What was the deal with Estes Big Daddy nose cones?

[Hobie1dog]

How many Door Knobs are lawn darting? NCR Big Brutes ?

i didn't know the Big Brute used the same NC. I like that rocket.

 

[Sooner Boomer]

BMS makes a nosecone very similar to the one used in da Daddy. It's slightly longer, and has more "cylinder", less "angle" at the base. I've replaced the (broken/pranged) nosecones on my Big Daddy and Bash Daddy with BMS.

 

[cwbullet]

Absolutely. I have everything to build another one in my parts bin minus a nose cone.

What size motor?

 

[Back_at_it]

What size motor?

29mm

 

[gldknght]

After reading a bunch of these posts, as well as the fb posts from Steve Kristal and Matt Steele, I cannot buy into the theory that the issues with the big Daddy are in any way due to a weak ejection charge.
Some rough math for the volume of a cylinder:

The internal volume of the unmodified Big Daddy to be pressurized by the ejection charge:

3"(internal length with nose installed) X 1.45"^2 (internal radius of bt) X 3.14 (pi) = 19.82 cubic inches

For comparison,
The internal volume of my Estes Super Neon XL (unmodified)
20" X 0.78^2 X 3.14 = 38.35 cubic inches

I've never had any issues getting my chute out on my Super neon xl, even though it has almost DOUBLE the internal volume. It does have a flat bottom balsa nose, though.

I'm still in the planning stages before building my first Big Daddy, so don't have any personal experience with this rocket, but I can say for sure I won't be building it stock.

 

[tsmith1315]

I don't see where anyone has done ground testing with variations in charge sizes and tightness of fit in an attempt to duplicate the problem.

Wouldn' that be a logical approach? Perhaps it was discussed on FB, I'm not there. I don't have one, but I've flown many kits over the years with that type of nosecone shoulder and no issues.

 

[SolarYellow]

If you buy K'Tesh's drag separation theory, a useful set of ground tests might be to insert the nose partially with increasing increments of gap opened up and see where the gap gets too big and allows the charge to escape without ejecting the nose.

 

[gldknght]

I don't see where anyone has done ground testing with variations in charge sizes and tightness of fit in an attempt to duplicate the problem.

Wouldn' that be a logical approach? Perhaps it was discussed on FB, I'm not there. I don't have one, but I've flown many kits over the years with that type of nosecone shoulder and no issues.

The problem with that is, we don't know how much bp Estes uses in the D motor ejection charges. To get an accurate sample, you would have to cut up at least three, preferably five or six from several different batches. Way too much money for most of us. Modifying the Big Daddy nose cone is much much cheaper.

 

[green dragon]

even if the partial drag seperation theory is correct, should still deploy ok if the wadding / chute protector makes an adequate seal - charge should NOT blow past the chute protector and escape without the chute being pushed out, even if nosecone was all the way off.

 

[gldknght]

No way you're ever going to get that good a seal with just wadding or a chute protector.

And the chute, protector, or wadding will never get pushed out if the nose cone is in the way, as it would be if it only partially separates from the body, whether its due to drag sep or due to venting the pressure due to the angled shoulder.

 

[tsmith1315]

The problem with that is, we don't know how much bp Estes uses in the D motor ejection charges. To get an accurate sample, you would have to cut up at least three, preferably five or six from several different batches. Way too much money for most of us. Modifying the Big Daddy nose cone is much much cheaper.

True, but it's still surprising that someone hasn't gone there.

I'd do it if I had a BD. Somebody here knows the BP charge size in a D12, surely.

 

[86mustang408w]

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I was looking through the threads, I bought 2 or 3 Big Daddys and always had an issue with ejection. I just bought another, I'm gonna have to do something like this. I didnt read thru all the thread yet but how did it work out?!

 

[MALBAR 70]

I was looking through the threads, I bought 2 or 3 Big Daddys and always had an issue with ejection. I just bought another, I'm gonna have to do something like this. I didnt read thru all the thread yet but how did it work out?!

Worked out excellent, I haven't had an ejection failure with either of my BD's since I did that.

 

[86mustang408w]

Worked out excellent, I haven't had an ejection failure with either of my BD's since I did that.

Yeah, they are cool little rockets! I'm working on a L1 cert build now, but I was thinking a 29mm in one, but you have to almost make it longer or put a coupler or body tube in the nosecone for the chute and make it slide into the main body like a forward section....I think I just gave myself an idea...

 

[Art Upton]

i didn't know the Big Brute used the same NC. I like that rocket.

Big Brute and AeroTech 4" nose cones have an angle on them.

AeroTech 2.6 Nose cones have an angle on them.. No Media on those issues.

What about Leviations , they have an angle... Issue is too loose or too tight

 

[K'Tesh]

Big Brute and AeroTech 4" nose cones have an angle on them.

AeroTech 2.6 Nose cones have an angle on them.. No Media on those issues.

What about Leviations , they have an angle... Issue is too loose or too tight

Leviathan's airframes have more mass and less drag than the BD... Thus less problems with drag separation.

 

[Art Upton]

Leviathan's airframes have more mass and less drag than the BD... Thus less problems with drag separation.

It is all about Nose Cone Fit, simple and pure as it always was for decades

 

[SolarYellow]

Leviathan's airframes have more mass and less drag than the BD... Thus less problems with drag separation.

Longer body tube gives more friction drag and bigger fins give more drag in all the ways they do. So I reckon it's more about the mass, or the ratio of mass to drag.

 

[bjphoenix]

Longer body tube gives more friction drag and bigger fins give more drag in all the ways they do. So I reckon it's more about the mass, or the ratio of mass to drag.

I always thought there would be a lot more drag on the nose cone than on the rest and thus the nose cone would not drag separate, then we had lots of discussions about applying the base drag hack in sims so I don't know what the true answer is.

 

[SolarYellow]

The Big Daddy and Leviathan use the same tube, so the base drag will be identical, except for any base drag generated by the fins, which will be infinitesimally greater in the case of the Leviathan, depending on how the TEs are shaped by the builder.

 

[icyclops]

After reading a bunch of these posts, as well as the fb posts from Steve Kristal and Matt Steele, I cannot buy into the theory that the issues with the big Daddy are in any way due to a weak ejection charge.
Some rough math for the volume of a cylinder:

The internal volume of the unmodified Big Daddy to be pressurized by the ejection charge:

3"(internal length with nose installed) X 1.45"^2 (internal radius of bt) X 3.14 (pi) = 19.82 cubic inches

For comparison,
The internal volume of my Estes Super Neon XL (unmodified)
20" X 0.78^2 X 3.14 = 38.35 cubic inches

I've never had any issues getting my chute out on my Super neon xl, even though it has almost DOUBLE the internal volume. It does have a flat bottom balsa nose, though.

I'm still in the planning stages before building my first Big Daddy, so don't have any personal experience with this rocket, but I can say for sure I won't be building it stock.

It’s not. It’s a cone problem. trim the cone bottom to 1.5 to 2 inches and glue a flat bulkhead with eye hook in it. It works and the nose cone will eject. If it really was an ejection charge issue models like the super big Bertha would have major issues with ejection and they don’t.

 

[gldknght]

It’s not. It’s a cone problem. trim the cone bottom to 1.5 to 2 inches and glue a flat bulkhead with eye hook in it. It works and the nose cone will eject. If it really was an ejection charge issue models like the super big Bertha would have major issues with ejection and they don’t.

Agreed. I just thought I'd "follow the science" or in this case, "the math". I think I'm going to put a piston in mine, since I already have the parts.

 

[Gunstar]

Has anyone 3D printed a replica NC without the slope? If so, I’d be interested in the file.

Its an ogive shape, right? How long is the shoulder part and how long is the nosecone part? I might be able to whip one up quick.

 

[CoolRockets]

I will be receiving a new Big Daddy kit to work on soon to help fight off boredom

But I remembered there was some sort of issue with the nose cone of this model.

I did a brief search and found lots of 'yes I modded my nose cone' but no real examples of what was actually done.

Thanks in advance

Yeah I’ve had similar problems, my first big daddy after the first launch, the nose cone just would not come off to the point I would just put the motor in and BOOM, divebomb. Although I have recently retired it after 67 flights over the course of 2014-2022

 

[Rex R]

3:1 ogive 9" Xposed cone 3" shoulder and bobs your uncle a patriot nose cone or, 4:1 conical(12" exposed) cone and you have an nc for a wac corporal

 

[SolarYellow]

Just to be pedantic about the scale info, an M104 Patriot nose cone has a fineness ratio of 2.70:1 if compared to the payload, and 2.63:1 if compared against the full diameter of the motor section.

Sounding rockets with 3:1 or really close to it include:

• Black Brant VC w/Saab guidance payload (Alway 1999)
• Doorknob (duh)
• Terrier-Malemute
• Nike-Tomahawk

 

[bjphoenix]

It’s not. It’s a cone problem. trim the cone bottom to 1.5 to 2 inches and glue a flat bulkhead with eye hook in it. It works and the nose cone will eject. If it really was an ejection charge issue models like the super big Bertha would have major issues with ejection and they don’t.

 

[Gus]

I will repeat here what I said on Facebook 3 years ago. There are over 400 flight logs of the Estes Big Daddy on Rocketreviews.com. Not a single crash listed. And none listed since my comment 3 years ago. It just amazes me that this supposed "big problem" keeps showing up on social media, generating tons of explanations, pontifications, and solutions, yet one of the biggest launch databases available for any rocket ever sold doesn't mention a single crash.

Estes has been selling the Big Daddy to anyone who wants to buy one, no special skills required, for 25 years now. They've never felt the need to modify the nosecone or the instructions.

If you want to modify the Big Daddy nosecone, modify away. But please don't claim that it's necessary. There's just no data that that's true.

 

[Gunstar]

Here is a quick Big Daddy nose cone model. Not print tested or compared to a real one. Let me know if it needs any changes.

Printables

www.printables.com

 

[icyclops]

What do you mean no data…if rocketeers are still having problems with nose cone ejection on the BD then that in itself is data enough. I have built 4 BDs over the years so far and 3 out of the 4 experienced this problem until I modified the cone. I believe the 4th model had either a little bit wider body tube or the cone was a smaller (looser) diameter for some strange reason….probably Estes’s quality control.
Which brings me to my last point. Just because a launch data base does not have a record of BD cone ejection problems does not mean it does not happen. Proven that it does so since its not on that so called data base begs the question how accurate it really is…Pontificate away…ya baby!

Estes has designed and produced many kits that have questionable problems due to many factors…. :0