By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by CML

Needle Valve Extensions

How to extend a needle valve

All Topics | Latest Posts

Search for:  in Thread Title in  
Tim Cheal23/06/2013 22:39:00
avatar
174 forum posts
41 photos

I am after some help in extending a needle so that it can be turned from outside the engine cowl.

I started with a small Allen key screwed in with the grub nut in the needle an ethics lasted a few flights, but was missing after a flight. So I reverted to wire, bent for some traction, and flattened on one side for the grub screw, but this lasted only minutes. I tried again with epoxy resin, a little better but it has now given in. So, the same again with cyano, on both the wire an the grub nut, and thia appears the best so far, but I fear it will be lost soon enough.

Does anybody have a method of attaching the extension wire or allen key that has stood the test of time?

Tim

Martin Harris23/06/2013 22:55:09
avatar
7117 forum posts
177 photos

I just tighten the grub screw...

If you're continuisly losing the extension, I can only think that you have excessive vibration. I would check the prop and spinner are balanced.

Tim Cheal23/06/2013 23:04:17
avatar
174 forum posts
41 photos

That's a thought, woud an unbalanced spinner (I have balanced the prop) be worse at low revs or high. I ask because it does seem to "rattle" at low revs.

Tim

Martin Harris23/06/2013 23:21:56
avatar
7117 forum posts
177 photos

Might be hitting a harmonic with the airframe at particular revs. What engine/model is it? I have found that some engines are prone to vibration in fairly lightly built airframes e.g. the Saito 82

I can't say that any of my extensions have ever come loose - the original bit of bent welding rod is still in my Chipmunk after more than 10 years of service.

crispin church24/06/2013 08:05:26
avatar
442 forum posts
102 photos

after sorting your spinner out

solder the extension to the needle

Steve Hargreaves - Moderator24/06/2013 09:39:57
avatar
Moderator
6516 forum posts
178 photos

Like Martin I can't remember an extension coming loose!! Might an allen key be a little heavy......thin piano wire around 1mm diameter should be adequate. Grind a small flat for the grub screw to grip & you should be fine.......passing the extension through a small piece of tuel tube where it emerges through the cowl can deaden most vibration....thumbs up

Plummet24/06/2013 10:24:36
avatar
1319 forum posts
40 photos

OR - an old trick from C/L days for extending or repairing broken needles.

Curtain spring. You know the sort of curtain spring that you use for your lace curtains. It is a long spring with a plactic sleeve over it. It is easily cut with plyers. You can cut a short length, then remove the plastic.

Cut the bend off the end on the needle, and solder the end of the spring to the end of the needle.

Solder a replacement bit of wire with a bend into the other end of the spring, and you have an extended and flexible needle.

Plummet

Martyn K25/06/2013 12:40:08
avatar
4335 forum posts
2962 photos
Posted by Plummet on 24/06/2013 10:24:36:

OR - an old trick from C/L days for extending or repairing broken needles.

Curtain spring. You know the sort of curtain spring that you use for your lace curtains. It is a long spring with a plactic sleeve over it. It is easily cut with plyers. You can cut a short length, then remove the plastic.

Cut the bend off the end on the needle, and solder the end of the spring to the end of the needle.

Solder a replacement bit of wire with a bend into the other end of the spring, and you have an extended and flexible needle.

Plummet

Good tip.. yes

Thanks

Martyn

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of RCM&E? Use our magazine locator link to find your nearest stockist!

Find RCM&E! 

Email News - Join our newsletter

Love Model Aircraft? Sign up to our emails for the latest news and special offers!

Latest Forum Posts
Support Our Partners
SHREK
Expo Tools 14 July
Overlander
electricwingman 2017
Wings and Wheels 2018
Gliders Distribution
CML
Advertise With Us
Latest "For Sale" Ads
How has your building graduated?
Q: Did you start with ARTF and move to building from kits or vice versa?

 Started with ARTF moved to building from kits only
 Started with ARTF moved to building from plans only
 Started with ARTF moved to building from kits and building from plans
 Started with building kits or from plans and moved to ARTF
 I only build from kits or plans
 I only build ARTF
 I only build from kits
 I only build from plans
 Other (Please specify in thread)

Latest Reviews
Digital Back Issues

RCM&E Digital Back Issues

Contact us

Contact us