How To Bend Wire & Assemble Model Aircraft Undercarriage

 There are a few elements in building a model plane that require a little more practice and patience than others.

Along with tissue covering, bending wire for undercarriage, tail wheels, propshafts, etc. is one of the trickier skills you will need to master.

This guide will show you how.

Follow Andrew Darby, designer of our Magnificent Flying Machines range, as he bends up the undercarriage for the Tiger Moth - one of the more complex models in the range.

TOOLS

Although the wire included with the Tiger Moth kit is light and malleable (just 22 swg), you will still need some hand tools to bend and form it accurately.

A pair of long nose pliers
A pair of side cutters
A pair of standard pliers
A pair of scissors or a craft knife
Some masking tape or sticky tape
Some strong sewing thread
Some cyanoacrylate (superglue)


FORMING A SMALL CIRCULAR LOOP

Many model aircraft designs feature a tail wheel and this is often formed from a circle of piano wire and filled with a balsa disc.

The following video shows how, by carefully pinching and bending wire in small increments using long nose pliers, you can form an approximately circular loop.

To make the wire loop circular, apply pressure to the outside edges by clamping between the jaws of the pliers.

With some gentle adjustment, you should be able to form a very acceptable, round loop.


Once the circle is formed, trim the overlapping wire with side cutters to form a closed circle.

Offer up the part to the plan, checking for a good fit - keep adjusting the wire with the pliers until you are happy with the roundness and size.

Mark any bends in the arm using a permanent marker

Hold the wire between the jaws of the pliers so that the bend mark is tight against the outside edge of the pliers.

Now, holding the pliers still with one hand, bend the wire a little with the other hand and then offer up the part to the plan. Bend a little more and then check again until the angle of bend you require is perfect.

Mark the wire at the correct point to trim, using the plan as a guide.

Trim the wire at your mark using side cutters.

At this point, you may need to take out any “twist” in the part so that it will lie flat on the plan and more importantly in the case of a tailwheel, will be square to the fuselage.

One way to do this is to take two pairs of pliers and carefully apply some pressure against the twist to flatten out the part.


The finished tail wheel!


TIGER MOTH UNDERCARRIAGE

The undercarriage on the Tiger Moth model is made up by bending several separate components from wire and then joining them using thread to give a three dimensional frame.

The first thing to do is to bend up the various components.


Notice how, wherever possible, you should hold the wire forming the component stationary, clamped in pliers, while bending the unformed wire with the other hand.

Make sure to do this in increments rather than in one action - it’s much easier to keep bending and checking than to have to “unbend” a wire.

Above all, take your time and keep checking parts against the plan.

You are now ready to bind the parts together.

One trick for doing this accurately, is to offer up the two parts to be joined and then temporarily stick them together with masking tape.

By then sticking them over the edge of a table, you have free access to the binding point with two free hands.

Take a length of thread.

Tie a simple reef knot in the thread around the binding point.

Apply a tiny drop of cyano glue using a wire offset so that the glue “wicks” through the knot and onto the wire.

Wind the long end of the thread around the knot a few times - the cyano glue will wick through the thread winds.

Pull the two ends of the thread taught and wait for a few seconds for the cyano glue to dry.

Using a craft knife or scissors, trim the thread ends tight to the knot.

Now follow the same process for the other binding points, moving the assembly around and resticking with masking tape where necessary.

Keep checking the assembly against the plan.

To bind the wire assembly to the wooden top support, apply a tiny amount of cyano to the points where the wire and wood meet and hold them until they are tacked together.

Apply a small amount of cyano glue to the end of a length of thread to stick it to the wooden top mount and wait for it to dry.

This anchors the thread to the wood and allows you to wind the thread around both the wood and wire.

Use a similar technique on the remaining joints.

Once the joints have set and the glue is dry, what seem to be glued solid  joints will, with a small amount of pressure, now become quite flexible and articulated.

You will be able to adjust the undercarriage to meet the anchor points on the fuselage by simply swinging the wire in its thread  “hinges”.


CONCLUSION

So there you have it.

With practice, bending up wire undercarriage, tail wheels, cabane struts on bi-planes, even your own prop shafts, becomes a quick and enjoyable task.

Of course the skills learned with these small model aircraft can be carried over to much larger models with much thicker gauges of wire.

The principles remain the same but the tools get beefier!

We hope you enjoyed this guide, but if there is anything you find unclear or don’t quite understand, please get in touch and we will update the guide to make it clearer.