---------------------------------------------------------- Stratus-List Digest Archive --- Total Messages Posted Fri 07/29/05: 3 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:10 PM - Belt life and failure. (Don Walker) 2. 03:20 PM - Belt life (Don Walker) 3. 09:02 PM - Re: Belt life and failure. (Jim and Lucy) ________________________________ Message 1 _____________________________________ Time: 03:10:31 PM PST US From: "Don Walker" Subject: Stratus-List: Belt life and failure. --> Stratus-List message posted by: "Don Walker" I have used a Jason belt for six years with no problems... now on my second one...from Stratus. The info below leads me to wonder about the Gates Powergrip GT2. Have any of you used it yet. Review the info below. It is from the article Michel refers to in the note below. don Walker The Gates PowerGrip GT2=AE version was introduced in February 2000. The GT2 belt features a longer and more robust life and with its redesigned deep cog profile is capable of transmitting up to 200% more power than previous PowerGrip GT and PowerGrip HTD belts. When tested against competitor belts at sprocket speeds up to 9000 rpm the GT2 belt outlasted the competitor belts more than two to one. As patented belt designs expire numerous generic versions enter the marketplace. There are presently at least 12 different brands of synchronous belts on the market. A recently introduced belt features a small lateral groove along the face of the cog. The purpose of the groove is to allow the release of trapped air and to reduce noise generation. QCU, the manufacturer of the Challenger Ultralight was requested to provide the research data or to provide the foundation for the imposition of their 100-hour, one-year in-use limitation placed on the re-drive belt. The stated belt limitations imposed b y QCU in the Challenger 50 Hour Inspection Report was found to be arbitrary and without foundation. The QCU imposed belt limitations remain unchanged despite technological advances in belt design and durability. The 880 8M 85 synchronous belt used on the Zenair 601 is about an inch wider and 6 inches shorter than the 960 08M 50 belt used on the Challenger. Belt life is projected to be a minimum of 500 hours of operation utilizing a Subaru 100 hp 4-stroke engine at 4500rpm. While utilizing pre-G2 belt technology and design, Zenair belt usage to 850 hours is commonplace in applications up to 200 horsepower. ----- Original Message ----- From: Hinde, Frank George (Corvallis) To: stratus-list@matronics.com Sent: Thursday, July 28, 2005 9:44 AM Subject: RE: Stratus-List: prop drive belt failure --> Stratus-List message posted by: "Hinde, Frank George (Corvallis)" > Yeah I was thinking about this and wondered the same thing. Belt drive failure so far (ha!) has been extremly rare. I wondered if the tooth failure in another post was a result of the belt chattering on the sprockets. So far my belt/teeth look in perfect condition and I changed the first one at about 3 years and 300 hours. The belt looked perfect. Frank -----Original Message----- From: owner-stratus-list-server@matronics.com [mailto:owner-stratus-list-server@matronics.com] On Behalf Of Michel Therrien To: stratus-list@matronics.com Subject: Re: Stratus-List: prop drive belt failure --> Stratus-List message posted by: Michel Therrien > I read an article recently about a Challenger ultralight crash due to a failed belt. The article explains that belt tension is critical. On this aircraft, there was not enough tension. Details are given on how to adjust tension. Look for belt redrive failure Challenger on google. Michel PS: From Airventure :-) --- John Karnes > wrote: > --> Stratus-List message posted by: "John Karnes" > > > > On power up yesterday, I experienced a belt failure. > Luckily, I still was on the ground. The belt had about 80 hours on > it but dated back to when Stratus changed from two belts to one (about > three to fours ago?). Upon examination, the "teeth" on the inside of > the belt separated from the rest of the belt, thus causing the belt to > lose grip of the pulley and resulted in a failure. When I called > Mykal, he said that "materials degrade over time and the belt should > be changed out every year". This, of course, is contrary to his > published maintenance schedule for this item. Given the critical > nature of this part and my recent experience, I would have to agree > and recommend a yearly change out of the belt. I can't imagine the > end result of a belt failure over hostile terrain...0D0A0D0AJohn > Karnes0D0AN601JK Zenith 601HDS0D0AWashington > > > > browse > Subscriptions page, > FAQ, > > > > > > ---------------------------- Michel Therrien CH601-HD, C-GZGQ http://mthobby.pcperfect.com/ch601 http://www.zenithair.com/bldrlist/profiles/mthobby http://pages.infinit.net/mthobby ________________________________ Message 2 _____________________________________ Time: 03:20:55 PM PST US From: "Don Walker" Subject: Stratus-List: Belt life --> Stratus-List message posted by: "Don Walker" Here are findings from the Challenger belt failure. FINDINGS 1) The engine driven reduction belt failed under high torque at a critical moment during take-off. 2) The lower than optimum engine rpm prior to the occurrence was evidence of excessive belt friction. 3) The belt failure was caused by inadequate tensioning of the belt. 4) The failed PowerGrip HTD belt was an earlier, less robust version of current PowerGrip GT belts. 5) Synchronous belt manufacturers' prescribed belt-tensioning values and procedures are not readily available to aircraft owners, pilots and maintainers. 6) The pilot was unaware that minor tachometer rpm fluctuations to above normal values at take-off power indicated imminent belt failure and total loss of thrust. 7) The one-year, one hundred hour service life imposed by QCU on the Challenger synchronous belt is arbitrary and without foundation. 8) For liability considerations the Gates PowerGrip belt application on the Challenger (and other) aircraft is not endorsed by Gates Rubber Company. 9) Direction of rotation should be identified on the belt and that direction should be maintained for the life of the belt. 10) The Challenger aircraft's docile stall characteristics averted a potentially serious accident. ________________________________ Message 3 _____________________________________ Time: 09:02:30 PM PST US From: Jim and Lucy Subject: Re: Stratus-List: Belt life and failure. --> Stratus-List message posted by: Jim and Lucy At 06:09 PM 7/29/2005, you wrote: >Zenair belt usage to 850 hours is commonplace in applications up to 200 >horsepower. I wonder how common are 850 hour belt drive zenairs. Also 200 hp zenairs seem to be commonplace also? Jim Pollard