Chair leg reinforcement + rocker base

[jb94]

Hi all,

I bought a B&Q armchair years ago for a big discount as it was missing a base and at the time bought some metal angled attachment brackets and screwed in some repurposed staircase spindles.

It’s lived in a corner since then and held up to plenty of abuse.

I would like to add some bracing and if possible a rocker bottom to it as my wife wants to use it as a nursing chair.

I’ve done bracing on a stool I’ve made but that was fairly easy as I drilled it all on the pillar drill and could rotate the legs inside the stool base mortise to get alignment.

What would be the best way to brace these legs and is it necessary if I build a rocker base on the bottom? The base of the armchair I believe was ply which the metal brackets were screwed into.

I would imagine for the rocker base I’d build the curve first, either steam or make curve on bandsaw and a. find angle with angle finder and drill a mortise for the leg end to fit into or b. Big dowel joint.

Thanks for advice / tips in advance!

 

[Jameshow]

Yes you could laminate out it or cut it out of some 4in deep stock.
A hard pine, would work, as would beech, or something similar ash?

 

[Cabinetman]

The only rocker I have made from my own design was for my A level tumty tumty years ago, it’s not just simply putting a curve under the legs. The curve maybe shouldn’t be all the same particularly at the back, you also need enough at the back to stop the chair tipping backwards, and what shape of curve? Also the chairs back legs are usually closer together than the front ones, this means that when you add rockers it’s possible to have the backs of the rockers too close together making the mother and baby tip over (congratulations btw).
Sorry to be negative, this means you will need to experiment perhaps by making a quick frame that the chair fits into that you can screw plywood prototypes to. The chair tipping over thing used to be fixed by joining the back ends of the rockers together with a piece of wood that then stuck out on both sides - in effect widening the base at that point.
Don’t be put off it’s not that hard especially now you know the pitfalls. And I managed it!
One last thing when you have the chair sat on it’s test rockers with a person on it you need to have the angle of the seat the same as it was before.
Ian

 

[jb94]

The only rocker I have made from my own design was for my A level tumty tumty years ago, it’s not just simply putting a curve under the legs. The curve maybe shouldn’t be all the same particularly at the back, you also need enough at the back to stop the chair tipping backwards, and what shape of curve? Also the chairs back legs are usually closer together than the front ones, this means that when you add rockers it’s possible to have the backs of the rockers too close together making the mother and baby tip over (congratulations btw).
Sorry to be negative, this means you will need to experiment perhaps by making a quick frame that the chair fits into that you can screw plywood prototypes to. The chair tipping over thing used to be fixed by joining the back ends of the rockers together with a piece of wood that then stuck out on both sides - in effect widening the base at that point.
Don’t be put off it’s not that hard especially now you know the pitfalls. And I managed it!
One last thing when you have the chair sat on it’s test rockers with a person on it you need to have the angle of the seat the same as it was before.
Ian

Thanks for the advice!
The legs should be the same front and back, as they were added ‘aftermarket’ with those angled metal brackets, and as such I can widen the base by screwing those into a slightly different place.

I’ll make a prototype and see how I get on!

I’ll add the braces anyway regardless of the rocker incase I don’t have time to do it!

I imagine just line of sight drilling with a drill through both legs should be accurate enough for the brace? I worry about alignment if I remove as they are screwed into the metal plate

 

[Cabinetman]

Thanks for the advice!
The legs should be the same front and back, as they were added ‘aftermarket’ with those angled metal brackets, and as such I can widen the base by screwing those into a slightly different place.

I’ll make a prototype and see how I get on!

I’ll add the braces anyway regardless of the rocker incase I don’t have time to do it!

I imagine just line of sight drilling with a drill through both legs should be accurate enough for the brace? I worry about alignment if I remove as they are screwed into the metal plate

Thank you, yes that should work, best of luck. I sat in my Alevel project today and I reckon I didn’t get it tilting quite far back enough, I may just be more laid back now lol.

 

[Richard_C]

If you look online for rocking chairs you see some with braced legs and some with bracing between the rockers. The rocker itself acts as fore-aft bracing, so a piece joining them may be all you need.

 

[HOJ]

I have concerns that introducing stresses by adding a rocking action to your "angled metal bracket" leg connectors will lead to them fracturing, and/or pulling the screws out of the plywood seat base, they aren't designed for movement, I've seen enough of them having failed just in normal static service, I would look at making a separate base structure with the rocking option and fix that to the seat as a complete unit.

 

[Jameshow]

I have concerns that introducing stresses by adding a rocking action to your "angled metal bracket" leg connectors will lead to them fracturing, and/or pulling the screws out of the plywood seat base, they aren't designed for movement, I've seen enough of them having failed just in normal static service, I would look at making a separate base structure with the rocking option and fix that to the seat as a complete unit.

I doubt it, as they will be braced by the rockers..