Lab/Launch station

[00_Discovery_00]

Hello everyone!
I was looking for a compact station able to help me during the three main stages of a scratched built rocket: prepare the solid propellant, test and log data of the rocket engine and launch the rocket (vehicle’s design apart).
I was’t able to find anything on the market so I decided to start designing something for this purpose.
Does anyone faced the same need yet?
Cheers.
Thanks

 

[Zeus-cat]

When you say prepare the solid propellant, do you mean use commercially made motors like Aerotech or making your own propellant? We can't discuss making your own propellant in the open part of the forum; only in the special section. To have access to the special section you must be a US citizen or equivalent, be in the US when accessing the special section and hold at least a level 1 high power certificate in NAR or Tripoli.

There are other places on the internet you can go for information on making your own motors, but I don't do that so I don't know what they are.

 

[00_Discovery_00]

Thank you Zeus for the quick reply and information. My question is more about the availability of a logger station specifically designed to test solid rocket engines (low-powered) and get useful data and trend curves out of them (Chamber pressure, load, flame temperature). The motor could be both commercial or handmade (knowing what you’re doing of course) but I don’t want to talk about the propellant. I just saw lot of products for launching the model rockets but nothing for testing. I’m just curious to know if any of you already found something Interesting for that purpose or not.

Thanks

 

[shockie]

Sounds like you want a thrust-test stand to test the various motors specific characteristics. Flame temperature could be done with a combination of thermocouples stationed at various points in the flame front. or along the length of the motor. NAASA used to sell a kit to perform chamber pressures of motors with a USB stat logger.:

 

[00_Discovery_00]

That’s one of the tasks. I’d like to have something compact, portable and reliable to get data during thrust-tests as well as launching model rockets.
if there’s any suggestion for a product already available would be cool, otherwise I’ll proceed with my design and it would be great to have your feedback later on!

 

[jqavins]

I may be confused about what you're looking for. Is it a test stand and launch pad in one? Those seem to me like items with very requirements, and I don't see the advantage in combining them. It'd be something like a microwave oven and toaster in one; sure, they're both electric appliances for cooking but, but what's gained by combine them?

I've never liked when someone askes "How do I do X" and someone else says "Why in the world would you want to do that?" or "You shouldn't do X, you should do Y instead." I'm trying not to do that, but asking "why?" to better understand your needs.

So, if I'm failing to understand what you're after, please clarify. And if you really want a microwave/toaster then don't let me stop you, and you should go ahead and post what you've got for a design so far.

 

[00_Discovery_00]

I may be confused about what you're looking for. Is it a test stand and launch pad in one? Those seem to me like items with very requirements, and I don't see the advantage in combining them. It'd be something like a microwave oven and toaster in one; sure, they're both electric appliances for cooking but, but what's gained by combine them?

I've never liked when someone askes "How do I do X" and someone else says "Why in the world would you want to do that?" or "You shouldn't do X, you should do Y instead." I'm trying not to do that, but asking "why?" to better understand your needs.

So, if I'm failing to understand what you're after, please clarify. And if you really want a microwave/toaster then don't let me stop you, and you should go ahead and post what you've got for a design so far.

Hi jquavins and thank you for the reply. I guess there’s a misunderstanding. What I’m looking for is not a stand test and launch pad in one. I’m looking for something that can be used as a logger when I perform static test of rocket engines so it should have the possibility of reading relevant sensors like load cell, thermocouple, pressure sensor. The same product should also be able to manage the ignition sequence for the launch phase. Last but not least, in case of making my own propellant, it should take care of temperature control which is a key point along the process.
I hope I’ve been clearer now

 

[jqavins]

I guess I'm still not seeing how those things fit together, unless...

Are you talking about liquid bi-propellants? We here almost exclusively use solids, and if it's not solid it's a hybrid. The ignition sequence for solids is "flip the switch then push the button". The ignition sequence for bi-propellants is more complicated, in ways that I only half understand, and I guess I could see reasons you might want or need it integrated with the sensors. I'm guessing this from your use of the phrase "temperature control". Temperature control during a burn is just not a thing with solids.

 

[00_Discovery_00]

I guess I'm still not seeing how those things fit together, unless...

Are you talking about liquid bi-propellants? We here almost exclusively use solids, and if it's not solid it's a hybrid. The ignition sequence for solids is "flip the switch then push the button". The ignition sequence for bi-propellants is more complicated, in ways that I only half understand, and I guess I could see reasons you might want or need it integrated with the sensors. I'm guessing this from your use of the phrase "temperature control". Temperature control during a burn is just not a thing with solids.

I use solid propellant too. The point is that if you want to design a solid rocket engine (model scale) from scratch (both external case, nozzle geometry and solid propellant) I would say there are three main stages: 1) make the solid propellant (you need temperature control) 2) it is then necessary to perform static tests and save useful data over time to understand the engine’s performance, like thrust curve, chemistry’s stability and above all reliability. All this before using it into a model scale rocket. 3) finally, for the ignition sequence I just meant a countdown timer with a short circuit at the end to turn on the rocket engine.

 

[shockie]

something along the lines of this:

 

[00_Discovery_00]

something along the lines of this:

There we go! Thank you shokie. That’s close to what I was looking for. Anyhow, I’m about to finish the videomaking phase of my project and I’ll be happy to share the final result. It would be great to have your feedback then

 

[tsmith1315]

1) make the solid propellant (you need temperature control)

That sounds like you're suggesting active temperature control.

Are you wanting a system to simply take measurements to help you with motor design iterations?

 

[jqavins]

While making propellant, sure, you need to control the temperature while it's curing. Well, I can see how you might need that, and if you say so then sure. Yet that seems like a third separate task, different from both testing and launching.

I guess I'll just wait for the video.

 

[00_Discovery_00]

While making propellant, sure, you need to control the temperature while it's curing. Well, I can see how you might need that, and if you say so then sure. Yet that seems like a third separate task, different from both testing and launching.

I guess I'll just wait for the video.

Hi guys,
here below the video that shows and explains my project. I hope you’ll enjoy and I would be glad to receive your feedback.
Cheers

 

[jqavins]

You've clearly done an outstanding job with this. Well thought out, nice design^*, well implemented and constructed.

If it were me, personally I'd rather have three different boxes so that each one could be dedicated to its own task. A temperature controller (simple), and launch controller (rather simple) and a test stand data logger (less simple). I would want to leave the cooker in my mixing lab semipermanently attached to my equipment there, the data logger semipermanantly attached to my test stand, and the launch controller in my range box. But this isn't about what I would hypothetically want if I were making my own engines. An all-in-one is what you want, and you've created a good one.

I have only one suggestion for an improvement. You've got the USB port for software updates; why not enable data uploads to a computer for analysis through the port as well? It would be a more convenient option than the SD card, and it would be in addition to the SD card, not instead. (I assume the data are logged directly to the card, so it could still be physically moved to the computer as you're doing now even if you also offer a USB transfer option.)

* Except for that extra width of the screen opening on the right side and the resulting gap, but we don't have to talk about that.

 

[00_Discovery_00]

You've clearly done an outstanding job with this. Well thought out, nice design^*, well implemented and constructed.

If it were me, personally I'd rather have three different boxes so that each one could be dedicated to its own task. A temperature controller (simple), and launch controller (rather simple) and a test stand data logger (less simple). I would want to leave the cooker in my mixing lab semipermanently attached to my equipment there, the data logger semipermanantly attached to my test stand, and the launch controller in my range box. But this isn't about what I would hypothetically want if I were making my own engines. An all-in-one is what you want, and you've created a good one.

I have only one suggestion for an improvement. You've got the USB port for software updates; why not enable data uploads to a computer for analysis through the port as well? It would be a more convenient option than the SD card, and it would be in addition to the SD card, not instead. (I assume the data are logged directly to the card, so it could still be physically moved to the computer as you're doing now even if you also offer a USB transfer option.)

* Except for that extra width of the screen opening on the right side and the resulting gap, but we don't have to talk about that.

Thank you for the feedback! I prefer to have everything combined in the same compact box because some of the tasks and sensors are used in more than one tasks so it was a sort of optimization of the project. Ragarding uploading data to the pc, it is possible of course. Anyway, I prefer to leave my pc at home, store all the data in the sd card and, once finished the tests, perform the required analysis.