Larry H. wrote: > I am curious if any of you ever have to re-torque, or if any of you ever > check the torque values of your wooden props. > One more question would be, what is your torque values on your props.
The exact wood species that the prop is made of would make a difference, so I'd say the first place to ask that question would be the manufacturer. Having said that, Sensenich recommends something like 15-20 ft-lbs (it's on their website somewhere) but when I torqued mine to 15 ft-lbs I hear wood "cracking", so I don't torque it that tight. I have to qualify that, because I use metal locknuts, which have a "running torque" (the torque it takes just to rotate the nut due to friction) of 5 pounds (determined with inch pound torque wrench and bolt clamped in a vice). That means when I torque my prop I set my inch pound wrench (which is more accurate since this is at about 75% or its range) to 180 inch pounds (10 prop + 5 locknut) and torque the nuts in alternating fashion. That means my prop bolts are actually torqued to 10 foot pounds. It doesn't change much past the second torquing after initial installation, but I do retorque it every 50-100 hours or so just for good measure. [12 inch pounds = 1 foot pound.] Yes, I do have a crush plate and my torque wrench is accurate and calbrated. And no, I don't use safety wire. Safety wire to me is a great excuse to never torque a prop, or whatever else is wired into submission. I don't believe in the stuff, and the only piece of safety wire on my plane is a 6" piece that I wrapped around the heat muff as a lightweight clamp. If I'm really worried about a bolt backing out or a nut coming off (like the ones that hold my prop hub to my crankshaft) I'll use red Loctite on them...- Mark Langford, Huntsville, Alabama see KR2S project N56ML at http://home.hiwaay.net/~langford email to N56ML "at" hiwaay.net ----- Original Message ----- From: "Larry H." <lah...@yahoo.com> To: "KRnet" <kr...@mylist.net> Sent: Friday, December 08, 2006 10:11 AM Subject: KR> My Purchase of KR-2 in Iowa! - Wood Prop Questions > Something I never really hear anyone talking about on KRs is torque values > on wooden props. Depending on the moisture in the air or the lack there of > the prop thickness can change. In the Rutan EZE world, regular torque > checking was a requirement. There were cases of flopping props and I also > thing there may have been some planes damaged or forced onto the ground > because of loosening caused by atmospheric changes over time. > I am curious if any of you ever have to re-torque, or if any of you ever > check the torque values of your wooden props. > One more question would be, what is your torque values on your props. > > Thanks > Larry H. > > > From: Marc Lee Winnig mlwin...@hotmail.com > Wood Prop Question > > > Sent a bank check for his asking price (overnight courier) BEFORE actually > seeing pictures of her! (Pretty sure she is mine!).Got some pictures > from his daughter, and she looks like a fine plane. Probably not too much > to do, though he has already mentioned the prop needs to go. Perhaps I > can use it on my Ultralight Amphib. project (if it is not wood). Ed > Sterba it will be! (The Sonerai IIL I came very close to getting was to > have a new ES prop.). Thanks for all the good info there. (Both VW > engines). > > One wood prop question... I hear they don't like running in the rain. > Just how serious is that limitation? (Are we talking anything above a > mist, heavy downpour, or what?). > Thanks! Looking forward to being a FULL-FLEDGED Member of this little > "Club"! > > Hope to meet many of you in Mt. Vernon, IL!Marc Lee Winnig > mlwin...@hotmail.com (815) 301-5011 Cell and Vonage (801) 749-9460 FAX > _______________________________________ > Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp > to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net > please see other KRnet info at http://www.krnet.org/info.html >
