rocking chair build
Moderator: admin
If you want to be precise in locating your rockers, you can calculate your longitudinal center of gravity and go from there.
Split up your pre-assembled pieces (excluding rockers) into three piles - back, front, and middle (seat, rails, and arm rests). Weigh each pile and fudge for glue and fasteners. Figure out what percent of the middle pile needs divied up to make the other two piles equal. That roughly marks the center of gravity for the chair.
Set the chair on the rockers and line the center of gravity of the chair with the center point of the rockers (roughly their center of gravity). Adjust from there. Moving the chair in either direction will change the center of gravity by a factor of the chair weight vs. rocker weight (chair weight back offset by rocker weight forward). I assume you don't want perfectly centered rockers which is why I include this step.
You can also do this while still on paper by calculating volumes. Add in the extra step of density to convert volume to weight if you're using more than one material.
Split up your pre-assembled pieces (excluding rockers) into three piles - back, front, and middle (seat, rails, and arm rests). Weigh each pile and fudge for glue and fasteners. Figure out what percent of the middle pile needs divied up to make the other two piles equal. That roughly marks the center of gravity for the chair.
Set the chair on the rockers and line the center of gravity of the chair with the center point of the rockers (roughly their center of gravity). Adjust from there. Moving the chair in either direction will change the center of gravity by a factor of the chair weight vs. rocker weight (chair weight back offset by rocker weight forward). I assume you don't want perfectly centered rockers which is why I include this step.
You can also do this while still on paper by calculating volumes. Add in the extra step of density to convert volume to weight if you're using more than one material.
Part 6: Joints & more joints
I begin to think I must be going for the record of the longest build time between start of a project & the finish! Regrettably, that finish is not yet in sight.
But this is a huge learning experience for me - this isn't in the Beginners section of the forum for no reason! 
I have made some progress though - I used experimentation to establish a balance position on the rockers & I'm quietly confident it will work. I cut the joints into the rockers & the base of the legs to form a "saddle" to lock the legs in position & minimize any risk of the rockers de-laminating.
The tops of the rear legs were then cut to accept the side sections which also had to be cut to slot into the legs. I'm happy with the result
Joint cut visible and one leg assembled:
[ATTACH]21431[/ATTACH]
The legs were freehand cut to shape on the bandsaw so they look a bit rough here. They look much better after lots of sanding!
The finished pair (still not sanded):
[ATTACH]21435[/ATTACH]
Note to self: tidy floor for pictures - and build a workbench!!
So with all those joints cut I re-assembled and it does now sit much better
[ATTACH]21432[/ATTACH][ATTACH]21433[/ATTACH]
Only the seat section is glued up so far but with all the angles established I was then able to cut the joints for the seat lower crossmembers to fit into the legs. The seat & leg assembly is now sitting upside down on my Workmate and the next move will be fitting the rockers onto that, clamping it all tight and measuring for the lower stretchers. I have plans for those that include carving - never tried that before but then I've never tried to build a chair before either!
[ATTACH]21434[/ATTACH]
The front legs are sanded smooth in this picture and they look pretty good. The holes you can see on the side of the legs were for bolts tying the old bed together (remember from part one that these were the legs of the old bunk bed). Part of my cunning plan has been to line those up with the crossmembers and I'll be making use of them to fit dowels to lock the joints. I'll also be using dowels for the same reason to lock the legs into the rockers - I'm thinking mahogany to get the contrast and make a feature of them.
I have made some progress though - I used experimentation to establish a balance position on the rockers & I'm quietly confident it will work. I cut the joints into the rockers & the base of the legs to form a "saddle" to lock the legs in position & minimize any risk of the rockers de-laminating.
The tops of the rear legs were then cut to accept the side sections which also had to be cut to slot into the legs. I'm happy with the result
Joint cut visible and one leg assembled:
[ATTACH]21431[/ATTACH]
The legs were freehand cut to shape on the bandsaw so they look a bit rough here. They look much better after lots of sanding!
The finished pair (still not sanded):
[ATTACH]21435[/ATTACH]
Note to self: tidy floor for pictures - and build a workbench!!
So with all those joints cut I re-assembled and it does now sit much better
[ATTACH]21432[/ATTACH][ATTACH]21433[/ATTACH]
Only the seat section is glued up so far but with all the angles established I was then able to cut the joints for the seat lower crossmembers to fit into the legs. The seat & leg assembly is now sitting upside down on my Workmate and the next move will be fitting the rockers onto that, clamping it all tight and measuring for the lower stretchers. I have plans for those that include carving - never tried that before but then I've never tried to build a chair before either!
[ATTACH]21434[/ATTACH]
The front legs are sanded smooth in this picture and they look pretty good. The holes you can see on the side of the legs were for bolts tying the old bed together (remember from part one that these were the legs of the old bunk bed). Part of my cunning plan has been to line those up with the crossmembers and I'll be making use of them to fit dowels to lock the joints. I'll also be using dowels for the same reason to lock the legs into the rockers - I'm thinking mahogany to get the contrast and make a feature of them.
- Attachments
-
- side joints.jpg (419.97 KiB) Viewed 4433 times
-
- with sides left.jpg (198.18 KiB) Viewed 4428 times
-
- with sides front.jpg (219.28 KiB) Viewed 4431 times
-
- base and legs.jpg (370.78 KiB) Viewed 4430 times
-
- joined sides.jpg (420.17 KiB) Viewed 4433 times
- terrydowning
- Platinum Member
- Posts: 1678
- Joined: Mon Jul 19, 2010 3:26 pm
- Location: Windsor, CO
I'm reminded of the early sequences in the movie the "Patriot" where Mel Gibson's character is trying to build a rocking chair and having less than positive results.
It looks like you are doing much better than that character. Have you sat in it yet?
Keep up the great work and keeping us posted. I have never tried anything like this.
It looks like you are doing much better than that character. Have you sat in it yet?
Keep up the great work and keeping us posted. I have never tried anything like this.
--
Terry
Copy and paste the URLs into your browser if you want to see the photos.
1955 Shopsmith Mark 5 S/N 296860 Workshop and Tools
https://1drv.ms/i/s!AmpX5k8IhN7ahFCo9VvTDsCpoV_g
Public Photos of Projects
http://sdrv.ms/MaXNLX
Terry
Copy and paste the URLs into your browser if you want to see the photos.
1955 Shopsmith Mark 5 S/N 296860 Workshop and Tools
https://1drv.ms/i/s!AmpX5k8IhN7ahFCo9VvTDsCpoV_g
Public Photos of Projects
http://sdrv.ms/MaXNLX
Great Workmanship!
I have been amazed and inspired while following your thread since the beginning and you are to be congratulated on several fronts.
I was surprised to see your choice of raw material. Thinking that it is a doubly hard chore to re-use wood from old projects, I thought this project may not get finished. You have surprised me and probably many of us with your ingenuity and craftsmanship that allowed you to adapt the old bed wood to the new rocker.
Also, although fairly capable my self, I have consistently been hesitant (maybe afraid) to take on planning and construction of a rocking chair. When I see the well thought out curves and joinery of your project, I am not only in awe, but also inspired.
Also you photography skills have enhanced your presentation to a beautifully illustrated extremely easily understood story.
Congratulations, on your work so far and here's sending you best wishes on construction ending and finishing beginning.
One thought in disagreement. - - This project will not at all become the longest build time project. It has only been a month since beginning and constructions is almost completed. Time is not important in furniture construction unless the project has been promised to another at a given date. Care in construction is primary! When my Son asked me when he could expect me to complete his new entertainment unit, the answer was, "I don't know! Time limits create stress! I no longer do stress!" He laughed and understood.
Most projects in my little shop take several months to complete and they are absolutely not as challenging as yours.
I was surprised to see your choice of raw material. Thinking that it is a doubly hard chore to re-use wood from old projects, I thought this project may not get finished. You have surprised me and probably many of us with your ingenuity and craftsmanship that allowed you to adapt the old bed wood to the new rocker.
Also, although fairly capable my self, I have consistently been hesitant (maybe afraid) to take on planning and construction of a rocking chair. When I see the well thought out curves and joinery of your project, I am not only in awe, but also inspired.
Also you photography skills have enhanced your presentation to a beautifully illustrated extremely easily understood story.
Congratulations, on your work so far and here's sending you best wishes on construction ending and finishing beginning.
One thought in disagreement. - - This project will not at all become the longest build time project. It has only been a month since beginning and constructions is almost completed. Time is not important in furniture construction unless the project has been promised to another at a given date. Care in construction is primary! When my Son asked me when he could expect me to complete his new entertainment unit, the answer was, "I don't know! Time limits create stress! I no longer do stress!" He laughed and understood.
Most projects in my little shop take several months to complete and they are absolutely not as challenging as yours.
Octogenarian's have an earned right to be a curmudgeon.
Chuck in Lancaster, CA
Chuck in Lancaster, CA
Part 7 A bit more glue & a bit of fun
Terry, I have sat in it - very gently because it was only clamped together; the structure survived &, I'm pleased to report, so did I 
Chuck, your words are too kind ... really, way too kind! I'm being somewhat selective in my photography - note the lack of close-ups of the joints, particularly assembled joints.
Honestly, they wouldn't inspire you 
My somewhat loose joints led to the first bad setback I've had - the glued up seat assembly didn't survive the rigors of test assembling the full chair & began to flex. That was the result of badly cut joints with significant gaps between the elements & my use of PVA glue (white glue?)
So, realizing that I needed something more substantial I made my way to my nearest wood turning/hobby retailer. Seeking the owner's wisdom & finding that to be in line with the collected wisdom of this forum I made my way home with a bottle of Titebond II & a smaller bottle of Gorilla Glue. The attraction of the Gorilla Glue being that it foams to fill small voids - and boy, do my joints have some voids to fill!
Well, the Gorilla Glue did the job and I was able to use the Titebond on the better joints for the crossmembers:
[ATTACH]21621[/ATTACH]
I've also now got the chair sides for the back glued into the lower back legs using Titebond so they must be reasonably made joints! And the side stretchers are cut ready to fit after the clamps come off the seat base. There are no pix of these items yet, partly because there is little to show and partly because I don't yet want to reveal some details.
I mentioned carving in my last post and these are the prototypes of what are on the stretchers:
[ATTACH]21622[/ATTACH] [ATTACH]21623[/ATTACH]
The ladybird (ladybug to the majority) was inspired by a little plastic one that had been stuck to the bunk bed - probably no. 2 daughter again, she does like sticking things - and I thought it might be cool to add something similar. The mouse recalls a story my father once told me about a woodworker who used a mouse as his trademark, carving one into furniture & Church fixtures that he made. I just Googled that & came up with Robert (Mouseman) Thompson for those who may be interested. That story intrigued me at the age of about 9 so this is just a nod to that.
Anyway, I had never carved anything before so I'm rather pleased, and surprised, with the results
:)
I've now set myself a deadline of the 8th/9th of June for completion because I'm keen to have my daughter get some use out of the chair before the baby becomes a toddler! That timescale is possible, the mahogany dowel should be here this week (after a major search to find a source!!) and most of the hard bits are almost complete.
What can go wrong now
Chuck, your words are too kind ... really, way too kind! I'm being somewhat selective in my photography - note the lack of close-ups of the joints, particularly assembled joints.
My somewhat loose joints led to the first bad setback I've had - the glued up seat assembly didn't survive the rigors of test assembling the full chair & began to flex. That was the result of badly cut joints with significant gaps between the elements & my use of PVA glue (white glue?)
So, realizing that I needed something more substantial I made my way to my nearest wood turning/hobby retailer. Seeking the owner's wisdom & finding that to be in line with the collected wisdom of this forum I made my way home with a bottle of Titebond II & a smaller bottle of Gorilla Glue. The attraction of the Gorilla Glue being that it foams to fill small voids - and boy, do my joints have some voids to fill!
Well, the Gorilla Glue did the job and I was able to use the Titebond on the better joints for the crossmembers:
[ATTACH]21621[/ATTACH]
I've also now got the chair sides for the back glued into the lower back legs using Titebond so they must be reasonably made joints! And the side stretchers are cut ready to fit after the clamps come off the seat base. There are no pix of these items yet, partly because there is little to show and partly because I don't yet want to reveal some details.
I mentioned carving in my last post and these are the prototypes of what are on the stretchers:
[ATTACH]21622[/ATTACH] [ATTACH]21623[/ATTACH]
The ladybird (ladybug to the majority) was inspired by a little plastic one that had been stuck to the bunk bed - probably no. 2 daughter again, she does like sticking things - and I thought it might be cool to add something similar. The mouse recalls a story my father once told me about a woodworker who used a mouse as his trademark, carving one into furniture & Church fixtures that he made. I just Googled that & came up with Robert (Mouseman) Thompson for those who may be interested. That story intrigued me at the age of about 9 so this is just a nod to that.
Anyway, I had never carved anything before so I'm rather pleased, and surprised, with the results
I've now set myself a deadline of the 8th/9th of June for completion because I'm keen to have my daughter get some use out of the chair before the baby becomes a toddler! That timescale is possible, the mahogany dowel should be here this week (after a major search to find a source!!) and most of the hard bits are almost complete.
What can go wrong now
- Attachments
-
- Seat base glue up 1.jpg (371.08 KiB) Viewed 4357 times
-
- Mouse prototype.jpg (374.02 KiB) Viewed 4356 times
-
- ladybird prototype.jpg (344.57 KiB) Viewed 4358 times
Well, I had to ask that question at the end of my last post!
What could go wrong?
Fortunately nothing irreparable; just several things that I would do differently if doing them again - like cutting tenons properly & giving more thought to dimensions when doing so, being more accurate with mortice cuts (Chuck's wedges have proved handy!), not dropping parts on the floor to see what could break off & how big a dent I could make, not dropping a chisel onto that same piece of wood to find out what mark (nasty) a freshly sharpened chisel could make... and more. Fortunately it is now going a bit better
Well, I missed my self imposed deadline - I found that I've still got difficult bits to do
.
So what progress? Well, I got all the holes for the dowels cut while all the faces were square
[ATTACH]21809[/ATTACH]
then I shaped the rockers & upper sides on the bandsaw to taper them.
With that done I was able to glue up the side assemblies - front & back legs, stretcher & rocker.
While the glue was drying I used the SS router function in drill press mode to slot the seat assembly for the back slats:
[ATTACH]21811[/ATTACH] [ATTACH]21810[/ATTACH]
Yet another dry assembly followed to get the angle for the top piece and the lengths for the slats. I know this should all be coming off my drawings but my drafting abilities don't run to compound angle dimension calculations:(. Dry assembly & a tape measure works for me!
[ATTACH]21807[/ATTACH]
with my new measurements I routed the slots in the top crossmember (did I mention I shaped that to give a curve in plan view to match the slat layout and I also made a curved cut in front elevation view for decorative effect. Those combined curves made mounting on the SS (in horizontal boring mode) somewhat ... challenging
. I also got the first slat cut and then assembled it all again to check:
[ATTACH]21806[/ATTACH]
It all held together without the aid of a clamp & I was able to sit in it & rock - very comfortable
It all worked well so I've now got the rest of the slats cut. A bit of sanding & maybe a bit more chiseling & it will all fit together pretty well.
That will leave only the arm-rests to cut & assemble to have all the component cutting completed. I've still to cut & fit the dowels; after that is done I'll finish the shaping work - surform & 60grit paper is doing the trick.
The plan is to finish all the shaping & then glue up the whole thing and finish sand. Finished for next weekend? Probably not
Fortunately nothing irreparable; just several things that I would do differently if doing them again - like cutting tenons properly & giving more thought to dimensions when doing so, being more accurate with mortice cuts (Chuck's wedges have proved handy!), not dropping parts on the floor to see what could break off & how big a dent I could make, not dropping a chisel onto that same piece of wood to find out what mark (nasty) a freshly sharpened chisel could make... and more. Fortunately it is now going a bit better
Well, I missed my self imposed deadline - I found that I've still got difficult bits to do
So what progress? Well, I got all the holes for the dowels cut while all the faces were square
[ATTACH]21809[/ATTACH]
then I shaped the rockers & upper sides on the bandsaw to taper them.
With that done I was able to glue up the side assemblies - front & back legs, stretcher & rocker.
While the glue was drying I used the SS router function in drill press mode to slot the seat assembly for the back slats:
[ATTACH]21811[/ATTACH] [ATTACH]21810[/ATTACH]
A little bit of table tilt added to the slope of the seat gave the correct angle for the slats:
Yet another dry assembly followed to get the angle for the top piece and the lengths for the slats. I know this should all be coming off my drawings but my drafting abilities don't run to compound angle dimension calculations:(. Dry assembly & a tape measure works for me!
[ATTACH]21807[/ATTACH]
with my new measurements I routed the slots in the top crossmember (did I mention I shaped that to give a curve in plan view to match the slat layout and I also made a curved cut in front elevation view for decorative effect. Those combined curves made mounting on the SS (in horizontal boring mode) somewhat ... challenging
[ATTACH]21806[/ATTACH]
It all held together without the aid of a clamp & I was able to sit in it & rock - very comfortable
It all worked well so I've now got the rest of the slats cut. A bit of sanding & maybe a bit more chiseling & it will all fit together pretty well.
That will leave only the arm-rests to cut & assemble to have all the component cutting completed. I've still to cut & fit the dowels; after that is done I'll finish the shaping work - surform & 60grit paper is doing the trick.
The plan is to finish all the shaping & then glue up the whole thing and finish sand. Finished for next weekend? Probably not
- Attachments
-
- with centre slat.jpg (179.6 KiB) Viewed 4289 times
-
- Chair with top.jpg (160.51 KiB) Viewed 4288 times
-
- Drilling Dowels.jpg (154.09 KiB) Viewed 4288 times
-
- slot angle.jpg (137.96 KiB) Viewed 4288 times
-
- Slot cutting.jpg (159.4 KiB) Viewed 4288 times
Time for a Rest
Arm rests: the final pre-assembly components! I originally intended to make these from the pine boards but I didn't have quite enough left 
So the bed slats were put to further use. They are some kind of dark red hard wood - one of the mahogany look-a-likes but not that hard &, I would expect from their original purpose, a fairly cheap product!
However, they are serving me well in this project & the color is not unpleasant - a good match for the mahogany dowels in fact!
To form the arm rests I started by cutting a square peg into the armrest supports:
[ATTACH]21887[/ATTACH]
Then I cut a hole into the lower section of each armrest to fit onto that
[ATTACH]21886[/ATTACH]
before laminating 2 slats per side to get a decent thickness:
[ATTACH]21885[/ATTACH]
After the glue had set I planed , shaped & sanded.
I had been hunting for a spoke shave to round the edges & just couldn't find one locally. I finally came across one in a local branch of a national DIY chain - the last place I would have expected to find that because their DIY has a focus on home furnishings, gardening, paint etc with a few tools thrown in for good measure; a spoke shave seemed a bit too specialized for them. So I now have a decent spoke shave and what a pleasure it is to round edges off with it - quite addictive actually so I better be careful not to round something that should be left square
:eek:
The slats to form the chair back are now all cut, as are the receiving holes in the seat and in the top crossmember. The slats will be loose in the structure to allow for flexing under load.
Base of slats:
[ATTACH]21888[/ATTACH]
and top of slats with, showing at either side, the slots cut into the seat for the base of the slats to fit into. You can perhaps see that the slats will form a curve.
[ATTACH]21889[/ATTACH]
Well, that's all the components ready for the final assembly which will happen soon.
So the bed slats were put to further use. They are some kind of dark red hard wood - one of the mahogany look-a-likes but not that hard &, I would expect from their original purpose, a fairly cheap product!
However, they are serving me well in this project & the color is not unpleasant - a good match for the mahogany dowels in fact!
To form the arm rests I started by cutting a square peg into the armrest supports:
[ATTACH]21887[/ATTACH]
Then I cut a hole into the lower section of each armrest to fit onto that
[ATTACH]21886[/ATTACH]
before laminating 2 slats per side to get a decent thickness:
[ATTACH]21885[/ATTACH]
After the glue had set I planed , shaped & sanded.
I had been hunting for a spoke shave to round the edges & just couldn't find one locally. I finally came across one in a local branch of a national DIY chain - the last place I would have expected to find that because their DIY has a focus on home furnishings, gardening, paint etc with a few tools thrown in for good measure; a spoke shave seemed a bit too specialized for them. So I now have a decent spoke shave and what a pleasure it is to round edges off with it - quite addictive actually so I better be careful not to round something that should be left square
The slats to form the chair back are now all cut, as are the receiving holes in the seat and in the top crossmember. The slats will be loose in the structure to allow for flexing under load.
Base of slats:
[ATTACH]21888[/ATTACH]
and top of slats with, showing at either side, the slots cut into the seat for the base of the slats to fit into. You can perhaps see that the slats will form a curve.
[ATTACH]21889[/ATTACH]
Well, that's all the components ready for the final assembly which will happen soon.
- Attachments
-
- arm rest glue up.jpg (236.1 KiB) Viewed 4226 times
-
- arm rest parts.jpg (365.46 KiB) Viewed 4230 times
-
- arm rest supports.jpg (355.05 KiB) Viewed 4227 times
-
- slat bases.jpg (226.33 KiB) Viewed 4228 times
-
- slat tops.jpg (352.44 KiB) Viewed 4226 times
Dry run
Well, I managed to do the dry assembly quicker than I expected so you get 2 posts in the one day - although, technically, being in Scotland I'm now into the next day.
So before packing up for the night I did this (not sure how much detail will show in the big pic - I'm cheating so that I fit 10 pix into the 5 allowed on a post
)
Progress shots through the dry assembly:
[ATTACH]21891[/ATTACH]
[ATTACH]21892[/ATTACH]
and some different angle views to give an idea of what it will look like:
[ATTACH]21893[/ATTACH][ATTACH]21894[/ATTACH][ATTACH]21895[/ATTACH]
Next step - the same exercise but with ... GLUE
As an aside:
I think I'd managed to use all the available Smilies bar 2 in this thread so when that opportunity above appeared - well, I just had to pop this one in:
which is fairly
- and there goes the other one that I hadn't found a suitable spot for
:D
So before packing up for the night I did this (not sure how much detail will show in the big pic - I'm cheating so that I fit 10 pix into the 5 allowed on a post
Progress shots through the dry assembly:
[ATTACH]21891[/ATTACH]
[ATTACH]21892[/ATTACH]
and some different angle views to give an idea of what it will look like:
[ATTACH]21893[/ATTACH][ATTACH]21894[/ATTACH][ATTACH]21895[/ATTACH]
Next step - the same exercise but with ... GLUE
As an aside:
I think I'd managed to use all the available Smilies bar 2 in this thread so when that opportunity above appeared - well, I just had to pop this one in:
- Attachments
-
- Build collage 1a.jpg (470.17 KiB) Viewed 4221 times
-
- build up 7.jpg (207.16 KiB) Viewed 4219 times
-
- Build up 8.jpg (215.42 KiB) Viewed 4216 times
-
- build up 9.jpg (197.78 KiB) Viewed 4216 times
-
- build up 10.jpg (207.63 KiB) Viewed 4216 times