Modification suggestion for Carriage

[masterxq]

I have a modification suggestion for the carriages: My model look like this:

The main modification is that the force will not be transferred into a small area of the Plastic as it will be in the current version. With the modifications the force will be evenly distributed and caught by the M8 bold and the side panels.

The underlying m8 bold would go from one side to the other.

In a prototype I used severed m8 threaded rod. This is very cheap and there is no need for a Nut if the holes have a diameter of 7.6 mm - 7.7 mm. This will hold itself.

The two to bold on the sides should be M8 or at least M6, but the two bolds in the middle don't need to be that thick.

Advantages:

• Much stiffer
• Much more stability
• Much fewer requirements on the printed part
• Likely much better durability
• No need for the nuts
• If m8 threaded rod will be used it is cheap
• Faster Printing

Disadvantages:

• Needs modifications on the side panels
• Much stiffer, what could cause problems if the square tube is irregular
• Maybe slightly harder to build

It is possible to use normal infill and wall thickness and have higher wall thickness and infill directly on the ball bearing. This is something i would suggest for printing these parts.

Additionally, it could be helpfully to add a hole under the button ball bearings to be able to easily remove dirt and easily grease the bearings. The holes can also be added to the top carriage, but they should be covered on normal operation.

I did my best to find the correct word to write this, I would like to apologize for any mistakes in the wording :)

Regards

[masterxq]

Here is my zipped FreeCAD 0.20 model: Carriage.zip

Use the table to change parameters.