Estes Protostar: Has anyone built this?

I have a build question for anyone who has the Protostar. The kit comes with three cubes of clay for the nose cone. This seems overkill to me. If you have built this how much clay did you pack into the nose cone? Thanks!

You should use the recommended amount in the instructions. John (Boren), the designer for all of the newer Estes kits, has probably flight tested this numerous times before coming up with that amount. Also look at the fin pods: heavy plastic! This puts the CG way back without the nose weight up front. The three pats should also cover stability when using the heaviest recommended motor (E12-6).

"When all else fails, read the instructions"

Tried to upload video, file might be too big. Anyway, built stock, minimum recommended engine (D-12), flew arrow straight, recovered close to the launch pad. Fun, retro sci-fi rocket.

Klatuso said:

I have a build question for anyone who has the Protostar. The kit comes with three cubes of clay for the nose cone. This seems overkill to me. If you have built this how much clay did you pack into the nose cone? Thanks!

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I am in the process of building mine, I just have fin fillets and paint to finish.

I think that the three cubes are probably a good idea as the CG is really far back without it - the heavy nosecone pods make it really back-heavy.

I followed the directions for the most part, although I did install the motor mount and launch lugs prior to attaching the fins.

I decided on "Metallic Driftwood" Duplicolor paint, it is a fairly light champagne.

kuririn said:

You should use the recommended amount in the instructions. John (Boren), the designer for all of the newer Estes kits, has probably flight tested this numerous times before coming up with that amount. Also look at the fin pods: heavy plastic! This puts the CG way back without the nose weight up front. The three pats should also cover stability when using the heaviest recommended motor (E12-6).

"When all else fails, read the instructions"

Tried to upload video, file might be too big. Anyway, built stock, minimum recommended engine (D-12), flew arrow straight, recovered close to the launch pad. Fun, retro sci-fi rocket.

Click to expand...

I have read the instructions. Unfortunately there are no words, just a picture of a hand rolling clay and an arrow pointing the "worm" to the nose cone. Very vague.

RocketFeller said:

I am in the process of building mine, I just have fin fillets and paint to finish.

I think that the three cubes are probably a good idea as the CG is really far back without it - the heavy nosecone pods make it really back-heavy.

I followed the directions for the most part, although I did install the motor mount and launch lugs prior to attaching the fins.

I decided on "Metallic Driftwood" Duplicolor paint, it is a fairly light champagne.

Click to expand...

I was a bit disappointed with the pods. They have no bottom, just flat hole. Hollow. So, I did this: I took the caps that are cut off the pod and carefully cut off the the cone portion. Epoxied it onto the pod and it looks great.

I'll let you decide on what you wish to do but I'll supply a little more information. Using RocSim the Center of Pressure is at 18.48" from the tip of the nose. I just checked the numbers on one of the test models I have here. It's center of gravity with the 3 lumps of clay in the nose is at 13.75" from the tip of the nose without the motor installed. The balance point of your model may be different from this one. With and Estes E9\E12 motor install the margin of stability is 1.4.

John Boren

Thank you for running that on RocSim. But now lets make it a bit more complicated. I added all the clay given but also added a generous amount of fillet epoxy clay to the fin pods. I will do a string test before launch but wonder about that extra bit. thinking I might add a bit more.

This is the rocket with the cones on the end of the pods.

https://photos.app.goo.gl/b1ryGnw5aBgXVn8u2

As a BAR this is my first attempt at posting a pic. Hope it's OK.

I finally was able to primer my Protostar. It needs a little sanding and a maybe some spot putty in a couple spots, but overall I am pretty happy with the finish.

Paint is on - "Light Driftwood Metallic" Duplicolor.

I just commenced the build of a Protostar...with a few slight modifications from stock. Posted part 3 of a build thread this morning on my blog (link is below).

I built this for my daughter over the winter, painted it pink and purple, we call it the pink and purple protostar. Just follow the directions, shes flown it 3 times and it flies great. Only thing i've done is use epoxy where the fins glue to the BT and pods, with small epoxy fillets.

I went with Krylon chrome, the picture shows how I modded the pods with the cones from the cutaway parts (sorry for such a big picture, I'm still trying to figure out how to size and post pictures):

I like the pod mods. Might have to try that on my build.

I love pods!

Especially the ones used in "Invasion of the Body Snatchers"!

milehigh said:

Especially the ones used in "Invasion of the Body Snatchers"!

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I am telling the good folks of Rocketville: "Please do not put these on your rockets, they are terrible for the CP and very dangerous!"

milehigh said:

I just commenced the build of a Protostar...with a few slight modifications from stock. Posted part 3 of a build thread this morning on my blog (link is below).

Click to expand...

I will definitely be following your blog! This rocket begs for creative mods.

Decals and clear coat are on.

I hate putting on decals and usually mess up at least one. I managed to get all of them on (not always the case) with only a couple of screw-ups that most people might not notice.

I have another one, I will probably try Klatuso's pod-closing tip. A steampunk version would be awesome, but I'm not sure I've got the artistry to pull it off...

I have to say that finishing this rocket was the hardest part. I committed myself to Krylon Chrome and it was the hardest paint I ever worked with. It never really dried and I live in the desert southwest where it is bone dry and hot every day. Every time I picked it up it left finger prints, crinkles, scuff marks. At the end after multiple additional coats of paint I wore nitrile gloves to pick it up and do some detail work and even that didn't work. Finally I went with a "weathered" aluminum look. Not by choice.

The decals for this kit were tough and rough. I don't know. I did another kit at the same time from a competitor on plain old gloss white paint and it came out fine. But these decals were weak and went on crinkled and stuck so I couldn't smooth them out. I'll try to post another picture later.

I flew it before painting and after adding additional nose weight to compensate for overbuilding with epoxy clay and cones on the pods it went straight up and landed within 20 feet of the launch pad (dead calm). Overall, happy with the build. I over built it so it could take Aerotech composite motors at some point entering mid power range. But I will never use Krylon chrome again and use soapy water or something with my next Estes build to reduce wrinkles and stuck-ness.

I didn't have the paint issues that Klatuso did, but I agree that the decals were a real pain. They were crammed on the sheet so tightly that it was difficult to get them cut out. Once applied they were really hard to get positioned without tearing.

I flew mine for the first time last Thursday. It went up on a C11-3 for a beautiful if not terribly high flight. I replaced the parachute with an 18" nylon one, I wonder if a 24" might be better...

RocketFeller said:

I flew mine for the first time last Thursday. It went up on a C11-3 for a beautiful if not terribly high flight. I replaced the parachute with an 18" nylon one, I wonder if a 24" might be better...

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I prefer my rockets to return quickly so I actually cut the largest hole in the stock parachute. Wanted to fly it today but too windy so I cancelled the flight.

I quit using Krylon due to the crinkling, and ditto for the horrid Walmart 99-cent cans of gloss black or white that are just plain crap.

I'm back to using mostly Rustoleum, because that is what is the most plentiful non-Krylon in the big box stores around me.

As for my Protostar, I built it per the plans.

The Krylon chrome paint continues to give me unpleasant surprises. When I sprayed with clear gloss enamel, which I like to do to protect the decals, it discolored and dulled the silver. I now have a "weathered" aluminum look. Not awful, just not the look I was seeking.

Clear coat over chrome is a no-no, at least if you want to preserve the chrominess. See this thread: https://www.rocketryforum.com/showthread.php?109931-What-Can-we-do-with-CHROME-paint

If even Micromeister can't figure it out, you know it's a lost cause.

Fluorescent paints have similar problems: clear coating kills the fluorescence.

Yea. I'm building a Pemberton 3FNC now and read in their instructions: "Beware, some metallic paints to do not take well to clear coats!" Now I know! Krylon Chrome is definately one of those paints.