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Engine basics => Engine set up tips => Topic started by: Leester on July 03, 2006, 11:10:00 PM
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I received an order which included NVA's. The needles came straight with no bend on the end. How do you bend these without screwing up the threads? Thanks
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I chuck up my needles in a lathe chuck and wack on them with a rubber mallet. ;D
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"I chuck up my needles in a lathe chuck and wack on them with a rubber mallet. "
I have a rubber mallet. Can I barrow your lathe? :)
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I received an order which included NVA's. The needles came straight with no bend on the end. How do you bend these without screwing up the threads? Thanks
Hi lee,
With the PA Needles, I hold them between my left thumb and forefinger then take a pair of snipe nose pliers and bend them where I want to, usually about 1/4" lever. Never seemed to be a problem. (??)
Bill <><
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Thanks Bill: I just wanted to make sure I could bend them without heating them. They won't work in my wire bender, Randy emailed and said they where not brittle, don't want to mess them all up.
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Measure Twice---Bend Once!! **)
Jim Oliver
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Do not bend it, n1 just solder a wheel collar to the needle and cut off what you do not need. :!
Scott
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My Super Tiger Needles are actually quite soft. I think it makes sense, since they ride in a brass spraybar.
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When I bought Danny Dirt's old ST G.51 (in the Mutant Magnum), it had a ST spraybar assembly, no bend on the needle. It had a pinion gear (aluminum!) from some R/C car for a knob. Set screw held it fine, with some locktite.
I thought this was a cool idea, so when I setup my DS .60bb with a Randy Aero NV assembly for the "Lancer", I did the same thing. Out flying one day, the ST NV snapped off at the spraybar. Hmmm. A few weeks later, the Randy NV snapped off at the spraybar.
I'm in a quandry. I know that the imbalance of the bent 'handle' on the NV is what makes them tend to rotate. Plus, the knob (pinion gear) is easier to use, less awkward, therefore less danger of putting your fingers into the prop. But the darned things break off the NV. Anybody got a good solution...a knob that doesn't weigh anything? I expect I'll have to shorten the NV as much as possible. Might also consider a non-needle mixture control valve (pinch fuel line, like the R/C in-flight systems), with a micro screw adjuster vs. servo.
Uhhhh...I use a TF magnetic prop balancer, engines didn't come loose. Also, how to get the broken NV out of the spraybar? n~ Steve
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I always bend about a 1/4" turn on my needles. I was wary of putting a "weight" on the end of the needle for the reasons Steve has mentioned. Plus no one around here uses a knob anyway. Including Randy Smith.
With the nylon seal lock nut on Randy's NVAs I have not experienced any loosening of the needle. And the needle is easy to turn! Now, ST's are another story. Get them tight enough to seal and you can't turn them! **)
Randy's are only finger tight. (my fingers)
Bill <><
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The "funny" thing is, the pinion gears don't weigh hardly anything. I'm thinking that if I was to cut off enough of the NV so that the weight of what I cut off is the same as the pinion gear, it should be same-same...yes?
Randy's spraybar assembly is truly a work of art, and exactly like Bill says...no problem turning the NV, and no moving. You can really get the collet set tight and still be able to adjust it easily. Also worth every dollar, IMO. Made by Henry Nelson. y1 Steve
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Hi Steve,
I think it is a "resonance" issue. The subtle vibrations of even our smoothest engines today when continuously resonating through the needle with "any" weight on the "pendulum" can lead to fatigue of the metal. The "bending and pulsing" is done at the point of attachment, causing the metal to fatigue there and eventually breaking. The relatively "soft" nature of the metal used might contribute to the flexing, speeding up the process.
Bill <><