Prototyping 2 Steel Chairs and Moving the Ratchet
Based on last weeks learning we needed more chairs to play with, we also wanted to try some steel chairs to see if they hold up much better than the Aluminum.
This is what we bought:
Like last week Ill talk about each item we purchased then go into overall lessons learned in our second round of prototyping.
This chair is pretty Great! It is sturdy and resisted torquing as one of the steel chairs. However it is shorted and way heavier than our current favorite the Coleman Rambler II.
This chair is also made of steel and has a great height, and may be fantastic in normal use. However for our uses this chair was useless. I broke this the first time we used it. Like the other loop chair it closed by fitting into its self and like that chair if came undone right away.
We built two small sheet metal Cages to support the unhooked side, which allowed us to keep playing with it, but also made it too heavy and difficult to produce for any final product
And as you can see even these eventually bowed.
The Coleman Rambler II still our number one chair.
Once we raise the mounting (the lowest angle, of the chair in its open position) to a minimum of about 2o degrees, the aluminum frame is strong enough to withstand many uses, This cost out-weighs the weight and literal dollar costs of switching to a steel chair.
The other thing we wanted to do was move the ratchet out to the side. First we tried this by hose clamping, steel pipes to the top bar of the rectangular steel chair (a good one for testing since we had given up on it).
The effect of this was to create a much larger chair, with a similar footprint. It looks very sketchy and weighs way to much and is too big to use.
Trying to use this chair from any kind of reasonable starting angle caused the whole thing to torque as the side with the ratchet closed faster than the rest. Unlike with the other chairs, where the curve of the bar restricted the maximum seat depth, friction suddenly becomes a problem. At first we though this was because of the number of wraps, but post testing, it became obvious it was part this but also critically the increase in the angle of the wrap which it turn out is bad.
Next we want to test if this torquing problem is just because the chair is so old and sad, and also try to find some small ratchets, now that we can have it mostly going in straight that, that have larger levers or at least better hand holds.
We have scheduled our next co design with T, so that will be the next post!