Lansbergen II: improved version, ready for launch.

[te_groen31]

Hello,

I just finished my updated version of my first big rocket, the Lansbergen 1
and called it.... (surprise)...... Lansbergen II.

It's a bit smaller, has a wider tube (BT 60) and bigger but lighter fins.
L-II measures 63,5 cm tall (25 inch), 40 mil diameter (1.57 inch),
fins are 75x60 mil, 16 cm tip to tip.
Flies on C11 and D12 engines.

Since its predecessor took quite a while to come on its big 48 cm
chute, I decided to give this one a much smaller chute.

Less paint, less decals, less nose weight, lighter fins, smaller
chute......all in all I managed to reduce the launch weight by
well over one quarter (!!!) of Lansbergen 1.
LB-1 weighs around 210 grams, launchweight. (7.5 ounce)
LB-2 stays under 140 grams ! (5 ounce)
This, combined with a better design and better balanced model,
I should see a faster launch and a more stable flight.
Probably it'll fly higher, too.

Not too high, I hope, since LB-1 already flew very high on a
D12-5 engine.......! ;-)

Here are some pics of the finished model.

Launch pics ?....as soon as the wind quiets down.....

I can't wait ...........!!!


Erik.

 

[te_groen31]

Nose cone.

In case it might end up in the bushes or tall grass:
glitter tape for the metallic tube, mirror foil for the
light grey nose cone.

 

[te_groen31]

I used mirror foil for the printing.

First I printed it in reverse at the desired size.
Cut out the strip with the text and glued it onto the
back side of the mirror foil.
Then I carefully cut out each letter.
I used soft sticky tape to create a line for the letters. Once they
were in place I could remove the tape and check for proper
alignment.

 

[jjnodice]

Hey Erik,

Looking good. There are some descent rate calculators on EMRR that can help you size your parachute.

EMRR_tools

Good luck and let us know how the flight goes. From your description, I think the answer will be "very high".

Jason

 

[te_groen31]

I love this shine.........


It turned out much better than I thought it would.
I just used the materials at hand. Improvised a bit.....

 

[te_groen31]

For the lower metallic part I wanted to use some glittery foil, too.

I used small bits of foil which I normally use for the solar panels of my scratch built models.

This foil is called 3D or hologram foil.

 

[te_groen31]

Hello JJ,

I may have a more reliable formula :
broken fins : chute = too small ( use a bigger chute ).
fins intact : chute = good ! ( don't change a thing )
Drive 10 miles or more to retreive rocket :
use smaller chute or don't launch in stormy weather.

Could it be any simpler ?? ;-)

Works for me ......! HA ! ;-)

Erik

 

[te_groen31]

Top view.


Not a very good picture, but it shows the big nose cone nicely.

 

[te_groen31]

This is a close-up of the printing.

That mirror foil is great stuff. I used for a scale 1:20 Hubble Space
Telescope model. It's just as shiny as chrome or a mirror.
Not as smooth, though, but here, that's a plus point.

The rocket was painted metallic silver all over, then I used metallic
blue for the lower half, graduately reducing, going up.



More pics later.


Erik.

 

[cjl]

VERY nice

For a 5oz model, I would reccomend a chute sized around 40cm. Anything less is asking for broken fins. It depends on your construction, but overall, that's the smallest I would go.

I fly at 5000 feet ASL though, so the air is a bit thinner, might make a difference...

 

[te_groen31]

Thanks CJL,

That's good advice.
But, stubborn as I am, I will use the chute I have now, end up with
broken fins, indeed, and then I imagine you saying to me...
"Told you so............."

That's why I will also take a bigger chute with me at launch day.
And a bottle of fast drying glue................... ;-)

I'll probaly use the one from LB-1 if the new chute proves to be
too small.
But like I said before, the Lansbergen 1 came down quite slow and
landed very softly on a +- 52 cm chute. Since LB-2 is much lighter,
I'm afraid this rocket will also land veeeeery gently. In a field somewhere
in the next county..... ;-)

I'm not scared of broken parts anymore, since I saw one of my
rockets land nose down ! The chute came out at only 50 feet ,
but it never deployed. Yet, there was only a very small dent
at the top of the tube. Nose cone and chute did not even had bit
of mud or grass on them !
I was really surprised.

I'll let you know how it all worked out. But right now, we have some
pretty bad weather going on. Very windy and lots of rain.

Erik.