Estes Cosmic Disaster Build, or Murphy's Rocket

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gna

average joe-overbuild member
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I thought I'd post a picture of my latest build, what started out as an Estes Cosmic Explorer. Pretty much everything that could go wrong with this build did go wrong, so I have taken to calling it the "Cosmic Disaster," or "Murphy's Rocket."

It all started on Labor Day weekend, when I was looking something up on the Estes webpage and discovered they were having a sale! Yay! I bought 3 kits because they looked cool. The first, a Hornet, went together fairly well, though the engine mount nearly got stuck as the glue grabbed faster than I expected when I inserted it. (Foreshadowing...)
The next one I decided to build was the Cosmic Explorer:

estes_cosmic%20explorer_lg.jpg


The advice I've come across always states to READ THE INSTRUCTIONS, so I did. I started the build, and had completed the engine mount, when I reached into the bag for something and pulled out a blue piece of paper with CORRECTED INSTRUCTIONS FOR THE ENGINE MOUNT!

D'oh! :facepalm:

It's ok, I thought, I can save it. I sent Estes an email explaining my problem and asking if I could buy just the engine mount assembly. While I was waiting, I thought I would skip ahead a step or so and glue the red coupler in and join the two body tubes. So what happens? Yes, the glue grabbed early and I couldn't get it together straight and all the way joined. While i was wrestling with it, I managed to crumple a few inches of the long body tube.

D'oh! :facepalm:

I put it away for a day.

Estes emailed back that they would send me a replacement kit free of charge, so Kudos to Estes! I figured I had nothing to lose, so I thought I would see if I could save the rocket. I cut out the crumbled section and managed to glue the tube together (mostly) straight. I glued the engine mount in, and figured I needed to notch the fins to fit around the centering rings, so I did. I read about papering fins, so I thought I would try it. I got some paper and picked up a glue stick from the desk.

For some reason, I could not get the paper to stick to the fins. The glue wasn't tacky at all. I checked it out more carefully and found it wasn't a glue stick:

banana-boat-sport-sunscreen-spf50-face-en.jpg


D'oh! :facepalm:

New paper and white glue later, I got the fins papered and glued to the body. I had to rock them in, but they seem solid. Sanded and primed, I thought I would paint the nosecone white. My Rustoleum 2x has always worked well, but it was getting a little cold, so I warmed the can and went outside to spray.

Plugged nozzle. :mad:

I cleaned it out. Paint came out in spatters and gobs. :(

Clean it up, try a different nozzle. Not great, but ok.
photo 2(5).JPGphoto 2(4).JPG

So I think maybe I can fly it this coming weekend. What happens this week?

cst%2017248%20November%20snow-L.jpg


It's going down to the single digits tonight, and more snow tomorrow.

:facepalm:

No flying for a while.

I fully expect this rocket to explode on the pad, or break apart at the joint, or hang up in a tree, or land on someone's roof, or lawn dart...

It's the Cosmic Disaster. It's Murphy's Rocket.
 
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Murphy's Rocket. I love it. That should be it's name, without a doubt.
 
I had a similar experience.

This was one of the first rockets I bought when I BARed. I really liked the TTW fins. I decided to try CWF instead of my tired and true stinky balsa filler coat. I followed the directions I saw on this forum, I applied the thinned CWF to one side of each fin before applying them to the rocket, and walked away. I came back some time later to sand the fins, but they were all curled up like doritos


Doritos_thumb.png





D'oh! :facepalm:




I wrote to estes asking to buy just the fins, and they sent me another kit also.

Once I got it built and painted, this time with stinky balsa filler coat, it ended up being a great rocket. I stuck to sanding sealer, or filler coat until doing papering on my latest LPR build.

I am sure I did something wrong since CWF or FnF as it was called at time is pretty popular with many builders.
 
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I decided to try CWF instead of my tired and true stinky balsa filler coat. I followed the directions I saw on this forum, I applied the thinned CWF to one side of each fin before applying them to the rocket, and walked away. I came back some time later to sand the fins, but they were all curled up like doritos

You need to apply the CWF to both sides of the fin at the same time or else the moisture causes the fins to warp
 
Murphy's Rocket. I love it. That should be it's name, without a doubt.

I'm going to try to get lettering or a decal that says "Murphy's Rocket." I know I've seen decal paper at the hobby shop, and lettering sets.

Either that or I'll just put on random decals from other places. Of course, I'm sure the decals will be an adventure, too.
 
The first, a Hornet, went together fairly well, though the engine mount nearly got stuck as the glue grabbed faster than I expected when I inserted it. (Foreshadowing...)

...

While I was waiting, I thought I would skip ahead a step or so and glue the red coupler in and join the two body tubes. So what happens? Yes, the glue grabbed early and I couldn't get it together straight and all the way joined. While i was wrestling with it, I managed to crumple a few inches of the long body tube.
This, right here, is what started my love affair with 30 minute epoxy for engine mounts and couplers. I just don't use anything else anymore... because if I do, Murphy makes an appearance. Every. Freakin'. TIME.

Yellow glue is for sticking fins on LPR rockets, and white glue... dunno, haven't used any in years. Epoxy is the only safe thing to use on a coupler or engine mount.

... and with a 40% off coupon at Hobby Lobby I can get more than I need for a reasonable price.
 
I had problems with the instructions when building this with my (then) six year old. Things didn't line up and I had to machine the fins to work properly in relationship to the centering rings, as I recall. Actually the rocket is still incomplete, sitting on my sons' work bench. IT has been there more than a year.... Maybe this thanksgiving weekend we'll finish the build (only a few steps remaining).
 
This, right here, is what started my love affair with 30 minute epoxy for engine mounts and couplers. I just don't use anything else anymore... because if I do, Murphy makes an appearance. Every. Freakin'. TIME.

Yellow glue is for sticking fins on LPR rockets, and white glue... dunno, haven't used any in years. Epoxy is the only safe thing to use on a coupler or engine mount.

... and with a 40% off coupon at Hobby Lobby I can get more than I need for a reasonable price.

I didn't think to use epoxy. I've got various kinds here in the house. My next build is a Flutter-By, yet another super-cheap sale rocket. I may try epoxy on that. I haven't had good success using epoxy on plastics in the past; does it work to hold nose cones to body tubes?
 
I had problems with the instructions when building this with my (then) six year old. Things didn't line up and I had to machine the fins to work properly in relationship to the centering rings, as I recall. Actually the rocket is still incomplete, sitting on my sons' work bench. IT has been there more than a year.... Maybe this thanksgiving weekend we'll finish the build (only a few steps remaining).

They made some changes to the instructions. The ones that came with my kit had two engine mount errors, in building it then gluing the fins on first. I downloaded the corrected ones at Estes Cosmic Explorer
 
I didn't think to use epoxy. I've got various kinds here in the house. My next build is a Flutter-By, yet another super-cheap sale rocket. I may try epoxy on that. I haven't had good success using epoxy on plastics in the past; does it work to hold nose cones to body tubes?
I've had good luck with styrene cones, which most of them are now. If you're not sure it will hold the cone as is, drill a few small holes in the shoulder for the epoxy to flow into, forming "rivets." Mostly I use epoxy for engine mounts and couplers, but if I'm mounting a nose cone permanently (like with my many rear ejection rockets), I do use it there also.

But for fins, it's always yellow glue. The "grab" that makes you curse when installing an engine mount is a relief on a fin.
 
I built one and didn't care for it after it was built. I figured I'd give it a D 10-5 send off.
Well, Murphy showed up and made my Cosmic Explorer fly PERFECTLY and land at the edge of the field.
I'll try to lose it again next summer...
 
This, right here, is what started my love affair with 30 minute epoxy for engine mounts and couplers. I just don't use anything else anymore... because if I do, Murphy makes an appearance. Every. Freakin'. TIME.

Yellow glue is for sticking fins on LPR rockets, and white glue... dunno, haven't used any in years. Epoxy is the only safe thing to use on a coupler or engine mount.

... and with a 40% off coupon at Hobby Lobby I can get more than I need for a reasonable price.

My problem with 30 minute epoxy, is when I epoxy an internal part in, then set the tube aside for a few minutes, I'll look at it and suddenly realized that the coupler (or motor mount) is slowly slipping inside the body tube. I've always managed to catch it while the epoxy is at the leathery state, but I'm now a fan of tacking the engine mount with CA before using epoxy to finish the bonding.
 
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Unless there's a real good reason to do otherwise, I install the engine mount before the fins. That way I can lay the sustainer down sideways and the engine mount goes nowhere.
 
First this is a very funny story! Thanks for sharing your learning experience with us. Sorry for the beginning trouble but that usually means the rocket will last a very long time. I had one that I've TRIED to fly away but the darn thing somehow always finds it's way home.

I'm with Solomoriah on using epoxy for installing motor mounts. but I don't usually use 30minute perferring 5 minute Devcon instead this allows plenty of time for positioning and cures fast enough to prevent part slip. 30minute is generally used for fin fillets where the model can be layed horizontally and two or more fins can have both sides applied from a single mixtured batch.

Still Like to use elmer's carpenters Yellow glue for basic fin attachement.

Note: Epoxy does not have any chemical bonding properties with ANY Plastic. if used on styrene or polyethylene or polyproplyene the surfece MUST be drilled and/or roughed up with 80 or 100girt sandpaper to give the epoxy something to grasp. The "Epoxy Rivet" method is used on most "Crayon" models as both the Nose and base pieces are Polyproplyene which just has NO good solvent welding adhesive.

That said Most ESTES and Quest Polystyrene Nosecones Should Be SOLVENT WELDED making both a chemical and mechanical bond between the shoulder and Cone. There are a number of products out there that well do a fine job. Weakest is Testors Water thin plastic cement but it is better then trying to use heavy tube type cement ment for static plastic models. Better are either PlasticStruct or Ambroid Pro-Weld.
Better yet would be Weld-on 3,4 or 16 solvent welding adhesives. By far the best Solvent Welding medium is Methlene Chloride (MC) Unfortunetely MC is only sold in Gallon Cans at Sign Supply or industrial supply stores. In a pinch it is possible to use either MEK or ACETONE as a solvent welding agent but you must be very careful as to much will destroy the parts being joined.

For a great deal more on Working with Plastics there is a free downloadable Tech-Tip with Photo examples over on the www.narhams.org wedsite in the library section accessed from the left side drop-down menu. Look for the Tech-Tips and folder Tech Tip-017 Working with Plastics. There is also another Tech Tip-009 Plastic Model Conversion that may also be of interest.
 
First this is a very funny story! Thanks for sharing your learning experience with us. Sorry for the beginning trouble but that usually means the rocket will last a very long time. I had one that I've TRIED to fly away but the darn thing somehow always finds it's way home.

I'm with Solomoriah on using epoxy for installing motor mounts. but I don't usually use 30minute perferring 5 minute Devcon instead this allows plenty of time for positioning and cures fast enough to prevent part slip. 30minute is generally used for fin fillets where the model can be layed horizontally and two or more fins can have both sides applied from a single mixtured batch.

Still Like to use elmer's carpenters Yellow glue for basic fin attachement.

Note: Epoxy does not have any chemical bonding properties with ANY Plastic. if used on styrene or polyethylene or polyproplyene the surfece MUST be drilled and/or roughed up with 80 or 100girt sandpaper to give the epoxy something to grasp. The "Epoxy Rivet" method is used on most "Crayon" models as both the Nose and base pieces are Polyproplyene which just has NO good solvent welding adhesive.

That said Most ESTES and Quest Polystyrene Nosecones Should Be SOLVENT WELDED making both a chemical and mechanical bond between the shoulder and Cone. There are a number of products out there that well do a fine job. Weakest is Testors Water thin plastic cement but it is better then trying to use heavy tube type cement ment for static plastic models. Better are either PlasticStruct or Ambroid Pro-Weld.
Better yet would be Weld-on 3,4 or 16 solvent welding adhesives. By far the best Solvent Welding medium is Methlene Chloride (MC) Unfortunetely MC is only sold in Gallon Cans at Sign Supply or industrial supply stores. In a pinch it is possible to use either MEK or ACETONE as a solvent welding agent but you must be very careful as to much will destroy the parts being joined.

For a great deal more on Working with Plastics there is a free downloadable Tech-Tip with Photo examples over on the www.narhams.org wedsite in the library section accessed from the left side drop-down menu. Look for the Tech-Tips and folder Tech Tip-017 Working with Plastics. There is also another Tech Tip-009 Plastic Model Conversion that may also be of interest.

Thanks for the advice and link. I may use Ambroid Pro-Weld on the plastic and put it in the tube if that works better. When my daughter and I built her Firehawk we used Ambroid Pro-Weld on the plastic parts, and I put some around the fin cone and put the tube in, but that was a pre-finished tube. I'll probably start a different thread on the Flutter-By.
 
I LOVE my Flutter-By's! I am on my third and I am also in the process of building a BT-80 upscale (Crossing fingers and praying to the rocket gods on this one). I just scuff the NC shoulder with 220 grit and bond with 5 min epoxy. On my latest, I papered the fins and left off the rib/fence and the fin is solid as a rock but I wish I had included it now just because it adds character to the rocket. If you haven't built one before, get a good, strong joint when you glue the fins or they may break off easily. I also advise staying with small motors or you will end up with a Flutter-Bye-Bye

BTW, Mr Murphy is my building partner and chief good idea fairy.
 
Update:

I made the modifications mentioned here. Looks like this now:

Murphy's Rocket.jpg


My luck must be changing, because we flew it yesterday, and it seemed to fly fine:

https://youtu.be/LbBp6kmzsAk

You can see a little corkscrew in the flight. Not sure what that is.

I used the stock 'chute, which was probably too big. It seemed to hang up in the air, and was drifting towards some trees and the railroad tracks, but the light breeze picked up and blew it right to me!
 
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I love the Cosmic Explorer. I've built three (one stock, two with an E mount), lost one on the first launch (the first E mount build), and I have one or two more, just in case.

I'm glad I'd built a few rockets before I did this one, because I didn't see the little pink slip before I started it, but I knew there had to be a mistake when it said to install the fins before the motor mount!

I know Estes mass-produces stuff and probably has to go through stock before making more, but I have heard of a number of rocketeers having problems with the Cosmic Disaster because of this. I think printing up new instructions would be a good idea for Estes - probably cheaper than sending out whole new kits.

Still, every time they have a big sale, the Cosmic Explorer seems to be included, and at $4.45 a pop, I can't resist...
 
I love the Cosmic Explorer. I've built three (one stock, two with an E mount), lost one on the first launch (the first E mount build), and I have one or two more, just in case.

I'm glad I'd built a few rockets before I did this one, because I didn't see the little pink slip before I started it, but I knew there had to be a mistake when it said to install the fins before the motor mount!

I know Estes mass-produces stuff and probably has to go through stock before making more, but I have heard of a number of rocketeers having problems with the Cosmic Disaster because of this. I think printing up new instructions would be a good idea for Estes - probably cheaper than sending out whole new kits.

Still, every time they have a big sale, the Cosmic Explorer seems to be included, and at $4.45 a pop, I can't resist...

Estes Website has the corrected instructions. Worth a download.

I built the replacement, too, as stock:

Rockets.jpg
(with Flutter-By and Murphy's)

We ran out of time but would have launched it as well.

I skipped the last few sales, but if they have one next weekend I will probably get a few more kits. I think they had a pack of the Monarch, Cosmic Explorer, and Hornet. I'd get a few of those just to play around with.
 
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Man, I wish I had read this thread before I started my own Cosmic Explorer.... Instead, I had to create a similar thread on my own...

BTW, the holiday sales have slowed somewhat, and the last one only included the three rockets they have now on clearance, the mini launch pad and controller and the typical four PSII kits (The Argent, Partizon, Ventris, and the Leviathan). It may be some time before they blow out a large number of kits at the same time... Then again, the 4th is a pretty big holiday.
 
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This, right here, is what started my love affair with 30 minute epoxy for engine mounts and couplers. I just don't use anything else anymore... because if I do, Murphy makes an appearance. Every. Freakin'. TIME.

Yellow glue is for sticking fins on LPR rockets, and white glue... dunno, haven't used any in years.

I use Aleen's Tacky Glue for motor mounts and couplers. Gives me enough time before lock up and no mixing required.
 
Update:

I made the modifications mentioned here. Looks like this now:

View attachment 266502


My luck must be changing, because we flew it yesterday, and it seemed to fly fine:

[video]https://youtu.be/LbBp6kmzsAk[/video]

You can see a little corkscrew in the flight. Not sure what that is.

I used the stock 'chute, which was probably too big. It seemed to hang up in the air, and was drifting towards some trees and the railroad tracks, but the light breeze picked up and blew it right to me!
Murphy liked that you named a rocket after him!

A little off topic maybe but for paper tube rockets, I use carpenter's glue and a cheap wooden drink stirrer with a rounded end. Think popsicle stick but only 1/4 inch wide. They were 100 sticks for a $1.50 at the local grocery store. :grin:
 
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