Big Bertha Nose Cone

[LakeWobegonMN]

Hi folks!

New member here and first post...just building a few rockets to have some fun with my kids. I haven't built/flown a rocket in at least 25 years! Great memories. Built an Alpha III, Big Bertha is in progress now, and Baby Bertha is in the mail. Plan to launch all 3 during our first session

I think I messed up the nose cone during painting just now. I painted that shoulder part that slides into the body tube. It's a little gloppy. I don't want to take any chances of it not ejecting properly. Can someone point me to the proper nose cone so I can get a new one? It's hard to tell online.

Thanks so much, and hopefully I'll be in here from time to time if it catches on with my kids...and if it doesn't, I still may keep up the hobby myself!

Alex

 

[David Schwantz]

Hi Alex. Great to get your kids into it. Mine flies with me also, he's 31.
Is your nose cone still wet? If so, some alcohol might just take off the paint and not hurt the plastic.
Here is a link to the Estes page. Good luck.

https://estesrockets.com/product/001948-big-bertha/

 

[trialsguy]

You could always just sand the paint on the shoulder area to get it to slip fit into the tube. If you’re not happy with the paint job on the exposed portion of the cone , you could sand and repaint.

 

[LakeWobegonMN]

Hello and thanks to both of you.

The alcohol suggestion worked well. The paint was partly dry but a light scraping to get it started, plus the alcohol got it pretty clean...I don't expect any problems. When the body tube is dry I'll test the fit out.

I like to overthink things! This was the first rocket that required any kind of assembly/painting. The Alpha III obviously required barely any work.

When the Baby Bertha arrives in a few days, we'll benefit from what we learned on the Big Bertha.

 

[kuririn]

As mentioned, you can remove the paint on the shoulder by sanding.
The nose cone is a PNC-60L (Estes part # 71020). Estes doesn't sell that separately.
If you really need the nose cone you can buy a kit like the Baby Bertha or Jetliner and scavenge the nose cone. You can use the rest of the kit for parts.
If you don't mind a slightly different shape you can get the balsa equivalent BNC-60L at erockets.
It's a bit shorter than the plastic.
Welcome to the forum.
EDIT: Whoops, too late.

 

[LakeWobegonMN]

As mentioned, you can remove the paint on the shoulder by sanding.
The nose cone is a PNC-60L (Estes part # 71020). Estes doesn't sell that separately.
If you really need the nose cone you can buy a kit like the Baby Bertha or Jetliner and scavenge the nose cone. You can use the rest of the kit for parts.
If you don't mind a slightly different shape you can get the balsa equivalent BNC-60L at erockets.
It's a bit shorter than the plastic.
Welcome to the forum.
EDIT: Whoops, too late.

Not too late thanks for the help and the welcome!

Can't wait to launch these 3. I got 6 engines...3 A8-3 and 3 B6-4.

My plan is 2 launches of each - the 2 A8-3 for the Alpha III, an A8-3 then a B6-4 for the Baby Bertha, and 2 B6-4 for Big Bertha. Sounds like a low risk/high chance of recovery set of launches for the kids' very first experience.

 

[David Schwantz]

Don't let the kids run and try to catch them. They usually get stepped on

 

[Cape Byron]

The nose cone is a PNC-60L (Estes part # 71020). Estes doesn't sell that separately.

And why they don't still escapes me. Such a commonly used cone for kitbashing, scratch building, Gooney cloning...

 

[markschnell]

And why they don't still escapes me. Such a commonly used cone for kitbashing, scratch building, Gooney cloning...

Because if they sell the NC separately you won't buy Baby Berthas anymore.

 

[Cape Byron]

Of course, silly me. Maybe I'll just start using Quest parts. Or balsa NCs.

 

[kuririn]

Because if they sell the NC separately you won't buy Baby Berthas anymore.

I've bought a few Baby Berthas, but never actually built a Baby Bertha.
They've all been kitbashed into something else.

 

[Cape Byron]

Unfortunately, Baby Berthas sell in Oz for ~$35 AUD, ($27 US) + freight. That's a lot for a nose cone...

 

[bwayne64]

Welcome Alex,
I always mask off the shoulder, but I leave about 1/8 open for paint. That way if there's any gap the color will show though. I sometimes have to put a little tape on the shoulder if its loose. And I agree they should sell the nose cones, but I get why they don't. The Almighty dollar ; )

 

[mikewrt]

Not too late thanks for the help and the welcome!

Can't wait to launch these 3. I got 6 engines...3 A8-3 and 3 B6-4.

My plan is 2 launches of each - the 2 A8-3 for the Alpha III, an A8-3 then a B6-4 for the Baby Bertha, and 2 B6-4 for Big Bertha. Sounds like a low risk/high chance of recovery set of launches for the kids' very first experience.

Yes those are all "lower risk" launches, remember it all depends on your field and conditions. An A8-3 in the Baby Bertha will go about 100 feet, the Big Bertha on the B about 200ish. Both great for kids they can see the whole flight.

Don't let the kids run and try to catch them. They usually get stepped on

Yes this is good advice. Even for the bigger kids.

 

[Senior Space Cadet]

Balsa Machining Service may have the nose cone in question.
PNC 80BB
They also have balsa versions:
BNC 80BB
BNC 80BBH
They have smaller ones if you ever want to make a smaller Big Bertha. In BT60 they have a long and short version.
I was going to give you the link to this nose cone at Apogee, but seems it's no longer there.

 

[Senior Space Cadet]

I was thinking it was Apogee that I got all my plastic Big Bertha nosecones from, but I get them directly from Estes.
https://estesrockets.com/product/003168-nc-80b-nose-cone-1-pk/

 

[kuririn]

PNC-80 is for the Super Big Bertha.
PNC-60 is for the Big Bertha.
As I said balsa also available but not quite the same shape as the plastic (a bit shorter).

 

[jrap330]

Hello and thanks to both of you.

The alcohol suggestion worked well. The paint was partly dry but a light scraping to get it started, plus the alcohol got it pretty clean...I don't expect any problems. When the body tube is dry I'll test the fit out.

I like to overthink things! This was the first rocket that required any kind of assembly/painting. The Alpha III obviously required barely any work.

When the Baby Bertha arrives in a few days, we'll benefit from what we learned on the Big Bertha.

Try not to overthink things on model rockets, too many people just drive themselves nuts. Also try using a nose cone as a die and insert it upside down to slightly widen the body tube....I do it if I think it is too snug. And as stated always mask the shoulder area if painting nose cone separately.

 

[BABAR]

What color are you painting the nose cone?

In any case, mask the shoulder of the cone so you don’t paint it (if you do get paint on it, easy enough to sand it off.)

If you are painting the cone black, you can use a Magnum Sharpie (right up there with Jumbo Shrimp and Military Intelligence in the oxymoron que) to color the shoulder black either before or after painting. Not a big deal, but you don’t have to worry about an unpainted white edge peeking out around the base of the cone (sort of like having your underwear showing.)

 

[Marc_G]

you can use a Magnum Sharpie (right up there with Jumbo Shrimp and Military Intelligence in the oxymoron que)

 

[jqavins]

Also try using a nose cone as a die and insert it upside down to slightly widen the body tube....I do it if I think it is too snug.

I wouldn't do that myself. Of course, lots of things work for some people that others cringe at. Me, I'd not try to widen a body tube unless it needs to be pushed back into round after some other problem. For one thing that would only effect the very end, and for another, if it works at all (which I gather it can) then I would be afraid of overdoing it and flaring the end. I'd rather sand the nose cone shoulder down if it's too tight. A little at a time with frequent testing.

And here's a warning, before you become frustrated finding it out on your own: "building rockets" = "sanding rockets". Refer to this for more information.

(I did once have to sand a shoulder down so much that I was afraid I'd weaken it, and it was still too tight. I glued it in, cut the body tube a couple of inches below, and added a coupler. Lesson: there's always another way to skin the cat.)