09/07/2017 at 12:26 •
The first problem to be solved is to find a mechanism that raises the delivered cigarette to the top of the box.
Because of the restricted space, the cigarette extracted from the reservoir is practically at the bottom of the box, so a system must be found which makes it rise by 11 cm and which is contained in this height. It's not that simple, with a rack and a pinion for example, it doesn't work.
I have kindly been told that a small door at the bottom right would elegantly solve this problem. This is obviously out of question. OK for 3D, but the absurd dimension is important and should not be overlooked..
1. With pulleys
Let's say that it could work, just 50g are needed to operate it every time, but I'm not very optimistic about long-term running, I would prefer a mechanism with a more direct contact.
2. Articulated arm
Here we try to have an arm of a fixed length to limit the friction on the bearing at the end of the arm:
It works too, but stalls a little at the end of the course.
Looks like I'm trying to make a Hoeken link:
With the right proportions, the movement has a rectilinear portion (→ arms of a fixed length), but it is too short. To have a height difference of 11cm, it would take an arm of 15cm, which is too long. Even by enlarging the left wheel, there won't be enough room.
3. Peaucellier link
Another trick that dates from the steam engine:
It is much more compact and the friction is almost constant over the whole length of the movement, so let's try with that.
The shafts of the joints are held by discs which slide over one another. They are made of sintered bronze (self-lubricating) and are very silent when they roll under the furniture.
The groove on the edge is for crimping them in the ABS to the soldering iron. They are turned and adjusted to 1/20 mm, in this project we are not kidding with precision.
The final mounting:
The spring is a little strong, but if I don't finish this project I can still make a toaster.