Remote Needle Valve Adjuster

[John Roberts 9]

I have recently been setting up my throttle/carb linkage on my Irvine 40 installed in a new Irvine Tutor trainer and (at the risk of stating the blindly obvious!) I was concerned that, when twidlling the needle valve, my fingers & knuckles are only a couple of millimeters away from that furiously whirring prop.

 

There is plenty of gruesome evidence on this forum & elsewhere of the devastating consequences of a momentary lapse of concentration (or even an unexpected cough or sneeze or an accidental nudge from someone nearby).

 

Is there a commercially available remote needle valve extender/adjuster that can be retro-fitted or even a diy solution to the problem? What I had in mind was something akin to a minature flexible drill extension, permanently attached to the model, that would allow safe twidlling 2 or 3 inches back from the prop?

 

I know that it is easy to pooh-pooh health and safety, especially when it goes completely over the top, but in this case I would feel much more comfortable with my delicate little digits well out of harms way .

 

Thanks for reading and for any advice you are able to give.

 

Cheers,

John

[FlyinBrian]

You could fit (solder) a piece of curtain wire to the NV then turn this through almost a 1/4 turn and support with a bracket.

[Martin Harris - Moderator]

Problem with these is that they tend to vibrate and wear the needle fits. The danger is from the front and tips of the prop and a slight error with your knuckle should only give you a slap.

 

Not the case with a pusher prop though and I still bear the scars from a small engine that bit me on each hand well over 30 years ago (hand one was bandaged and dripping blood a bit) while tuning it before I realised what was happening!

[Former Member]

[This posting has been removed]

[Steve Hargreaves - Moderator]

I don't see why you couldn't buy a remote needle designed for another engine (an ASP or an SC perhaps) & use this.

 

Give Just Engines a call...I'm sure they'd be happy to advise you...

[Peter Miller]

SC 32s have a remote needle assembly that can be used.

[Biggles' Elder Brother - Moderator]

Some engines do have a rear mounted carb - which takes your fingers a bit further away - but that's not a lot of use to you!

 

I'd suggest that you do nothing about it. I know that might sound strange - but here's my reason:

 

In my experience prop accidents nearly always occur because of "lack of thought". Its unusual for someone to hurt themselves when the danger is very much in the front of their mind. The classic accident seems to be when we stop thinking about the possible danger; for example reaching straight through the prop to catch a falling glow stick, or move a starter cable etc. Its when we get "over familiar" that accidents happen.

 

I've noticed over the years that it very unusual for a beginner to have a prop accident - its nearly always the "old hands" that end up hurt. Why? I would suggest its because the beginner is unfamiliar with what is going on and is very focussed on that dangerous looking whirly thing at the front! The more experienced modellers have become a bit blase about it all, they've started an engine a thousand times etc. etc.

 

So, I'd leave things just as they are - it will be a reminder to stay focussed on the prop and treat it with respect. And hopefully you'll develop good safe habits so that when the day comes - which it will - when you are starting an engine but actually thinking about the forthcoming flight, the fact that the grass is wet and its soaking into your trousers or what you'll be having for tea - hopefully those good in-grained habits will save your fingers!

 

BEB

Edited By Biggles' Elder Brother - Moderator on 24/09/2011 20:37:12

[Former Member]

[This posting has been removed]

[andy watson]

I completely disagree with BEB. If this was good reasoning then seat belts would be banned.

 

Add the remote extension- the flexible wire OS type or a simple piece of thin wire with a 90 degree bend at the end.

 

BEB is correct about over familiarity, or momentary lapses of concentration causing most accidents, but I don't think a remote glow will make you over confident.

[Martin Harris - Moderator]

Thing is, the needle position isn't really the danger as I explained - you'd need to be very ham-fisted to do any real damage while needle twiddling - it's how you approach the exercise that counts and I understand where BEB's coming from although I think there are benefits from a remote needle.

 

Re. the seatbelt analogy, there is a school of thought that says the greatest contribution to road safety would be a six inch steel spike mounted on the steering wheel!

[Barrie Dav 2]

I've bought rear engine needle valve adjusters from Just Engines for most of my engines and they work well. Better safe than sorry..........

[Peter Miller]

On the subject of accidents with props, even if not quite on this thread. I have seen some of the worst accidents with propellers when it is ina strange place.

 

We are used to the prop in front of the model but when it is a pusher or in some other unconventional location the potential for accidents goes sky high.

 

Examples. A scale Spad A2 which has the prop in a cut out in the leading edge of the wing and a gun position in front of it. In the club we were used to picking up bi planes by the leading edge of the top wing with the engine running. YES! someone tried to pick the Spad up that way. I leave the resulting mess to your imagination.

 

My Don Kichot Polish home built with the pusher prop 1/2" behind the trailing edge. A friend picked it up from in front and ran his hand down the trailing edge. It took eleven stitches to put his finger together. It also destroyed my beautiful home carved Beechwood pusher propeller.

 

Another pusher in a control line stunter. Not sure how it happened but I was off work for a week with my thumb opened up.

 

I now refuse to have anything to do with any model where the prop is anywhere but in the front.

Edited By Peter Miller on 25/09/2011 08:43:42

[John Roberts 9]

Thanks to everyone who has taken the time and trouble to post some helpful, interesting and thought provoking ideas.

 

I reckon that it is essential for a beginner to develop good safety habits right from the very beginning so that we become conditioned into instinctively doing the right thing. More experienced club members can be extremely helpful in this respect with timely airfield reminders about where not to stand and how & when to safely remove a glow stick after start up etc. etc.

 

BEB is, I believe, probably correct in his rationale regarding beginners/accidents/over familiarity etc. but I still feel that moving my fingers away from the whirling prop is a sensible precaution.

 

Aside from safety considerations I think it will also make needle valve adjustments easier to do. Why so? Well (maybe this is just me!) I find that due to the extremely close proximity of the prop I tend to hold my hands and fingers in a rather unnatural & uncomfortable stance. Essentially I am trying to hold & turn the needle valve between my thumb & first finger but without bending my finger joints & knuckles (the bending & twisting actions both automatically bring my fingers closer to the action).

 

Thanks again for the helpful advice .

 

Cheers,

John

 

 

[Peter Miller]

John

 

I agree with you, They will tell you that the rear of the prop will push your finger away. My last nasty accident was adjusting a .15 from behind. took the top of my knuckle which opened a tiny artery.

 

That took a visit to A&E.

 

The annoying thing is that I don't even have a scar to show for it. Oh well, got a couple of others for the show and tell sessions!

[Biggles' Elder Brother - Moderator]

Posted by andy watson on 25/09/2011 00:52:55:

I completely disagree with BEB. If this was good reasoning then seat belts would be banned.

 

Add the remote extension- the flexible wire OS type or a simple piece of thin wire with a 90 degree bend at the end.

 

BEB is correct about over familiarity, or momentary lapses of concentration causing most accidents, but I don't think a remote glow will make you over confident.

 

Andy - how is a bit of wire with a 90 degree bend in the end going to take John's hand any further away fromn the prop? I frequently fit such an extension, but I don't see it as a safety aid - simply as a matter of convienence, being a way of adjusting the needle valve whilst its inside a cowl.

 

On the completely different matter of remote glows I would completely agree. As I have posted elsewhere they are fitted on pretty well all of my models. But it is my belief that their safety contribution lies not so much in terms of moving the point of application away from the prop as in decreasing the likelihood of a glow stick threatening to topple into a prop from on top of an engine - I believe that the reflex to try and catch such a falling stick is the cause of many prop accidents. By moving the point of application to an approximately horizontal position I think remote glows are major safety feature. Hence I support them completely.

 

But a bent bit of wire in the needle valve as a safety feature? No I don't think so. I remain convinced that the very best way to stay safe with an engine is to develop sound working proceedures to the point that they become ingrained habits and to remain respectful and as focussed as possible on the potential of that prop to injure you!

 

BEB

[Bob Cotsford]

BEB - i think you've got the wrong type of extension in mind. As I understand it, the type proposed is made from a flexible extension - think old fashioned curtain wire, or a close wound spring. This is bent back 90 degrees through a bearing bracket so it lies along the same axis as the engine.

I've used this sort of thing in the past, the only down sides in operation are that they are a spring so there's some lost motion, and they put a side load on the needle and can cause the needle/spraybar threads to wear.

[andy watson]

I remain convinced that the very best way to stay safe with an engine is to develop sound working proceedures to the point that they become ingrained habits and to remain respectful and as focussed as possible on the potential of that prop to injure you!

 

BEB

I agree BEB, but I would suggest a needle valve extension that allows the OP to keep his fingers a little further away from the back of the prop is also unlikely to cause the kind of overconfidence and negligence you are referring to. So why not fit one and allow him to feel a little happier if the engine needs a tweak.

[Peter Beeney]

I, too, am in agreement with BEB’s logic here. I’m a great believer in keeping to a strict regime when starting engines. So that’s BEB’s ‘sound working procedures’ in action, for over 50 years now, on and off, in my case. Rightly or wrongly, that’s what I’ve always done, and will probably continue to do so, at least for a little while longer. However, I think there may be a small rider here, my SWPs may well be someone else considering that I’m too cautious, for instance. Or, indeed, perhaps not cautious enough! Certainly a view taken by some, but it has to be consistent, otherwise it will most certainly not guarantee immunity from accidents.

Being responsible for showing the beginners, particularly the youngsters, does help in this respect and also helps to make me think more seriously about this. I feel that most people might regard starting the engine just as a means to an end, simply to get the model in the air, I try and treat it as an entity in it’s own right. I think one way of describing the attitude to it would be confident but cautious. Plus you have to make your own rules regarding these procedures and never break them. It seems to me that when someone decides to do something different is exactly the time when it can leap out out of nowhere and bite you, in some cases, very hard indeed. So with regard to the wire extension to the needle valve, as an example, if someone is happier to do this, I wouldn’t have any objections. But, as with anything to with engines particularly, it needs to be a sound engineering job. If a flimsy fixing became loose and broke away, and then was somehow flicked into someone's face by the prop, that also could be nasty. Unusual and unlikely perhaps, but then all these accidents invariably are.

I think I would be more than somewhat upset and depressed if someone had an accident after I’d been showing them the ropes. Or more specifically, the restraints. Yesterday a 13 year old lad was practising starting my engine, he’s very keen, it’s not the first time he’s done it, but I still can’t help feeling slightly apprehensive whilst I’m watching him. Unfortunately there’s no buddy aids here, if he did make a mistake I couldn’t take control! I suppose the success story works both ways, though, for me the satisfaction of (usually!) getting the right answer (for me) when I ask many random questions, and for the youngster the ecstasy when I eventually say to him “Ok, fire it up, I’ll carry it out for you, and you can show me how to fly.” Or something similar.

I’m not keen on the seat belt analogy, either. This is an action after the event again. I think it’s better to consider trying not having the incident in the first instance if at all possible. Perhaps not always easy; I don’t have any proof, but it’s always seemed to me the incident rate is relatively high. Difficult to find a longer term modeller that hasn’t been involved in at least one little knock.

Always an interesting and emotive subject, I’m sure this will crop up for as long as model engines are around; and then of course there is the existing electric debate to follow on. Which I’m sure will also claim some victims in the future……

PB

[Steve Hargreaves - Moderator]

One point I always come back to here is the size of the engine....many of the people posting here started their modelling career long long ago when small engines were the order of the day.

 

If an 049 glow engine or a 1 - 1.5cc diesel "bit" you, you knew about it..cursed & swore & learnt the lesson but your fingers survived less a bit of skin. My dad knows this too cos he started my first engine....

 

Nowadays people often start with a 0.40 sized engine & if these "bite" you, you stay bitten with dire consequences for your fingers....

 

The last time my fingers got tangled with a prop was around 1979 when my PAW2.5 kicked back & split my finger open......lots of blood & howls of pain but no lasting damage thank goodness.....& I learned the lesson.

 

My 7 year old has just started to get interested & I dread him starting up his first engine.....his enthusiasm is bound to outweigh his ability & as we know it only takes a minutes inattention for a dreadful accident to occur. I think a prop would take his little fingers clean off......

 

Our club has a rule preventing anyone under 14 from starting an engine.....

[Peter Miller]

If you still want a remote needle valve you might like this one. I have just bought one and it is a very good item.

 

Remote NVA on Ebay

[John Roberts 9]

Thanks Pete .

 

I did speak to Just Engines a few days ago but the OS remote assembly they supply wouldn't work with my old Irvine apparently. They suggested a replacement carb instead but that seemed a relatively expensive route especially because the Irvine 40 is basically a cheap 'stop-gap' whilst I am learning to fly.

 

Whilst I love all kinds of IC engines my plan (once I have mastered the basics of flying) is to go electric. It must be a sign of getting old or something but the noise and oily mess created by a glow engine no longer has the same appeal as it did during my youth. Sad but true!

 

Cheers,

John

[Erfolg]

It is very surprising to be that both the carb adj. and glow plug attachment and operational points have not been addressed earlier, with a view to moving them away from the propeller. There does seem to be anecdotal evidence, that it is the operation of these items which are responsible for most IC propeller accidents.

 

It seems bizarre in an age where playing conkers and other low risk task activities can require the use of safety equipment, with the source of the hazard preferentially eliminated, that it is not mandatory requirement to have both items remotely operated. Should H&S Executive be informed when an accident occurs, where say a finger requires attention by a Health Professional or at Hospital?

 

On the face of the issue, there would seem the opportunity for a good after sales market for remote operation. I seem to remember that Perry made (in the 70's) an attachment to operate the needle via the transmitter for fine adjustment. Could not a simple servo type attachment be made to operate the needle, as an after market universal attachment?

 

It seems a great pity that IC engines which give so much pleasure to many modellers, can also be the source of much pain and anguish to the same modellers. As engines get bigger/more powerful, the issue of accidents and injuries tend to be greater. I would be surprised that there are not any modellers who have not been injured at some time by their motors. In the days of small Diesels getting caught by the prop, was just painful, at worst a slight cut. Today the consequences are generally be more serious.

 

[John Roberts 9]

Erfolg, I totally agree that it is somewhat surprising that hazardous whirring propellors have manged to avoid being regulated in some way.

 

Taken to its ultimate conclusion the authorities would prevent anyone doing anything which could be considered to be slightly risky or hazardous (and I certainly not in favour of that) but, by the same token, it makes sense (to me anyway) to take sensible personal precautions to reduce & minimise the chances of my soft flesh tangling with a prop whizzing round at 16,000 rpm.

 

I wonder why the engine designers & manufacturers haven't taken the initiative on this (altho I note that a few engines are available with rear mounted carbs)? As you correctly observe there seems to be almost overwhelming anecdotal evidence that large numbers of model flyers are sustaining injuries (sometimes truely horrific) and, especially in the litigious USA, I would have expected somebody to have sued for damages by now.

 

Cheers,

John

[Erfolg]

Maybe these products will be of interest Remote needle valve and inflight mixture adjustment

[John Roberts 9]

Thanks Erfolg .