Redshift #3 (Green glass prototype)

[Konrad]

I’ve always thought that all force vectors other than gravity were oriented to the airframe. If true then the flex is lift*. Now if the snap back can twist to give a thrust vector (much like a bird’s wing) then we might be on to something. But just a downward motion leads me to think this just another complication that a pilot has to deal with.

*Now not all lift is aerodynamic.

 

[purview]

no engine konrad , ping

 

[Konrad]

no engine konrad , ping

???

Thrust in a glider is changing potential energy to speed. In this case we are talking the energy stored in the pre loaded wing.

 

[purview]

yes storage

 

[gp49]

Since I spent more of my life on snow skis then flying gliders, here is what my snow ski analogy is for a carving skis. I have some old Atomic Slalom race skis that, when loaded would 'ping' me out of a turn and into the next... Some skis stored more energy then others. Some had fancy top layers of materials to limit the amount of vibration after the 'pinggggg'

 

[Doc James Hammond]

I’ve always thought that all force vectors other than gravity were oriented to the airframe. If true then the flex is lift*. Now if the snap back can twist to give a thrust vector (much like a bird’s wing) then we might be on to something. But just a downward motion leads me to think this just another complication that a pilot has to deal with.

*Now not all lift is aerodynamic.

A downward motion is not a downward motion when the wings are vertical.

Then it all goes sideways...

Doc.

 

[Doc James Hammond]

Since I spent more of my life on snow skis then flying gliders, here is what my snow ski analogy is for a carving skis. I have some old Atomic Slalom race skis that, when loaded would 'ping' me out of a turn and into the next... Some skis stored more energy then others. Some had fancy top layers of materials to limit the amount of vibration after the 'pinggggg'

Hey GP:

The Mongols used this "fancy top layer" theory (I like that!) on thier short but very powerful bows. The bows had to be short as they were used from a galloping horse. (or so my dad told me)
Different types of woods with different bending tensions along with sinew bonded with resins in strategic positions on the structure gave a REALLY good ping.

Probably one of the first composite structures that really did its job...which was to...PING.

Just imagine what would have happened if they had continued to use those super rigid 3" oak beams as bows...death would probably have been part of the equation.

It's all been done before; Its all there for the taking...

Lets PING!

Doc.

 

[Doc James Hammond]

Wing development over 10 years.

Doc

 

[Konrad]

What are we seeing?

P.S.
I like the other model much better!

 

[Doc James Hammond]

What are we seeing?

P.S.
I like the other model much better!

He's got to go...

This is the new Alpenbrise 4M.

Cheers,

Doc.

 

[Konrad]

What are we seeing?

P.S.
I like the other model much better!

I was thinking this 2 legged model. She appears to be a bit more elegant and graceful.

 

[Doc James Hammond]

Did you ever meet Julia?

Doc.

 

[Konrad]

Yes, at one of the ISR. That is how I know of what I speak.

 

[Doc James Hammond]

Yes, at one of the ISR. That is how I know of what I speak.

Aha! Thought so as Julia said she remembered you.

Cheers,

Doc

 

[Konrad]

In this thread I mentioned that I had problems figuring out the ballast tube in the heat of battle. Well, I've just learned that the ballast tube in the green light weight Redshift is 400mm long. Most of my ballast tubes are 330mm long. I don't know why I made the wise decision to not race the green Redshift last month. But I'm glad I didn't! I'm sure I'd have made a smoking hole in the ground had I tried to ballast the ship with the mass being off by 70mm.

Now that I know the length of the ballast tube. I'm thinking of coming up with a 70mm spacer to glue to rear of the ballast tube. I plan to do this to keep some kind of commonality across all my Redshifts. One less thing for my feeble brain to keep track of in the heat of a race!

 

[gp49]

In this thread I mentioned that I had problems figuring out the ballast tube in the heat of battle. Well, I've just learned that the ballast tube in the green light weight Redshift is 400mm long. Most of my ballast tubes are 330mm long. I don't know why I made the wise decision to not race the green Redshift last month. But I'm glad I didn't! I'm sure I'd have made a smoking hole in the ground had I tried to ballast the ship with the mass being off by 70mm.

Now that I know the length of the ballast tube. I'm thinking of coming up with a 70mm spacer to glue to rear of the ballast tube. I plan to do this to keep some kind of commonality across all my Redshifts. One less thing for my feeble brain to keep track of in the heat of a race!

I have not followed your escapades closely on this thread but it sounds like you have not checked the CG after you put the ballast tube in?

Looks like you got lucky.

 

[Konrad]

The ballast tube was installed when I purchased this model. I did not receive a ballast kit.

No luck involved. At the field I knew I couldn't maintain my CG with the slugs and spacers I had for the ballast tubes I installed in my other two Redshifts. (Heck, I couldn't even fill this 400mm ballast tube with enough spacers [400mm vs 330mm]).

I will now configure this Redshift to match the ballast system used in my other two Redshifts.

 

[Konrad]

Where does the time go?

It took me close to 4 hours to turn down a broom stick to make the back stop fillers, and size a set of spacer! In the end I now have 3 Redshifts that use the same ballast system. I can up the mass by 755 grams using 5 tungsten slugs. Not that this is something I want to do with this light weight glass Redshift. But the option is there!

All three Redshifts have the ballast mass setup to move the CG aft 1 to 2 mm aft at full weight from the unballasted trim setting. Seeing how tolerant the Redshift wing is to gross CG changes ,I might have been able to move the ballasted CG even more aft. But as I fly with an AFT CG in the first place I thought it best to play it safe.

 

[Konrad]

It is with a heavy heart that I must report the loss of this light glass (green) Redshift. Postmortem to follow in a few days.

 

[Doc James Hammond]