Linear rod bearing

Linear rod ball and sled bearing. More...

Collaboration diagram for Linear rod bearing:

Files
file	bearing_linear_rod.scad
	Linear rod ball and sled bearing.

Functions
module	make_bearing_linear_rod (pipe, ball, count, angle, h, tunnel, feed, load=1, offset=1, delta=0, gap=10, reveal=50, dilate=15, type=0, align=2, verb=0, view)
	Transform 2d or 3d shape into a linear rod ball or sled bearing. More...

Detailed Description

Linear rod ball and sled bearing.

Requires:
include <omdl-base.scad>;
include <tools/operation_cs.scad>;
include <parts/3d/bearing/bearing_linear_rod.scad>;

Function Documentation

make_bearing_linear_rod()

module make_bearing_linear_rod	(	pipe	,
		ball	,
		count	,
		angle	,
		h	,
		tunnel	,
		feed	,
		load	= 1,
		offset	= 1,
		delta	= 0,
		gap	= 10,
		reveal	= 50,
		dilate	= 15,
		type	= 0,
		align	= 2,
		verb	= 0,
		view
	)

Transform 2d or 3d shape into a linear rod ball or sled bearing.

Parameters

pipe	<decimal-list-2> pipe or rod diameter [outer, inner].
ball	<decimal> ball bearing diameter.
count	<integer> ball bearing tunnel count.
angle	<decimal> ball bearing tunnel angle.
h	<data-list-3> bearing block height.
tunnel	<decimal-list-2> ball bearing tunnel size.
feed	<decimal-list-4> ball bearing feed specification.
load	<integer> ball bearing feed load position (0=none, 1=inner, 2=outer, 3=top, 4=bottom).
offset	<integer> pipe-to-bearing alignment offset mode (0=ball-tunnel, 1=ball, 2=ball-tunnel + 50% of gap).
delta	<decimal> pipe-to-bearing alignment absolute adjustment.
gap	<decimal> ball bearing gap percentage.
reveal	<decimal> ball bearing reveal percentage.
dilate	<decimal> ball bearing circulation tunnel-return enlargement percentage.
type	<integer> bearing type (0=ball, 1=slide).
align	<integer> bearing block zero alignment location. (0=+block_h/2, 1=+tunnel_h/2, 2=center, 3=-tunnel_h/2, 4=-block_h/2)
verb	<integer> verbosity (0=quiet).
view	<integer-list-3> bearing block internal view (0=block, 1=pipe-tunnel, 2=ball-tunnel). Use, for example, [1, 2] to view multiple.

This module transforms a child object into a linear bearing. By default, a 2d profile is extruded into a linear bearing, but the parameter h can be configured to operated on a 3d child object.

The parameters pipe, ball, count, angle, and h are required but the remaining are optional. Default values are used for all unspecified parameters. Default values are also used for unspecified elements positions for parameter that accepts a list of values. For example, the following table are all valid specifications for h:

parameter h	value description
10.5	bearing block height, defaults for remaining
[10.5]	same as above
[10.5, 5]	block height and end cap thickness
[10.5, undef, false]	block height and extrusion options only
[10.5, 5, false]	block height, end cap thickness and extrusion

A single scalar value can be used to specify the first value of a multi-value parameter as shown in the above table.

Multi-value parameters

h

e	data type	default value	parameter description
0	decimal	required	total bearing height
1	decimal	ball/4	bearing end-cap height
2	boolean	true	extrude child object

tunnel

e	data type	default value	parameter description
0	decimal	ball/4	perpendicular tunnel dimension
1	decimal	ball	tunnel corner turn radius

feed

e	data type	default value	parameter description
0	decimal	1	ball bearing feeder size factor
1	decimal	0	tunnel position factor [0:1]
2	decimal	0	rotation angle
3	decimal	tunnel-diameter	ball bearing feeder length

When the first value position of feed is assigned 0, the feed option is disabled. The bearing feed can also be disabled by assigning load = 0.

Bearing example script

    include <omdl-base.scad>;
    include <tools/operation_cs.scad>;
    include <parts/3d/bearing/bearing_linear_rod.scad>;
 
    emt  = [length(0.706, "in"), length(0.622, "in")];
    ball = length(6, "mm");
 
    r = 21.5; h = ball*8; c = 6; a = 85;
 
    make_bearing_linear_rod
    (
       pipe = emt,
       ball = ball,
      count = c,
      angle = a,
          h = [h, undef, false],
       view = 2,
        $fn = 36
    )
    minkowski()
    {
      linear_extrude(h-ball, center=true)
      rotate(a) ngon(n=c, r=r);
      sphere(r=ball/2);
    }
 
    // end_include

Bearing example diagram

top	right	diag

This example uses the view options to see the bearing internals. Click image above to expand.

Definition at line 418 of file bearing_linear_rod.scad.

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