Filament Winder – An Introduction

A Short Introduction

I’ve decided that I don’t just want to build a rocket, I wish to acquire new skills and capabilities and potentially be part of the bigger picture – potentially supplying Carbon Fiber Tubes.

The most rewarding way to do this I’ve decided is to design and build a Tube winder, much like the one you see at http://x-winder.com.

What the Filament Winder does

The Aim of a Filament winder is to very accurately lay down Carbon Fiber tow (or any other fiber) on to a mandrel. The filament travels through a bath of Epoxy.  Usually multiple layers of Carbon Fiber are wound on to the mandrel at varying orientations and at the end, some tape is wound over the last layer. This tape is special heat-shrink tape that when heated (with a heat gun) causes the tape to shrink and remove excessive epoxy.

After several hours of curing, the tube is then post-cured by placing it in a temperature controlled “oven” which helps to improve the properties of the tube under temperature.

Components of the Winder

The framework

The design is similar to X-Winder, but not based on it.  We have used 80-20 components before and the lack of a complete machine workshop makes this an intelligent choice for the bulk of the design.

Motion components

We use Stepper motors from OMC, which are affordable, reliable. These are Chinese brand and considerably cheaper than alternatives.

Drive components

We have decided to use XL gears and XL belts to drive all the components. We are coming to the realisation that the large XL belt for the train might a little under-spec, but it has worked ok so far.

Controller

We are using LinuxCNC on an old DELL workstation to drive the Stepper motors. It is free and easy to use. I wanted to avoid crafting up my own electronics/code to do what was already being done well by LinuxCNC.

Wind Code Generator

We still needed a means to generate the codes that LinuxCNC would follow to control the motors, to get the desired outcome. We decided to “home brew” a PHP application (web-based) to generate this code based on inputs on a webform. This PHP application resides on the DELL server.