---------------------------------------------------------- Zenith601-List Digest Archive --- Total Messages Posted Fri 06/28/13: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 01:08 PM - Datum Line (BobbyPaulk@comcast.net) 2. 01:58 PM - Re: Datum Line (Jay Bannister) 3. 02:03 PM - Re: Datum Line (Larry McFarland) 4. 07:05 PM - Re: Datum Line (Mark Hubelbank) ________________________________ Message 1 _____________________________________ Time: 01:08:59 PM PST US From: BobbyPaulk@comcast.net Subject: Zenith601-List: Datum Line Guys, Can anyone verify what station on the wings to drop a plumb line to get the proper Datum line. My information says it is the fourth nose rib or the one just outside the fuel tank ( 15 gal. ). I now hear that we should add 20mm outboard of this rib. I am helping a friend get his ready to weigh and would like to know. I used the fourth rib and have not had any problems. Is there a place on the Zenith website that would show the latest info? The distance from my right wheel to the datum is 26.016" The left is about 5/16" less. Is this close to what most are getting? Thank you for your help Bobby ( age 75 ) Zodiac 601 XL "B" Jabiru 3300 S/N 1141 Sensenich 64" x 51" Prop Bing Carb 260 Main & 285 Needle Jet Status - Flying 181 hrs. Do Not Archive ________________________________ Message 2 _____________________________________ Time: 01:58:31 PM PST US Subject: Re: Zenith601-List: Datum Line From: Jay Bannister Bobby, There is no "proper datum line." The datum can be anywhere you want it. M ost find it convenient to locate it at the leading edge of the wing. I cho se to locate my datum line at the leading edge of the wing, adjacent to the fuselage, taking the forward sweep of the wing out of the picture. I supp ose locating it further out on the wing could make it easier to draw on the floor. Both my main gear wheels were the same distance from the datum. Jay -----Original Message----- From: BobbyPaulk Sent: Fri, Jun 28, 2013 3:10 pm Subject: Zenith601-List: Datum Line Guys, Can anyone verify what station on the wings to drop a plumb line to get the proper Datum line. My information says it is the fourth nose rib or the one just outside the f uel tank ( 15 gal. ). I now hear that we should add 20mm outboard of this rib. I am helping a friend get his ready to weigh and would like to know. I used the fourth rib and have not had any problems. Is there a place on the Zenith website that would show the latest info? The distance from my right wheel to the datum is 26.016" The left is about 5/16" less. Is this close to what most are getting? Thank you for your help Bobby ( age 75 ) Zodiac 601 XL "B" Jabiru 3300 S/N 1141 Sensenich 64" x 51" Prop Bing Carb 260 Main & 285 Needle Jet Status - Flying 181 hrs. Do Not Archive ________________________________ Message 3 _____________________________________ Time: 02:03:43 PM PST US From: "Larry McFarland" Subject: RE: Zenith601-List: Datum Line HI Bobby, You can use any point you wish for a Datum line, so long as you=99re consistent with it. The sum of the moments divided by total weight will locate a CG for any object. Zenith would have you loading the CG limits to the design they established though. Larry McFarland (age 73) From: owner-zenith601-list-server@matronics.com [mailto:owner-zenith601-list-server@matronics.com] On Behalf Of BobbyPaulk@comcast.net Sent: Friday, June 28, 2013 3:08 PM Subject: Zenith601-List: Datum Line Guys, Can anyone verify what station on the wings to drop a plumb line to get the proper Datum line. My information says it is the fourth nose rib or the one just outside the fuel tank ( 15 gal. ). I now hear that we should add 20mm outboard of this rib. I am helping a friend get his ready to weigh and would like to know. I used the fourth rib and have not had any problems. Is there a place on the Zenith website that would show the latest info? The distance from my right wheel to the datum is 26.016" The left is about 5/16" less. Is this close to what most are getting? Thank you for your help Bobby ( age 75 ) Zodiac 601 XL "B" Jabiru 3300 S/N 1141 Sensenich 64" x 51" Prop Bing Carb 260 Main & 285 Needle Jet Status - Flying 181 hrs. Do Not Archive ________________________________ Message 4 _____________________________________ Time: 07:05:37 PM PST US From: Mark Hubelbank Subject: Re: Zenith601-List: Datum Line Bobby, As pointed out, to use Zenith's recommended CG limits (which you really should) you do have to start with their datum point. I believe the good news is that the CH601 leading edge is basically perpendicular to the centerline (at least the CH601XL is) so the exact spot is not too critical, I can't see that +/- 20 mm along the leading edge makes any measurable difference. On 06/28/2013 5:03 PM, Larry McFarland wrote: > > HI Bobby, > > You can use any point you wish for a Datum line, so long as youre > consistent with it. > > The sum of the moments divided by total weight will locate a CG for > any object. > > Zenith would have you loading the CG limits to the design they > established though. > > Larry McFarland (age 73) > > *From:*owner-zenith601-list-server@matronics.com > [mailto:owner-zenith601-list-server@matronics.com] *On Behalf Of > *BobbyPaulk@comcast.net > *Sent:* Friday, June 28, 2013 3:08 PM > *To:* zenith601-list@matronics.com > *Subject:* Zenith601-List: Datum Line > > Guys, > Can anyone verify what station on the wings to drop a plumb line to > get the proper Datum line. > My information says it is the fourth nose rib or the one just outside > the fuel tank ( 15 gal. ). > I now hear that we should add 20mm outboard of this rib. > I am helping a friend get his ready to weigh and would like to know. I > used the fourth rib and have not had any problems. > Is there a place on the Zenith website that would show the latest info? > The distance from my right wheel to the datum is 26.016" The left is > about 5/16" less. Is this close to what most are getting? > > Thank you for your help > > > Bobby ( age 75 ) > Zodiac 601 XL "B" > Jabiru 3300 S/N 1141 > Sensenich 64" x 51" Prop > Bing Carb 260 Main & 285 Needle Jet > Status - Flying 181 hrs. > > Do Not Archive > > * * > * * > ** > ** > ** > ** > ** > *http://www.matronics.com/Navigator?Zenith601-List* > ** > ** > *http://forums.matronics.com* > ** > ** > ** > ** > *http://www.matronics.com/contribution* > ** > * * > * > > > * -- Mark Hubelbank NorthEast Monitoring 2 Clock Tower Place Suite 555 Maynard, MA, 01754 - USA mhubel@nemon.com 978-443-3955 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message zenith601-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Zenith601-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/zenith601-list Browse Digests http://www.matronics.com/digest/zenith601-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.