README.md 2.83 KB
Newer Older
Ruben Castro's avatar
Ruben Castro committed
1
# Clear Air Turbulence (CAT)
Jake Read's avatar
Jake Read committed
2

Jake Read's avatar
Jake Read committed
3

Ruben Castro's avatar
Ruben Castro committed
4
The [CAT](https://en.wikipedia.org/wiki/List_of_spacecraft_in_the_Culture_series) is meant (largely) to serve as an easily-replicated, well known machine that can be put to use on a range of common fab processes: pcb milling (or light milling: i.e. molds), 3d printing (swappable extruder heads would be cool), pen plotting (etc), and knife-cutting...
Jake Read's avatar
Jake Read committed
5

Ruben Castro's avatar
Ruben Castro committed
6
7
A few design goals are held in mind for this machine that could make or break the possibility of this machine:
This machine is meant to be made with plastic using mainly a laser cutter and set of 3D printers. The first version of this was made using acrylic. Moving forward, Delrin will be used to prevent cracking, however, both are useable depending on your specific machine needs.
Jake Read's avatar
Jake Read committed
8

Ruben Castro's avatar
Ruben Castro committed
9
10
Total lasercut runtime: ~ 5 hrs
Total 3D print runtime: ~50 hrs
Jake Read's avatar
Jake Read committed
11

Ruben Castro's avatar
Ruben Castro committed
12
The machine CAD is also parametric, meaning you can tune the width, length, depth, structural strength, height, etc.
Jake Read's avatar
Jake Read committed
13
14


Ruben Castro's avatar
Ruben Castro committed
15
16
## Material Selection
A few different plastics can be used. We can talk here about the Pros and Cons of each one to help you better select a material to use.
Jake Read's avatar
Jake Read committed
17

Ruben Castro's avatar
Ruben Castro committed
18
Since we are laser cutting, Acrylic and Delrin are the two main options. If you have access to something like a router, perhaps different plastics can be considered.
Jake Read's avatar
Jake Read committed
19

Ruben Castro's avatar
Ruben Castro committed
20
Delrin ultimately would be the best option if you can. The thing about Delrin is that it's a bit tedious to cut 1/4" on a not-so-hot laser. If you have the ability to do 1/4" Delrin, that's definitely the best option as Acrylic can crack quite a bit. Another thing that we must take into account is hardness. Acrylic is harder than Delrin, and for the bearing rails, there is worry that use will cause heavy wear on Delrin. This will be something to keep an eye on towards the future.
Jake Read's avatar
Jake Read committed
21

Ruben Castro's avatar
Ruben Castro committed
22
23
## CAT 0020
This is prototype version 2 of the CAT. The first attempt ended up being not quite so rigid.
Jake Read's avatar
Jake Read committed
24

Ruben Castro's avatar
Ruben Castro committed
25
![firstrun](media/CAT0020firstrun.mp4)
Jake Read's avatar
Jake Read committed
26

Ruben Castro's avatar
Ruben Castro committed
27
28
### Joining plastic sheets
In order to join the plastic laser cut sheets, 3d printed joinery is made. There is a few types of joinery. The bed uses HexTrompo joints. Named that because they look like the toy commonly used in Mexico: [Trompo](https://en.wikipedia.org/wiki/Trompo). These little dudes help tension the two bed sheets together with the webbing pieces sandwiched in the middle. There is a male one which lies on the top and a female one with a heat insert on the bottom sheet. An M4x55 bolt runs between them and keeps it all nice and taught. This way, all the loads that go on to the bed first come through a 3d printed part softening the load on the acrylic hopefully preventing some of the cracking if you use acrylic. A whole bed's worth should take about 10 printer hours to make.
Jake Read's avatar
Jake Read committed
29

Jake Read's avatar
Jake Read committed
30

Ruben Castro's avatar
Ruben Castro committed
31
32
33
34
35
36

### Making the parts
From the fusion model, you can create dxfs of all the required pieces along with STLS for all the 3d prints.

### Assembly
First up, you want to assemble the bed part.