Saturday, October 29, 2016

DCBE 2016, Roubo campaign stool.

The day before yesterday, I started a Roubo style campaign folding stool in elm and canvas, and that is one of the quickest projects that I have ever done.
Technically it doesn't count as a chair, but we agreed that it was OK to make it during the event despite that.

I silver soldered a tri-arm bolt from some of the 8 mm lag bolts that we used for the arm rests on the Roorkees. I think that it took me around 5 minutes in total to make such a bolt.
First I cut some lag bolts to a correct length so the legs would rotate on the part without a thread.
Next the ends were filed so they had a 120 degree angle on the end, and I placed them on a piece of heat resistant brick. The brick I used is actually a spare vermiculite stone for our wood burning stove, but it won't damage the stone to do a bit of use before one day replacing one of the stones inside the stove.

The legs for the Roubo campaign stool are pie shaped. It is relatively easy to make those on a table saw. Just remember that they shouldn't be 120 degrees, but more something like 115 degrees. Otherwise the chair won't be able to open up the way it should. After sawing them out to something like a diamond shape, I drew a circle with a compass, and worked to this line with a scrub plane and a smoother. Finally I sanded it to a very round shape.
The holes were drilled with the help of a piece of wood with a V shaped notch in it to hold the leg in position.
I applied two coats of shellac and followed by some homemade paste wax made out of beeswax, orange oil and a bit of turpentine.

I didn't have anymore leather of the same colour as that on my Roorkee, so I tried to use some canvas instead. I am not quite decided if I like it or not.
The good thing about it is that it is lightweight, and it doesn't look too heavy like some of the leather versions I have seen. It also folds really easy, which I doubt that a leather version would do. But the colour would look better with leather.


Roubo folding campaign stool.

Diamon shaped legs.

Don't aim for 120 degrees like this!

This is how they should look.

Opened legs with a 115'ish degree angle.

Lag bolts cut to length.

video

The completed bolt before trimming the excess thread off.
Placed on top of the legs (still at 120 degrees).



14 comments:

  1. That is an impressive looking tri-bolt

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    1. Thanks Ralph.
      I have often wanted to try making one of those, since I have had the general idea how to do it. It turned out my idea was spot on, and it really didn't take more than 5 minutes.
      Well, first I had stripped the zinc of the bolts, as they were hot/dip zinc plated. But I didn't have to look at that part while the acid did its job, so I don't count that into the time equation.
      Brgds
      Jonas

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  2. Cool stuff, Jonas. Is that a standard propane torch that you used, or something else. And what was the solder material? Please let us know if anything ever fails with the tri-bolt.

    Matt

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    Replies
    1. Hi Matt.

      the propane torch is a slightly larger torch that fits on top of a tank filed with a propane/butane mix. So it is connected with a hose since the tank I use is an 11 kg tank (the same size that also fits the gas grill).
      But a regular Mapp torch will generate enough heat to do silver soldering.
      The silver solder material is something called "Unitor AG 60". So it has a 60% silver content. But I am sure there are other different brands that will do the same. It is a type where the flux material is coated outside the silver core. But you could just as well use a model where the flux is in a small jar and the silver rod itself is bare metal.

      I'll let you know if it ever fails.

      Brgds
      Jonas

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  3. Hi Jonas,

    The stool is beautiful. The finish looks really nice, especially in person!

    I can't see your video on my iPad, so I uploaded it to YouTube. Feel free to embed it in your post if you like. Here is the link:

    https://youtu.be/lBDp7nNnjzg

    ReplyDelete
    Replies
    1. Hi Brian

      Thanks for the link.
      I just tested on our Ipad, and I can't see it on that one either. I have no idea why not.

      Cheers
      Jonas

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  4. Very nice Jonas! The tri-bolt is a thing of beauty. I think I actually prefer the look of this stool with the canvas seat over the leather versions.

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    1. Hi Greg.
      Thank you so much for the nice comment.
      I considered making a recess for a large grommet with roughly a 3/4" hole in it, so the seat could be dismounted for easy storage. But I had already rounded the legs at that time. Perhaps I'll make another one some other time.
      I am also thinking about making another tri-bolt the same way, and make some tests to see how much it will hold up to.

      Brgds
      Jonas

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  5. Nice work! I really like the diamond legs over the round ones.

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    1. Thanks Jeremy.
      It really like the looks of the legs, but I am still not 100% happy with the seat. But I might make another version some day. But it will have to do for now.

      Brgds
      Jonas

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  6. It is always fun to see something that at a glance looks so simple. only to find out on closer examination that it is actually quite involved and took some careful thought and planning by its maker.

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    1. Hi Johann.

      At first I assembled the stool with the nearly 120 degree legs. The result was that it couldn't open unless the tri-bolt was very loose. So I guess that is why Roubo's drawing shows the legs with something like 115 degrees angles..

      Brgds
      Jonas

      Delete
  7. Hej Jonas

    Skamlen ser virkelig fin ud! Får helt lyst til at prøve at lave en selv.

    Stødte på din blog via Brian Eves blog/instagram profil og opdagede at du bor på Mors.

    Jeg er selv vokset op på Mors, men vidste ikke at der var andre folk deroppe med samme interesser som jeg selv. I det hele taget virker det ikke som om, at træmiljøet her i Danmark er særligt godt forbundet, så det er altid fedt at opdage nye folk. Især når de findes på ens egen fødeø.

    Hvis du vil se hvad jeg laver kan du prøve at kigge på instagram. Jeg har profilen "Haandkraft". Har også en gammel profil på blogspot, som jeg dog ikke har brugt i flere år. Der finder du mest gamle projekter og mest middelalderting.

    Jeg vil følge med her på bloggen fremover og derudover vil jeg bare sige hej :-D

    MVH
    Mikkel

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    Replies
    1. Hej Mikkel

      Tusind tak for at du kiggede forbi.

      Jeg er i modsætning til Brian aldrig kommet igang med instagram, da jeg sværger til gammeldags telefoner med knapper. (Mine "fede" pølsefingre harmonerer ikke særligt godt med touch skærme.) Så det er super at jeg kan køre lidt med på frihjul på hans konto.

      Jeg er så heldig at have fundet Olav, der også bor her på Mors som også arbejder i træ (udover hans daglige job som tømrer) Men jeg er enig i, at det ikke er helt så almindelig en hobby som f.eks. håndbold hvilket er synd.

      Jeg har lige prøvet at kigge på din Instagram profil, og det er da superfine ting du laver.

      Skamlen er virkelig hurtig at lave. Der er minimalt forbrug af træ, og når man har savet det ud er det bare et spørgsmål om at høvle ydersiden rund.
      Tri-bolten lavede jeg af nogle 8 mm bræddebolte, og så monterede jeg nogle topmøtrikker på den. Det tog ikke meget mere end 5 minutter at lave den, og fordelen ved sådan en sølvloddet model i forhold til f.eks. den som man kan købe hos Lee Valley er, at man kan få benene helt samlet.

      Mvh
      Jonas

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