---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Tue 09/27/05: 23 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:12 AM - Re: FW: Wiring details for Vans 60A alternator (Mickey Coggins) 2. 12:42 AM - Re: Belt replacement (was Alternator Speed) (Jim Jewell) 3. 12:49 AM - Re: Belt replacement (was Alternator Speed) (Jim Jewell) 4. 04:22 AM - Re: Solid State Gyros (Rico Voss) 5. 06:26 AM - Re: Belt replacement (was Alternator Speed) (James H Nelson) 6. 10:39 AM - Re: FW: Wiring details for Vans 60A (Robert L. Nuckolls, III) 7. 11:15 AM - Re: FW: Wiring details for Vans 60A alternator (Hinde, Frank George (Corvallis)) 8. 12:06 PM - Re: FW: Wiring details for Vans 60A alternator (Matt Prather) 9. 01:08 PM - Re: FW: Wiring details for Vans 60A (Robert L. Nuckolls, III) 10. 01:09 PM - Re: FW: Wiring details for Vans 60A (Robert L. Nuckolls, III) 11. 01:54 PM - Re: Hobbs meter wiring (D Wysong) 12. 02:35 PM - Re: Hobbs meter wiring (Jim Baker) 13. 03:12 PM - Re: Hobbs meter wiring (Matt Prather) 14. 04:41 PM - Not quite electrical (Hinde, Frank George (Corvallis)) 15. 07:21 PM - Re: Not quite electrical (LarryRobertHelming) 16. 08:07 PM - (bob noffs) 17. 08:20 PM - Re: (Robert L. Nuckolls, III) 18. 09:01 PM - Re: (Jim Jewell) 19. 09:01 PM - Re: (Jim Jewell) 20. 09:04 PM - Re: () 21. 09:25 PM - Re: (Sigmo@aol.com) 22. 09:26 PM - Re: (Richard E. Tasker) 23. 11:32 PM - Re: (HCRV6@comcast.net) ________________________________ Message 1 _____________________________________ Time: 12:12:16 AM PST US From: Mickey Coggins Subject: Re: AeroElectric-List: FW: Wiring details for Vans 60A alternator --> AeroElectric-List message posted by: Mickey Coggins > If ALL ND alternators have a bus sense lead (and > from what I've been able to deduce so far, they > do) this opens some VERY interesting opportunities for > crafting a positive ON/OFF control scheme that meets > the design goals I've suggested for integration of > the internally regulated alternator into aircraft. > I'll continue to pursue this line of thinking and > share my findings and deductions with the group at > some time in the not too distant future. My ND alternator does not have an independent bus sense lead, but perhaps it is sensing this via the IGN terminal? http://www.rv8.ch/article.php?story=2004112513263691 -- Mickey Coggins http://www.rv8.ch/ #82007 finishing ________________________________ Message 2 _____________________________________ Time: 12:42:03 AM PST US From: "Jim Jewell" Subject: Re: AeroElectric-List: Belt replacement (was Alternator Speed) --> AeroElectric-List message posted by: "Jim Jewell" Hi Terry, I don't remember the brand name of the belt you might be thinking of: The camshaft grinding company that provided a space for us to maintain various race cars used a leather multi-link type belt on their cam grinding lathes. They use this type of belt because the multiple leather links absorbed vibrations transmitted to and from the drive motor during the finishing stage of grinding cams. This allowed the operator to reduce if not eliminate the almost microscopic ripples on the finished cam lobe surfaces that would be present if a standard vee belt was used. I would be wary of using this type of belt as the RPM limit and loading might be beyond the design capability of these belts. Checking for application suitability with the manufacturer before use would be a must! There might be a non leather variety out there. Though unlikely, each link has a metal clip that might cause trouble should a failure occur while airborne. Standard vee belts failure mode is most often benign. The belt breaks and falls away. However. if the broken belt somehow comes to rest on the exhaust it could make for some precision upholstery button removal! {[8-o Keep the battery up. Jim in Kelowna ----- Original Message ----- From: "Terry Watson" Subject: RE: AeroElectric-List: Belt replacement (was Alternator Speed) > --> AeroElectric-List message posted by: "Terry Watson" > > > I recall seeing v-belts that were made up of removable links. The > advantage > was claimed to be that you could adjust the length to fit. It would seem > to > be an excellent spare that you could install to get home without pulling > the > prop, IF they work. Does anyone have any experience of knowledge of them? > > Terry > > > -----Original Message----- > From: owner-aeroelectric-list-server@matronics.com > [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Ed > Anderson > To: aeroelectric-list@matronics.com > Subject: Re: AeroElectric-List: Belt replacement (was Alternator Speed) > > --> AeroElectric-List message posted by: "Ed Anderson" > > > Strongly support Bob's suggestion of using Gates Belts for alternator. > Prevention is always better than the cure.. > > I used a less expensive brand of belt once and after only 20 hours, a > keen > eyed Nephew fortunately notice that "cogs" were missing from the belt. > Replaced the belts immediately with Gates and after 160 hours they still > appear brand new. > > Ed Anderson > Rv-6A N494BW Rotary Powered > Matthews, NC > eanderson@carolina.rr.com > > > ________________________________ Message 3 _____________________________________ Time: 12:49:19 AM PST US From: "Jim Jewell" Subject: Re: AeroElectric-List: Belt replacement (was Alternator Speed) --> AeroElectric-List message posted by: "Jim Jewell" Hi again Terry, I found this link to a site that seems to have some good information re multilink type vee belts. http://www.fennerindustrial.com/products/powertwist_ind.html I hope this helps, Jim in Kelowna ________________________________ Message 4 _____________________________________ Time: 04:22:32 AM PST US From: Rico Voss Subject: Re: AeroElectric-List: Solid State Gyros --> AeroElectric-List message posted by: Rico Voss --- Larry McFarland wrote: > --> AeroElectric-List message posted by: Larry McFarland > > > Deke, > Take a serious look at their Model 4000 pictured on the > link below, for > the new Horizon EFIS. > http://hometown.aol.com/enginfosys/ > Seriously good people to deal with. Also-- I dont think I've seen mentioned the Blue Mountain EFIS-Lite/G3. Looks similar, but includes internal GPS w. moving map for the same $2800. Is it time for some competitive price-reductions?? See: http://www.bluemountainavionics.com/elitemain.php --Richard, 601-XL, Jab3300 do not archive ________________________________ Message 5 _____________________________________ Time: 06:26:24 AM PST US Subject: Re: AeroElectric-List: Belt replacement (was Alternator Speed) From: James H Nelson --> AeroElectric-List message posted by: James H Nelson Terry, I sell that type of belting. Its a urethane based product so it fairly tough and chemically resistant. Its drawback is the flexability in the length mode. Its a great backup item. You just need to know that you will need to install it in the shortest configuration because it streaches due to the links taking up the slack as you tension the belt. Not a biggie, just a heads up. I had not thought about it myself but now you have raised the issue, I will put several feet (determined after I get my engine installed) in my maintenance cubby under the floor in the back. By the way, it only takes a pair of pliers to adjust the length. The belt does not have any metal in it. It will carry the same loads as a standard belt. Its rather expensive in comparison to a regular v-belt. But, it beats removing the prop some where (not at home). Jim Nelson ________________________________ Message 6 _____________________________________ Time: 10:39:49 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: FW: Wiring details for Vans 60A alternator --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 09:09 AM 9/27/2005 +0200, you wrote: >--> AeroElectric-List message posted by: Mickey Coggins > > > > If ALL ND alternators have a bus sense lead (and > > from what I've been able to deduce so far, they > > do) this opens some VERY interesting opportunities for > > crafting a positive ON/OFF control scheme that meets > > the design goals I've suggested for integration of > > the internally regulated alternator into aircraft. > > I'll continue to pursue this line of thinking and > > share my findings and deductions with the group at > > some time in the not too distant future. > > >My ND alternator does not have an independent bus sense >lead, but perhaps it is sensing this via the IGN terminal? > > http://www.rv8.ch/article.php?story=2004112513263691 Aha! A two-lead version. Can't speak directly to the control philosophy in ND's regulator chip but similar devices offered to the same market will watch the bus sense lead and if there is no connection, the chip reverts to b-lead sense mode. See: http://www.aeroelectric.com/Reference_Docs/Alternator_Data/MC33099_Schematic.pdf This schematic is an exemplar regulator chip offered by Freestyle (Motorola). This is a pretty "busy" chip! In 1975, the functional equivalents to this device had about 8 transistors, a couple of precision zeners and a relay. In the upper left corner of the schematic we see the automatic changeover from local to remote sensing of regulation voltage depending on whether or not the remote sense pin is hooked to anything interesting. In the lower right corner, we see the current and temperature limited lamp driver circuit which allows one to make a hard connection between LAMP and IGN terminals without serious risk to the chip. A further feature of note is what's called an OVER VOLTAGE DETECTOR in the middle. No doubt this section of the chip has some functionality for the implied purpose. However, nobody I know of in the aviation world would consider an embedded OV protection circuit to have adequate separation between CONTROL and PROTECTION. While a citation for "Built in ov protection" looks good on the marketing hype for any alternator that uses this chip, it's a huge stretch to assume that all failure modes capable of precipitating an OV condition will be sufficiently isolated from the OV protection system to pass muster for a certified power generation system for aircraft. It's interesting to note that OV protection of ANY kind is included on the chip. If the chip manufacturer held their product to the same levels of infallibility as those who preach the gospel of running internally regulated alternators barefooted, why would they find it useful to include ANY form of OV protection in their product (in spite of its minimal levels of protection)? This little study of schematics and/or block diagrams is crucial to a learned critical design review and failure mode effects analysis. Not having such data for the ND regulators is the primary reason I've been reluctant to endorse these products for indiscriminate use on aircraft. The product may be just fine but without such data for analysis, I can't encourage their use from a position of understanding. In response to the question about remote bus sensing, it's really easy to identify the sensing method of a particular alternator/regulator combination. Add a temporary diode in series with the wire that carries bus voltage toward the alternator system. If that wire is truly a bus-sense connection, bus voltage will jump up about 0.6v while the diode is in place and go back down when it's removed. Bob . . . ________________________________ Message 7 _____________________________________ Time: 11:15:03 AM PST US Subject: RE: AeroElectric-List: FW: Wiring details for Vans 60A alternator From: "Hinde, Frank George (Corvallis)" --> AeroElectric-List message posted by: "Hinde, Frank George (Corvallis)" Hmmm...and similarly...If the volt sensing lead got disconnected the Alternator would sense "zero volts" and presumably go to max output? Maybe then, this is a good reason NOT to have an alt with a separate sensing lead?? Frank If that wire is truly a bus-sense connection, bus voltage will jump up about 0.6v while the diode is in place and go back down when it's removed. Bob . . . ________________________________ Message 8 _____________________________________ Time: 12:06:34 PM PST US Subject: RE: AeroElectric-List: FW: Wiring details for Vans 60A alternator From: "Matt Prather" --> AeroElectric-List message posted by: "Matt Prather" Uh... Mmm.. Actually, it looks like there's circuitry in there to detect that condition and fail over to running with the internal reference from the B-lead. Check it out... The Vrem is fed to both an input buffer and a comparator circuit with (presumably) a diode pulled up to 0.6V. If the Vrs (tapped from the voltage divider driven by Vrem) drops below 0.6, the comparator will flip states, causing the input source select to change from remote sense to local.. At least that's the way it looks to me. Regards, Matt- > --> AeroElectric-List message posted by: "Hinde, Frank George > (Corvallis)" > > Hmmm...and similarly...If the volt sensing lead got disconnected the > Alternator would sense "zero volts" and presumably go to max output? > > Maybe then, this is a good reason NOT to have an alt with a separate > sensing lead?? > > Frank > > If that wire is truly a bus-sense connection, bus voltage > will jump up about 0.6v while the diode is in place and > go back down when it's removed. > > Bob . . . > > ________________________________ Message 9 _____________________________________ Time: 01:08:13 PM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: FW: Wiring details for Vans 60A alternator --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 01:05 PM 9/27/2005 -0600, you wrote: >--> AeroElectric-List message posted by: "Matt Prather" > >Uh... Mmm.. Actually, it looks like there's circuitry in there to detect >that condition and fail over to running with the internal reference from >the B-lead. Check it out... The Vrem is fed to both an input buffer and >a comparator circuit with (presumably) a diode pulled up to 0.6V. If the >Vrs (tapped from the voltage divider driven by Vrem) drops below 0.6, the >comparator will flip states, causing the input source select to change >from remote sense to local.. At least that's the way it looks to me. That's correct . . . and the feature I was attempting to point out. If you hook up the remote sense, it performs as expected. If you don't hook it up, the alternator defaults to v-sense internally at the b-lead. The concept and value of remote sensing via a zero current conductor is not well understood. I'm not surprised that few if any folks giving advice suggest using it. Then, there's the 2-wire alternators that omit this feature entirely. The "universal" installation calls for allowing a 3-lead machine to default to b-lead sensing. One installation schematic fits all. Bob . . . ________________________________ Message 10 ____________________________________ Time: 01:09:32 PM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: FW: Wiring details for Vans 60A alternator --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 11:11 AM 9/27/2005 -0700, you wrote: >--> AeroElectric-List message posted by: "Hinde, Frank George (Corvallis)" > > >Hmmm...and similarly...If the volt sensing lead got disconnected the >Alternator would sense "zero volts" and presumably go to max output? > >Maybe then, this is a good reason NOT to have an alt with a separate >sensing lead?? Every regulator I've designed defaults to a secondary if less accurate sense path if the primary sense path is lost. Alternatively, the system is designed for passive shutdown if either (+) or (-) sense leads become disconnected. Such is the case with the Motorola chip as well. Bob . . . ________________________________ Message 11 ____________________________________ Time: 01:54:56 PM PST US From: D Wysong Subject: Re: AeroElectric-List: Hobbs meter wiring --> AeroElectric-List message posted by: D Wysong Rodney - How much current does your Hobbs draw? The 914F manual that I have says that the Ducati "L" (lamp) line is good for a 3W/12V bulb. Seems like a neat idea if that's enough juice to power the Hobbs. BTW - thanks for the heads up on the lamp logic! I had assumed that the operation of the "charge-indicating lamp" would be just the opposite... "off" during normal operation and "on" if the system was not charging (like the red ALT lamp in a ratty old C-150). D Rodney Dunham wrote: > --> AeroElectric-List message posted by: "Rodney Dunham" > > I've noticed on the Rotax 912UL wiring diagrams that the "L" pin on the VR > is for a lamp which indicates charge and is usually only "on" at run-up > speed or greater. > > Has anyone tried using this as a DCV source for the Hobbs meter? Seems it > would give good "flying time" readings and, or course, no falsely high "I > left the master switch on overnight" readings! Only engine on and RPM's > above warm-up times. > > I was thinking run a wire to the meter with an in-line fuse, say 3 amps, > would do the trick. > > Any thoughts? > > Rodney in Tennessee > > > > > > > ________________________________ Message 12 ____________________________________ Time: 02:35:40 PM PST US From: "Jim Baker" Subject: Re: AeroElectric-List: Hobbs meter wiring --> AeroElectric-List message posted by: "Jim Baker" > BTW - thanks for the heads up on the lamp logic! I had assumed that > the operation of the "charge-indicating lamp" would be just the > opposite... "off" during normal operation and "on" if the system was > not charging (like the red ALT lamp in a ratty old C-150). Of course you could always wire in a normally open relay that closes on loss of power to create the first indicator scenario. My Bellanca behaves in that manner..... Jim Baker 580.788.2779 '71 SV, 492TC Elmore City, OK ________________________________ Message 13 ____________________________________ Time: 03:12:16 PM PST US Subject: Re: AeroElectric-List: Hobbs meter wiring From: "Matt Prather" --> AeroElectric-List message posted by: "Matt Prather" The LCD display Hobbs hour meter draws 0.8mA. Wow, though I guess it really isn't any different than a digital watch which runs from a very small battery. http://content.honeywell.com/sensing/hss/hobbsparts/products/lcdHourMeters.asp I couldn't find an "I" value for the mechanical meters, but 3 watts should be plenty - roughly 250mA. Regards, Matt- > --> AeroElectric-List message posted by: D Wysong > > Rodney - > > How much current does your Hobbs draw? The 914F manual that I have says > that the Ducati "L" (lamp) line is good for a 3W/12V bulb. Seems like > a neat idea if that's enough juice to power the Hobbs. > > BTW - thanks for the heads up on the lamp logic! I had assumed that the > operation of the "charge-indicating lamp" would be just the opposite... > "off" during normal operation and "on" if the system was not charging > (like the red ALT lamp in a ratty old C-150). > > D > > > Rodney Dunham wrote: >> --> AeroElectric-List message posted by: "Rodney Dunham" >> >> >> I've noticed on the Rotax 912UL wiring diagrams that the "L" pin on >> the VR is for a lamp which indicates charge and is usually only "on" >> at run-up speed or greater. >> >> Has anyone tried using this as a DCV source for the Hobbs meter? Seems >> it would give good "flying time" readings and, or course, no falsely >> high "I left the master switch on overnight" readings! Only engine on >> and RPM's above warm-up times. >> >> I was thinking run a wire to the meter with an in-line fuse, say 3 >> amps, would do the trick. >> >> Any thoughts? >> >> Rodney in Tennessee >> >> >> >> >> >> >> > > ________________________________ Message 14 ____________________________________ Time: 04:41:39 PM PST US Subject: AeroElectric-List: Not quite electrical From: "Hinde, Frank George (Corvallis)" --> AeroElectric-List message posted by: "Hinde, Frank George (Corvallis)" Without thinking too hard I made provision for a vertical card compass (2 1/4") about an inch away from my audio panel and radio stack in an RV7. It is also about an inch above the Pictorial Pilot (auto pilot). I was about to can the idea and install a VSI in that hole and mount a whiskey compass on top of the panel...But being a tip up canopy I'm not sure how resilient the compass would be to this kind of abuse. So I thought I would ask....Is the Vert card compass completely unworkable in this location? Thanks Frank ________________________________ Message 15 ____________________________________ Time: 07:21:23 PM PST US From: "LarryRobertHelming" Subject: Re: AeroElectric-List: Not quite electrical --> AeroElectric-List message posted by: "LarryRobertHelming" That is where I mounted mine with the flexible base mount on top of the glare shield. It is still working after 63 hours. I figure in a plane doing aerobatics, it would be going through the tilt up and down anyway. I had originally planned to mount it in the panel but changed after reading the warnings and concerns of others due to magnetic and radio frequency interference. I would like it better in the panel from a sight and appearance stand point. However, I have more room in my panel for something else if I want it later. From my setup the compass is only a backup instrument in case I lost all my electronics AND hand helds with GPS capability. What are the odds of that?? Indiana Larry, RV7 Tip Up SunSeeker ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ " Happiness: like a butterfly, when pursued, is always beyond our grasp, but which, if one sits quietly, may light upon you." Nathaniel Hawthorne ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ----- Original Message ----- From: "Hinde, Frank George (Corvallis)" Subject: AeroElectric-List: Not quite electrical > --> AeroElectric-List message posted by: "Hinde, Frank George (Corvallis)" > > > Without thinking too hard I made provision for a vertical card compass > (2 1/4") about an inch away from my audio panel and radio stack in an > RV7. It is also about an inch above the Pictorial Pilot (auto pilot). > > I was about to can the idea and install a VSI in that hole and mount a > whiskey compass on top of the panel...But being a tip up canopy I'm not > sure how resilient the compass would be to this kind of abuse. > > So I thought I would ask....Is the Vert card compass completely > unworkable in this location? > > Thanks > > Frank > > > ________________________________ Message 16 ____________________________________ Time: 08:07:34 PM PST US From: "bob noffs" Subject: AeroElectric-List: --> AeroElectric-List message posted by: "bob noffs" hi all, i have the washers for toggle switches that have the small tab which locks into a 1/8'' hole drilled in the ins. panel. before i drill all these 1/8'' holes in a so far perfect panel does anyone have any opinions or experience with this system? can the holes be hidden with the control labels? etc. seems like a good idea to keep all the switches from turning. thanks for any input. bob noffs ________________________________ Message 17 ____________________________________ Time: 08:20:14 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 10:06 PM 9/27/2005 -0500, you wrote: >--> AeroElectric-List message posted by: "bob noffs" > >hi all, > i have the washers for toggle switches that have the small tab which > locks into a 1/8'' hole drilled in the ins. panel. before i drill all > these 1/8'' holes in a so far perfect panel does anyone have any opinions > or experience with this system? can the holes be hidden with the control > labels? etc. seems like a good idea to keep all the switches from > turning. > thanks for any input. > bob noffs I recommend them. You can put anti rotation washers on the back side of the panel, trim the tabs to be flush with the front surface and the cover them with an engraved overlay that labels the switches. Bob . . . ________________________________ Message 18 ____________________________________ Time: 09:01:52 PM PST US From: "Jim Jewell" Subject: Re: AeroElectric-List: --> AeroElectric-List message posted by: "Jim Jewell" Hi Bob, options: Drill holes for positioning tabs install the tabbed washers out front (in sight) and live with the look. Drill very shallow holes from the rear side of the switch panel. If the switch panel seems too thin for this add a doubler with the holes predrilled in it. Put the tabs onto the switches tab out then install the switches without the tabs or holes visible from the front. Flat washers without tabs will keep the scratches to a minimum during install keep building, Jim in Kelowna ----- Original Message ----- From: "bob noffs" Subject: AeroElectric-List: > --> AeroElectric-List message posted by: "bob noffs" > > hi all, > i have the washers for toggle switches that have the small tab which locks > into a 1/8'' hole drilled in the ins. panel. before i drill all these > 1/8'' holes in a so far perfect panel does anyone have any opinions or > experience with this system? can the holes be hidden with the control > labels? etc. seems like a good idea to keep all the switches from turning. > thanks for any input. > bob noffs > > > ________________________________ Message 19 ____________________________________ Time: 09:01:52 PM PST US From: "Jim Jewell" Subject: Re: AeroElectric-List: --> AeroElectric-List message posted by: "Jim Jewell" Hi Bob, options: Drill holes for positioning tabs install the tabbed washers out front (in sight) and live with the look. Drill very shallow holes from the rear side of the switch panel. If the switch panel seems too thin for this add a doubler with the holes predrilled in it. Put the tabs onto the switches tab out then install the switches without the tabs or holes visible from the front. Flat washers without tabs will keep the scratches to a minimum during install keep building, Jim in Kelowna ----- Original Message ----- From: "bob noffs" Subject: AeroElectric-List: > --> AeroElectric-List message posted by: "bob noffs" > > hi all, > i have the washers for toggle switches that have the small tab which locks > into a 1/8'' hole drilled in the ins. panel. before i drill all these > 1/8'' holes in a so far perfect panel does anyone have any opinions or > experience with this system? can the holes be hidden with the control > labels? etc. seems like a good idea to keep all the switches from turning. > thanks for any input. > bob noffs > > > ________________________________ Message 20 ____________________________________ Time: 09:04:53 PM PST US From: Subject: Re: AeroElectric-List: --> AeroElectric-List message posted by: Bob One method of utilizing these washers which does not impact the panel itself, is to add a strip of aluminium behind the panel where the switches are mounted into which you drill these tab holes and which you drill for the switch bushings. If your switches are in groups you can make one of these plates for each group of switches. They are retained by the switches themselves and give the washers the required antirotation grip without defacing the panel. As long as your panel plus the backup strip thickness total less than the grip length of your switches this will work. The added strip just needs to be as thick as the depth of the washer tab. Bob McC > > From: "bob noffs" > Date: 2005/09/27 Tue PM 11:06:16 EDT> To: "aeroelectric list" > Subject: AeroElectric-List: > > ________________________________ Message 21 ____________________________________ Time: 09:25:43 PM PST US From: Sigmo@aol.com Subject: Re: AeroElectric-List: --> AeroElectric-List message posted by: Sigmo@aol.com You can mount the tab washers on the back of the panel and drill the hole part way through the panel. Do not archive ________________________________ Message 22 ____________________________________ Time: 09:26:40 PM PST US From: "Richard E. Tasker" Subject: Re: AeroElectric-List: --> AeroElectric-List message posted by: "Richard E. Tasker" Unless your panel is really thin, you can drill a hole partially into the rear of the panel and use these that way. No rotation, no visibility! You do have to be careful, but you might be able to use a the same thing you use to limit the depth of the countersinks or if you have a drill press with stops. Dick Tasker bob noffs wrote: >--> AeroElectric-List message posted by: "bob noffs" > >hi all, > i have the washers for toggle switches that have the small tab which locks into a 1/8'' hole drilled in the ins. panel. before i drill all these 1/8'' holes in a so far perfect panel does anyone have any opinions or experience with this system? can the holes be hidden with the control labels? etc. seems like a good idea to keep all the switches from turning. > thanks for any input. > bob noffs > ---- Please Note: No trees were destroyed in the sending of this message. We do concede, however, that a significant number of electrons may have been temporarily inconvenienced. ---- ________________________________ Message 23 ____________________________________ Time: 11:32:16 PM PST US From: HCRV6@comcast.net Subject: Re: AeroElectric-List: --> AeroElectric-List message posted by: HCRV6@comcast.net I drilled a very small hole, #40 I think, and then used a needle file to elongate the hole just enough to fit the tang on the washer. The holes are competely filled by the tang and don't show at all. -- Harry Crosby RV-6 N16CX, 133 hours I drilled a very small hole, #40 I think, and then used a needle file to elongate the hole just enough to fit the tang on the washer. The holes are competely filled by the tang and don't show at all. -- Harry Crosby RV-6 N16CX, 133 hours