Fantasy Motors

[Donnager]

So, your laser gets blasted as soon as it ignites the motor? Good way to lose an expensive laser, I'd think. Of course, there may be a way around it. I just don't see one.

Maybe something along these lines, only smaller....

 

[rharshberger]

The "double" in double-base propellant refers to nitrocellulose and nitroglycerin.

They are not "slow" burning propellants either which iirc is what NFPA calls out specifically (working from memory here).

 

[bad_idea]

Unfortunately Aerotech has already come out and said they won't be manufacturing any more Micro Maxx motors, so what is made is what we have to work with.

According to Bill Stine, Estes bought the Micro Maxx equipment from Quest, though as of early 2022, there were no current plans for it:

 

[Antares JS]

According to Bill Stine, Estes bought the Micro Maxx equipment from Quest, though as of early 2022, there were no current plans for it:

I hadn't heard that... it's certainly interesting though. Maybe there's hope.

 

[NateB]

A pressed color-smoke delay grain might not fall under the rules for sugar propellants due to the oxidizer usually used for colored smoke. And a composite delay grain that produces color is kinda difficult due to the much higher combustion temperature that turns almost everything that can burn into tiny, tiny molecules & fragments that have no color.

I thought the commonly used oxidizer for colored smoke formulas would be the part that would prevent them from being used as part of a sugar motor. I assume the rules apply to propellant and delay grains. I experimented with one KN based smoke formula and it produced too much hydrogensulfide and still burned too hot too destroy the color. I might be overly cautious, but I never purchased AP due to the potential for reactions with the other oxidizer. Now AP on the expensive side.

 

[prfesser]

I thought the commonly used oxidizer for colored smoke formulas would be the part that would prevent them from being used as part of a sugar motor.

That's what I was trying to say, it wouldn't fall under the rules, it would be outside them. Apparently didn't say it very well. Oops.

 

[cwbullet]

CTI has some pretty nice moonburners (F30, G65 in 24mm; G33, G54, H54, H42, H53 in 29mm). No longburn I's in 29mm, but a 29mm I is a fairly rare beast.

The I69 is a beast. I still have 3. I also like J110 and H50. I have one of each of those. The G20 and G37 were pretty slick, also. I like CTI, but the bets thing about Ellis was they were single-use.

 

[heada]

The I69 is a beast. I still have 3. I also like J110 and H50. I have one of each of those. The G20 and G37 were pretty slick, also. I like CTI, but the bets thing about Ellis was they were single-use.

If you look hard enough, there are still some old stock SU long-burn motors out there. I have 3x F14-PJ and 2x G25W-15 motors.

 

[jqavins]

The "double" in double-base propellant refers to nitrocellulose and nitroglycerin.

Indeed. And you can buy the stuff for reloading ammunition. There may be technical difficulties in using it as rocket propellant, but I don't understand what legal difficulties there'd be beyond those that exist for 1) other stuff for rockets and 2) this stuff for bullets.

They are not "slow" burning propellants either which iirc is what NFPA calls out specifically (working from memory here).

So maybe that.

If you look hard enough, there are still some old stock SU long-burn motors out there. I have 3x F14-PJ and 2x G25W-15 motors.

And there is Apogee's F10.

 

[CoyoteNumber2]

Not a motor per se, but I would love to see a standardized, off-the-shelf head-end ignition solution. (And less expensive than this one.)

 

[Neutronium95]

Look on John Cokers ( jcrocket.com ) as he has flown a couple

I looked and couldn't find anything. Are you sure you have the right person?

 

[3stoogesrocketry]

I looked and couldn't find anything. Are you sure you have the right person?

100 percent sure. His website appears to be down at the moment. It was a "scale" Nike Asp made from carbon/kevlar honeycomb . Super light. The motor is 5 inches in diameter of I recall correctly.

 

[bad_idea]

It would be amazing if Aerotech could developed a version of the Pegasus fin tip motor for the hobby market. It's mentioned in the Warp 9 white paper. A 20 second burn N motor would be amazing.

Look on John Cokers ( jcrocket.com ) as he has flown a couple

I looked and couldn't find anything. Are you sure you have the right person?

100 percent sure. His website appears to be down at the moment. It was a "scale" Nike Asp made from carbon/kevlar honeycomb . Super light. The motor is 5 inches in diameter of I recall correctly.

Here is a Wayback Machine archive of that page:

"During Summer 2000, Gary Rosenfield of AeroTech discovered some left-over motors built for a commercial customer of ISP (AeroTech's parent company). These motors were used to provide additional thrust for steerable fins on the Pegasus rocket, three motors per fin. The neatest thing about these motors are that they are end-burners which have a burn time over 20 seconds! "

 

[dr wogz]

More odd-sized cases that have only one or two reloads for it..

(and require "unique" closures..)

 

[Neutronium95]

Here is a Wayback Machine archive of that page:

"During Summer 2000, Gary Rosenfield of AeroTech discovered some left-over motors built for a commercial customer of ISP (AeroTech's parent company). These motors were used to provide additional thrust for steerable fins on the Pegasus rocket, three motors per fin. The neatest thing about these motors are that they are end-burners which have a burn time over 20 seconds! "

Thank you very much for the link. I know tht I've read about that project before, I must have forgotten what the sustainer motor was. I still want to fly one.

 

[TomBroad]

I believe it was MRC that had an "FX" smoke only motor.
Apogee had a 10 mm mini motor.

Still have some of those old FX motors left.
Thanks for the reminder -- need to build a project for them!

 

[CoyoteNumber2]

Still have some of those old FX motors left.
Thanks for the reminder -- need to build a project for them!

What are their dimensions? Something standard?

 

[bjphoenix]

I've noticed in some of my sims that a C6-7 gives a higher apogee than a C11-7. I assume because it's lighter, as well as being a slower burn. And it's cheaper and easier to buy at Hobby Lobby, so...

I have a Goblin kit that I'm about to start on, I'm building it with an 18mm mount. I built a Cherokee-E with its long 24mm mount but I have a homemade adapter and I'll probably never launch it with anything bigger than a C.

I would like to have higher thrust black powder B and C motors. I've been using B6 and C6 because they are easy to get at Hobby Lobby. I've got a pack of C5 to try, they might be closer to what I need.

 

[prfesser]

I have a Goblin kit that I'm about to start on, I'm building it with an 18mm mount. I built a Cherokee-E with its long 24mm mount but I have a homemade adapter and I'll probably never launch it with anything bigger than a C.

I would like to have higher thrust black powder B and C motors. I've been using B6 and C6 because they are easy to get at Hobby Lobby. I've got a pack of C5 to try, they might be closer to what I need.

My understanding is that the kind of BP motor that has high thrust but short duration, is too fragile to ship reliably. The same kind of motor is used in fireworks but nobody cares if a skyrocket CATOs. Usually.

I wonder if a silicone-coated insert—similar to a motor plug—that could support the fragile interior of such a motor would increase reliability (possibly decrease it, I don't know). Yes, the price would go up dramatically, since the insert would have to be manufactured and inserted in each motor. Just a wild thought.

 

[bjphoenix]

My understanding is that the kind of BP motor that has high thrust but short duration, is too fragile to ship reliably. The same kind of motor is used in fireworks but nobody cares if a skyrocket CATOs. Usually.

I wonder if a silicone-coated insert—similar to a motor plug—that could support the fragile interior of such a motor would increase reliability (possibly decrease it, I don't know). Yes, the price would go up dramatically, since the insert would have to be manufactured and inserted in each motor. Just a wild thought.

There has been a lot of discussion about these motors. When I started in rocketry we could buy the B3 (later B14) motors and I did use them occasionally but most of our rockets back then were relatively small so they weren't needed. I did use them in my Astron Ranger cluster rocket for heavy payloads. I've read that the motors were manufactured by drilling out the holes after the motors were manufactured. I don't see why they couldn't still make them, they would just cost more. Maybe there isn't enough enthusiast market to justify it. You can't even buy a C5 at Hobby Lobby so they likely wouldn't have a more expensive core burner either. A core burner D or E would be awesome.

 

[smstachwick]

There has been a lot of discussion about these motors. When I started in rocketry we could buy the B3 (later B14) motors and I did use them occasionally but most of our rockets back then were relatively small so they weren't needed. I did use them in my Astron Ranger cluster rocket for heavy payloads. I've read that the motors were manufactured by drilling out the holes after the motors were manufactured. I don't see why they couldn't still make them, they would just cost more. Maybe there isn't enough enthusiast market to justify it.

It’s also safety, I believe there was a fatal accident that occurred during manufacture.

You can't even buy a C5 at Hobby Lobby so they likely wouldn't have a more expensive core burner either. A core burner D or E would be awesome.

Estes is looking at a core-burning E in the 24x95mm casing, somewhere in the neighborhood of an E57. John Boren did an interview recently and said he could almost get his pinkie finger in the nozzle.

Not sure if those will come to market, but it’s cool to know they’re playing around with motor development. I assume they’re doing this with methods that are unique to these motors and aren’t just upscaling the B14 process.

 

[jqavins]

I would like to have higher thrust black powder B and C motors.

Why black powder? I'd like to see higher thrust 18 mm engines, whatever the propellant. I think it's both a shame and a mystery that Q-Jet C and D engines come with higher thrust than the C and D BP offerings, but the A and B engines only come with lower thrust. You'd think something like an B12 or an A10 (I mean engine correctly labeled A10) would be possible.

 

[smstachwick]

Why black powder? I'd like to see higher thrust 18 mm engines, whatever the propellant. I think it's both a shame and a mystery that Q-Jet C and D engines come with higher thrust than the C and D BP offerings, but the A and B engines only come with lower thrust. You'd think something like an B12 or an A10 (I mean engine correctly labeled A10) would be possible.

It’s the nature of a C grain, you get higher thrust for a longer chunk of propellant. You might get higher thrust in a narrower, longer casing and propellant slug, but you run into engineering and manufacturing difficulties making composites at the 13mm scale.

Maybe a Blue Thunder or faster motor might produce more thrust? I just don’t know if it’s economical to develop and support more of these Q-Jet motor types (and yes I realize that’s the opposite of the point of this “fantasy thread).

Also the Estes A8 is more like an A3.

 

[bad_idea]

Why black powder?

Black powder is easier for clustering, and for staging, it's super easy, barely an inconvenience.

That said, I'd like more 13 and 18mm options both composite and black powder to fly in my local park in between the club launches where I can fly larger motors.

 

[shockie]

Firefox advertised a reloadable BP motor kit that was "coming soon." I believe that was in the mid-90s...<snork>

Back then I liked the idea too but suspected some specific practical problems, which I won't go into.

Terry, do the math... If you could increase the combustion chamber pressure from say 250 psi to say 600-750 psi, how much would the Isp increase? Assume an Isp of 70-75 for the 250 psi case.
When you increase the chamber pressure at which a solid propellant is combusted, does the physical particles vaporize better?

 

[Initiator001]

According to Bill Stine, Estes bought the Micro Maxx equipment from Quest, though as of early 2022, there were no current plans for it:

Estes purchased the original/brown plastic casing Micro Maxx motor making equipment.

Quest currently has tens-of-thousands of the second-generation (Better performing) Mk-II Micro Maxx motors available for sale.

 

[smstachwick]

Estes purchased the original/brown plastic casing Micro Maxx motor making equipment.

Quest currently has tens-of-thousands of the second-generation (Better performing) Mk-II Micro Maxx motors available for sale.

That’s a truly impressive stockpile.

 

[dhbarr]

That’s a truly impressive stockpile.

It's almost high power! ( somewhere in the K neighborhood? )

 

[prfesser]

Terry, do the math... If you could increase the combustion chamber pressure from say 250 psi to say 600-750 psi, how much would the Isp increase? Assume an Isp of 70-75 for the 250 psi case.
When you increase the chamber pressure at which a solid propellant is combusted, does the physical particles vaporize better?

I just did. Propep says that Isp would increase...but not all that much. Theoretical Isp for BP at 250 psi is around 111 seconds. At 750 psi it's around 126 s. Assuming that the actual Isp at 250 psi is only around 80 seconds due to combustion inefficiencies, that suggests that actual Isp at 750 psi would be around 90 seconds.

I doubt that a 10-15% increase is worth the trouble of developing the technology, especially for a motor company.

 

[shockie]

There has been a lot of discussion about these motors. When I started in rocketry we could buy the B3 (later B14) motors and I did use them occasionally but most of our rockets back then were relatively small so they weren't needed. I did use them in my Astron Ranger cluster rocket for heavy payloads. I've read that the motors were manufactured by drilling out the holes after the motors were manufactured. I don't see why they couldn't still make them, they would just cost more. Maybe there isn't enough enthusiast market to justify it. You can't even buy a C5 at Hobby Lobby so they likely wouldn't have a more expensive core burner either. A core burner D or E would be awesome.

The major problem with BP core burners, is that they operate at higher chamber pressures. The mechical bond between the pressed clay nozzle and the paper engine casing, just isn't strong enough to contain the higher chamber pressures, resulting in the nozzle being forcibly ejected.

Instead of using 75/15/10 fast BP, it might be feasible with slow BP, i.e. 60/30/10.

But then you are reducing the Isp.

Now if you placed a paper cased BP slug into a CFRP casing that can contain higher chamber pressures, you'd be good to go.