VansAirForceForums  
Home > VansAirForceForums

- POSTING RULES
- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics


Go Back   VAF Forums > Model Specific > RV-7/7A
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
  #41  
Old 03-14-2017, 09:46 AM
Chattin35 Chattin35 is offline
 
Join Date: Jul 2014
Location: Boise, ID
Posts: 190
Default

Quote:
Originally Posted by roadrunner20 View Post
IO360, 2005 catto 3 blade

Here's my morphed 7A to 7 data
7A CG = 81.88, empty weight 1081
7 CG = 81.11, empty weight 1065

Since I will be installing the landoll ring, I was looking at the data today, my cg moved forward on the conversion.

The 12# ring will help, but I will also keep my lead scuba bean bags on my inside firewall. I created a dam to hole them forward.
Very interesting. Thanks Dan.

I'm about a week away from weighing mine -- taildragger, IO-360-M1B, Hartzell BA, light VFR glass panel, built to plans. Should be interesting. I'll post the #'s when I have them.
Reply With Quote
  #42  
Old 03-14-2017, 11:18 AM
rzbill's Avatar
rzbill rzbill is offline
 
Join Date: Nov 2005
Location: Asheville, NC
Posts: 2,434
Default

Quote:
Originally Posted by roadrunner20 View Post
IO360, 2005 catto 3 blade

Here's my morphed 7A to 7 data
7A CG = 81.88, empty weight 1081
7 CG = 81.11, empty weight 1065

Since I will be installing the landoll ring, I was looking at the data today, my cg moved forward on the conversion.

The 12# ring will help, but I will also keep my lead scuba bean bags on my inside firewall. I created a dam to hole them forward.
Interesting indeed. The CG change data is counterintuitive to me.

On the assumption that there were not any other items relocated unrelated to the 7A to 7 change, the CG moving forward indicates that the main gear relocation has a major effect on CG position between the 7 and 7A.

The nose gear removal and tail wheel addition are both "rearward CG" moves so the main gear repositioning had to more than compensate for both of them.

I have had recent "idle" thoughts about converting to a 7. It will take a mighty big "round tuit" though.

When I was building 7A 10 years ago, I had seen posts about rear CG tendency but I did not realize it was the taildragger being described. I pushed everything forward during construction and have an empty CG of 78.7" which is quite far forward. It is essentially impossible for me to load the craft out the back of the envelope. Downside is my nosewheel weight is high although still within Vans limits in all loading scenarios.

For reference:
7A unpainted tip up
IO-360-M1B/Hartzell
IFR Glass w/ steam BU
Some fabric interior by SWMBO
Kevlar/ceramic floorboards
1109 lbs
78.7 empty CG
__________________
Bill Pendergrass
RV-7A: Flying since April 15, 2012. 650hrs
YIO-360-M1B, mags, CS, GRT EX and WS H1s & A/P, Navworx
Unpainted, polished....kinda'
My RV Construction Page

Last edited by rzbill : 03-14-2017 at 04:29 PM.
Reply With Quote
  #43  
Old 03-14-2017, 12:32 PM
roadrunner20's Avatar
roadrunner20 roadrunner20 is offline
 
Join Date: Feb 2005
Location: Bay Pines, FL (based @ KCLW)
Posts: 1,756
Default

Quote:
Originally Posted by rzbill View Post
Interesting indeed. The data is counterintuitive to me.

On the assumption that there were not any other items relocated unrelated to the 7A to 7 change, the CG moving forward indicates that the main gear relocation has a major effect on CG position between the 7 and 7A.

The nose gear removal and tail wheel addition are both "rearward CG" moves so the main gear repositioning had to more than compensate for both of them.

I have had recent "idle" thoughts about converting to a 7. It will take a mighty big "round tuit" though.

When I was building 7A 10 years ago, I had seen posts about rear CG tendency but I did not realize it was the taildragger being described. I pushed everything forward during construction and have an empty CG of 78.7" which is quite far forward. It is essentially impossible for me to load the craft out the back of the envelope. Downside is my nosewheel weight is high although still within Vans limits in all loading scenarios.

For reference:
7A unpainted tip up
IO-360-M1B/Hartzell
IFR Glass w/ steam BU
Some fabric interior by SWMBO
Kevlar/ceramic floorboards
1109 lbs
78.7 empty CG
I also have the forward induction, but mine is a Superior model. But notice, my catto prop weighs in at 18# moving my cg considerable aft
__________________
Dan "RoadRunner" Landry
Morphed RV7, N20DL, PNP Pilot
1025+ hours, hit 1000 enroute to Oshkosh
2017 Donation Paid
Reply With Quote
  #44  
Old 03-24-2017, 02:31 AM
Pin 21 Pin 21 is offline
 
Join Date: Mar 2009
Location: South Australia
Posts: 16
Default VH-UER

Fairly disappointed in the results from a loooong slow build (10 years)

RH main = 531
LH main = 530
Tailwheel = 75

C of G = 80.8"

Painted and ALL parts fitted. RV-7 Io-360 parallel valve, Whirlwind prop. Classic interior.

Last edited by Pin 21 : 03-27-2017 at 03:08 AM.
Reply With Quote
  #45  
Old 03-24-2017, 06:17 AM
roadrunner20's Avatar
roadrunner20 roadrunner20 is offline
 
Join Date: Feb 2005
Location: Bay Pines, FL (based @ KCLW)
Posts: 1,756
Default

I installed the landoll ring last weekend.
It moved my cg forward from 81.11 to 80.48
__________________
Dan "RoadRunner" Landry
Morphed RV7, N20DL, PNP Pilot
1025+ hours, hit 1000 enroute to Oshkosh
2017 Donation Paid
Reply With Quote
  #46  
Old 03-29-2017, 09:43 PM
Chattin35 Chattin35 is offline
 
Join Date: Jul 2014
Location: Boise, ID
Posts: 190
Default N437T #'s

RV-7
Quickbuild
IO-360-M1B
Hartzell BA CS Prop
VFR glass panel (dual GRT Horizons)
Classic Aero Sportsman seats
Built light and to the plans
Weighed on certified and calibrated scales
Equipped for 1st flight (see pic below)

Left: 492
Right: 494
Tail: 57

Total: 1043

Stoked!

Reply With Quote
  #47  
Old 06-30-2017, 10:04 AM
EinEngineer's Avatar
EinEngineer EinEngineer is offline
 
Join Date: Jun 2017
Location: Lafayette, LA
Posts: 4
Default Same problem on the -14?

Quick question from the new guy:

I'm still a ways away from starting a build, but my mission includes light aerobatics, occasionally with a friend. While I'm just under 170#, some of my compatriots are around 220#. Playing with a few of the numbers you've listed, I just don't see how it'd be possible to stay within the aerobatics 84.5" aft CG limit if my empty CG comes out to anything above 80".

Does anyone know if the -14 suffers from a similar aft CG tendency? After a quick search I didn't see any discussion in the -14 forums about a similar topic, so I figured I'd address it here before starting something new over there.

Best,
Will

Note: I'm more concerned about Aerobatics CG comparison between the two. I know both the -7 and -14 will perform well for me during cross country flight.

Last edited by EinEngineer : 06-30-2017 at 10:47 AM. Reason: Note
Reply With Quote
  #48  
Old 09-19-2017, 08:37 PM
Rbb469 Rbb469 is offline
 
Join Date: Jul 2014
Location: 2M8
Posts: 24
Default

1101
80.9
__________________
Paid 5/2017
Reply With Quote
  #49  
Old 09-20-2017, 08:35 AM
Raymo's Avatar
Raymo Raymo is offline
 
Join Date: Nov 2014
Location: Richmond Hill, GA (KLHW)
Posts: 1,297
Default

Quote:
Originally Posted by EinEngineer View Post
Quick question from the new guy:

I'm still a ways away from starting a build, but my mission includes light aerobatics, occasionally with a friend. While I'm just under 170#, some of my compatriots are around 220#. Playing with a few of the numbers you've listed, I just don't see how it'd be possible to stay within the aerobatics 84.5" aft CG limit if my empty CG comes out to anything above 80".[/i]
I ran the numbers on my -7A and could get to 1600 lbs with you, your compatriot and 18 gallons of fuel. You could take off with a little more fuel and calculate when you burned off enough to be under 1600.

I installed a 20 lb plate in front of my 3 blade Catto to keep CG such that it would allow 100 lbs of baggage. Using the above numbers of 170, 220 and 18 gallons:
CG is 79.55 empty; 83.96 on take-off and 84.11 after burning 10 gallons of fuel. Empty fuel with co/pilot is 84.24.

I had planned to swap the PC680 on the firewall for an EarthX to save 10+ lbs but will have to run the numbers to be sure I keep my CG about where it is.
__________________
Ray
RV-7A - Slider - N495KL - First flt 27 Jan 17
O-360-A4M w/ AFP FM-150 FI, 1 PMag, Vetterman Trombone Exh, SkyTech starter,
PlanePower Alt, Catto 3 blade NLE, FlightLines Interior, James cowl & plenum
All lines by TSFlightLines (AKA Hoser)
NSDQ

"The object of the game, gentlemen, is not to cheat death: the object is not to let him play."
Patrick Poteen, Sgt. U.S. Army


- - 2016/17 donation compliant - -

Last edited by Raymo : 09-20-2017 at 09:32 AM.
Reply With Quote
  #50  
Old 10-04-2017, 11:53 AM
High_Flyer's Avatar
High_Flyer High_Flyer is offline
 
Join Date: Sep 2010
Location: Saint-Jorioz, France.
Posts: 179
Default 1123 Lbs



Left: 520,7 Lbs
Right: 521,6 Lbs
Tail: 80,7 Lbs
Total: 1123 Lbs

Engine: Aerosport power IO-375
Prop: Whrilwind 200RV
Avionics: Full Dynon package including 2 Dynon SV-1000T, AP with panel modules, VP-X Sport
Interior: Full Classic Aero Sportsman pakage

Its a bit on the heavy side, but OK considering that I have a big engine and a constant speed prop, a nice comfortable interior and superb avionics.
Just on the aft side of the enveloppe with max bagages, two pax and minimum fuel, as expected...
I'm happy...
__________________
Location: France
RV7 (F-PRVZ), Tip Up, Aerosport IO-375, Dynon Skyview, VP-X, Day VFR.

Flying since June 2017.

Last edited by High_Flyer : 10-05-2017 at 10:12 AM. Reason: New picture
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 05:44 PM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.