Rigging

[Suffolk Lad]

"Damp and Slack" 

Damp and Slack was the (tongue in cheek) term we (my wife and I) used to use late in the evening whilst flying tissue covered model aircraft. The air would become damp and the tissue would slacken - considerably. Those who've ever participated in the hobby will I'm sure recognise the situation.

Well it would appear my rigging is suffering in a similar way so I would like to ask a few questions of those members who have perhaps experienced, solved and put well behind them the issues now faced.

This morning, I took a look at my first rigged model, the Camel previously described elsewhere on here, and I was somewhat distressed to find that the main rigging had slackened off considerably.


Like all my other models in the work shop it sits under a cardboard box cover. The workshop is heated and well insulated so no humidity problems. The rigging line used was mono-filament. At first I thought perhaps it was due to the top wing having settled down and sagging slightly - or possibly the last time I took it to my club I had stressed the lower fixings by gently lifting it via the top wing tips.

I have witnessed mono filament, used as an aerial on a Ju-52, slackening off in cold weather only to tighten again once warming up but the workshop temp was its usual 20+ degrees so dismissed this as the cause.

I have heard and read about striking and extinguishing a match and using the heat of the head to tighten the line so tried this. I could see immediately that this does work but found, due the rapid heat loss, that this was very localised. I then used one of those butane gas fired soldering irons turned down as low as possible which proved very successful and the lines quickly tightened though it's a fraught process in case of touching something. It did tighten up the lines better that I would have envisaged and confirmed (I hope) that the fastenings at each end is sound.

I'm afraid this is rather blurred but you can see a big improvement.


All of this has led to considerable thought about what lies ahead in future builds and the best approach to rigging material. So far I have acquired varying grades of mono-filament and differing brands of the 'elastic' type line - Ushi, EZE-Line,  Model Kasten, PRYM. From a structural point of view I favour continuing to use mono-filament  and have give a lot of thought to the end fastening. On future builds I think I can make them very secure but am concerned over having a repeat of the above situation especially when the rigging becomes far more complicated. Using the 'elastic' type obviously over comes this problem but I'm rather concerned about it's longevity as anything elastic usually deteriorates over time - sometimes quite a short time too.

So, this boils down to the following -

1, Is mono-filament something that will slacken off over time, even if adequately tensioned initially ?

2, (Assuming the anchor points are sound) Once tightened by heat will it slacken again?

3, If so, can it be tightened again (by heat)

4, Has anyone experienced degrading of the elastic type line and if so over what kind of time span.

5, Is the elastic type line affected by paint - even acrylics - over time

6, Any other advice you may think relevant.


I really would appreciate advice and opinions from those who have the knowledge and experience gained over time to witness any ageing effect. I have never considered how long a model 'should last' before - I have models made thirteen years ago as pristine as the day made but the thought of deterioration in the rigging is something that now concerns me. Anything you could advise to help alleviate that concern will be extremely well received.

Kind Regards - Tug

[RAGIII]

Tug,
I am sure you will get many and varied opinions and experiences. I have WW1 models rigged with mono that are 15 years old with no sagging. I also have models rigged with Heat Stretched sprue that remain tight. The sprue rigging does react to humidity on occasion, but then tightens back up. On occasion I have used both methods and the rigging is still tight. I do not use turnbuckles but don't think that should make a difference. As for the rare times when rigging slackens I use the heat method. In my case it is a burning incense stick allowing the smoke to do the work from a safe distance.
RAGIII

[coyotemagic]

I've used the match method, Tug, but as Rick has pointed out, smoke has to pass over the line.  So, as soon as you blow out the match, run it under the line.  Also, like Des, I have rigged most of my models with monofilament and they are all still nice and tight.
Cheers,
Bud

[Des]

Sorry to hear you are having rigging issues Tug. For most of my models I have used mono for the rigging and to date they are all still taut, on the very rare occasion that a line slackens off I use a small soldering iron which has been heated to maximum temperature, run this under the offending line making sure you keep the soldering iron clear of the rigging and always moving along the length of the line, a few seconds will see the line regain its tension. Under no circumstance allow the hot tip of the soldering iron to touch the rigging line, the line will break instantly if this happens. For situations where mono rigging will exert undue tension on the control surfaces I use Modelkasten 0.13mm elastic thread. This product, although quite expensive, does a brilliant job and will not sag over time, it is not overly stretchy but is easy to use.

Des.

[ALBATROS1234]

i model predominantly 1/48 and i  use the modelksten stuff exclusively now, i use to use mono in the form of .1 mm black "invisible thread" from the sewing /fabric shop.the modelkasten is a little stretchier than mono therefore allowing for better tightening.it seems sometimes ca doent stick really well to the line itself so the wing thru method without any fasteners is a little tricky. i just let the thin ca wick into the brass tube. neither type have given me problems with sagging over time.i use similar method as des with home made eyelets and brass micro tube. the only times i had a line really go slack was due to me not having it tight enuff in the first place and after rigging an adjacent line which could pull the wing celluel out of alignment just enuff to allow a line which is not quite tight enuff to go slightly slack in which case heat to tighten.it takes some practice ia m sure your next model will be fine.

[stefanbuss]

I had one cause of slackening rigging while using monofilament (my last build, the DFW C.V). I used a soldering iron, like Des already reported, to solve the issues.

S.

[Suffolk Lad]

Rick, Bud, Des, 'Albie' and Stefan - my thanks indeed to all of you for taking the time to respond 

From what you are all more or less saying I have concluded that monofilament is the choice for me going onwards. On the Camel, though I was sure (confident) that the top wing fixing was secure I was not so certain about the lower where the line was just pulled tight through holes and Cyano'd in place. When it slackened I thought that perhaps the line had pulled through the join but seeing how it tightened with the application of heat it must still be quite firm. I think I have come up with a method (as yet to be tried I hasten to add) that will improve that low end security considerably. This is of course not using eyes and tubing type fixing which, thinking about it though, I can see the advantage of easier replacement of a line if that method is used. Hmmm Horses for Courses springs to mind.

None of you have said whether it can slacken off again and whether you can re-tighten it using heat again - have you experienced that situation?

Des - I was a little surprised that you turn the heat right up on your soldering iron. I would have thought that radiant heat could possibly cause additional worries.  I kept the temp as low as possible on this gas type I used which proved more than enough but still seemed too much. I have looked on ebay this morning and found a very nice soldering 'station' with variable heat control and a very thin soldering point which looks to be ideal so will be ordering one of those forthwith  .

Finally, as no one has mentioned any negative experience with elastic types deteriorating I will assume you've had no problems there either but I have decided to only use it for minor applications. I cannot visualise this kind of product standing up to the effects of light over the long term - say ten years plus - though as I said previously I have never thought to consider how long a model should 'last' for.

Once again my thanks - if anyone else has anything to add I'd be very pleased to hear from them too

Kind Regards - Tug

PS Just been out to the workshop and checked the Camel - everything is still tight and looking much better than it did

[RAGIII]

Tug, As for the stretchy elastic types I have never personally used them. I do recall some negative feedback YEARS ago on the WW1 modelers list about the elastic deteriorating and snapping causing catastrophic damage. This may be an issue that no longer exists with more modern products. Don't know for sure either way?
RAGIII

[Borsos]

I have good experiences with Uschi van der Rostens elastic rigging material for 1/48 scale. It is actually very very elastic and keeps straight since I used it the first time (which is just about one year ago, so to be honest I have no real long time experience).
But I can't see any risks of snapping the plastic parts because it is a really very soft material compared to other elastic rigging material. It simply hasn't the strenght to snap parts as I estimate it. But I will try fishing line for 1/32 scale.
The big advantage of non elastic rigging material is that you can thread it much easier through eyelets/brass rod than the elastic stuff.
Best wishes
Borsos

[Suffolk Lad]

Thanks Rick, that seems in part to bear out my thoughts - I don't think I will risk using it for anything other than internal cables.

Borsos, thanks for your reply too. It isn't so much the risk of stressing the plastic parts as to whether it will degrade in light much as elastic materials do - elastic bands for instance and simply wither away spoiling the model.

I have two small indoor flying model aircraft hanging from the ceiling in my workshop (a nostalgia thing ) - the wings are held on by  orthodontic bands used by dentists but even they degrade after a couple of years and perish completely. I have also noted that the silicone elastic I use on my yachts - a carp fishing product I believe - also begins to degrade slowly after a year or so.

Mono filament it is then 

Regards - Tug

[Des]

Good to hear that you have solved the rigging issues Tug. The soldering iron I use is not a variable temp type, just a small plug in soldering iron so the maximum temp is only what the iron is designed to operate at, not extremely hot. I do have a fully variable soldering station but use it for soldering my small brass tubes etc. Sorry if I gave you the wrong info on the soldering iron.

Des.