Tim Cheal Posted June 23, 2013 Share Posted June 23, 2013 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 Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted June 23, 2013 Share Posted June 23, 2013 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. Quote Link to comment Share on other sites More sharing options...
Tim Cheal Posted June 23, 2013 Author Share Posted June 23, 2013 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 Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted June 23, 2013 Share Posted June 23, 2013 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. Quote Link to comment Share on other sites More sharing options...
crispin church Posted June 24, 2013 Share Posted June 24, 2013 after sorting your spinner out solder the extension to the needle Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted June 24, 2013 Share Posted June 24, 2013 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.... Quote Link to comment Share on other sites More sharing options...
Plummet Posted June 24, 2013 Share Posted June 24, 2013 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 Quote Link to comment Share on other sites More sharing options...
Martyn K Posted June 25, 2013 Share Posted June 25, 2013 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.. Thanks Martyn Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.