TVC Booster

[jqavins]

This is probably a notion that deserves a thread in a particular topic area, but I'll be darned if I know which. So here it is.

I asked @JoeBarnard once if his TVC works in conjunction with fins, or if the combination leads to trouble*. He said yes, that works fine.

So, today, years later, I had a flash of an idea: use a TVC in a booster that gets a rocket up to speed then have a finned sustainer take over. You get all the beauty of a slow lift off without a rod or rail, and all the advantages of a rocket that remains stable after burnout.

Thoughts?

* On some systems, if an active control system were to detect a deviation from nominal then compute and apply a correction, but another mechanism were applying a correction at the same time, the active system would have overcompensated for the deviation, leading to an overshoot that requires a new correction, thus a new overcorrection, and such a system can, in some cases, experience growing oscillation that leads to failure. Fortunately, the BPS.space TVC is not subject to this failure mode, I've been told.

 

[Cape Byron]

Sounds like a plan.

 

[lakeroadster]

And TVC stands for...

 

[Raythain]

And TVC stands for...

Thrust Vector Control. Or gimballing the engine to maintain vertical orientation.

 

[lakeroadster]

So a Thrust Vector Controlled booster? Yikes... that sounds expensive.

 

[Charles_McG]

A couple of years ago, I asked Joe about using a TVC in the -upper- stage of a multistage rocket. Use a high thrust booster to get up to speed, then use a TVC with a long burn motor to keep it upright. He thought his particular implementation would handle the boost poorly - that the PIDs would wind up during boost when there isn't any response to their output.

 

[jqavins]

In response to a similar question, he told me that his implementation doesn't work well when the rocket is going really fast; its responses are not fast enough due to limited torque from the motors. His web site currently states that, and recommends only low thrust, long burn motors. The potential fly in my ointment is getting up to safe "rod exit" speed while staying under the TVC's speed limit.

So a Thrust Vector Controlled booster? Yikes... that sounds expensive.

Yes, it would be. His particular system costs $349.99. And it's out of stock. So I won't be doing this myself any time soon

 

[neil_w]

I do like the idea. A slow boost that also ensures verticality when staging. Sounds good in theory, at least.

I didn't think that Joe was actually selling his system anymore?

 

[lakeroadster]

Yes, it would be. His particular system costs $349.99. And it's out of stock. So I won't be doing this myself any time soon

 

[Rschub]

Ada will do fins, see here,
but he seems to have little interest in that application.

 

[jqavins]

I didn't think that Joe was actually selling his system anymore?

I hadn't heard that, but I was wondering once I saw that it was "sold out". Would it ever be in stock again? And if not, why is BPS still there? There don't seem to be any other products.

 

[neil_w]

I hadn't heard that, but I was wondering once I saw that it was "sold out". Would it ever be in stock again? And if not, why is BPS still there? There don't seem to be any other products.

From his web page:

BPS.space is now a proper company and full time job for me (Joe). It is currently funded through flight computer sales, the BPS.space Patreon page, ad revenue on YouTube, and sponsorships.

My impression has been that flight computer sales are now pretty much done, or at least minimal, and the other stuff is what keeps him going. He does still sell the 3D printer files for the TVC mount, and plenty of merch.

Or maybe he'll start selling those things again, who knows. But it clearly is not his focus at the moment.

 

[Rschub]

I am fairly close to an "influencer" in another hobby, and I think I understand their mindset.
First of all, they are wholly consumed by their passion, and want other people to hear about it.

They also don't really want to deal with people.

Selling a physical product, doing customer service, and all that stuff is an impediment to doing the thing they are passionate about.
Clicks, likes and views are the primary revenue stream, so creating content [which they love doing] takes top priority.

Unless someone in his merry band of true believer's volunteers to handle all that other stuff for him, the chances of him doing it himself are approximately zero.

 

[jqavins]

Every part of that makes sense, except making a company out of it. Maybe once upon a time he intended to keep selling the product. Oh well, not my problem.

 

[Rschub]

The product is "Joe's Big Adventure."

The man has 600k subscribers, patreon income, and sponsers.

It is possible that he did want to sell it at one time, but reality eventually intruded, there is no real market for it.