User:Scottlawsonbc
English • العربية • български • català • čeština • Deutsch • Ελληνικά • español • فارسی • français • hrvatski • magyar • italiano • română • 日本語 • 한국어 • lietuvių • Nederlands • norsk • polski • português • русский • Türkçe • українська • 中文(中国大陆) • 中文(台灣) • עברית • azərbaycanca • |
Release status: concept
Description | Lawson is a 3D printer with accurate linear motion and a mechanically stiff frame.
|
License | |
Author | |
Contributors | |
Based-on | |
Categories | |
CAD Models | |
External Link |
Contents
Introduction
Lawson is a 3D printer design by Scott Lawson featuring excellent linear motion accuracy and a mechanically stiff frame. Compared to the MendelMax 2, Lawson eliminates the need for custom sheet metal, significantly lowers build cost, and uses higher quality linear motion components for the X, Y, and Z axes. It is easy to source components for the Lawson printer as 95% of the components can be sourced from only two suppliers.
Introduction
Lawson is a high precision and mechanically stiff 3D printer. Components can be substituted to tailor the printer for higher accuracy and precision, or to lower build costs.
Features
- Stiff, rigid frame with no play
- High accuracy and precision
- Mechanical components can be purchased from two suppliers, minimizing the reliance on a middleman supplier.
- Components can be substituted to achieve higher quality or lower build costs, appealing to a wide audience.
Specifications
Component | λ Variant | ϵ Variant |
Mechanical parts (exc. motors, electronics, screws) | 26 | 26 |
Printed parts (exc. motors, electronics, screws) | 0 | 17 |
Hardware Cost (exc. motors, electronics, screws) | $443.41 | $369.52 |
Controller Electronics | Almost all RepRap | Almost all RepRap |
Printing Size | 200 x 200 x 240 | 200 x 200 x 240 |
Motors | 4x NEMA-17 Stepper, 1x NEMA-23 | 5x NEMA-17 Stepper |
Pro | High accuracy, speed, stiffness | Lower cost, high speed |
Con | Higher cost | Lower mechanical stiffness and accuracy |
Overview
Design Goals
- All printed components can also be purchased off-the-shelf
- 95% of components available from two suppliers, to simplify component sourcing
- High accuracy and mechanical stiffness
- Component substitution can tailor design for high precision or mechanical stiffness
Cost
The total build cost of the Lawson printer is approximately $900 USD. This is the price for all components needed to build a working Lawson printer. Build costs can be reduced by up to approximately $120 USD if printed components are used.
Component Sourcing
To simplify component sourcing, 95% of the components can be obtained from only just two suppliers, Misumi and OpenBuilds Parts Store. Parts that cannot be obtained from these suppliers are:
- Hotend and extruder
- Electronics
- Heated bed
- Glass bed
This gives users the freedom to easily purchase Lawson components themselves, without needing to go through a middle-man supplier selling a kit.
X-axis
The x-axis is a belt driven linear stage powered by a NEMA 17 stepper motor. The axis is constrained by OpenRail which is screwed into a length of 2020 aluminium extrusion. The x-carriage wheels have eccentric spacers that can be adjusted to prevent excessive friction. The belt tension can be adjusted easily by loosening the belt idler and sliding it left or right on the extrusion. A bowden feed extruder is reccommended over a direct drive extruder because it significantly reduces the mass of the x-carriage, permitting higher acceleration and speed values and reducing resonance.
Y-axis
The y-axis is a belt driven linear stage powered by a NEMA 23 stepper motor. The axis is constrained by a precision Misumi linear slide. Compared to y-axes in other designs such as the MendelMax 2, this triangular belt configuration permits higher speed and acceleration values, reduces component costs, and simplifies construction and maintenance access. The NEMA 23 was selected instead of a NEMA 17 because it simplifies mounting and has generally higher performance characteristics.
The y-axis belt tension can be adjusted by loosening the screws on the NEMA 23 motor and sliding the motor left or right.
Z-axis
The z-axis is a lead screw driven linear stage powered by two NEMA 17 stepper motors wired in parallel. The z-axis is accurate to ±150 µm over the full travel. The wheels have eccentric spacers that can be adjusted to prevent excessive friction from overconstaint.
Printable Components
A number of Lawson components can be 3D printed to reduce build costs, with the caveat that printed components are less stiff than their metal counterparts. Unlike many other RepRap printers, all printable components are purchasable, but not all purchasable components are printable. This means that printed components are not mandatory and that individuals without access to 3D printers, or individuals who prefer metal components are able to build a Lawson printer. The use of printed components can save up to approximately $120 USD in build costs.
Electronics
Almost all RepRap electronics such can be used to control the Lawson. Electronics confirmed to be working include the RUBMA Board, Printrboard, GEN7, RAMPS, and Rambo board.