodbloke]

The prototype was finished this afternoon and the finish was left from the gouge and rasp, but the concept appears to work;







...and I only broke through into a dowel hole on one of the rear back support rails;



...so on the actual project this dowel will be made 20 instead of the current 30mm. Phill Edwards (Phillyplanes) suggested the inspired idea of gauging the depth of the steel dowel by using a powerful rare earth magnet and it does surprisingly work very well.

Encouragingly it appears to even....



...be quite comfy to sit on - Rob

 

[Malc2098]

:text-bravo:

 

[DaveL]

Nice, but that seat reminds me of Noel Edmonds [emoji1787]

 

[Simon_M]

In the original chair, is the grain orientated in different directions for the upper/lower seat? It looks like the upper seat has the grain through to the ground (vertical) and the underneath is across (horizontal)? What's are the advantages/disadvantages of doing it like that?

 

[Woodbloke]

In the original chair, is the grain orientated in different directions for the upper/lower seat? It looks like the upper seat has the grain through to the ground (vertical) and the underneath is across (horizontal)? What's are the advantages/disadvantages of doing it like that?

You're correct Simon; in the proper stool(s) that I'll be starting shortly, the grain is orientated through 90deg. No inherent advantage or disadvantage, just the way it was done in the original - Rob

 

[Rod]

How deep is it - it looks like a perching stool from the photos?

Rod

 

[Woodbloke]

How deep is it - it looks like a perching stool from the photos?

Rod

Here's the original...



...so yes, not a seat you'd care to take root on tipping down pints on Friday night :lol: - Rob

 

[Malc2098]

This is only an estimate guess, Rob, but I reckon the model's bum is smaller than yours. :?