New default extruder + improved X carriage

[josefprusa]

Printer definitely needs new extruder drive mechanism.

• Gregstruder based, but less smooth carvy stuff (its pain to work with and looks gay :-))
• Smaller footprint
• ! Possiblity to mount two without big issues side by side
• ?! Compatibility with drive screws we have now

X-Carriage

• Needs to be updated to lm8uu (I think I know how, will draw later in comments)
• Needs to firmly support the extruders, what we have know is springy :-((( [nozzle and carriage are parallel, while joined only on one side, makes C shape and acts as spring]

[AxTheB]

x-carriage is already updated to lm8uu, reducing springiness is on the way.

[AxTheB]

vlnofka is working on extruder

[vlnofka]

extruder added in df8e338 . We need to check if it won't wobble.

[Lodran]

The current carriage may have an issue with the belt dragging, given that x axis belt idler has been changed back to 22mm diameter.

[AxTheB]

Lodran: Yes, carriage has issues with belt atm. Thinking about it.

[Lodran]

From what I can see, the choices are:

1. Use a smaller idler bearing.

Smaller diameter bearings generally come with a smaller width, and therefore require a printed belt guide. In my experience, the belt guide is one of the more difficult parts to print correctly.

2. Increase the distance between the rails (50mm would be enough).

May reduce build height, or may not - depending on the height of the extruder.

3. Move the belt.

Of the three, I like this option least. The current belt path helps keep the carriage small.

[kliment]

On 07/03/2012 09:16 AM, Lodran wrote:

From what I can see, the choices are:

1. Use a smaller idler bearing.

Smaller diameter bearings generally come with a smaller width, and therefore require a printed belt guide. In my experience, the belt guide is one of the more difficult parts to print correctly.

2. Increase the distance between the rails (50mm would be enough).

May reduce build height, or may not - depending on the height of the extruder.

3. Move the belt.

Of the three, I like this option least. The current belt path helps keep the carriage small.

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Reply to this email directly or view it on GitHub:
#4 (comment)
Option 4 - move the belt clamp on one side of the carriage only. That
way the belt path is straight on both sides.

[Lodran]

Kliment: the problem isn't that the belt path isn't straight, it's that there's not enough room for belt and bearing clamps, with a 45mm spacing, and a 22mm idler. It gets worse if you put a belt guide on the idler.

[Lodran]

With the vertical X axis design I'm working on personally, I ended up going with option 2, and increased the distance between the rails to 50mm, as the 45mm spacing was forcing far too many of my design decisions.

My vote is for increasing the rail spacing to 50mm, and keeping the 22mm bearing.