New Estes BP Motor - E12

Estes has released a new BP motor, the E12.

The stats are attached.

Its thrust curve is similar to the D12, except it burns for another second.

Thanks goes to Gus posting the NAR data on YORF and Thrustcurve.org for the cool data tool to draw out the curve.

Greg

; NAR Date Tested ...: 2011-09-25
; Total Impulse .....: 27.24 n-s (s 0.35)
; Peak Thrust .......: 33.29 n (s 3.49)
; Burn Time .........: 27.24 n-s (s 0.35)
; Average Thrust ....: 11.17 n
; Exported using ThrustCurveTool, www.ThrustGear.com
; Exported by .......: Greg Gleason
; Export Date .......: 2011-10-30

E12 24 95 0-4-6-8 0.0359 0.0588 ES
0.017 2.222
0.064 6.519
0.103 11.556
0.163 19.704
0.202 25.481
0.245 31.259
0.284 32.889
0.296 30.667
0.309 27.407
0.331 20.889
0.352 15.407
0.387 13.333
0.464 11.852
0.657 10.667
0.842 10.37
0.889 9.778
1.125 10.074
1.297 9.481
1.323 10.37
1.336 9.481
1.74 9.333
2.04 9.185
2.143 9.185
2.174 10.222
2.199 9.481
2.332 9.63
2.371 9.926
2.397 6.222
2.431 2.222
2.44 0.0

Click to expand...

View attachment EstesE12.pdf

View attachment Estes.E12.eng

Any idea when it will be available?

My "guess" (and it's just that) is by around Christmas time, or by 1Q-2012. I'll see if I can find out something that's a little more accurate.

I think that this motor will be better for anyone's E9 birds that are somewhat marginal on that motor. I'm looking forward to hearing launch reports in that regard.

Greg

I'm definitely never flying my Saturn V on an E9 again!

I'm looking forward to trying it.

its not listed in the "coming soon" section of the Estes website. I'd love to give them a try if/when they come out. I'm rebuilding my Sunward payloader to take 24mm motors and I'd love to loft it on one of those!

thanks for the eng file.
ran some sims on my mega mosquito...
engine,alt(in feet),max speed(mph),speed off pad(mph)
D12-5, 539, 132, 60.5
D15t-5, 613, 161, 83.8
E9-6, 877, 165, 47.8
E12-6, 885, 174, 64.7
E15W-7, 1241, 232, 72.4
E18W-7, 1145, 247. 81
F12J-5, 1278, 245, 68.8
rod length 39.37inches.
at first glance there appears to be little difference between the E9 & E12...its when one looks a little deeper that the differences really show, I would not like to use the E9 in this bird(it weathercocks enough on a D12).
rex

Any idea if this will replace the E9 or be a compliment to it?

I don't know.

AFAIK, Estes has yet to acknowledge their existence (publicly).

Greg

Ive lost/damaged too many of my larger rockets to ever trust an E-9 again.

dhurstell said:

Ive lost/damaged too many of my larger rockets to ever trust an E-9 again.

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There is never a need to "trust" any motor. you simply look at the specs and at your rocket liftoff weight fully loaded and the type of rod you are using and the wind. You choose based on science.

And the number after the dash is the delay time, so if you used an E-9, you may have had a problem.....

GregGleason said:

I don't know.

AFAIK, Estes has yet to acknowledge their existence (publicly).

Greg

Click to expand...

They probably aren't too happy that we announced the certification because now everybody is going to start asking when they're going to be available. S & T has to (it's in our rules) announce certification in no more than a month after the motors are certified. I was ready to buy a bunch while the ones we tested were still warm.

My TLP Perseus is gonna like that motor!

DAllen said:

My TLP Perseus is gonna like that motor!

Click to expand...

My Vagabond and Magnum Sport Loader is gonna love these too!

GDJ said:

My Vagabond and Magnum Sport Loader is gonna love these too!

Click to expand...

I was just thinking about the Vagabond and Eliminator, both would do well with this motor. But I had an E9-6 CATO in an Aspire:

I would hate to see that happen to the odd size BT of the Eliminator. Would have to start over with that.
I guess that the larger BP motors are prone to cracks, and when they crack, they go BOOM!

shreadvector said:

There is never a need to "trust" any motor. you simply look at the specs and at your rocket liftoff weight fully loaded and the type of rod you are using and the wind. You choose based on science.

Click to expand...

That may be true.... however Estes has recommended the E9 for a few kits it's pretty marginal in. And the listed max liftoff weight is pretty optimistic. The chart shows 12 oz max for the E9-6. I've had 10oz birds bury their nose in the dirt a second or two before the charge blew. There's a million different factors in every crash.... But the E9 is pretty low thrusting. Add in marketing lines like

"This Big Daddy is a real head-turner at the launch field! It's been redesigned to handle our super powerful E engines so it will fly over twice as high as it used to."

And it's easy to see why people have issues.

I can't wait to see the E12's roll onto shelves...

Any word on length?

DizWolf said:

... Any word on length?

Click to expand...

95 mm.

Greg

I've got an old Pro-Series Maxi-Force that should do well on those. Also an ARG Trident-24. Hope they get them tested & authorized by ERD so us Canucks can get our mitts on them!

Interesting. According to my copy of OpenRocket, this new motor does better as a booster than a upper stage engine. Best apogee I got for the Vagabond and Magnum (simulated) used a E12-0 booster and a E9-8 for the upper stage. The E12 for the upper stage is consistently lower by 75 metres.

i would assume its because the E12 has a higher propellant mass, so lifting it will lower the total alt, and the big impulse kick isn't that important once you're past 15 m/s

Yeah, probably right on that.

Hmmmm...hopefully this will allow the Interceptor 'E' to actually fly with an Estes 'E' motor...

FC

Rex R said:

thanks for the eng file.
ran some sims on my mega mosquito...
engine,alt(in feet),max speed(mph),speed off pad(mph)
D12-5, 539, 132, 60.5
D15t-5, 613, 161, 83.8
E9-6, 877, 165, 47.8
E12-6, 885, 174, 64.7
E15W-7, 1241, 232, 72.4
E18W-7, 1145, 247. 81
F12J-5, 1278, 245, 68.8
rod length 39.37inches.
at first glance there appears to be little difference between the E9 & E12...its when one looks a little deeper that the differences really show, I would not like to use the E9 in this bird (it weathercocks enough on a D12).
rex

Click to expand...

Looks like your "off rod speed" is 17 mph or 27% faster with the E12-6 vs. the E9-6. Could make a significant difference in terms of flight stability and resistance to weathercocking while clearing the rod.

I have a Maxi-series V-2 (Bumper-WAC) and a 1/100 Saturn V, and they both chug, chug, chug off the rod on E9-4's, and usually reach apogee and nose over slightly before burnout due to the very low sustaining thrust (I am sure both are significantly over 'book weight', especially the V-2, which has putty in the fin fillets, the dummy 'WAC', etc etc).

As a result ejection is usually at a teeth-grinding 20-30 feet off the ground -- just high enough to get the laundry out. The knowledge that ejection delays are sometimes off as much as a second or more is not encouraging. :y:

They fly a little straighter, and a little lower, on D12-3's, also resulting in very low ejections.

E12's could be a good option to address this problem. Of course composite motors are an option but also very expensive.

edwinshap1 said:

i would assume its because the E12 has a higher propellant mass,

Click to expand...

It has .1g more.

billspad said:

It has .1g more.

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E12 has more mass than D12 for lifting the upper stages of a multi-stager. Total rocket mass will be greater.

Correct me if I'm wrong, but the thrust curve shows more impulse for the E12, than a D12. Seems to me that it would be suitable for just about anything and better for what a normal E9 would do.

FastCargo said:

Hmmmm...hopefully this will allow the Interceptor 'E' to actually fly with an Estes 'E' motor...

FC

Click to expand...

Mine has flown all its flights on E9 motors, all have been great. Here's an example.

[YOUTUBE]OeEpU-_2Iy8[/YOUTUBE]

kj

kelltym88 said:

Correct me if I'm wrong, but the thrust curve shows more impulse for the E12, than a D12. Seems to me that it would be suitable for just about anything and better for what a normal E9 would do.

Click to expand...

Exactly. This may be the reason Estes made this motor, but that's just speculation on my part.

Greg

Same size engine casing as the E9, so... why didn't Estes just produce an E12, to begin with?

It would've saved a lot of heartache, watching Maxi V2's lawn dart.

I, for one, hope that they do NOT get rid of the E9. With the right rocket, that long burn is great. Sure it's low thrusting, but if the numbers say it won't safely lift your rocket and you have a "sub-optimal" flight, don't blame the motor!

The only problem I ever had with E9's was having all 3 motors in a cluster pop their nozzles out at ignition. You think the burn time is long normally? Try it with no combustion chamber pressure!:y: Quite painful to watch your rocket burn on the pad for SOOOO long.

-Ken