Help equating RRC3 graph to data.

[Bat-mite]

Hi, all. I downloaded a recent flight from my RRC3. The graph is below. I don't understand why the graph shows a consistent descent rate, where the summary beneath shows a drogue descent rate of 59 and a main descent rate of 18.

I would have expected it to look more like the simulation, which is the image below.

As an FYI, my main charge blew at 1000', but the main took a long time to open up. That's why the graph shows the main at about 400'.

 

[SpaceManMat]

I’m seeing a slight deflection in the graph as the main opens, so I’m thinking your main is ineffective for what ever reason. And the event for main is at 400 feet, defiantly not at 1000. Are you sure you are looking at the right log? Perhaps you run redundant altimeters? How much of the flight did you actually observe?

The rocket appears to ascend after drouge deployment, so wondering if the summary is put out because of this. I would take points on the graph and confirm both drouge and main decent rates.

 

[tim cubbedge]

I am seeing deflection too at 400. And if you do the math, it looks like it was traveling about 40 fps from 400 feet until it hits the ground.
Can you put the velocity data on plot?

 

[Bat-mite]

I am seeing deflection too at 400. And if you do the math, it looks like it was traveling about 40 fps from 400 feet until it hits the ground.
Can you put the velocity data on plot?

As I wrote, the main took a long time to open. When the video is uploaded, you'll here me yelling, "Open! Open! Open! Open! ..." So 400' is about where it opened fully and should have slowed the descent rate.

Here is the plot without smoothing and with velocity.

 

[cerving]

Can you get a time vs altitude/velocity data dump out of it? The raw data sometimes is a good clue when weird things happen.

 

[ben]

Can you export and upload the RRC3 flight file for the flight?

 

[tim cubbedge]

Your rocket never really slowed down from 60ish to 40ish fps based on velocity data. If your chute was fully deployed at 400 feet I’d say you need a bigger chute. You sure it was fully deployed?

 

[SpaceManMat]

As an FYI, my main charge blew at 1000', but the main took a long time to open up. That's why the graph shows the main at about 400'.

The graphs show that the main charge went off at 400 and chute inflated at about 375. If you saw something at 1000 then I suspect that your NC may have come loose, but the line labeled main on both graphs is where the altimiter fired the charge.

 

[Bat-mite]

The video will reveal all. Unfortunately, I have no control over when that gets uploaded to YouTube. The forum software won't allow me to upload the RRC data dump (.rff file). Is there a trick to that?

 

[ben]

Rename it with a txt extension

 

[Bat-mite]

Hey, I'm an idiot. Too many assumptions. This is the wrong flight file. I remember this flight, in a different rocket with HED, and I had the main set to deploy at 400' on that flight. The main stayed in the NC and it continued to descend under drogue. Sigh.

I though the RRC3 was supposed to automatically select the most recent flight when you start the plotter. Oh, well. I already wiped the memory.

In short, this is a big NEVER MIND!

Sorry.