Fun fact. As of today, the Sopwith Pup has been on my bench for 90 days. Longer than the Achilles (65 days), and double my average build time (45 days).
Granted, I’ve been taking my sweet time, moving slowly and methodically, but still.
Thankfully, the build’s hitting the home stretch.
Of course, with a biplane, “home stretch” is extremely relative, since the final steps include final assembly and rigging of the main wings.
Fear of rigging has kept me from attempting a biplane before now, but I’m finding that, with the right materials and techniques, it’s pretty much foolproof.
Tedious, but foolproof.
Rigging is definitely one of those activities where the materials matter. Scour the internet and you’ll find as many different recommendations as there are modelers. Like so much else in modeling, there’s a deeply personal “what works for you” thing at work.
After playing with several materials, here’s where I landed. Not saying these are the end-all-be-all of rigging materials, but they’ve worked very well for me.
Before you start your rigging, or even prepping for your rigging, you’ll want to assemble several tools…
– Tweezers – Seriously, the more the merrier. I use a small, angled tweezer to thread my cable, another set for general gripping, and several locking tweezers to hold the cable taut.
– Xacto and a sheet of glass – For cutting tubing into turnbuckles.
– Pin vise – For drilling out micro tubing, if so desired, as well as for making eyebolts.
– Old airbrush needle – The most versatile tool on my bench proved instrumental yet again…
– Thin and medium CA glue – For attaching eyebolts, securing turnbuckles.
– Some sort of cutting tool – You’ll need something that can get in close and cut off excess cable without messing everything up.
Biplane rigging can be broadly divided into three main components – eyebolts, turnbuckles, and the rigging cable itself.
– Eyebolts – I’ve been making my own eyebolts out of extra-small Ultra Wire. To make wire eyebolts, bend a hook out of some brass rod (I’ve been using a 0.2mm rod) and put it into a pin vise. Wrap a length of Ultra Wire over the hook, clamp the ends together with a pair of pliers, and turn the vise. Viola, the wire will twist up, leaving an “eye” the diameter of the rod its looped over.
– Turnbuckles – Albion Alloy 0.5mm silver nickel micro tubing, cut down to 2-3mm lengths. I prefer the silver nickel to more common brass tubing because it’s already the proper color, and tarnishes slightly as you handle it, so, instant weathering.
To cut the tubing, I set it on a hard surface (glass) and roll it under an Xacto until it cuts. This way you can cut through the tubing without collapsing the walls. I’ve seen people create cutting rigs to churn out very exacting lengths, but I just eyeball mine. When you’re talking the difference between 2 an 3 millimeters, differences are very hard to pick out unless you have them side-by-side, and when I need like sizes I just dig around until I find them.
– Cable – Uni-Mono .004” monofilament line. This fly-tying monofilament is exceptionally fine and easy to work with. It also has a slight degree of elasticity which many monofilament fishing lines lack.
The Rigging Process
The rigging technique I’ve been using is actually quite simple. It’s the miniscule scale that makes it a challenge. If we were dealing with rope and PVC pipe instead of monofilament and micro tubing, it’d be pretty much foolproof.
Before you start – Plan! Rigging a biplane is a serious undertaking. Before you start your rigging – or better yet, before you start your build – develop a plan of attack. What holes need to be drilled? What parts need to be left off so you can attach the necessary anchor points? Should you pre-rig the upper wing before attaching it, or are you willing to try to work in the cramped area between the wings?
1 – Identify your anchor point. The anchor is what the rigging line will mount to. This should be either an eyebolt or turnbuckle attached to the fuselage or wing surface, or a control horn. Basically, something with a hole through which you can thread your rigging material.
Wingnut Wings thoughtfully pre-drilled the various anchor points on the wings and fuselage. To mount eyebolts in these anchor holes, I trim all but about a millimeter off the eyebolt’s “tail”, dip it in medium-viscosity CA, and then insert it into the hole. I started out with thin CA, but when you’re working with anchor holes like this the thicker glue does a much better job of filling the hole.
Something to watch out for on the Pup specifically – in addition to the wing rigging, you also have to deal with strut rigging. No biggie, but you will need to drill mounting holes in the strut brackets. I did not realize this until the brackets were already painted, detailed and decaled. Next time I’ll know – drill FIRST!.
2 – Thread the turnbuckle. Starting with a generous length of line (I use about 15”), thread one end through a turnbuckle. I find the easiest way to do this is to hold the turnbuckle with a pair of pliers, and carefully insert the monofilament with a pair of tweezers. It may take a few stabs at first, but once you get the hang of it, it goes fast.
3 – Thread the anchor point. With the turnbuckle on the line, thread the line through your anchor point.
4 – Turnbuckle Bolo. Grab the end of the line that you threaded through the anchor point, and thread it back through the turnbuckle. Think of the turnbuckle as a bolo.
5 – Pull it taut. Gripping the turnbuckle with a pair of tweezers, slowly pull the monofilament line taut. Be careful as you do to not get it snagged on other details or caught up in other rigging lines. Make sure the turnbuckle on the opposite end of the line (if applicable) is properly aligned, and not caught in some bizarre direction. Better to catch this now than after locking everything in place!
6 – Glue it. Apply a small amount of thin CA glue to the turnbuckle end facing AWAY from the anchor point. The thin CA will wick into the turnbuckle and lock the monofilament in place.
7 – Trim the line. With a pair of scissors or shears of whatever you’re comfortable with, carefully cut away the excess line, as close to the turnbuckle as you can get. While it sounds awful, it’s actually fairly simple. I only accidentally cut through one main rigging line.
8 – Paint. Monofilament is frustratingly clear, so it’ll need some color to look right. I painted mine with Floquil Old Silver.
Overall, I found it easiest to work from the inside out, tackling the cabane struts first, then the rear runs of double wires, and working out from there. This way I wasn’t tripping over rigged lines trying to get to ones behind them.
After a few nights of rigging, I have to say I’m happy with the results! I still have a little ways to go. I have to finish the aileron and tail rigging, and perform some light weathering. But the hardest part is now behind me – and it wasn’t so bad!