Category - DIY

The chair is now complete and in use! If anyone has any questions you can email me via the contact form (comments were abused so I turned them off).

Here are a couple of diagrams showing how I put the parts together – you need to refer to parts #1 (plus update), #2, and #3 (plus update) for this to make sense, of course.

First of all, this is the seating section (the seating plate attaches to the top).

To put it together, I used a pair of small G-clamps to hold to spacers (SP2a and SP2b) in the positions I had determined for them on one of the struts (A1). I made a weld along one edge so I could get the clamps out of the way, then finished off the welding in a vice. Then, I used the G-clamps again to hold the other strut (A2) in place – I used a mallet to knock it into position to obtain the correct spacing (so my screw-adjust riser would fit). Note that at this stage I also made sure the curved bottom ends were level with each other so the foot (C1) would be horizontal. Then I made the welds as described above.

I used a pair of powerful welding magnets to hold the foot (C1) in place while I welded it in place.

I made sure the 45º angle cuts were level with each other (just a little filing was needed to get the Seat Plate to sit level), then I used the welding magnets to hold it in place while I welded it.

Once the seat plate was welded in place (see diagram opposite for placement), I was able to slide in the Seat Support Struts (A1a and A2a) – again holding them in place using the magnets. They actually fit almost perfectly, but I did a little trimming to make sure I got the best fit possible. In each case I welded one side so I could get the magnetic clamps out of the way, then finished off the whole weld (all four sides) in a vice. Note that the dotted squares in the diagram show the approximate placing of the struts on the Seat Plate.

Next, the Knee Section. This is a little easier – note that I originally planned to use two spacers on this section, but I didn’t allow for having to slot the Seating Section through it, and a spacer higher up would have got in the way.

I assembled this in more or less the same way as the Seating Section. Initially, I clamped the spacer (SP1a) in place on one strut (B1) and did a single weld, then finished it off in the vice with the G-clamp out of the way. Then I positioned the other strut (B2), making sure the curved cut-out was level with the other one (for the foot) and that the spacing was correct along the whole length. Then I welded it. I welded on the foot as described for the seating section.

I used my angle grinder and a flap wheel to grind down all the welds and to remove spatter.

Next came the test assembly. Omitting the second spacer from the Kneeling Section had the additional benefit of allowing a little flexibility when it came to sliding the Seating Section between the kneeling struts. But I’d got it right and everything fit. I did have to do a little widening of the holes to get the bolts through – with hindsight I would have drilled after welding (unless you are millimetre perfect there is always going to be a slight mis-alignment).

I painted all the parts using Hammerite Metallic Black (from a tin). I inititially tried Hammerite Silver (from aerosol), but apart from the fact it doesn’t fill in imperfections very well, it also looks a bit cheap – too silver, if you ask me! It also makes a bloody mess.

This is the finished stool, fully painted and assembled. You can see how the riser mechanism fits between two sets of holes, and the other set is where the two sections are joined.

You can also see the crappy cushions I am using at the moment – the final stage of this project is going to be to make a decent pair (I’ve found a great company called eFoam who can cut foam to measure).

I’m putting the parts together at the moment – just finished the seating half.

While I was assembling it I discovered an error in one of the dimensions on the diagram in Part 2 of this project.

You can find Part #4 (the final) of this project here.

The support strut longest length should be 90mm and not 110mm.

I’ve amended the original diagram and annotated the Part 2 write up. Apologies to anyone who has been following this (and there appear to be quite a few) – but at least it is an error in the right direction – the part will just need trimming slightly. I used a flap wheel on my angle grinder to work it down.

I don’t know how it happened. I made a mock-up out of paper when I did the original calculation, so I can only guess that I put the wrong dimension in the drawing as a typo – and that’s what I was following!

Incidentally, I’m getting better at welding as I do this and one thing I’ve learned – probably obvious to those with more experience – and that is GO SLOWLY . You get a nice weld without gaps or pockets of slag.

EDIT: If you came to this page from a search engine, don’t forget to look for Kneeling Chair Project parts #1, #2, #3, and #4 (plus a couple of updates) using the site search facility. This project is now complete and there are drawing/blueprints in the other parts.

Here’s an update to my on going project (Part 1 here and here, Part 2 here) to build a kneeling chair .

Also take a look at the Part #3 Update here.

The diagram below – you can call it a blueprint or whatever (I make no claims in that area) – shows the holes and necessary cut outs for the support struts I am going to fabricate from the steel I purchased recently.

Don’t forget that I am using some of the parts from my existing chair, and that explains some of the oddities (e.g. the 9mm holes, the hole spacings on the seat plate, and so on).

The plans above should make sense – the 9mm holes are in the sides of the A and B struts, and there are a set of 5mm holes in the top faces of the B struts for the knee-cushion to be fixed to. All the holes go through both faces of the struts.

At the bottom end of the A and B struts, in the side faces, there needs to be a cut out 30mm across (the width of the box section metal) and with a radius of curvature of ¾” (so it fits the 1½” diameter tube which forms the feet of the chair).

I’ve spent a few hours over each night of the last week sanding the parts to remove corrosion and oil coating, cutting out the curved notches, and drilling holes. I’m hoping to at least start the assembly over the weekend.

EDIT: If you came to this page from a search engine, don’t forget to look for Kneeling Chair Project parts (#1), #2, #3, and #4 (plus a couple of updates) using the site search facility. This project is now complete and there are drawing/blueprints in the other parts.

OK. This ongoing project for a DIY kneeling chair is well on its way now. Here’s the schematic of the parts I’m using and the relevant dimensions. You could call it ‘plans’ or ‘blueprint’, but I’m not making any claims in that area!

Also refer to the next article (Part #3) here.

EDIT: Please note the dimension in yellow… this corrects an error I discovered when I put the seating section together (it originally said 110mm).

I spent today (had most of the day off in order to get this going) trimming the parts. Last week I used an angle grinder to take the 3m lengths of 30mm box and 1½” round steel sections down to manageable pieces. The diagram below shows roughly how the parts will fit together – I’ll put up a better drawing with dimensions later.

Basically, there are two seat struts (A) parallel to each other, and two knee struts (B) the same. The seat struts are closer together and fit inside the knee struts in a distorted X shape. I’ll use the spacers to make sure that the struts are the right distance apart.

You can see how those seat support struts (Aa) I mentioned in Part #1 will work. The original chair didn’t have these, so you can imagine how weak it would have been. In order to accommodate these struts I increased the size of the seat plate from the original, though the hole spacings will be the same. At a later stage I’m going to build my own upholstered seat and knee pads, but for the time being I’ll just transfer the ones off this existing chair (hence the hole spacings).

Anyway, I ended up using a good old hacksaw to cut the 45º angles. It was far less hassle then I’d imagined (from metalwork days back in school). I must confess I used the angle grinder and a coarse grinding wheel to trim the ends, though. I finished/squared these off with a metal file.

EDIT: If you came to this page from a search engine, don’t forget to look for Kneeling Chair Project parts (#1), #2, #3, and #4 (plus a couple of updates) using the site search facility. This project is now complete and there are drawings/blueprints in the other parts.

Well, following on from my previous post on this project, the metal has arrived!

You can find Part #2 of this project here.

I’m just drawing up the plan I need for the component parts at the moment. I also nipped into Makro today and bought a few tools to make the job easier.

Makro stocks a wide range of tools, especially the Fairline range. In the original post Welding Isn’t Easy I mentioned that I’d bought a Fairline arc welder – well, today I also bought a bench grinder . Hard to believe that it only cost £14.99! EDIT: Note that in the finished project I never actually used the grinder.

Looking at the poorly-built original chair I’m using as a template, one of the key weaknesses is the way the seat is attached to the main struts (and that’s apart from the fact that they didn’t weld it on all sides). The two struts are welded on to the plate at an angle of about 40° and although the angle itself isn’t crtitical, the fact that having only two contact points means that repeated standing up and sitting down flexes the metal slightly. This eventually leads to fractures along lines of weakness – either the weld or across the strut itself. It’s all about cutting costs to save money as far as the manufacturers are concerned.

What I’m going to do is include a pair of smaller struts projecting almost vertically from the main struts on to the seat plate (these are not on the original – see diagram to the left). This will give four points of contact and create a strong triangular section (which adds strength). Combined with the fact I have chosen 2.5mm thick box section (the original looks to be about half this), it should yield a very strong finished article.

EDIT (20 May 2009): Incidentally, I was playing with various bits of software tonight and I’ve decided that there is no way I am going anywhere near drawing up a proper blueprint. I’d be here until Christmas! My sketches will be made using my existing art packages, which I know how to use properly.

Instead, I’m going to work out the dimensions of each component, produce them, then assemble them as sub-assemblies in stages. I’ve already measured up the existing chair and the most critical part is going to be making sure the spacing between the pairs of struts is correct to allow them to be inserted one inside the other.

EDIT: If you came to this page from a search engine, don’t forget to look for Kneeling Chair Project parts (#1), #2, #3, and #4 (plus a couple of updates) using the site search facility. This project is now complete and there are drawings/blueprints in the other parts.

Right! A while back I wrote about how welding isn’t easy. Surprisingly, it has been one of the most popular pages – mainly people asking about sticking welding rods, or kneeling chairs.

There is an update to this project here.

I said that come the new year I was going to build a kneeling chair from scratch. One that is bomb-proof. Well, the project has begun, and I’ve ordered the materials from Metals4U (website at www-metals4u-co-uk with those dashes replaced by dots*):

3 metres of 1½” x 14swg mild steel tube for the floor spars

3 metres of 30mm x 30mm x 2.5mm mild steel box section for the main struts

500mm x 500mm x 3mm rolled mild steel plate for the seat mount and spacers

I’m going to draw up the plans (don’t expect a precise blueprint) and post them on here as an on going commentary of the project. I’ll also maybe take some pictures of the intermediate stages and – with any luck – I should end up with a solid metal kneeling chair along the same basic design lines as the one in that picture on the left, but minus the inherent design weaknesses I’ve discovered across three different purchases from online retailers.

To start with I’m going to use the riser and the seat/knee cushions off my existing one (which is falling apart again), but I want to make better/more comfortable cushions at some stage – and that will mean dabbling in woodworking and upholstery!

EDIT: If you came to this page from a search engine, don’t forget to look for Kneeling Chair Project parts (#1), #2, #3, and #4 (plus a couple of updates) using the site search facility. This project is now complete and there are drawing/blueprints in the other parts.

* Note that Metals4U asked me to remove the direct link to their site. As far as I can understand it, as well as getting too big for its boots these days, Google also appears to have outgrown its brain and is penalising companies for links to their websites from “lesser ranked” websites such as this one.