VansAirForceForums  
Home > VansAirForceForums

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

- Today's Posts | Insert Pics

  #11  
Old 03-03-2007, 07:24 AM
Radomir's Avatar
Radomir Radomir is offline
 
Join Date: Jan 2005
Location: Charlotte, NC
Posts: 1,523
Default

Pierre, I haven't done this (as I went straight to glass) but I know that GRT Sport weighs 2.8lbs..... let's call it 3 lbs with wires and magnetometer.... that should be less than the six-pack combined.. right?


Quote:
Originally Posted by pierre smith
Mornin' all,
While we're on the subject, has any of you converted from a full six-pack panel to glass and measured the weight savings, if any?


Regards,
__________________
Radomir
RV-7A sold
Reply With Quote
  #12  
Old 03-03-2007, 09:06 AM
az_gila's Avatar
az_gila az_gila is offline
 
Join Date: Jan 2005
Location: 57AZ - NW Tucson area
Posts: 10,011
Exclamation Glass - no contest on weight

Quote:
Originally Posted by Radomir
Pierre, I haven't done this (as I went straight to glass) but I know that GRT Sport weighs 2.8lbs..... let's call it 3 lbs with wires and magnetometer.... that should be less than the six-pack combined.. right?
RC Allen lists their vacuum gyros (AH - DG) at 3 lbs. each

Altimeters/Airspeed/VSI are all about 1/2 lb each

TC somewhere in between, say 2 lbs...

This gives the 6 pack at 9.5 lbs.

Then you have to add the vacuum pump (3 lbs - RAPCO), hoses and regulator....

The Dynon D-100 is similar to the above one at 3 lbs. with the internal back-up battery.

It's absolutely No Contest on the weight.....

gil in Tucson

was detailing this last night but my IE7 hung up....
__________________
Gil Alexander
EAA Technical Counselor, Airframe Mechanic
Half completed RV-10 QB purchased
RV-6A N61GX - finally flying
Grumman Tiger N12GA - flying
La Cholla Airpark (57AZ) Tucson AZ

Last edited by az_gila : 03-03-2007 at 09:24 AM. Reason: added pump weight
Reply With Quote
  #13  
Old 03-03-2007, 12:29 PM
gmcjetpilot's Avatar
gmcjetpilot gmcjetpilot is offline
 
Join Date: Jan 2005
Posts: 4,285
Default Every little bit helps

There are a few choices with the wing, mostly lighting and pitot, as well as priming internal parts.

Every little bit helps, but the big weight items are the prop, engine and than accessories (panel, light, interior and exterior)

From tip to tail:

Prop: wood (RV-7's suffer from tail heaviness so metal props not such a liability CG wise, RV-9? I don't know?)

Engine: (I)O320, with RV-9, heavier 360's are not really an approved option.

Engine instrumentation: CHT, EGT on all cylinders and Fuel Flow is optional. I think its probably weight worth spending, but many planes have flown for many decades (cessna, piper, etc) with out these items monitored. Leaving it off saves, weight, cost and build time. How about just one or two CHT/EGT channels. Flying GA planes in the 80's I can't remember many that had more than one CHT or EGT if any. We seemed to get along fine with out engine monitors. With that said with a well balanced Fuel Injection (FI) and careful leaning, you can run Lean of Peak (LOP), saving some gas. A 4x4 channel engine monitor is key to getting safe LOP operations. If you are carburated than LOP is pretty hard to impossible to get regardless of engine instruments, so standard roughness or 75-150F ROP ops works as well as it always has, therefore a single CHT/EGT may be good enough. Again I love the 4x4 engine monitor and its a great tool.

Cowl: Finishings and filling pin holes, read about it, search these archives for threads. The idea is to fill with min weight. You can add lots of weight with excessive filler.

Lighting: Nav lights, strobes, landing light...... LED Nav lights could save some weight. For night two all in one (nav/strobe/nav) wing tip units mounted externally is probably best. If you go with lots of lights, landing light and tail light/strobe, you may need a larger alternator than a smaller (lighter) one. Each light adds wiring, fuse/CB and switch for each light cuircuit. Also running wire out to wing tips and tail is not totally trivial. Landing lights are not needed even at night. How much night are you going to do if any? Do you need two landing lights or one or none?

Heated Pitot: My "Pet Peeve" on VFR planes with VFR pilots. This one item adds big cost and yes weight. Heavy current demand adds heavy wires run out the wings and demands a bigger alternator. If you can hold back from this popular "must have" you can save some weight. Do your really need it, even if you plan on occasional IFR?

Panel & Electrical: Some obvious weight to be saved with autopilots, dual EFIS and panel mounted entertainment systems. I am a circuit breaker (CB) man, but the popular use of an automotive plastic fuse block and blade fuses looks lighter than a bank of CB's. On the other hand you don't NEED a fuse or CB for each item.
Builders today tend to put in 20-30 separate fuse's or CB's in. You can gang several items on one fuse or CB if the total load does not exceed the capacity of the fuse or CB and the wire is protected. The key is the wire gage, which is what you are protecting, not the individual device. For example 10 amp protection for sevral devices, all with 18 awg feed wire, is fine, for example, five 2-amp items or three 3 amp items. Look at Vans planes, they have a hand full of CB's for the whole plane and that is it. The last few Van prototypes I saw actually had a few CB's or a few fuses mounted visibly in the panel. Van's factory planes tend to be very light weight when compared to average builder weights and this is one reason, simple, minimal, functional. Bottom line, the popular electrical design books like Aeroelectic (by Bob Nuckolls) tend to be very involved and promote dual battery, dual alternators, multiple buses, diodes and more switches. There is good stuff here but KISS - Keep It Simple Stupid, saves weight. If you have an all electric aircraft for IFR flight or an electrically depended engine, than redundancy of the electrical system is needed, so the weight of two batteries or alternators may be justified. If you are a day / occasional night VFR pilot with a magneto fired, mechanical fuel pump Lyc with basic instruments, than you don't need that Boeing 747 electrical system. Is it ok to put 30 fuses in that VFR plane? Yes, but it adds weight.
Vacuum system: Pretty much gone the way of the DoDo bird. Leaving it out will save lots of weight. Of course that puts the emphasis on the electrical system with electrically dependant flight and engine instruments.

Interior: Bare, painted upholstered, except covered seat cushions. It does not have to be horrible or crude, just spartan.

Paint and Priming: If you prime all parts inside and out, it will add weight. That is a fact. How how much weight is debatable, but it does add weight. If you do prime use "wash primer" which is translucent. In fact its reported widely that Van does not PRIME his factory planes, at least in the past. Van just etched, alodine and painted the exterior. Why? Weight. If you leave it un-primed and unpainted you can save $4000-$8000 and up to 30 lbs. How long will it last? Depends on many factors but probably will out live you.

Everything: Every little nylon tie wrap, nut, bolt, washer, clamp, bracket adds weight. Consider using electrical lace tape verses nylon ties.


Now some weight is good for your comfort, safety (fire extinguisher) or type of operation (big dual landing lights for night ops off of dark private fields). One basic thing is build it per plans. Anything you add or change will usually add one or more of the following: time, money and almost always weight.
__________________
George
Raleigh, NC Area
RV-4, RV-7, ATP, CFII, MEI, 737/757/767

2020 Dues Paid

Last edited by gmcjetpilot : 03-03-2007 at 12:49 PM.
Reply With Quote
  #14  
Old 03-04-2007, 05:45 PM
Captain Avgas Captain Avgas is offline
 
Join Date: Oct 2005
Location: Melbourne, Australia
Posts: 1,868
Default

Quote:
Originally Posted by Harvey
However, the easiest weight saving of all is not what you take out, but what you don't put in. Extra do-dads, sound deadening, leather seats, nav lights, landing lights, anything other than the basics....
Martin in Oz
But Martin, the do-dads are the fun parts. I luuuurv do-dads. Stuff the weight.
__________________
You’re only as good as your last landing
Bob Barrow
RV7A
Reply With Quote
  #15  
Old 03-04-2007, 09:07 PM
N941WR's Avatar
N941WR N941WR is offline
 
Join Date: Jan 2005
Location: SC
Posts: 12,887
Default

Quote:
Originally Posted by gmcjetpilot
Builders today tend to put in 20-30 separate fuse's or CB's in. You can gang several items on one fuse or CB if the total load does not exceed the capacity of the fuse or CB and the wire is protected. The key is the wire gage, which is what you are protecting, not the individual device. For example 10 amp protection for sevral devices, all with 18 awg feed wire, is fine, for example, five 2-amp items or three 3 amp items. Look at Vans planes, they have a hand full of CB's for the whole plane and that is it. The last few Van prototypes I saw actually had a few CB's or a few fuses mounted visibly in the panel...
Very good point George.

I elected to put in "20-30 separate" CB's, one for each item in the plane and I was surprised at how much $400 worth of CB's and switches weighed.

The quickest way to build a light plane is to start with a light kit. Van's will be very happy to tell you the lightest combination is a tip-up tail dragger. Add to that a small engine and a composite prop and you can get down to (and below) 1,000 lbs empty. At least in a -9 you can. I know of one O-290-D2 powered -9 that came in at 998 lbs and a -9A w/ vacuum and the same engine that tipped the scales at 1020 lbs.

Just more food for thought.
__________________
Bill R.
RV-9 (Yes, it's a dragon tail)
O-360 w/ dual P-mags
Build the plane you want, not the plane others want you to build!
SC86 - Easley, SC
www.repucci.com/bill/baf.html
Reply With Quote
  #16  
Old 03-10-2007, 07:21 PM
phil9diesel phil9diesel is offline
 
Join Date: Mar 2007
Location: Upper ny
Posts: 78
Default building light

Just because your plane is going together in a dry acid reduced climate, does not mean you should not prime. I'm going to be using MFP varish, enamel, enamel hardener, et throughout the process. For all interior surfaces and between sheets, I'll use thin varnish with the hardener applied wet with a brush on the spot. most of the objects that we own, were not built for us individually. They're legacies from something else. Leaving out corrosion protection is overdesigning.
Reply With Quote
  #17  
Old 03-10-2007, 07:41 PM
Mel's Avatar
Mel Mel is online now
 
Join Date: Mar 2005
Location: Dallas area
Posts: 10,769
Default

My -6 is primed entirely and weighs in at 1028 lbs with paint. Dual coms, dual GPS, O-320, Catto 3-blade.
Oh yea, Tip-up taildragger.
__________________
Mel Asberry, DAR since the last century.
EAA Flight Advisor/Tech Counselor, Friend of the RV-1
Recipient of Tony Bingelis Award and Wright Brothers Master Pilot Award
USAF Vet, High School E-LSA Project Mentor.
RV-6 Flying since 1993 (sold)
<rvmel(at)icloud.com>
Reply With Quote
  #18  
Old 08-16-2015, 01:50 PM
sibriggs sibriggs is offline
 
Join Date: Nov 2014
Location: Concord, NH
Posts: 215
Default

Quote:
Originally Posted by phil9diesel View Post
Just because your plane is going together in a dry acid reduced climate, does not mean you should not prime. I'm going to be using MFP varish, enamel, enamel hardener, et throughout the process. For all interior surfaces and between sheets, I'll use thin varnish with the hardener applied wet with a brush on the spot. most of the objects that we own, were not built for us individually. They're legacies from something else. Leaving out corrosion protection is overdesigning.
Empennage paint weight

Hi I need some guidance. I'm building a 9 and trying to keep the weight down, have read all the posts and really appreciate the valuable info.

I have a question on how much my paint weights, I am using single stage with a primer under and have finished the all the empennage components.

Is there any numbers available on the unpainted weight of the empennage pieces either assembled or free standing. I wanted to match the unpainted weight to my painted pieces and see how my paint coverage is working out and how much weight I have added.

I will use a FP light prop with the O-320 engine. So I figure because I will be light way up front I don't any extra empennage weight that would need to be offset. I plan on buying the lightest good quality tailwheel to help.

Thanks for any numbers, looking forward to seeing how I'm doing with trying to keep the painting light.

Steve in NH
Reply With Quote
  #19  
Old 08-16-2015, 02:19 PM
N941WR's Avatar
N941WR N941WR is offline
 
Join Date: Jan 2005
Location: SC
Posts: 12,887
Default

When I first flew, my EW was 990 pounds. That was with no paint, interior by Rustolum (sp?), and an O-290.

It is now up to 1068 pounds, with two stage paint, fully primed, different panel, leather interior, auto pilot, and an O-360 w/ a Catto two bladed prop.

The baggage compartment is not carpeted, which is fine with me.

Just don't add all the options you see on this forum and you will be fine. For example, flap position sensors (you can see the flaps), etc. If an option requires solenoids, leave it off. They just add weight and complexity for little gain.
__________________
Bill R.
RV-9 (Yes, it's a dragon tail)
O-360 w/ dual P-mags
Build the plane you want, not the plane others want you to build!
SC86 - Easley, SC
www.repucci.com/bill/baf.html

Last edited by N941WR : 08-16-2015 at 03:54 PM.
Reply With Quote
  #20  
Old 08-16-2015, 02:23 PM
Mel's Avatar
Mel Mel is online now
 
Join Date: Mar 2005
Location: Dallas area
Posts: 10,769
Default

And don't forget Mr. Rutan's old adage about aircraft add-ons; "Take the item in question and throw it up into the air. If it comes back down, it's too heavy."
__________________
Mel Asberry, DAR since the last century.
EAA Flight Advisor/Tech Counselor, Friend of the RV-1
Recipient of Tony Bingelis Award and Wright Brothers Master Pilot Award
USAF Vet, High School E-LSA Project Mentor.
RV-6 Flying since 1993 (sold)
<rvmel(at)icloud.com>
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 08:08 AM.


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.