RV8 CofG question…

[Rich Pulman]

I fly my RV8 solo 99% of the time. It has an IO-360-A1A in the nose which makes it nose heavy. The obvious (and easy) way to move the CG aft is to strap a bunch of weight into the back seat. However, I would rather add 10 pounds further back instead of 100 pounds in the back seat. Has anyone devised a simple solution to easily add/remove a small weight way back on the fuselage? I was thinking of something like a small tube running through the fuselage just in front of the horizontal stabilizer (kind of like the handle on the RV15 in a similar location) with removable end caps (recessed) and into which a small lead weight could be inserted as/when needed. Have any clever people out there built anything like this? Are there any other simple solutions?

Thanks in advance for your ideas!

Richard

[2theskyy]

Originally Posted by Rich Pulman

I fly my RV8 solo 99% of the time. It has an IO-360-A1A in the nose which makes it nose heavy. The obvious (and easy) way to move the CG aft is to strap a bunch of weight into the back seat. However, I would rather add 10 pounds further back instead of 100 pounds in the back seat. Has anyone devised a simple solution to easily add/remove a small weight way back on the fuselage? I was thinking of something like a small tube running through the fuselage just in front of the horizontal stabilizer (kind of like the handle on the RV15 in a similar location) with removable end caps (recessed) and into which a small lead weight could be inserted as/when needed. Have any clever people out there built anything like this? Are there any other simple solutions?

Thanks in advance for your ideas!

Richard

Composite or metal prop?
Battery in aft location already?

[Mikeyb]

I can’t find them now but I’ve seen a couple of methods to add counterweight to the tail. One was a tube that went through the fuselage that you put a lead rod in.

The coolest one was an aluminum tank under the empennage fairing where you poured lead shot in cap at the top and emptied it at the bottom. I think it was VAFer ronschreck.

I wish I would have known about it when I started. I want to do it too but it’s too invasive for me at this point.
I have a parallel valve IO360 with a composite CS prop with an empty CG of 78.5 so it’s pretty good as is.

[2theskyy]

This is of interest to me because I’ll be in the same situation. O-360 A1A and all
I’ve done and plan on things to mitigate. Superior cold air sump to reduce ~3lbs up front. SDS flywheel that takes 1lbs of nose. Grove gear takes 15lbs off but not out front. Composite prop if I need and finally to place battery in the most effective location. I want it up front for shortest cables. Finally a weight placed in the most rear location. Maybe a fishing pole tube placed down tail and lead secured at aft most portion.

[Rich Pulman]

Originally Posted by 2theskyy

Composite or metal prop?
Battery in aft location already?

Battery is aft. Heavy CS metal prop up front.

[PhatRV]

This is an old article from the CAFE Foundation which tested the Vans factory RV8A. Dick recommends putting 50# in the rear baggage compartment.

Link: https://cafe.foundation/v2/pdf_cafe_apr/RV-8A%20APR.pdf

[Dan 57]

Thanks for the link to that CAFE article, PhatRV, interesting stuff I didn’t remember.
I’m „only“ 71kg (157lbs) and usually make sure to stow at least 10kg (22 pounds) of tooling in the rear most compartment of the -8, same config as the OP.

Having a quick, and safe, solution to add weight at the rearmost possible location would be neat.

[Webb]

A 2 gallon plastic flat SUV water tank mounted to the side of the baggage compartment will give you up to about 17 pounds of ballast and won’t take up much room.

[olyolson]

Richard,

I’m sure you have a traveling tool kit bag. Add tools/weight to get your desired CG and keep it tied down in the aft baggage compartment. You can put a lot of weight back there and easy to remove when you have a passenger.

[Mikeyb]

https://vansairforce.net/community/s...d.php?t=133740