State: Early draft, work in progress and likely will receive updates.

Updates

• 2018/08/15: Added Slider with PTFE tube inlets with 1 and 2 axis support with photos and brief test video
• 2018/08/05: First overview with a 3 approaches

While waiting for the shipment to arrive, I thought to study some of the alternatives to wheels on alu extrusions, such as sliders.

Nylon 2020 Slider

Commercially manufactured, apprx. cost EUR 2.50 per piece, sold in 10 pieces bag.

 

 

 

 

 

3D Printed Sliders

Simple Slider

A simple replicate of one of the simple 2020 sliders:

The sliding nose is 5.8mm wide. Ideally this would be printed in nylon; PLA might work as well but tends to stick more and grease or oil is required therefore.

TODO

• print samples and measure friction with PLA
• publish model

Slider (2 Sides) with PTFE tubes

Improving the simple slider with 10mm long 4mm PTFE chunks to decrease surface and use proper material for sliding:

and in use for the Y axis of a Prusa i3 like style:

and a small improvement to take care of the 2nd axis as well (reducing 2nd axis wiggle):

and then mounting them with a carriage together with M3 screws to control tightness:

and a brief test:

Slider (4 Sides) Carriage with PTFE tubes

A bit more complex using PTFE tubes on all 4 sides:

each inner side has 8 tube chunk insets, which gives you the variable option:

• 4 chunks (a 10mm) x 4 sides = 160mm total
• 8 chunks (a 10mm) x 4 sides = 320mm total
• 12 chunks (a 10mm) x 4 sides = 480mm total
• 16 chunks (a 10mm) x 4 sides = 640mm total

The OpenSCAD module takes parameters such as length of the carriage and the diameter of the PTFE tube (e.g. 3mm or 4mm), default length 60mm.

And the adjustable version with 75mm width looks like this:

which breaks the one surface apart with the mounting hole; if a plate would use all 4 holes that side would become non-adjustable that way – so this isn’t ideal, but perhaps work for single side use.

A possible application as X carriage and two Z carriages in a Prusa i3 use case:

TODO

• print model and make actual physical tests, measure friction of the possible options
• publish model

 

 

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