Estes core burners?

[jim fustini]

Why did Estes stop production of core burner motors like the B-14?
Do you think they would ever make them again?

 

[gpoehlein]

Why did Estes stop production of core burner motors like the B-14?
Do you think they would ever make them again?

Estes discontinued them because they were dangerous to make - They had to be hand drilled after they were filled. And, according to John Boren from Estes, the answer is a solid "NO". These motors will not ever be produced again at Estes.

 

[mwtoelle]

I think that Estes stopped production of the B14s because of the extra step of drilling out the core was too time consuming and expensive. They were always more expensive than the regular B6 and B4 motors.

 

[edwinshap1]

yeah, drilling BP grains is a fun way to get a 3rd degree burn

 

[luke strawwalker]

There is such a thing as pressed "cored" motors, using a longer pintle tooling than that used to make the propellent grain end "dimple" found in Estes engines, but it's not particularly amenable to machine production methods used for mass produced motors... and the pressing is very hard on the tooling.

Estes motors had the core hole physically drilled through the propellant grain, which was dangerous. That's why you won't see them anymore.

I WOULD like to see the return of some of the "deeper dimpled" semi-coreburner motors like the C5 though... those could be mechanically made. As for true coreburners I think you can pretty well forget about those unless they're either brought in from say China or somewhere else. I don't think any US company will take the risks to manufacture them. If you want a coreburner you'll have to go with the much safer and simpler to manufacture APCP motors.

I doubt we'll be seeing even the 'semi-coreburners' again either... I just doubt Estes will want to spend the time and money to bring them back (much as I'd like to be proven wrong... )

Later! OL JR

 

[GDJ]

I always thought of the B-14's as "Rocket Rippers". If you built it right, the rocket just ripped thru the air. IF you didn't, the fins ripped right off.

 

[MarkII]

I always thought of the B-14's as "Rocket Rippers". If you built it right, the rocket just ripped thru the air. IF you didn't, the fins ripped right off.

I knew about them, but I never got to see any back in the B14's heyday. (I couldn't afford them.) Was the ignition and motor burn visibly different from regular B motors? These "super motors" were still, after all, just B motors.

 

[GDJ]

From what I remember they pretty much dumped their power within .25 seconds, give or take a little bit. It was all impulse, just a really powerful kick right off the launch pad.

I built a rocket in my early teens using a B14-0 as a booster. The entire burn was over within 50 or so feet, but it got there in a real FAST hurry. I wish I could recover some of the graphs and show them here.

 

[RadManCF]

So in what time period were these motors available? I've been into rocketry for about ten years now and I've never seen them.

 

[cavecentral]

The B14s I have are in the Estes Blue diamond packs (B14-0s, 5s, 7s). I think they are 70s. Also have some in centuri boxes (B14-0).

Not sure which other eras they existed in.

 

[GDJ]

I saw them as late as 1985 up here. Not sure after that tho'.

 

[gpoehlein]

The B14 motors were discontinued in 1980 (79 is the last catalog they appear in. If you go back to the 1964 catalog, you'll find B3 motor listed that is what became the B14 (in '64, they were still labeling motors using the english system, so with the new labeling system, the B.8 became the B6 and the B3 became the B14). You can tell that the B3 was what became the B14 because it is noted as a Series II motor, whereas the B.8 was a Series I motor. Series I is the standard motors (A8, B4, B6, etc.) while Series II was the core burner (B14). For history's sake, there was a Series III motor, which were the same as series I but labeled S for short - for example, the A8-3S was the same as the A8-3 except that it was one inch shorter (1.75" instead of 2.75"). The Series III short motors were discontinued in 1973 when the mini motors (such as the A10-3T) came out.

 

[shreadvector]

The B14 motors were discontinued in 1980 (79 is the last catalog they appear in. If you go back to the 1964 catalog, you'll find B3 motor listed that is what became the B14 (in '64, they were still labeling motors using the english system, so with the new labeling system, the B.8 became the B6 and the B3 became the B14). You can tell that the B3 was what became the B14 because it is noted as a Series II motor, whereas the B.8 was a Series I motor. Series I is the standard motors (A8, B4, B6, etc.) while Series II was the core burner (B14). For history's sake, there was a Series III motor, which were the same as series I but labeled S for short - for example, the A8-3S was the same as the A8-3 except that it was one inch shorter (1.75" instead of 2.75"). The Series III short motors were discontinued in 1973 when the mini motors (such as the A10-3T) came out.

Was there ever an A8-3S ??? The shorty motors used the original super thick casings and so a fully loaded motor was a B (B4). An A motor (A5) waws only half filled, and so to eliminate the dead weight of the super thick and empty casing, they cut off 1 inch.

When thinner and stronger casings came out, they were able to make the A8, the B6 and the C6 motor. They continued the A5 and B4 line even for a while after the new thin walled mini motors arrived, but eventually the A5 was dropped and the B4 was re-engineered for the new thin walled casing.

 

[Rocketjunkie]

I'd love a full core burning C30(?)-0 :smile:

 

[MarkII]

Estes started listing the Series II B14 (called the B3 then) in 1964. Here is the time/thrust curve for it from the 1967 catalog. The 1979 catalog was the last one to list them. In 1980 they were replaced by the semi-core burning B8 and the new C5. These were also listed as Series II engines. The B8s were discontinued around 1997 and the C5s were made until around 2001.

I knew that it had a real quick burn, but I was just curious about the experience of launching B14s. On a Farside or Farside-X, for instance, where did the first staging event occur? It must not have been very high up at all, right?

 

[JStarStar]

I may have one of the world's largest stashes of B14-0's -- a lawn/equipment/toy store near me had an old dusty dingy aisle of rocket stuff way in the back of the store, and a couple years ago I went back there and lo and behold found nearly a full carton of old blue-diamond pack Estes engines. I think something else was stacked on top of them. There were 30 or so 3-packs of B14-0's and a dozen or so other scattered engine types. There was a date on the carton that said 1974.

They had obviously sat there for several decades -- there was a thick coating of dust on top of the carton -- so I offered the manager some nominal sum to take them off his hands (a dollar a pack, I think). He said "fine" so I tossed him the bills and I walked out the door. He said, "those are way out of warranty so if they are all duds, no returns. " I said, "I'll take my chances."

I've only got three or four staged rockets in my current fleet, so it may be some time until I burn through 'em all. I've used maybe a dozen or so of them and they've all fired just fine -- no ignition or staging problems.

They do have a very interesting flight profile. You push the button, and whoosh-whoosh, the second stage is burning away through its thrust phase.

The booster rarely lands more than 20-30 feet from the pad. But the B14's do boot those rockets up off the pad and into the air in a hurry. I don't remember exactly (look at the thrust-time curve in Mark II's post) but I think burn time for the B14's is .028 seconds or something like that.

They're cool because you can see the whole staging process -- second stage ignition is rarely more than 30-40 feet off the ground. I haven't yet launched a 3-stager on B14-0's but I would guess second-stage separation would not be REAL high. But that third stage would probably get some altitude.

It would be cool if Estes, or somebody, would make B14's (and probably for that matter, C16's, too) but from the sounds of things the mechanical and production problems involved make it pretty impractical for what would be a very specialized product.

Although... they DO make both the A3 and the A10 mini-engines. The process has to be at least somewhat similar.

 

[gpoehlein]

Was there ever an A8-3S ??? The shorty motors used the original super thick casings and so a fully loaded motor was a B (B4). An A motor (A5) waws only half filled, and so to eliminate the dead weight of the super thick and empty casing, they cut off 1 inch.

When thinner and stronger casings came out, they were able to make the A8, the B6 and the C6 motor. They continued the A5 and B4 line even for a while after the new thin walled mini motors arrived, but eventually the A5 was dropped and the B4 was re-engineered for the new thin walled casing.

You're right - it was the A5-2S. I never got any of them at the time (by the time I started flying no 1973, the short motors were discontinued and I never got any). What I was trying to point out, however, was that the short motors were the same as the regular motors, but just an inch shorter.

 

[Daddyisabar]

I know this guy who got some unmarked 18mm core burners from an estate of an old rocket dude. He could not even use plastic D plugs the nozzles were so big. The clay cap was at the very back of the tube and you had to use a vintage Estes igniter or a copperhead or one of those new fangled Q2's to light 'em off. He took these motors to a run of the mill rouge launch and for some reason his rockets that flew like poo on a C6 were ripping off the pad nice and straight. Finally he was happy with his Galactic Wave and Hostile Projectiles V2, and the Night Whisperer never looked or flew better. And none of the hot ejection charges of a D21 AP motor to char a thin tube or melt LPR plastic! One of the on lookers asked where he could get some of these motors and the guy I know simply said "prison."

That guy went to another rouge launch and and another old rocket dude who remembered the B-14 and who was acting like the LCO really wanted some of these motors and asked the guy I know if he could spare a few. The guy I know went back to his car and brought back a 1972 black Samsonite brief case and when he opened it a gold light shown out just like the case Jules had in the movie Pulp Fiction. I looked in and said "Is that really what I think it is . . . it is beautiful!" . . . That part is the only honest and truthful part to this whole post.

Anyway, the guy I know gave the old LCO dude some of the motors and you would have thought it was Christmas morning times two! A real blast from the past that will not often be repeated in the future as BP and a drill press don't mix. Too bad this was just a dream and never really happened, but it does make for a good modern story of core burning BP motors.:wink:

 

[MarkII]

I know this guy who got some unmarked 18mm core burners from an estate of an old rocket dude......

I looked in and said ...

That part is the only honest and truthful part to this whole post.

Cool story, bro!

 

[jim fustini]

I'd love a full core burning C30(?)-0 :smile:

CTI makes an F-240 V-max 24mm I have the hardware and reloads But I have yet to build a rocket to handle it . ( I will this winter) I seen one fly at my local club launch. It is one crazy little motor!:y:

 

[Rocketjunkie]

CTI makes an F-240 V-max 24mm I have the hardware and reloads But I have yet to build a rocket to handle it . ( I will this winter) I seen one fly at my local club launch. It is one crazy little motor!:y:

I flew 2 F240's in a Viper IV (airstarting 2 D12's). Lots of fun

 

[RadManCF]

There is such a thing as pressed "cored" motors, using a longer pintle tooling than that used to make the propellent grain end "dimple" found in Estes engines, but it's not particularly amenable to machine production methods used for mass produced motors... and the pressing is very hard on the tooling.

Why is it not amenable to mechanization, and how is it hard on the tooling?

 

[[POW]Eagle159]

Why is it not amenable to mechanization, and how is it hard on the tooling?

Heat?



Did the B14 need any special igniters? like the composite engines?

 

[jim fustini]

Why is it not amenable to mechanization, and how is it hard on the tooling?

I would ask the same. I could see the cost for mass production, and paying off the overhead to make a profit. But the ware on tooling?

 

[RadManCF]

Heat?

I was asking about pressing the core into the grain, rather than drilling it out. Unless you're saying that pressing the core into the grain produces an exceptional amount of heat.

 

[[POW]Eagle159]

I was asking about pressing the core into the grain, rather than drilling it out. Unless you're saying that pressing the core into the grain produces an exceptional amount of heat.

But will pressing it into the core over and over very quickly keep a nice constant shape? I have no idea but just a thought...

 

[RadManCF]

But will pressing it into the core over and over very quickly keep a nice constant shape? I have no idea but just a thought...

Well, Estes is able to press dimples into BP grains at high speed, how would a core be different? I've looked at some other posts on this same subject, and it is apparently possible to press cores into BP grains using a hand press, Why shouldn't it be possible in an automated machine? My first guess would be space constraints in the Mabels...

 

[[POW]Eagle159]

Well, Estes is able to press dimples into BP grains at high speed, how would a core be different? I've looked at some other posts on this same subject, and it is apparently possible to press cores into BP grains using a hand press, Why shouldn't it be possible in an automated machine? My first guess would be space constraints in the Mabels...

I think someone will have to help us on why it is soo unsafe to core BP...

 

[RadManCF]

I think someone will have to help us on why it is soo unsafe to core BP...

While we're at it, does anyone know of any websites that describe the workings of the Mabels?

 

[[POW]Eagle159]

While we're at it, does anyone know of any websites that describe the workings of the Mabels?

Marbels?