---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sat 11/29/03: 14 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:14 AM - COM antenna feedback (Neville Kilford) 2. 06:18 AM - Re: Best CAD for printing (Antonio Augusto Todo Bom Neto) 3. 06:54 AM - Aeroflash wiring (Darwin N. Barrie) 4. 06:57 AM - Pitch Trim Help (BAKEROCB@aol.com) 5. 08:56 AM - Re: Aeroflash wiring (Robert L. Nuckolls, III) 6. 12:18 PM - Please Support Your Email Lists... (Matt Dralle) 7. 01:18 PM - Re: AeroElectric-List Digest: 59 Msgs - 11/25/03 (Glen Matejcek) 8. 02:10 PM - Re: COM antenna feedback (Robert L. Nuckolls, III) 9. 04:30 PM - Firewall Junction Box (Jeffrey Steenson) 10. 05:26 PM - Re: COM antenna feedback (Franz Fux) 11. 07:23 PM - Re: Aeroflash wiring (Darwin N. Barrie) 12. 08:14 PM - Pitch Trim Help (BAKEROCB@aol.com) 13. 09:36 PM - Re: Firewall Junction Box (Robert L. Nuckolls, III) 14. 09:39 PM - Re: COM antenna feedback (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 04:14:03 AM PST US From: "Neville Kilford" Subject: AeroElectric-List: COM antenna feedback --> AeroElectric-List message posted by: "Neville Kilford" Just wanted to let you guys know about my COM antenna. It's a straight (read: cheap - $17.85) stainless rod antenna from Aircraft Spruce with a six-spoke groundplane made from 2.5" wide strips of .020" aluminium. It's all mounted vertically upside-down inside the Jodel's wood fuselage. Connections to the rod and groundplane are made with PIDG ring terminals. Anyway, to cut a long story short, I tried it today for the first time by connecting the coax to an Icom hand-held radio, and it worked a treat! Radio signals were clear as a bell, and I could hear stations from a great distance. All this was on the ground in the hangar, so I'm thinking the in-air performance will be even better. So... thanks for the advice, Bob -- looks as though it's going to work a treat. Nev -- Jodel D-150 in progress UK ________________________________ Message 2 _____________________________________ Time: 06:18:35 AM PST US Subject: Re: AeroElectric-List: Best CAD for printing From: Antonio Augusto Todo Bom Neto Organization: LAX Eletr\303\264nica e teleco... --> AeroElectric-List message posted by: Antonio Augusto Todo Bom Neto Just for notes: To an EDA (Eletronic Design Automation) I use gEDA professionally in my office. I believe that is great for Electric and Electronic design. Is GPL ans is expanding to fast. Now it runs over Linux and Windows too (using MinGW) Regards, Antonio Augusto Todo Bom Neto LAX Eletronica e Telecomunica=E7=F5es Ltda. Digital Signature: Please, look for my public key at: http://www.keyserver.net to verify this enclosed signature. ________________________________ Message 3 _____________________________________ Time: 06:54:07 AM PST US From: "Darwin N. Barrie" Subject: AeroElectric-List: Aeroflash wiring --> AeroElectric-List message posted by: "Darwin N. Barrie" I have installed Aeroflash power supplies in my RV7. One in the tail and one in each wing. Is there any need to run a ground forward to the firewall ground or is a local ground sufficient? Darwin N. Barrie Chandler AZ ________________________________ Message 4 _____________________________________ Time: 06:57:12 AM PST US From: BAKEROCB@aol.com Subject: AeroElectric-List: Pitch Trim Help --> AeroElectric-List message posted by: BAKEROCB@aol.com AeroElectric-List message previously posted by: Dave Morris << Have you tried the Strong pitch trim servo? http://www.strongpitchtrim.com/ I believe it is rated at 40 lbs. Wait a minute... if you're putting 80 to 100 lbs of force on that thing, how are you planning to override it? And what kind of plane requires 80 to 100 lbs of force to operate the elevators anyway? Dave Morris >> 11/28/2003 Hello Dave, I really appreciate your input -- you raise a very good question. I think that there are two things wrong with my spring bias pitch trim design. One is very poor leverage, the other is use of tension rather than compression springs. Right now I feel like the Wright brothers who suffered years of failure before they successfully flew, but with the help of others I hope to overcome. In the meantime let me kick the can down the road a bit. 1) I believe that the fundamental precept of a spring bias pitch trim system is that one should be able to control the aircraft with reasonable stick pressures regardless of what the trim system does or does not do. Mine was designed and ground tested to accomplish this. In flight I had insufficient trim force, particularly nose down. 2) Using compression springs rather than tension springs is a superior approach, but I am not exactly sure of all the reasons thereof. I suspect that one of the reasons is that in the neutral state the compression springs do not have to be compressed nearly to the extent that the tension springs have to be stretched in their neutral state. 3) It is much easier to use tension springs than compression springs. Compression springs would normally encircle the push rod with some sort of electrically powered screw driven yoke in the center between the two springs. Collars are pinned or clamped to the push rod at the outer extremities of the two compression springs. But the push rod slides back and forth through the springs whenever the stick is moved so clearance and friction issues need to be considered and solved. This is fairly complex construction, particularly if you go through several trial and error efforts to come up with the right springs. 4) For a tension spring system one can just use worm gear hose clamps to hold some small metal corner brackets to the push tube where ever desired and fasten the tension spring ends to the brackets and the center movement lever with split rings. This is a much simpler and more easily modified construction, but as I have learned the tension spring and lever system can be a real gotcha. 5) I think the forces involved and the freedom of movement required are very deceptive. Try a little experiment: Go to some place in the elevator push rod run, forward of any idler if the system has one, and grab that place with your hand with the intention of not letting the push rod move fore or aft. Then have someone go to the trailing edge of the elevator and attempt to move it up and down. I think you will be surprised at how much leverage the person at the edge of the elevator has and how easily he can overpower the person attempting to prevent the push rod movement. Similarily if the person at the edge of the elevator goes to the cockpit and moves the control stick fore and aft at the grip he will also easily overpower the person attempting to prevent push rod movement at the rod itself. 6) As for freedom of movement, now envision that little MAC servo with 1.2 inches of movement maximum. Maybe the total fore and aft elevator push rod movement is on the order of only two or three inches, but A) the tension springs must be long enough so that the push rod can be moved by the control stick from one extreme to the other regardless of trim position, and B) the screw drive must be strong enough to overcome the adverse leverage created by the need to gain enough movement to accomplish the nose up or nose down trim force needed in spite of the forces on the elevator. 7) I think that a spring bias pitch trim system, either electrically or mechanically positioned, properly designed with compression springs, is superior to a trim tab system. Just examine the pitch trim systems on such modern airplanes as the Diamond DA20-C1 and Cirrus. Also note how huge the compression springs are. 8) I will concede that there is one significant drawback: If the push rod becomes disconnected from the elevator horn there is no pitch control available other than engine power modulation. In the case of a completely independent elevator trim tab system, either electrically or mechanicall operated, one still has some degree of pitch control. But like Bob Nuckolls points out from time to time, we don't really provide spare wings and propellers just in case the ones we primarily use may fail. 9) I guess the things that dismay and stymie me are: A) That throwing together an electrically driven pitch trim system is not all that simple, intuitive, and straight forward, and B) That our community doesn't already have several articles or plans floating around on how to build such systems. Have we let the type certificated crowd get ahead of us on this feature? Have I been asleep at the switch? 'OC' Baker, Builder of KIS TR-1 #116 4/14/97 - 11/17/03 PS: Yes, I have just become aware of the Strong trim system and examined my elevator control system with a view to incorporating that trim system. So far I see no feasible incorporation method. ________________________________ Message 5 _____________________________________ Time: 08:56:51 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Aeroflash wiring --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 07:53 AM 11/29/2003 -0700, you wrote: >--> AeroElectric-List message posted by: "Darwin N. Barrie" > >I have installed Aeroflash power supplies in my RV7. One in the tail and >one in each wing. Is there any need to run a ground forward to the >firewall ground or is a local ground sufficient? Local ground is fine. Bob . . . ________________________________ Message 6 _____________________________________ Time: 12:18:45 PM PST US From: Matt Dralle Subject: AeroElectric-List: Please Support Your Email Lists... --> AeroElectric-List message posted by: Matt Dralle Dear Listers, There's only about a day and a half left until the official end of the Email List Fund Raiser! You can still get your name on the List of Contributors by making your Contribution today or tomorrow. I will be posting the official List of Contributors on Tuesday or Wednesday. Its your Contribution that makes these Lists available. Your $20 or $30 pays the bills that keeps the Internet Connection turned on and the servers upgraded to the latest and fastest hardware. Please support your lists by making a quick Contribution today. Using the SSL secure online Contribution form, its fast, easy and safe... http://www.matronics.com/contribution Thank you to everyone that has already made a Contribution. Be looking for *your* name on the up coming List of Contributors! Best regards, Matt Dralle Email List Admin Matt G Dralle | Matronics | PO Box 347 | Livermore | CA | 94551 925-606-1001 V | 925-606-6281 F | dralle@matronics.com Email http://www.matronics.com/ WWW | Featuring Products For Aircraft do not archive ________________________________ Message 7 _____________________________________ Time: 01:18:01 PM PST US From: "Glen Matejcek" Subject: AeroElectric-List: RE: AeroElectric-List Digest: 59 Msgs - 11/25/03 --> AeroElectric-List message posted by: "Glen Matejcek" Or would you rather Mai Bock? Time: 07:40:09 AM PST US From: "Werner Schneider" Subject: Re: AeroElectric-List: Magneto Replacements --> AeroElectric-List message posted by: "Werner Schneider" Maybach =(;o) do not archive ________________________________ Message 8 _____________________________________ Time: 02:10:17 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: COM antenna feedback --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 12:16 PM 11/29/2003 +0000, you wrote: >--> AeroElectric-List message posted by: "Neville Kilford" > > >Just wanted to let you guys know about my COM antenna. It's a straight >(read: cheap - $17.85) stainless rod antenna from Aircraft Spruce with a >six-spoke groundplane made from 2.5" wide strips of .020" aluminium. It's >all mounted vertically upside-down inside the Jodel's wood fuselage. >Connections to the rod and groundplane are made with PIDG ring terminals. > >Anyway, to cut a long story short, I tried it today for the first time by >connecting the coax to an Icom hand-held radio, and it worked a treat! Radio >signals were clear as a bell, and I could hear stations from a great >distance. All this was on the ground in the hangar, so I'm thinking the >in-air performance will be even better. > >So... thanks for the advice, Bob -- looks as though it's going to work a >treat. It's neat that the laws of physics cannot be re-written nor ignored by anyone. Folks have been using this simple antenna design to good advantage for nearly 100 years. Bob . . . ________________________________ Message 9 _____________________________________ Time: 04:30:34 PM PST US From: "Jeffrey Steenson" Subject: AeroElectric-List: Firewall Junction Box --> AeroElectric-List message posted by: "Jeffrey Steenson" On the Murphy Elite I am building I have brought all my wires through one hole in the firewall, including the bundle from the E.I.S. engine monitor. My question is: What options should I be looking at to gather together neatly all the splices that must be mae to EGT and CHT probes? I was thinking of a simple aluminum cover over all of this. But are there boxes available for this purpose, without heading into the expensive certified world? Thanks in advance for your advice! Jeffrey Steenson ABQ, NM ________________________________ Message 10 ____________________________________ Time: 05:26:07 PM PST US From: "Franz Fux" Subject: RE: AeroElectric-List: COM antenna feedback --> AeroElectric-List message posted by: "Franz Fux" Would this system also work in a RV7, say mounting the antenna in the back of the luggage compartment one way or another, thanks, Franz -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Robert L. Nuckolls, III Subject: Re: AeroElectric-List: COM antenna feedback --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 12:16 PM 11/29/2003 +0000, you wrote: >--> AeroElectric-List message posted by: "Neville Kilford" > > >Just wanted to let you guys know about my COM antenna. It's a straight >(read: cheap - $17.85) stainless rod antenna from Aircraft Spruce with a >six-spoke groundplane made from 2.5" wide strips of .020" aluminium. It's >all mounted vertically upside-down inside the Jodel's wood fuselage. >Connections to the rod and groundplane are made with PIDG ring terminals. > >Anyway, to cut a long story short, I tried it today for the first time by >connecting the coax to an Icom hand-held radio, and it worked a treat! Radio >signals were clear as a bell, and I could hear stations from a great >distance. All this was on the ground in the hangar, so I'm thinking the >in-air performance will be even better. > >So... thanks for the advice, Bob -- looks as though it's going to work a >treat. It's neat that the laws of physics cannot be re-written nor ignored by anyone. Folks have been using this simple antenna design to good advantage for nearly 100 years. Bob . . . --- Incoming mail is certified Virus Free. --- ________________________________ Message 11 ____________________________________ Time: 07:23:36 PM PST US From: "Darwin N. Barrie" Subject: Re: AeroElectric-List: Aeroflash wiring --> AeroElectric-List message posted by: "Darwin N. Barrie" Thanks Bob!! Darwin ----- Original Message ----- From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Aeroflash wiring > --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > > At 07:53 AM 11/29/2003 -0700, you wrote: > >--> AeroElectric-List message posted by: "Darwin N. Barrie" > > > >I have installed Aeroflash power supplies in my RV7. One in the tail and > >one in each wing. Is there any need to run a ground forward to the > >firewall ground or is a local ground sufficient? > > Local ground is fine. > > Bob . . . > > ________________________________ Message 12 ____________________________________ Time: 08:14:20 PM PST US From: BAKEROCB@aol.com Subject: AeroElectric-List: Pitch Trim Help --> AeroElectric-List message posted by: BAKEROCB@aol.com AeroElectric-List message previously posted by: Dave Morris << Have you tried the Strong pitch trim servo? http://www.strongpitchtrim.com/ I believe it is rated at 40 lbs. Wait a minute... if you're putting 80 to 100 lbs of force on that thing, how are you planning to override it? And what kind of plane requires 80 to 100 lbs of force to operate the elevators anyway? Dave Morris >> 11/28/2003 Hello Dave, I really appreciate your input -- you raise a very good question. I think that there are two things wrong with my spring bias pitch trim design. One is very poor leverage, the other is use of tension rather than compression springs. Right now I feel like the Wright brothers who suffered years of failure before they successfully flew, but with the help of others I hope to overcome. In the meantime let me kick the can down the road a bit. 1) I believe that the fundamental precept of a spring bias pitch trim system is that one should be able to control the aircraft with reasonable stick pressures regardless of what the trim system does or does not do. Mine was designed and ground tested to accomplish this. In flight I had insufficient trim force, particularly nose down. 2) Using compression springs rather than tension springs is a superior approach, but I am not exactly sure of all the reasons thereof. I suspect that one of the reasons is that in the neutral state the compression springs do not have to be compressed nearly to the extent that the tension springs have to be stretched in their neutral state. 3) It is much easier to use tension springs than compression springs. Compression springs would normally encircle the push rod with some sort of electrically powered screw driven yoke in the center between the two springs. Collars are pinned or clamped to the push rod at the outer extremities of the two compression springs. But the push rod slides back and forth through the springs whenever the stick is moved so clearance and friction issues need to be considered and solved. This is fairly complex construction, particularly if you go through several trial and error efforts to come up with the right springs. 4) For a tension spring system one can just use worm gear hose clamps to hold some small metal corner brackets to the push tube where ever desired and fasten the tension spring ends to the brackets and the center movement lever with split rings. This is a much simpler and more easily modified construction, but as I have learned the tension spring and lever system can be a real gotcha. 5) I think the forces involved and the freedom of movement required are very deceptive. Try a little experiment: Go to some place in the elevator push rod run, forward of any idler if the system has one, and grab that place with your hand with the intention of not letting the push rod move fore or aft. Then have someone go to the trailing edge of the elevator and attempt to move it up and down. I think you will be surprised at how much leverage the person at the edge of the elevator has and how easily he can overpower the person attempting to prevent the push rod movement. Similarily if the person at the edge of the elevator goes to the cockpit and moves the control stick fore and aft at the grip he will also easily overpower the person attempting to prevent push rod movement at the rod itself. 6) As for freedom of movement, now envision that little MAC servo with 1.2 inches of movement maximum. Maybe the total fore and aft elevator push rod movement is on the order of only two or three inches, but A) the tension springs must be long enough so that the push rod can be moved by the control stick from one extreme to the other regardless of trim position, and B) the screw drive must be strong enough to overcome the adverse leverage created by the need to gain enough movement to accomplish the nose up or nose down trim force needed in spite of the forces on the elevator. 7) I think that a spring bias pitch trim system, either electrically or mechanically positioned, properly designed with compression springs, is superior to a trim tab system. Just examine the pitch trim systems on such modern airplanes as the Diamond DA20-C1 and Cirrus. Also note how huge the compression springs are. 8) I will concede that there is one significant drawback: If the push rod becomes disconnected from the elevator horn there is no pitch control available other than engine power modulation. In the case of a completely independent elevator trim tab system, either electrically or mechanicall operated, one still has some degree of pitch control. But like Bob Nuckolls points out from time to time, we don't really provide spare wings and propellers just in case the ones we primarily use may fail. 9) I guess the things that dismay and stymie me are: A) That throwing together an electrically driven pitch trim system is not all that simple, intuitive, and straight forward, and B) That our community doesn't already have several articles or plans floating around on how to build such systems. Have we let the type certificated crowd get ahead of us on this feature? Have I been asleep at the switch? 'OC' Baker, Builder of KIS TR-1 #116 4/14/97 - 11/17/03 PS: Yes, I have just become aware of the Strong trim system and examined my elevator control system with a view to incorporating that trim system. So far I see no feasible incorporation method. ________________________________ Message 13 ____________________________________ Time: 09:36:38 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Firewall Junction Box --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 05:29 PM 11/29/2003 -0700, you wrote: >--> AeroElectric-List message posted by: "Jeffrey Steenson" > > >On the Murphy Elite I am building I have brought all my wires through one >hole in the firewall, including the bundle from the E.I.S. engine monitor. >My question is: > >What options should I be looking at to gather together neatly all the >splices that must be mae to EGT and CHT probes? I was thinking of a simple >aluminum cover over all of this. But are there boxes available for this >purpose, without heading into the expensive certified world? See http://www.aeroelectric.com/articles/Firewall_Penetration/firewall.html Most firewall penetrations carry a variety of systems wiring and fluid lines . . . I don't recall ever seeing a junction box on either side . . . but after you've brought the wires through a fire proof fitting, you could do about anything else you wished. I'd suggest keeping the number of breaks in any wiring to the lowest practical minimum. Bob . . . ________________________________ Message 14 ____________________________________ Time: 09:39:35 PM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: COM antenna feedback --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 05:25 PM 11/29/2003 -0800, you wrote: >--> AeroElectric-List message posted by: "Franz Fux" > > >Would this system also work in a RV7, say mounting the antenna in the back >of the luggage compartment one way or another, thanks, >Franz On a metal airplane, you don't need the radials . . . just poke the antenna through the skin and ground the feedline shield to the skin at the base of the antenna. Bob . . .