TimberSurf’s Model Railway  

Modelling tips & Model Railway Controls Guide

Lumsdonia Railway

A web page for my indulgence and sharing ideas and irregular updates on my Model railway

Lumsdonia Flag

Bench

Pens

Pen/Carving

A guide to the many options to buy/make hot wire cutters

Polystyrene shaping with hot knifes

Hot Wire Cutter

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Supply list

Nichrome wire - 26AWG (0.4mm) or smaller

For the sculpting tool, use 0.7 to 0.9mm


Online calculator for working out wire size/wire length/voltage/current/temperature


PWM Controller - Minimum 3A


Power supply - Any wall plug at the desired voltage with a current capacity greater than required


2 Look up on a chart online else use the calculator above

An anatomy

A Hot Wire cutter is very useful to cut both expanded Polystyrene (EPS) and Extruded Polystyrene (XPS {Styrofoam}). Cutting thin sheets is fine with a knife, but beyond 1 inch thick, it becomes very difficult/inaccurate, else you have to use a saw which leaves a rough edge and both of these methods can only cut straight lines.

Similarly, carving contours can be done with a saw/knife and further shaped with rasps and sanding, but a Hot Wire sculpting tool makes light work of the job.


There are four types of cutter:-

Bow - for free hand straight flat cuts

Bench - for cutting flat sheet

Knife/pen - for incisions, free hand and holes

Carving - for curved/shaped cuts

Here is a Video of the technical side!


This Video shows how to construct a bench hot wire (Luke Towen)


This Video is of my bow and my cross cut table in action


This video is of how to make a slicer for reducing thickness (Left pic)

Back to HOW TO

Options


There are a number of suppliers of ready made, the most famous, The Hot Wire Foam Factory do a 3 in 1 kit for about £100. There are several bench cutters available for a range starting at about £100. Hand devices or a bow can be bought for about £30, there are even very small battery operated ones for less than £10!


Some of the 3 in 1 kits come with a knife/pen, but these can be purchased individually in 50mm increments from 50mm to 250mm at £5-7ea


Or


Make your own! See below!

Bow - for free hand straight flat cuts

Construct a C shape from wood/metal tube1/plastic tube

Add two metal screws to the end and connect electrically to the controller/supply.

Wrap the Nichrome wire around the screws (it will stay on if wrapped with 2-3 turns).

Measure the length between the screws and work out the required supply voltage/current.2


1 Ensure the wire is insulated from the tube.

Bench - for cutting flat sheet

Construct a C shape from wood/metal tube1/plastic tube

Add two metal screws to the end and connect electrically to the controller/supply.

Insert a flat sheet of wood at the bottom with four legs or a frame (could be the bottom of the C shape)

Wrap the Nichrome wire around the screws (it will stay on if wrapped with 2-3 turns).

Measure the length between the screws and work out the required supply voltage/current.2


Knife/pen - for incisions, free hand and holes

It is not really possible to make one of these, just buy one as they are not expensive.

Carving - for curved/shaped cuts

Construct a handle from tube, epoxy glue two metal bars (brass screws with head chopped off) into wood or plastic.

Attache the metal post and Nichrome wire with block connectors (remove the plastic casing)

So as more rigid, a thicker Nichrome wire will be needed

Be warned this will need a lower voltage and very high current 3

Measure the length between the screws and work out the required supply voltage/current.2


3 Mine (shown) is 0.9mm and draws 7amps at 5V!

!!!  DANGER  !!!

Can cause severe burns.

Unattended, can start fires.

Be warned this device comes on when the supply is connected!

My very long Bow, that can be mounted in a Black&Decker Workbench and be used as a Bench cutter! Here is a Video of it in action

My (shaped) sculpting tool with its high power 5V supply

!!!  WARNING  !!!

Only use in a well ventilated area as the fumes are poisonous.