Screw-drivenLinearStage

From RepRap
Jump to: navigation, search

The RepRap Screw-driven Linear Stage

Version 1 *DRAFT*

-- Main.VikOlliver - 02 Jan 2006


1. Summary

This describes how to construct a linear stage envisaged for use in the RepRap from FDM'd parts. As with other RepRap components, this stage was designed to be made by the RepRap rapid prototyper itself, and thus consists of standard parts plus rapid-prototyped components. No modifications are required to the standard components.

The stage designed to be stepped back and forth to an accuracy of better than 0.1mm by means of a stepper motor and threaded rod. The stage is designed to be transported on top of the Vertical Platform, though it can be stacked upon a copy of itself to make a servicable, compact X-Y table. An X-Y pair in turn can fit on any convenient Z-axis to make a simple RepRap.

Screw-drivenLinearStage-Mk1 Stage Assembled.jpg
  • Stage assembly without end stops wired in place

2. Introduction

The stage makes use of 150mm M6 bolts as guide rails spaced by spreaders, and is designed to be mounted on a square of 4x 4mm bolts at 50mm centres. This matches the top of the Vertical Platform as well as holes in the stage table itself.

A stepper motor is attached to a central support, and a length of studding (threaded rod) is attached to the stepper motor with a flexible plastic coupling such that the studding passes through the centre of a bearing attached to a spreader. Plastic washers and opposing nuts are used to secure the threaded rod to the centre race of the bearing.

The table slides on the four guide rails, and is attached by a restricted sliding linkage to a nut on the threaded rod. Rotation of the rod causes the nuts to draw the table back and forth.

The control electronics are currently hand-assembled, of no fixed abode. No machining other than basic cutting of the hardware is required to assemble the stage itself.

3. Assembly

TBA

4. Components

Mechanics (Under development)
Number off/quantity Description Supplier
1 Support bracket (A) RP part
1 Stage (B) RP part
1 Linkage (C) RP part
2 Spacers (D) RP part
1m 8mm ground steel rod, halved (Z)  ???
110 mm steel M5 studding (E) RS (530-315), Farnell (517343)
50mm 4mm ID PVC tubing (F) Garden shops & hydroponic centres
15mm 2mm ID PVC tubing (G) Garden shops & hydroponic centres
1 12V 7.5 deg stepper motor 48+/-2mm centres or NEMA-17 Mitsumi M42SP-5
4 steel or brass M6 nuts
4 140mm+ M6 bolts, smooth shafts
3 steel M5 nuts
2 steel M3 nuts RS (837-206), Farnell (758796)
2 steel or brass M3 washers RS (560-338), Farnell (149687)
2 steel 25 mm M3 cap screw RS (376-4555), Farnell (100165)
1 steel 35 mm M3 cap screw Toolfastdirect (0150M390035)
4 steel or brass M6 washers
3 steel or brass M3 or 1/8" washers, 10mm dia.
1 13mm o/d, 5mm i/d ball bearing assy.
Electronics (Under development)

Select unipolar or bipolar stepper motor and matching stepper motor driver board.

TBA

-- Main.VikOlliver - 02 Jan 2006

  • Axis controller prototype board on Vero (Vik's version):