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  #21  
Old 03-27-2018, 08:30 PM
Reaver Reaver is offline
 
Join Date: Sep 2017
Location: Claremont, CA
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Resurrecting this thread, I have a related question that searching hasn't answered. Has anyone here done a build with a CS composite prop? Is that enough weight in the nose to still carry near-full baggage? Or would one need to add more weight to the nose or push the engine forward (likely with a James cowl to fit the IO360 then)?
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  #22  
Old 03-27-2018, 09:26 PM
jimgreen jimgreen is offline
 
Join Date: Apr 2006
Location: Vancouver island, BC Canada
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I have an IO360 with Whirlwind 200RV composite prop. Lightweight tailwheel.
EW is 1060lbs empty CG 81.0 - seat upholstery only, no carpet etc.
300lbs combined passenger weight, 10usg fuel and 80lbs baggage puts me right on the rear limit.
To gain full baggage of 100lbs, I would need min fuel of 25usg.

240lb pilot only, 10usg fuel, 100lbs bags, CG is right on the limit.

For me in practise this works out OK Because 80lbs bags is quite generous, and if I ever need to carry extra I can bump up the fuel load.

However, I find my machine fairly sensitive in pitch, probably accentuated by the rear CG.
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  #23  
Old 03-27-2018, 09:51 PM
Bicyclops Bicyclops is online now
 
Join Date: Oct 2012
Location: LA, California
Posts: 125
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One thing that helps is to make a spot between the pilot and passenger's rudder pedals to securely store heavy stuff like a tool bag, extra qts of oil, etc. I made a box there and mounted my O2 bottle on top of it. Doubles as a glove box for nasal cannulas, pulse ox, etc. When you have lots of baggage, make sure you put as much of the heavy stuff as far forward as you can. I've been known to use an airbed as a booster under my wife's seat. 12 lbs on the cg instead of behind the seat.

Ed Holyoke
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  #24  
Old 03-27-2018, 10:46 PM
Reaver Reaver is offline
 
Join Date: Sep 2017
Location: Claremont, CA
Posts: 11
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Quote:
Originally Posted by jimgreen View Post
I have an IO360 with Whirlwind 200RV composite prop. Lightweight tailwheel.
EW is 1060lbs empty CG 81.0 - seat upholstery only, no carpet etc.
300lbs combined passenger weight, 10usg fuel and 80lbs baggage puts me right on the rear limit.
To gain full baggage of 100lbs, I would need min fuel of 25usg.

240lb pilot only, 10usg fuel, 100lbs bags, CG is right on the limit.

For me in practise this works out OK Because 80lbs bags is quite generous, and if I ever need to carry extra I can bump up the fuel load.

However, I find my machine fairly sensitive in pitch, probably accentuated by the rear CG.
This is very useful info, thank you! And just to clarify, are you running this as a CS prop with stock Van's engine mount, cowling, and no unusual balast or spacers up front?

And Bicyclops that's also a very useful hint. By chance have you done a write-up of those mods?
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  #25  
Old 03-27-2018, 10:47 PM
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CubedRoot CubedRoot is offline
 
Join Date: Sep 2013
Location: Ooltewah, TN.
Posts: 520
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Quote:
Originally Posted by Bicyclops View Post
One thing that helps is to make a spot between the pilot and passenger's rudder pedals to securely store heavy stuff like a tool bag, extra qts of oil, etc. I made a box there and mounted my O2 bottle on top of it. Doubles as a glove box for nasal cannulas, pulse ox, etc. When you have lots of baggage, make sure you put as much of the heavy stuff as far forward as you can. I've been known to use an airbed as a booster under my wife's seat. 12 lbs on the cg instead of behind the seat.

Ed Holyoke

Ed,
You wouldn't happen to have any photos of that would you? I'd like to consider something like that for my own build.
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  #26  
Old 03-28-2018, 06:17 AM
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uk_figs uk_figs is offline
 
Join Date: Jan 2005
Location: Tulsa, OK
Posts: 826
Default Define other stations

To maximize the effective distribution of the baggage load for longer trips you can easily define additional load stations on your W&B spreadsheet.

In my case I have defined a station behind the seats and forward of the flap bar, and have divided the main baggage area into a fwd and aft station. You can also put some stuff in bags forward of the spar where they are under your knees and it is easy to mount a strap to keep the bags in place (good place for tiedown/tool bag which can weigh 14 lbs)

If flying solo obviously a lot of baggage can go in the pax seat and as noted above put heavy stuff forward.

So far with good load management and fuel burn planning (to keep the CG in range) the -7 has met all my mission needs including 2 up and stuffed full for a weeks camping at Oshkosh.

Other threads also note that the 320 mount moves the motor 2 inches further forward which would help with lightweight props and the standard cowling blanks have enough extra length to accommodate this. Also battery and starter selection have an impact on the CG.
Figs
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  #27  
Old 03-28-2018, 08:34 AM
Reaver Reaver is offline
 
Join Date: Sep 2017
Location: Claremont, CA
Posts: 11
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Quote:
Originally Posted by uk_figs View Post
To maximize the effective distribution of the baggage load for longer trips you can easily define additional load stations on your W&B spreadsheet.

In my case I have defined a station behind the seats and forward of the flap bar, and have divided the main baggage area into a fwd and aft station. You can also put some stuff in bags forward of the spar where they are under your knees and it is easy to mount a strap to keep the bags in place (good place for tiedown/tool bag which can weigh 14 lbs)

If flying solo obviously a lot of baggage can go in the pax seat and as noted above put heavy stuff forward.

So far with good load management and fuel burn planning (to keep the CG in range) the -7 has met all my mission needs including 2 up and stuffed full for a weeks camping at Oshkosh.

Other threads also note that the 320 mount moves the motor 2 inches further forward which would help with lightweight props and the standard cowling blanks have enough extra length to accommodate this. Also battery and starter selection have an impact on the CG.
Figs
Does the 320 mount work with either a 180 or 200hp IO360 and the standard cowl? I’m leaning toward a FP composite prop and a LiFePO4 battery, both of which are great for useful load but not CG. If a 320 engine mount is just a drop-in replacement for the 360 mount that would be excellent!
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  #28  
Old 03-28-2018, 11:34 AM
Bicyclops Bicyclops is online now
 
Join Date: Oct 2012
Location: LA, California
Posts: 125
Default Oxygen under the panel

Mine is a 6 with a parallel valve IO-360 engine and Whirlwind 74 RV. I put an auxiliary fuel tank behind the passenger seat and couldn't afford the aft weight and space to put the Oxygen back there too. I also have a second battery right behind the firewall which I enclosed in the O2/glove box.





I laid up the carbon fiber sheets under vacuum with hexcell to make it a bit thicker and stronger, then just made the box with hinge material as if it were sheet metal. I glued and riveted. The top will come off by pulling pins so I can get in there to change the battery and service the fuel pump/filter assembly. I push my toolkit all the way forward on top of the battery. I have a tag on it so I can easily pull it back out.

When we want oxygen, it is easy to grab the cannulas, in zip loc bags, out of the glove box, hook it up and get it flowing. The valve is accessible without effort. I like this location much better than behind the seat where I had it temporarily in our 6A. I pull the bottle and clamps to save 12lbs. when I don't expect to need the O2. I do usually pump the aux fuel into a main as soon as I can make room for it, and I have landed with fuel in the aux and a bunch of baggage without the dreaded aft CG sloppy stick issue. Did that once in the 6A and that was the day the tools moved forward. ;-)

Ed Holyoke

The engine mount is stock, no spacers. The Whirlwind is CS. It's lighter than a Hartzell and heavier than FP. I have a PC 680 on the firewall and another right behind the FW. If I change these out for EarthX, I'll have to reweigh, but I think the CG will still work OK. The cowl is modified Van's.

The composite core material I used is: https://store.acpsales.com/products/...-mat-soric-xf-




Quote:
Originally Posted by Reaver View Post
This is very useful info, thank you! And just to clarify, are you running this as a CS prop with stock Van's engine mount, cowling, and no unusual balast or spacers up front?

And Bicyclops that's also a very useful hint. By chance have you done a write-up of those mods?

Last edited by Bicyclops : 03-28-2018 at 11:56 AM. Reason: Didn't answer all the questions
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  #29  
Old 03-28-2018, 05:05 PM
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longranger longranger is offline
 
Join Date: Mar 2007
Location: 45G, Brighton, MI
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Quote:
Originally Posted by Reaver View Post
Resurrecting this thread, I have a related question that searching hasn't answered. Has anyone here done a build with a CS composite prop? Is that enough weight in the nose to still carry near-full baggage? Or would one need to add more weight to the nose or push the engine forward (likely with a James cowl to fit the IO360 then)?
I think the “long” James cowl is only longer between the front of the engine and spinner opening, to make room for the horizontal induction, and/or room for diffuser ducts between the cooling inlets and the plenum. If you move the engine forward with a longer mount, you’ll have to add length to the aft end of the cowl.

You can also move the CG forward with a prop extension. The “long” James cowl requires a 2.5 to 4 inch extension, depending on the propeller.
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  #30  
Old 03-28-2018, 05:42 PM
Kyle Boatright Kyle Boatright is offline
 
Join Date: Aug 2005
Location: Atlanta, GA
Posts: 3,115
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Quote:
Originally Posted by uk_figs View Post
To maximize the effective distribution of the baggage load for longer trips you can easily define additional load stations on your W&B spreadsheet.

<snip>

Figs
I have a station right in front of the main spar on my -6. My legs "bridge" over it and I don't even notice items down there. That station is where I generally store my tool bag and tiedowns on trips where CG would otherwise be troublesome.
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