Next Build- Does This One Make Sense?

[GlenP]

Don’t worry if not perfect the first time, you will get lots of practice glueing back on the fins after each launch, when one pops off on a hard landing.

 

[K'Tesh]

S

Should I get one of those yellow Estes fin alignment jigs to help in the build?

Dear Lord... No!!!

Go to payloadbay.com, find the free fin guide tool, enter your values, then print out the.pdf generated at 100%. Apply the printout to a piece of cardboard or dollar store foamcore, and use that.

 

[OverTheTop]

After marking the lines for the fins you can glue the fins on with the side of the fins on the lines, rather than the center of the fin. I find that makes alignment easier. Just make sure you offset them all in the same direction.

 

[MadRocketer]

I used to lay the body tube next to a book. Then I’d find the page where the fin would lay 90 degrees to the tube. Apply enough glue to the fin so that it would stick but not be messy and close the book on the fin. Can only do the fins one at a time. Had to move the rocket to the edge of a table for the third fin to be attached. It worked though!

 

[Hyak]

Ahhhh I remember the Bertha. Always ;liked that rocket for its slow lifetoff. Looked Cool (Of course the motors we used had something to do with that!

Anyway, great rocket!

No, don't use the Estes Yellow 'Jig". It has some issues. I agree with the other folks who have indicated mark your lines and glue them up by eye

 

[CalebJ]

Don’t worry if not perfect the first time, you will get lots of practice glueing back on the fins after each launch, when one pops off on a hard landing.

I don't remember ever having issues with Bertha fins popping off?

 

[neil_w]

Don’t worry if not perfect the first time, you will get lots of practice glueing back on the fins after each launch, when one pops off on a hard landing.

LOL.

I'll generalize this advice further: don't try to make this build perfect. If this is your first one (or first one in a very long time), and you're unsure about tools and techniques, then just treat it as a learning experience. You'll get better with each successive build.

In addition to Chris Michielssen's techniques articles over at the NAR website (someone linked previously), I also would suggest reading his blog if you have not already done so. There are about a billion useful tips and examples there: https://modelrocketbuilding.blogspot.com/. Reading his blog is where I relearned pretty much everything before my first BAR build.

 

[Back_at_it]

Everyone says this, as they have years or decades of experience. I took 50 years off from model rocketry. Of course I want the darned thing to work. I did some reading before diving back in, and one common thread was the nightmare of fin alignment.

Another option would be to get a rocket with precut slots in the body tube. There are a ton of rockets out there that have this feature built in and it does make assembly must easier. The Estes Doorknob, Big Red Max, Star Orbiter and Big Daddy are good options.

The 3 inch rocket from Balsa Machine is also a good option and inexpensive. https://www.balsamachining.com/#

LOC Precision also has a a few options that will fly on Estes black powder motors and smaller composites. I’m currently building their Scout rocket and have a build thread going in the mid-power section if you're interested in seeing what this looks like.

 

[CalebJ]

If you're patient, you can even find the Mini Honest John at WalMart for $3.13 and order a dozen for free shipping. Lots o' practice.

 

[neil_w]

I did some reading before diving back in, and one common thread was the nightmare of fin alignment.

Not a nightmare, especially when talking LPR. Certainly, it is something everyone has their own approach to, and everyone is always trying to figure out the easiest way to get perfect alignment, hence the proliferation of different jig types.

But if you simply make good straight pencil marks on the body tube, and make the the fins are aligned with the mark, your rocket will fly straight, even if the fins don't end up perfectly perpendicular to the body. As @OverTheTop suggested, put the fins *next to* the pencil lines (always on the same side) for easiest placement.

By all means try your best to do as good a job as possible, but don't kill yourself with worry over your first build. Just do it, get practice, learn, get better.

I'll take it one step further: for your first build, consider not using a jig, just try doing it by eye. See how it goes. Not every fin on every rocket is suitable for a jig (depending on design). There are times when you'll have to just eyeball it, unless you're going to get very creative with custom jigs. (not everyone may agree with me on this piece of advice)

 

[hcmbanjo]

My first BAR build wasn't perfect - Just have fun and learn as you go!
Stop by my blog at: modelrocketbuilding.blogspot.com

Here's some general tips in two Apogee Peak Of Flight articles:
https://www.apogeerockets.com/education/downloads/Newsletter424.pdfhttps://www.apogeerockets.com/education/downloads/Newsletter425.pdf
Welcome back!

 

[Pappy]

i like the Estes fin jig, but not so much for alignment. too much wiggle. i usually just eyeball 'em, and double check against a jig. i use the base of it all the time, though, for painting and glue drying time. the big tube marker is useful, too. the small one with the ruler on it is comparatively useless. i also like the little marking disks, though i think they might be included with the crappy marking guide/ruler. Bertha is a fine choice.

When i take a dirt nap, i hope my kids do as you're doing, and launch in my memory. noble stuff.

 

[Grant_Edwards]

If you're patient, you can even find the Mini Honest John at WalMart for $3.13 and order a dozen for free shipping. Lots o' practice.

I've got three of them arriving today.

When I ordered, max quantity was 3 per order, so you have to add something else to the order to get free shipping. I added an Estes Interceptor kit that was a a few dollars cheaper than usual. I noticed that the prices for Estes kits on Walmart.com are all over the place, some are above MSRP and some below.

 

[GlenP]

I don't remember ever having issues with Bertha fins popping off?

Just a joke, yeah we are not talking about a Wizard or Viking.

 

[neil_w]

My first BAR build wasn't perfect

Curious: what was it, and when?

 

[hcmbanjo]

Curious: what was it, and when?

An Estes Nike Apache. I started it until I found the BT-55 tube was slightly crushed.
It sat for years (1985 -2006) when I got back in the hobby.
Restarting the model I made a lot of corrections with a new BT-55.

In 2006, I ordered a Semroc (Centuri) Javelin and Point.

 

[Antares JS]

From what I can see, Big Bertha is described as an "Intermediate" build. Would this rocket be a good choice? Or, should I try something easier, say, like an Alpha/Alpha III?

Nowadays, "intermediate" just means you have to actually glue the fins to the body tube and "beginner" kits have one-piece plastic fin cans. If you built a rocket before, you will be fine.

And like others have been saying, you don't need to worry about getting the fins super-precise on a basic build. Eyeballing it is almost always good enough unless you are Machbusting or something similarly extreme. I am working on my level 3 and have never used a fin jig in my life.

 

[OverTheTop]

I documented my method of getting fins square here:
https://forum.ausrocketry.com/viewtopic.php?f=5&t=5412&start=3