---------------------------------------------------------- Zenith-List Digest Archive --- Total Messages Posted Fri 05/28/04: 14 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:07 AM - Re: 701 CG Question (Dirk Slabbert) 2. 04:40 AM - Re: 701 CG Question (Don & Jo Gordon) 3. 05:25 AM - XL front side skins position? (DEGlass1@aol.com) 4. 07:34 AM - Re: 701 CG Question (Ken Szewc) 5. 09:00 AM - kitplanes article (David Barth) 6. 09:21 AM - Re: 701 CG Question (Graham Kirby) 7. 11:12 AM - Re: kitplanes article (Larry McFarland) 8. 11:33 AM - Re: kitplanes article (Cory Emberson) 9. 12:47 PM - Re: XL front side skins position? (Rico Voss) 10. 05:13 PM - Top mounted senders (Bob Gibfried) 11. 05:27 PM - Re: Top mounted senders (Joemotis@aol.com) 12. 06:47 PM - Re: Top mounted senders (Scott Laughlin) 13. 08:46 PM - Re: Top mounted senders (Chuck Deiterich) 14. 10:08 PM - Re: Top mounted senders (Joemotis@aol.com) ________________________________ Message 1 _____________________________________ Time: 12:07:18 AM PST US From: "Dirk Slabbert" Subject: Re: Zenith-List: 701 CG Question --> Zenith-List message posted by: "Dirk Slabbert" Mike, Basic theory is the more aft the CG the closer it gets to aircraft neutral point, which in turn means a smaller static margin. Which indicates a more unsteady aircraft, this to me sort of defies the meaning of he 701, for it was designed to fly slow and be quite controlable at low speed. I would ditch the BRS and keep the plane well within its limits. The last thing you need is an unpredictable airplane. Chances are you'll never need the BRS, if you keep it, well you may need it, but too close to ground for it to do you any good. Dirk. ----- Original Message ----- From: Mike Sinclair To: zenith-list@matronics.com Sent: Friday, May 28, 2004 2:54 AM Subject: Zenith-List: 701 CG Question --> Zenith-List message posted by: Mike Sinclair Hey Guys Hoping for an answer from someone that has a 701 where the CG is in the aft range. Zenith lists a limit of 10-18 in. aft of datum. Mine is a taildragger and has a BRS mounted in the forward portion of the baggage compartment (basically no baggage capacity left, unless it goes in the right seat). My CG is coming in at 16-17 in. aft through most scenarios. The worst case one that I could work up so far involved starting out with the 6 gal. header tank only being full and a 240# passenger to bring it up to 1100. Still right around 17 inches aft, but when it runs out of gas the CG shifts to 17.9 aft. Just .1 ahead of the aft design limit (don't see myself getting near this situation, but still was playing with the numbers to see where it could get). Have any of you had experience with a plane that is balancing to the rear of the limit. and what performance problems might be expected. I am already aware that I will have to be very sensitive about airspeed to avoid a departure or approach stall. Would just like to hear if others have experienced any other downsides to an aft CG in this airplane. Hoping that there is some cushion built into the design in this area and performance at lower speeds isn't depreciated significantly. With some major rework I can shave a couple more pounds out of the tailwheel assy. Other than that I would have to ditch the BRS and really don't want to go there. Thanks Mike Sinclair Augusta, Ks ________________________________ Message 2 _____________________________________ Time: 04:40:21 AM PST US From: "Don & Jo Gordon" Subject: Re: Zenith-List: 701 CG Question --> Zenith-List message posted by: "Don & Jo Gordon" maybe .1 from aft limit but consider worst case senario what would be the result if a water hose blew and you lost you water in you engine you didn't notice the temp rise till 2 late and the engine quite also loosing all it's oil. now you have no water no oil out front and now you CG is right out the back your in deep shit and no where to go ----- Original Message ----- From: "Mike Sinclair" Subject: Zenith-List: 701 CG Question > --> Zenith-List message posted by: Mike Sinclair > > Hey Guys > > Hoping for an answer from someone that has a 701 where the CG is in the aft > range. Zenith lists a limit of 10-18 in. aft of datum. Mine is a taildragger and > has a BRS mounted in the forward portion of the baggage compartment (basically > no baggage capacity left, unless it goes in the right seat). My CG is coming in > at 16-17 in. aft through most scenarios. The worst case one that I could work up > so far involved starting out with the 6 gal. header tank only being full and a > 240# passenger to bring it up to 1100. Still right around 17 inches aft, but > when it runs out of gas the CG shifts to 17.9 aft. Just .1 ahead of the aft > design limit (don't see myself getting near this situation, but still was > playing with the numbers to see where it could get). Have any of you had > experience with a plane that is balancing to the rear of the limit. and what > performance problems might be expected. I am already aware that I will have to > be very sensitive about airspeed to avoid a departure or approach stall. Would > just like to hear if others have experienced any other downsides to an aft CG in > this airplane. Hoping that there is some cushion built into the design in this > area and performance at lower speeds isn't depreciated significantly. With some > major rework I can shave a couple more pounds out of the tailwheel assy. Other > than that I would have to ditch the BRS and really don't want to go there. > Thanks > > Mike Sinclair > Augusta, Ks > > ________________________________ Message 3 _____________________________________ Time: 05:25:48 AM PST US From: DEGlass1@aol.com Subject: Zenith-List: XL front side skins position? --> Zenith-List message posted by: DEGlass1@aol.com To those who have built the XL fuse: I'm not sure why I'm having so much trouble being comfortable with this positioning - if you have a photo that shows the amount of overlap of the bottom aft end of the front side skins 6B11-2 and rear side skins (where the attach plate exits), please send it to me off-list. Maybe this is over-caution before I make the spar and gear channel cutouts. Thanks for all the good scoop from the List! David Glass XL - building the fuselage, more slowly than planned ________________________________ Message 4 _____________________________________ Time: 07:34:44 AM PST US From: Ken Szewc Subject: Re: Zenith-List: 701 CG Question --> Zenith-List message posted by: Ken Szewc Mike, The weight and balance report from zenith shows a CG range of 11 to 20 inches or 280 to 500mm. I have just performed a weight and balance for my 701SP and it easily fell into the range at 12.75 inches or 324mm. However mine is not a taildragger and I do not have a BRS. It's hard to say where you issue lies without comparing apples to apples. I have a 912ULS installed and the basic panel with Microair radio and transponder with a rather heavy (26lb) battery 26AH oddyssey battery located behind the passenger seat. I also have all of the options (trim, tanks, strobes, bbl doors) except the folding wings. All of this came in at 650lbs. You didn't mention where your battery is located. I would say that if your battery is anywhere behind the CG then it should be moved foward as far as possible. I have seen pictures where two batteries were installed on the shelf in the engine compartment to keep the weight foward. I would recommend calling Zenith to see if other tail dragger configurations have had issues also. Ken Szewc 701SP 912ULS (inspection tomorrow) ----- Original Message ----- From: "Mike Sinclair" Subject: Zenith-List: 701 CG Question > --> Zenith-List message posted by: Mike Sinclair > > Hey Guys > > Hoping for an answer from someone that has a 701 where the CG is in the aft > range. Zenith lists a limit of 10-18 in. aft of datum. Mine is a taildragger and > has a BRS mounted in the forward portion of the baggage compartment (basically > no baggage capacity left, unless it goes in the right seat). My CG is coming in > at 16-17 in. aft through most scenarios. The worst case one that I could work up > so far involved starting out with the 6 gal. header tank only being full and a > 240# passenger to bring it up to 1100. Still right around 17 inches aft, but > when it runs out of gas the CG shifts to 17.9 aft. Just .1 ahead of the aft > design limit (don't see myself getting near this situation, but still was > playing with the numbers to see where it could get). Have any of you had > experience with a plane that is balancing to the rear of the limit. and what > performance problems might be expected. I am already aware that I will have to > be very sensitive about airspeed to avoid a departure or approach stall. Would > just like to hear if others have experienced any other downsides to an aft CG in > this airplane. Hoping that there is some cushion built into the design in this > area and performance at lower speeds isn't depreciated significantly. With some > major rework I can shave a couple more pounds out of the tailwheel assy. Other > than that I would have to ditch the BRS and really don't want to go there. > Thanks > > Mike Sinclair > Augusta, Ks > > ________________________________ Message 5 _____________________________________ Time: 09:00:50 AM PST US From: David Barth Subject: Zenith-List: kitplanes article --> Zenith-List message posted by: David Barth Hi List. There is a great article in kitplanes about panel designs and our very own Larry McFarland is featured there. Nice job Larry! It really looks like you did a lot of work for the author of the article so I hope he paid you. David ===== David Barth 601 XL Plansbuilder 15% done? Making Spars - ready for Chromate and riveting __________________________________ http://messenger.yahoo.com/ ________________________________ Message 6 _____________________________________ Time: 09:21:55 AM PST US From: "Graham Kirby" Subject: RE: Zenith-List: 701 CG Question --> Zenith-List message posted by: "Graham Kirby" Mike, I remember reading that one of the earlier builders in the UK took care of a similar problem on a 601 by moving the engine forward a little. Given the weight of the engine it may be as simple as adding spacers between the firewall and engine mount. Of course, something like this is definitely worth chatting to ZAC about. Graham Kirby (601HD) ________________________________ Message 7 _____________________________________ Time: 11:12:34 AM PST US From: "Larry McFarland" Subject: Re: Zenith-List: kitplanes article --> Zenith-List message posted by: "Larry McFarland" Subject: Zenith-List: kitplanes article It really looks like you did > a lot of work for the author of the article so I hope > he paid you. > David Barth David, Pleased you liked the article, but not everything today is about money as I wouldn't accept any payment for this. It was expected to be condensed to a couple of paragraphs and as submitted, too much was written in the first person. I'm only 6-ft tall, not 6'-4" and some very minor things were redundant. But I hope it provides some nutrition to those yet considering that area of their plane. Larry McFarland Do Not Archive ________________________________ Message 8 _____________________________________ Time: 11:33:19 AM PST US From: "Cory Emberson" Subject: Re: Zenith-List: kitplanes article --> Zenith-List message posted by: "Cory Emberson" Hi Larry, Thanks for pointing out that you hadn't experienced a mid-life growth spurt! Sorry about that! I enjoyed corresponding with you about your panel, and was really pleased that the editor left your compliments about the Zenith Matronics list intact! best, Cory > David, > Pleased you liked the article, but not everything today is about money > as I wouldn't accept any payment for this. > It was expected to be condensed to a couple of paragraphs > and as submitted, too much was written in the first person. I'm only > 6-ft tall, not 6'-4" and some very minor things were redundant. > But I hope it provides some nutrition to those yet considering that > area of their plane. > > Larry McFarland > Do Not Archive > > > Subject: Zenith-List: kitplanes article > > > It really looks like you did > > a lot of work for the author of the article so I hope > > he paid you. > > David Barth > > ________________________________ Message 9 _____________________________________ Time: 12:47:58 PM PST US From: Rico Voss Subject: Re: Zenith-List: XL front side skins position? --> Zenith-List message posted by: Rico Voss --- DEGlass1@aol.com wrote: > --> Zenith-List message posted by: DEGlass1@aol.com > > To those who have built the XL fuse: > I'm not sure why I'm having so much trouble being > comfortable with this positioning - if you have a > photo that shows the amount of overlap of the bottom > aft end of the front side skins 6B11-2 and rear side > skins David -- The short answer is that somewhere (photo maunal?) it is written to overlap the skins 35mm -- make sure it's at the bottom, as there is less overlap there on the pre-cut skins. I assumed that would be enough and went on. To position the rear channel, I was advised to place it using the wing jigs, instead of the dimension given (235mm or something). So, first I made the sideskin cutout for the spar inserts, then mounted and leveled the wing jigs, then marked and cut the slots for the rear channel attach plates, which leads to the position of the rear channel. Assuming that the wing jigs are accurate, it should work. I, too, am cursed with the desire to do things accurately, and it aint easy with the numerous errors and omissions in the documentation. I labored as you did over the angle of incidence, but so far, all looks OK. As you did, I had to put a shim (.040 I think) under the rear flange of the center spar, in order to make it sit at 78 deg from the floor (81 from horiz). When I measured carefully, I found one center spar flange was bent at 78, one at 81 -- ??? . [please keep me away from that soapbox...] Good luck, Rico, XL, working (too slowly) on fwd fuse, in KC __________________________________ http://messenger.yahoo.com/ ________________________________ Message 10 ____________________________________ Time: 05:13:47 PM PST US From: "Bob Gibfried" Subject: Zenith-List: Top mounted senders --> Zenith-List message posted by: "Bob Gibfried" Would sure be nice if we could get a drawing or pictures of the top mounted fuel sender installation. Any chance of an email attachment from one or more of those who have done it? Thanks Bob, Wichita ________________________________ Message 11 ____________________________________ Time: 05:27:37 PM PST US From: Joemotis@aol.com Subject: Re: Zenith-List: Top mounted senders --> Zenith-List message posted by: Joemotis@aol.com Here is one (of a top mounted sensor) on a 601 XL http://www.cooknwithgas.com/3_5_04_WingTank.JPG Joe Motis 601 XL Do not archive ________________________________ Message 12 ____________________________________ Time: 06:47:35 PM PST US From: "Scott Laughlin" Subject: Re: Zenith-List: Top mounted senders --> Zenith-List message posted by: "Scott Laughlin" ----Original Message Follows---- From: Joemotis@aol.com Here is one (of a top mounted sensor) on a 601 XL http://www.cooknwithgas.com/3_5_04_WingTank.JPG Wow! I've seen that before. Somewhere...... Scott Laughlin ________________________________ Message 13 ____________________________________ Time: 08:46:56 PM PST US From: "Chuck Deiterich" Subject: Re: Zenith-List: Top mounted senders --> Zenith-List message posted by: "Chuck Deiterich" My sender and tank installation is on my website look under Airplane, www.geocities.com/cffd66 Chuck D. N701TX Do not archive ----- Original Message ----- From: "Bob Gibfried" Subject: Zenith-List: Top mounted senders > --> Zenith-List message posted by: "Bob Gibfried" > > Would sure be nice if we could get a drawing or pictures of the top mounted > fuel sender installation. > > Any chance of an email attachment from one or more of those who have done > it? > > Thanks > > Bob, Wichita > > ________________________________ Message 14 ____________________________________ Time: 10:08:36 PM PST US From: Joemotis@aol.com Subject: Re: Zenith-List: Top mounted senders --> Zenith-List message posted by: Joemotis@aol.com I am sorry Scott! I forgot to give credit to you.Great site!!! Joe Motis Do not archive