I was looking for runners of a rocking chair info and saw your video. I’m so glad to view this segment of less than 10 minutes but so valuable. I am on my way to build myself a rocking chair for relaxing after work with your tutor under my belt. Thank you sir. Much appreciate.
- Thanx David. This is the most valuable info re: rocking chairs available anywhere. It takes a knowledgeable level of ingenuity to "figger out" the dynamics of how to make wood rock. Glad you shared this with us. Thanx, again.
Thank you David, I'm currently renovating a Victorian chair full of woodworm and battered by time, but as my ancestors have been sitting in it through two world wars I figure it's worth doing. However the rockers had worn flat and I wanted to re profile them, but didn't know where to start, your video gave me exactly the information I needed, just perfect, many thanks. Roger Southcombe Torquay England
That was useful. Especially since even the geometry of a fixed chair seat, proved a lot more complicated than I was expecting. I appreciate the issue of the person shifting the chair's center of gravity. It can make something completely uncomfortable when "loaded", even if it's a fixed chair.
Great explanation. I'm an Industrial Designer in italy, and thanks to you now I understand better this tipology so I can innovate. about the front and rear "dead zones" where you can change the curve without affecting the rocking movement, if you put it flat tangent to the necesary circunference , and you rock forward, it will stop? it's like you can stay in that position, were your upper body goes forward, and your elbows touch your knees, it feels comfortable? ? or you will feel some force that push you backwardas again? (this position people use tipically when seated on benches without back support) I will aprreciate the answer mr. David, and thank you very much.
Consider where the center of mass moves as you rock. It is no longer in a stable location (directly below the center of the radius nor directly above the contact point with the floor). The further you rock, the further it is displaced from stability and the more it will try to make the rocker return to its neutral point. I do not see a way that the chair would find a second stable point. In reality the purpose of increasing the radius or the rockers past the active rocking zone is to make it a little more safe from tipping over backwards when the person (most likely a child) gets too exuberant while rocking. You do not want to increase the radius on the front side because that will likely make the chair too hard to get out of. I hope this answers your questions. If not, ask again. DW
You mentioned wanting the center of radius to be about one fist in front of your sternum. I'm wondering how to achieve or adjust this. Would you set the height of the front of the seat by the person's leg length behind the knee and then shorten the rear leg posts below the seat to bring the center of radius further away from the sternum? In the other direction, would you lengthen the rear posts below the seat to bring the center of radius closer?
If you want it to rock easier you need to get the center of mass (with the person in it) closer to the center of the rocker's radius. To do that reduce the radius of the rockers which brings the center of radius down or move the seat higher so the center of mass is higher. Which one you choose depends on the height of the user or the stage of construction you are in. For an existing rocker consider putting a pad or pillow on the seat to raise the sitter but you may then need a footrest to keep his/her feet on the ground. Good luck.
Yeah I know your video could be a lot better by changing wide view to a standard view you so we could see you a little better instead you look squatty but it's kind of like the Rockers you can play with it but find the one you like.
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This guy knows his chairs. I've seen a lot of chair builds but not one talked about the physics of their design. Thank you
I was looking for runners of a rocking chair info and saw your video. I’m so glad to view this segment of less than 10 minutes but so valuable. I am on my way to build myself a rocking chair for relaxing after work with your tutor under my belt. Thank you sir. Much appreciate.
helped me a lot with my school project. Much appreciated :D
- Thanx David. This is the most valuable info re: rocking chairs available anywhere. It takes a knowledgeable level of ingenuity to "figger out" the dynamics of how to make wood rock. Glad you shared this with us. Thanx, again.
Thanks for the video...never thought about how a rocker really functions...food for thought.
Thank you David, I'm currently renovating a Victorian chair full of woodworm and battered by time, but as my ancestors have been sitting in it through two world wars I figure it's worth doing. However the rockers had worn flat and I wanted to re profile them, but didn't know where to start, your video gave me exactly the information I needed, just perfect, many thanks.
Roger Southcombe Torquay England
That was useful. Especially since even the geometry of a fixed chair seat, proved a lot more complicated than I was expecting. I appreciate the issue of the person shifting the chair's center of gravity. It can make something completely uncomfortable when "loaded", even if it's a fixed chair.
Fantastic overview. Thank you.
Great explanation. I'm an Industrial Designer in italy, and thanks to you now I understand better this tipology so I can innovate. about the front and rear "dead zones" where you can change the curve without affecting the rocking movement, if you put it flat tangent to the necesary circunference , and you rock forward, it will stop? it's like you can stay in that position, were your upper body goes forward, and your elbows touch your knees, it feels comfortable? ? or you will feel some force that push you backwardas again? (this position people use tipically when seated on benches without back support) I will aprreciate the answer mr. David, and thank you very much.
Consider where the center of mass moves as you rock. It is no longer in a stable location (directly below the center of the radius nor directly above the contact point with the floor). The further you rock, the further it is displaced from stability and the more it will try to make the rocker return to its neutral point. I do not see a way that the chair would find a second stable point. In reality the purpose of increasing the radius or the rockers past the active rocking zone is to make it a little more safe from tipping over backwards when the person (most likely a child) gets too exuberant while rocking. You do not want to increase the radius on the front side because that will likely make the chair too hard to get out of. I hope this answers your questions. If not, ask again. DW
Excellent video David. I see that you haven't added any videos for over 6 years. I hope you're well and also hope you restart making these.
I get filled with dread when I notice a TH-cam creator has stopped producing. Sometimes the reason is tragic.
You mentioned wanting the center of radius to be about one fist in front of your sternum. I'm wondering how to achieve or adjust this. Would you set the height of the front of the seat by the person's leg length behind the knee and then shorten the rear leg posts below the seat to bring the center of radius further away from the sternum? In the other direction, would you lengthen the rear posts below the seat to bring the center of radius closer?
Interesting information concerning how a rocking chair rocks.
thank you! I'm looking to buy a rocking chair. I hope to use this information to help me buy a good one :)
Good video. At our woodworking club recently there was discussion of rocking cribs. Any thoughts?
So profesional ! Have you worked for NASA before ? Thanks for the information David.
Full of tips and tricks
well done
how to increase the rocking effect when you sit with feet off the ground ?
If you want it to rock easier you need to get the center of mass (with the person in it) closer to the center of the rocker's radius. To do that reduce the radius of the rockers which brings the center of radius down or move the seat higher so the center of mass is higher. Which one you choose depends on the height of the user or the stage of construction you are in. For an existing rocker consider putting a pad or pillow on the seat to raise the sitter but you may then need a footrest to keep his/her feet on the ground. Good luck.
@@DavidOWade Thanks a lot, i gotchya!
Nice disclaimer :-)
I read somewhere that ellipse is a good shape for rockers, did u try that?
Oi, what a good vid, and i am not even making a rocking chair.
What a shame this video is stretched, especially since the content requires visual clarity.
⭐⭐⭐⭐⭐ 🇺🇲
I really like the Woodglut plans.
Center of gravity has nothing to do with rocking chairs
Yeah I know your video could be a lot better by changing wide view to a standard view you so we could see you a little better instead you look squatty but it's kind of like the Rockers you can play with it but find the one you like.