R.I.P Lansbergen, or : when manufacturers fail...

[te_groen31]

Hello,

Not long ago I proudly announced the first successful flight of my
first big rocket.

This evening, I witnessed its last flight.

Estes decided to give me D12-0 engine but marked it as a D12-5.....

See attachment.
1. This is what the engine looks like after a good launch.
2. This is the result of a good ignition. A nice, fast, high flight.
3. Very long smoke trail.......beautiful.
4. This is what the other side of the engine looked like, AFTER
its flight..............No ejection charge.....
5. This is the result. I already pulled the rocket out of the clay, here.
6. This is how I found it. Believe it or not, but the nose cone was
almost intact ! Just a few scratches. I could rebuild this rocket, but
I probably won't, since it wasn't such a good rocket, anyway.

Let's hope I won't get more of these engines when I start launching
its successor.


Erik.

 

[lessgravity]

That's a bummer. I remember reading your earlier post.

I had similar thing happen recently except it was the other way around. I put a D12-0 in the booster of a scratch build. ...except it wasn't a D12-0. I knew that when there was a delay followed by ejection. At first I though I picked up the wrong engine but later discovered it was marked D12-0.

 

[mwiggins367]

Sorry for your loss. It is hard when another's mistake causes a failure.

Estes has been having quality control in their D12 motors lately.

Actually, you got a D12-P. A D12-P does not eject.

A D12-0 has a delay of 0 seconds after burn out, but it does eject.

 

[te_groen31]

Marty,


You're right. That's what I meant. I was a plugged version (x-P), not one
with a charge without delay ( x-0 ).

Fortunately, I also had a few great launches. Since there was hardly
any wind, some rockets landed very close to the pad ! I have some
movies to prove it. I used my Nikon Coolpix 4500 to film the
launches. AND landings !

And I am still impressed by the power of those small A3-4T engines....
Just 13 mm, but what a power. Those rockets really fly high. And I mean
high... I guess a lot higher than 200 feet.
If only they weren't so hard to get............

Erik.

 

[mr_fixit]

Ya hate to lose that first one.....cut it short, stick the nose cone back in it and hang it over the workbench! Inspiration for the next new and improved Lansbergen II!

I guess out of the thousands of motors they make, every now and again you're gonna get one that has a suprise inside! You never know when your number is gonna be up.

Best of luck on the new one! I really liked the paint job on the original.

Tom and Maggie - getting ready for NERRF in NY!

 

[MetMan]

I have a bunch of D11-Ps stashed away but I don't recall what the plugged end looks like. Is it possible that it is a D12-5 with a non-existent ejection charge? Have you considered sendiing the casing back to Estes with a picture of the loss? They will replace the engines and provide a comparable rocket. They may not be able to ship motors overseas but I'm sure they will do their best to make good on their mistake.

MetMan

 

[jflis]

Originally posted by mwiggins367
Sorry for your loss. It is hard when another's mistake causes a failure.

Estes has been having quality control in their D12 motors lately.

Actually, you got a D12-P. A D12-P does not eject.

A D12-0 has a delay of 0 seconds after burn out, but it does eject.

Just to be clear, a D12-0 doesn't have a "delay of 0 seconds", rather it has no delay at all. Also, it doesn't actualy "eject" in that it doesn't have an ejection charge. Rather, it is possible for it to push a nose cone off because when the fuel burns through it will create back pressure.

If you look into the top of any booster motor (any BP motor ending in "-0", what you are seeing is the top of the fuel slug.

Also, I wasn't aware that they ever made a D12-P motor...

 

[dwmzmm]

I had a very similar situation last year or so using the D12-7; used two in a four engine cluster model (along with two E9-6) and noted that the clay cap on one of the D12-7 was still in place following the recovery. My take is that some of the clay caps are
too thick to be ruptured forward by the ejection gases. And, yes,
I did file a MESS report for that motor even though there was no
real problem recovering the model (the Maxi-Alphax4, a four engined 24 mm clustered model).

Contact Estes customer service about your problem(s). Trust me,
they will do whatever it takes to make it right.

 

[dwmzmm]

Forgot to mention in my previous post that I'll be flying the
Maxi-Alphax4 at NSL - 2006 on Sunday (day after tomorrow) using the same cluster combination: 2 - D12-7 & 2 - E9-6.

 

[te_groen31]

Hello,

I'll give it a try. I'll write them and see what they'll can do for me.
It never crossed my mind, though. I knew it would happen one day.
Damage is part of the game. It's a risc I was willing to accept.

In the attachment you can see one LB1's last good landings.
There was a bird way up, going in circles, and stayed there even though
several rockets flew right by him.....
What was that bird thinking..... ? ;-)

I made a movie where you can see a rocket fly very close to the bird,
and he did was make a turn. But he stayed close for quite a while...


Erik.

p.s. Somebody is thinking " If you knew a bird was up there, why
did you take the risc and continue launching rockets ?"
Hmm...good question.
However, this time it wasn't me who decided when the rocket
would go up. This time I did the filming and some friends, who did not
notice the bird, did all the "hard" work for me ! ;-)

 

[te_groen31]

Hello,

Yesterday evening I decided, after a discussion with some other club
members, to hang the Lansbergen-1 up on the wall, damaged and
all. Chute hanging out and muddy nose cone....
Maybe with a piece of paper underneath, saying "The price of rocketry".

Or something like that.

Erik.

 

[te_groen31]

This is just a nice pic of a good chute deployment.
You can also see the cotton wadding flying, left from the rocket.

Perfect, launch, flight and landing !

Erik.


p.s. Picture was taken by a friend, who had a new digital Nikon
SLR camera and zoom lens.

 

[te_groen31]

This is just a nice pic to show that I DID have a nice launch day,
in spite of having a few set-backs...
As a matter a fact, we all had fun, all evening. Went home smiling ! ;-)


This a close-up of the blast-off of my worst looking rocket.
Looks cheap, toy-ish.... But this one IS my best rocket. Flies
just about any engine I can put in, it has survived nose down landings
without a chute deployment and still end up without any critical damage,
it flies fast and straight and so far, only had one bad landing because
the engine I used ( 1/2A6-2 ) was just a bit too weak, causing the
ejection charge to pop when it was already nose down, 15
feet from the ground.

With a C6-5 ( my favorite engine already..... |-) ) it flies VERY
high.
But which rocket doesn't, with a C6-5 ... ?


BTW, is it my imagination or did I see it right.... I think this rocket
flies higher and faster on a B4-4 than on a B6-4..............
Isn't a B6 supposed to be a bit more powerful ?

If not, what am I missing here ....?

Erik.

 

[te_groen31]

Hello,

Okay, last picture.
This is the Lansbergen-1 on a C11-3. Its one but last good flight.

Look at the launch pad lighting up, after the engine burnt another
hole through the metal plate..... ;-)


Erik.

 

[rocketking]

This was for the Rocket Gliders, right?!

Why no to a D12-P?!? Interesting!

 

[te_groen31]

Hello,

Come to think of it...... after reading the posts....
I wanted to know more about those plugged motors. I asumed
my rocket failed because it accidentally had a plugged engine
instead of one with an ejection charge.
After visiting several websites I still haven't found a real
plugged version. I did find D12-0 engines, but not a single
D12-P .........

So now I start to doubt too...... Do they exist or not ?

Erik.

 

[Hank]

Was that a fishing rod guide used for a rail guide?
R

 

[dwmzmm]

Originally posted by te_groen31
Hello,

Come to think of it...... after reading the posts....
I wanted to know more about those plugged motors. I asumed
my rocket failed because it accidentally had a plugged engine
instead of one with an ejection charge.
After visiting several websites I still haven't found a real
plugged version. I did find D12-0 engines, but not a single
D12-P .........

So now I start to doubt too...... Do they exist or not ?

Erik.

The only plugged motors on the market are the Estes A10-PT,
D11-P, and E9-P. These have NO smoke delay nor ejection charges. The A10-PT are intended for the Estes race cars, and the D11-P & E9-P were intended for R/C boostgliders. However,
I've used the A10-PT's for special strapon boosters in advanced
model rocket clustering, and intend to use the plugged D & E
motors for the same purpose. The lack of ejection charge opens
many excellent applications for clustered/staged model rockets.

 

[te_groen31]

Hank,

yes, that's right. I just came up with the idea. But I was not the first !
Many people used them long before I did. I just never knew. It just
seemed like a good idea because I had fishing rods, myself.
These type of guides have a very hard and very smooth ring,
made out of something ceramic, I guess.....!?

Super smooth and very wear resistant. Also, I spray the metal
launch rods with silicone spray, making it even smoother.
Resistance is almost zero, now.... ;-)

For how LONG you can use these guides, depends on how reliable
you engines are.... |-(


Erik.

p.s. For your information : I could not tell ANY difference in behaviour
between rockets with fishing rod guides and "normal" guides,
the usual "straws".
However, because of their size and weight ( if ANY...) I would use
them only on larger rockets and not the smaller ones.
I think they work fine for rockets of about 20 inch tall or more
and 5 ounce or more.
They would look quite bulky on small rockets like the Eclipse I built.
It's only 3/4 inch x 12 inch. I use straws for this one. It goes
300 ft plus on a A3-4T engine..........!

 

[BobH48]

Originally posted by te_groen31
BTW, is it my imagination or did I see it right.... I think this rocket
flies higher and faster on a B4-4 than on a B6-4..............
Isn't a B6 supposed to be a bit more powerful ?

If not, what am I missing here ....?

Erik.

Erik,

The total impulse of both are almost the same. Based on the thrust curve information the B4-4 has a slightly higher inital thrust than the B6-4 but then burns at a lower thrust for a longer period of time, which accounts for the lower "average" thrust.

So with the higher initial thrust, it looks quicker off the pad and with the longer burn, it's possible that it goes higher with the B4-4 since the delay time is the same and it appears to be a fairly light rocket.

B4 thrust curve

B6 thrust curve

Hope this helps,

Bob

 

[dwmzmm]

Originally posted by dwmzmm
Forgot to mention in my previous post that I'll be flying the
Maxi-Alphax4 at NSL - 2006 on Sunday (day after tomorrow) using the same cluster combination: 2 - D12-7 & 2 - E9-6.

Well, just got back from NSL - 2006, and it happened. Flew the Maxi-Alphax4 in the cluster configuration mentioned in the post attached to this, and this thing literally went into near orbit. We
followed it descending on the yellow 22" nylon (FSI) parachute,
and walked the line to where it appeared to touched down. My
son and I simply could not find it. So, to my first Maxi-Alphax4,
R.I.P.

I will have to build another, more improved version...

 

[m85476585]

Originally posted by te_groen31
Hello,

Come to think of it...... after reading the posts....
I wanted to know more about those plugged motors. I asumed
my rocket failed because it accidentally had a plugged engine
instead of one with an ejection charge.
After visiting several websites I still haven't found a real
plugged version. I did find D12-0 engines, but not a single
D12-P .........

So now I start to doubt too...... Do they exist or not ?

Erik.

It looks like you had a D12-5 with no ejection charge. Look at the motor case in the first attachment. The printing is in green, which means it is a regular motor (plugged is black, booster is red, and upper stage (AKA long delay) is purple. It is also possible to make out D12-5 in picture number 4. The only plugged D is a D11, but that's not what you had. Call or email Estes and they will send you a new pack of engines and maybe a new rocket (they can't replace a scratchbuilt one, but they might offer you a kit.)

https://www.estesrockets.com/cgi-bin/contact.cgi

You should also file a MESS report. The problem with your motor is "No ejection charge (cap retained)", and engine type is D12-5.
https://nar.org/NARmessform.html

 

[m85476585]

Originally posted by BobH48
Erik,

The total impulse of both are almost the same. Based on the thrust curve information the B4-4 has a slightly higher inital thrust than the B6-4 but then burns at a lower thrust for a longer period of time, which accounts for the lower "average" thrust.

So with the higher initial thrust, it looks quicker off the pad and with the longer burn, it's possible that it goes higher with the B4-4 since the delay time is the same and it appears to be a fairly light rocket.

B4 thrust curve

B6 thrust curve

Hope this helps,

Bob

I recently saw a Big Bertha drag race, one B4-4 and one B6-4. The B6 had almost double the altitude of the B4 because Big Berthas have a lot of drag.


<hr>

Originally posted by te_groen31
Hank,

yes, that's right. I just came up with the idea. But I was not the first !
Many people used them long before I did. I just never knew. It just
seemed like a good idea because I had fishing rods, myself.
These type of guides have a very hard and very smooth ring,
made out of something ceramic, I guess.....!?

Super smooth and very wear resistant. Also, I spray the metal
launch rods with silicone spray, making it even smoother.
Resistance is almost zero, now.... ;-)

For how LONG you can use these guides, depends on how reliable
you engines are.... |-(

Erik.

I doubt they are ceramic, It is much too brittle. They are probably enameled or epoxy coated steel, but I don't know for sure.

 

[BobH48]

Originally posted by m85476585
I recently saw a Big Bertha drag race, one B4-4 and one B6-4. The B6 had almost double the altitude of the B4 because Big Berthas have a lot of drag.

Very true.. But in a light, low drag design the difference isn't as noticeable.

Sort of like the comparison between A10-3T and A3-4T in the 13mm size. In light paper rockets, I find the A3 outperforms the A10 most of the time. In my paper Vostok, however, the A10 is the better choice because the Vostok has a lot of drag.

 

[te_groen31]

Matt,


I'm afraid I can not agree with you. Though ceramics are brittle
indeed, they are much tougher and harder than ceramics you find
at home.

This type of ceramic is ultra hard and does not compare at all to the
type used for cups and plates, f.i.

Also, these industrial (or synthetic type ) of ceramics are much more
wear resistant than steel !
I have a high quality steel file. Files away most types of steel.
Try to file away these ceramics and all the file does is slide
over it.......
As if it were made of plastic.....

Brittle ? Yes. But they're very....VERY hard. Takes a lot of force to break
these rings.

That was - and is - the main reason why I chose these fishing
rod guides with ceramic rings.

I got this idea because I once remembered I never saw a fishing rod
with worn-out ceramic guides....

Try it. If they don't work as well as I say they do, I'll buy them from you ! ;-)


Erik.

 

[Speedtek]

Contact Estes customer service. the will ask you to email the pictures and send them the casing. They will not only send you a pack of motors they will replace your rocket of equal value. I sent back D engines that were about 20 years old and they "took care of it" Estes sent me a 36D Squared for the damaged rocket.

I had the same problem happen to my clone Cherokee-D. The ejection charge never went off.

 

[adrian]

Originally posted by BobH48
Very true.. But in a light, low drag design the difference isn't as noticeable.

Sort of like the comparison between A10-3T and A3-4T in the 13mm size. In light paper rockets, I find the A3 outperforms the A10 most of the time. In my paper Vostok, however, the A10 is the better choice because the Vostok has a lot of drag.

This and the previous message about the Big Bertha surprise me. For a high drag model, I'd have thought that a low thrust, long burn motor would be preferable because a short, high thrust motor will accelerate the rocket to a higher velocity, increasing drag even further. The Big Bertha is heavy, though, which is why it does better on a B6 - it's not wasting as high a proportion of its energy fighting gravity. I'd guess that the Vostok is also relatively heavy.

 

[BobH48]

Originally posted by adrian
This and the previous message about the Big Bertha surprise me. For a high drag model, I'd have thought that a low thrust, long burn motor would be preferable because a short, high thrust motor will accelerate the rocket to a higher velocity, increasing drag even further. The Big Bertha is heavy, though, which is why it does better on a B6 - it's not wasting as high a proportion of its energy fighting gravity. I'd guess that the Vostok is also relatively heavy.

I think you are correct and it's the weight and not the drag. The Vostok is rather heavy for a paper model.

I should have known that. I guess I wasn't thinking.

In high drag designs, like saucers, longer burning low thrust motors outperform high thrust short burning motors.