John Boren Interview On The Model Rocket Show

[smstachwick]

Sorry if that sounded a little snarky. That wasn't my intention.

Wasn’t trying to admonish you, just provide helpful information. From my perspective, you’re good.

 

[Daddyisabar]

It's a core-burning BP motor. I got to try a prototype after getting it at NSL last year. OH. MY.

FlightSketch -

flightsketch.com

I witnessed another E57 8 test flight today at SCORE and I would give it a George Takei level "OH MY!" Big nozzle for huge gap staging, massive flash pan ignition, rack rockets, ripping off the pad minimum diameter and silly oddroc clusters! 24mm clustering fun. Please Santa, have the Elves put it in production, booster and all levels of delay.

 

[smstachwick]

E57-2, that would be neat to see something that could work on one of those.

Are we confirmed that it’s an E57 specifically?

(Minor edits)

 

[SecondRow]

E57-2, that would be neat so see something that could work on one of those.

Are we confirmed that it’s an E57 specifically?

Yes, and 24 mm. John Boren confirmed it on YORF. Post #26.

Ye Olde Rocket Forum - John Boren Interview On The Model Rocket Show

Ye Olde Rocket Forum is for the discussion of old model rockets.

forums.rocketshoppe.com

 

[BEC]

The prototype motors John referred to in that show (and the one that he gave me at NSL last year, the flight of which is mentioned above) are hand-marked E57-8. I imagine the official designations will come out of further testing, both at Estes and by the certifying group (NAR or Tripoli). I have some beta-test Q-Jets that are marked C19. These were early White Lightning C impulse Q-Jets that are now being sold as C18s.

So I wouldn't say "E57" is cast in stone (or catalog print) just yet. But it certainly will be in that neighborhood somewhere, I expect.

 

[Daddyisabar]

Looks like a standard ole E9 or E12 until you get a look at the hind end. Stick yer pinky finger in the nozzle! Just a thin ring of poopy clay around the edge of the casing! Core burning black powder awesomeness!

 

[Daddyisabar]

Forget your Shake and Bake E9 and E12 CATOS . Now you have the Magic Man E57. NOW YOU SEE ME...NOW YOU DON'T! Like Ricky Bobby says: "That's just plain awesome!"

 

[BEC]

Looks like a standard ole E9 or E12 until you get a look at the hind end. Stick yer pinky finger in the nozzle! Just a thin ring of poopy clay around the edge of the casing! Core burning black powder awesomeness!

You ain't kidding.

Here's the aft end of my Eliminator after that flight. John's comparing these to Vmax motors in the podcast is not too far off the mark....

 

[smstachwick]

You ain't kidding.

Here's the aft end of my Eliminator after that flight. John's comparing these to Vmax motors in the podcast is not too far off the mark....

View attachment 538087

Indeed. The Vmax E motor was the E75. Next highest thrust is the snagged-up Quest E35W, followed by the readily-available CTI E31.

 

[lakeroadster]

Just curious: where can I get the episode? It doesn’t appear to be on the show’s website, Apple Podcasts, Spotify, or Google Podcasts.

[The Rocketry Show] Episode #39: John Boren from Estes​

 

[kuririn]

I wonder if that E57ish will come with a HAZMAT fee?

 

[Alan15578]

I wonder if that E57ish will come with a HAZMAT fee?

It was revealed on YORF that this will be 30 gram propellant HAZMAT free low end E. I'm waiting to see if it gets contest certified such that we can fly E57-D12-7 in say E DEL? There also seems to be a 29mm PB core burner in development.

 

[smstachwick]

[The Rocketry Show] Episode #39: John Boren from Estes​

Thank you, I found it a bit earlier.

 

[jmasterj]

It was revealed on YORF that this will be 30 gram propellant HAZMAT free low end E. I'm waiting to see if it gets contest certified such that we can fly E57-D12-7 in say E DEL? There also seems to be a 29mm PB sore burner in development.

I figured it would be a pretty small E. The E12 is only 27Ns, so if this uses the same case it must have less propellant to be a core-burner. Maybe 23Ns or so? Puts the burn time around .4 seconds.

 

[smstachwick]

I figured it would be a pretty small E. The E12 is only 27Ns, so if this uses the same case it must have less propellant to be a core-burner. Maybe 23Ns or so? Puts the burn time around .4 seconds.

So did I. I ran a few simulations with an idealized E57 (nearly-square thrust curve) in a Hi-Flier XL based on precisely these assumptions. Hopefully we’ll get more useable data on the thrust curve and the like soon.

For those curious, the liftoff speed nearly doubles compared to an E12. Almost 60mph off a 1 meter rod, and not much less for a two-stager.

 

[BEC]

I figured it would be a pretty small E. The E12 is only 27Ns, so if this uses the same case it must have less propellant to be a core-burner. Maybe 23Ns or so? Puts the burn time around .4 seconds.

So did I. I ran a few simulations with an idealized E57 (nearly-square thrust curve) in a Hi-Flier XL based on precisely these assumptions. Hopefully we’ll get more useable data on the thrust curve and the like soon.

For those curious, the liftoff speed nearly doubles compared to an E12. Almost 60mph off a 1 meter rod, and not much less for a two-stager.

Not quite square. Here's a screenshot of the accelerometer data from the flight of my Eliminator (see post 22 above). The data also show a marked 8s delay that was actually ~7.8s. Pretty good. I've had some B6-4s lately with 2.5s delays, so much better than that.

 

[rharshberger]

Not quite square. Here's a screenshot of the accelerometer data from the flight of my Eliminator (see post 22 above). The data also show a marked 8s delay that was actually ~7.8s. Pretty good. I've had some B6-4s lately with 2.5s delays, so much better than that.

View attachment 538132

And the burn time looks to be in the .3 to .4 second range, das V-max territory.

 

[BEC]

Yup. Ignition (or first acceleration above a static 1G) at 0.06s and burnout (or when the acceleration curve crossed below 1G) at 0.44s. Peak acceleration 26.7 Gs.

 

[SolarYellow]

A widely available 29mm nosecone is pretty exciting!

This. Estes nose cone pricing and weight combined with Estes BT weight makes long-burn, MD 29mm very interesting.