---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Fri 11/20/20: 5 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:36 AM - Re: heat probe (bobnoffs) 2. 07:54 AM - Re: Re: heat probe (Robert L. Nuckolls, III) 3. 09:22 AM - Re: Re: heat probe (Bill Allen) 4. 10:00 AM - Re: Re: heat probe (C&K) 5. 04:36 PM - Re: heat probe (bobnoffs) ________________________________ Message 1 _____________________________________ Time: 03:36:36 AM PST US Subject: AeroElectric-List: Re: heat probe From: "bobnoffs" the chip detecter looks like a good idea but i don't have a place to mount it. it is way over my head to drill and tap a hole in the gearbox case. maybe down the road it would be a job for someone competent when it is inspected. bob Read this topic online here: http://forums.matronics.com/viewtopic.php?p=499444#499444 ________________________________ Message 2 _____________________________________ Time: 07:54:14 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: heat probe At 05:31 AM 11/20/2020, you wrote: > >the chip detecter looks like a good idea but i don't have a place to >mount it. it is way over my head to drill and tap a hole in the gearbox case. > maybe down the road it would be a job for someone competent when > it is inspected. > Adding a pipe-thread hole in the casting is probably the easiest of tasks. Straight thread taps are not 'self aligning' and it's too easy to have your tap start cutting on a slightly axially mis-aligned orientation. Pipe threads are tapered and they start cutting with a minimum of attention to position and force . . . you can concentrate on axial alignment and the tap takes care of the rest. This thread begs some questions: Is this a flooded, pressurize gearbox? Fed with engine oil? Are there any instances of field failures due to degraded gearing? Were these judged to be conditions long-in-the- making that MIGHT have telegraphed impending failure by increased temperature, metal chips in oil, noise, etc? What are the recommendations of the manufacturer for monitoring gear box condition? If it is judged that addition of any sensors by penetrating the gearbox case is a good thing to do, where is the best place for locating those sensors. There will be optimum locations after consideration of structural issues, temperature gradients, optimal chip-congregation points, etc. If this box is lubricated with circulated engine oil, then I'm skeptical of the value of adding any single temperature sensor. You've got hot oil coming in. You'll want to know TEMPERATURE RISE attributable to gear box wear. What is the experience of the user community with respect to this topic? It naturally seems like a cool thing to add such sensors but before you venture forth, it would pay to know if such sensors are KNOWN to be effective along with protocols for interpreting what a temperature gage is telling you. I seem to recall a similar discussion many moons ago on another forum . . . perhaps Compuserv AVSIG . . . wherein a reader suggested that the best harbinger of impending gearbox doom was a dial indicator he could firmly affix to some part of the airplane to measure backlash in the gearing. The observed number would rise noticeably long before the gearbox trashed. Bob . . . Un impeachable logic: George Carlin asked, "If black boxes survive crashes, why don't they make the whole airplane out of that stuff?" ________________________________ Message 3 _____________________________________ Time: 09:22:03 AM PST US From: Bill Allen Subject: Re: AeroElectric-List: Re: heat probe Most chip detectors fit where the drain plug goes. You can get them from salvage yards where they break helicopters. That=99s where I got mine .. On Fri, 20 Nov 2020 at 11:42, bobnoffs wrote: > > the chip detecter looks like a good idea but i don't have a place to moun t > it. it is way over my head to drill and tap a hole in the gearbox case. > maybe down the road it would be a job for someone competent when it is > inspected. > bob > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=499444#499444 > > =========== =========== =========== =========== =========== > > > -- Sent from Gmail Mobile ________________________________ Message 4 _____________________________________ Time: 10:00:18 AM PST US Subject: Re: AeroElectric-List: Re: heat probe From: C&K A few folks have made their own chip detector. A pair of metal probes with a magnet epoxied into a pipe plug. Where possible expose it to oil flowing in a line going to a filter. It's important to catch bearing failures before they progress too far and periodic oil and filter changes may not be frequent enough. Ken On 20/11/2020 11:47 AM, Bill Allen wrote: > Most chip detectors fit where the drain plug goes. You can get them > from salvage yards where they break helicopters. Thats where I got mine. > > On Fri, 20 Nov 2020 at 11:42, bobnoffs > wrote: > > > > > the chip detecter looks like a good idea but i don't have a place > to mount it. it is way over my head to drill and tap a hole in the > gearbox case. > maybe down the road it would be a job for someone competent when > it is inspected. > bob > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=499444#499444 > > > ========== > - > Electric-List" rel="noreferrer" > target="_blank">http://www.matronics.com/Navigator?AeroElectric-List > ========== > FORUMS - > eferrer" target="_blank">http://forums.matronics.com > ========== > WIKI - > errer" target="_blank">http://wiki.matronics.com > ========== > b Site - > -Matt Dralle, List Admin. > rel="noreferrer" target="_blank">http://www.matronics.com/contribution > ========== > > > -- > Sent from Gmail Mobile ________________________________ Message 5 _____________________________________ Time: 04:36:32 PM PST US Subject: AeroElectric-List: Re: heat probe From: "bobnoffs" I admit adding a chip detector is a stretch but I think a temp probe could be valuable. You are not looking for absolute temp but a trend compared to engine oil temp. If I had a gearbox with a hx of failure I would probably be looking for another gearbox. Kind of like having an engine oil analysis. Maybe I will see something coming Read this topic online here: http://forums.matronics.com/viewtopic.php?p=499457#499457 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.