Drill + Insulation = Nice Nose Cones

[SPONGE]

...and this is my collection of foam-nosed rockets. They are all 29mm, but the three biggest ones are clusters. On the rocket with the orange tip you can see some damage from the last flight.

 

[plasticpaul]

Songe thank you fo rth ekind words and for sharing your ideas. Those are excellent ideas. I have actually been wrapping my shoulder section with masking tape and this makes a very smooth fit. I like the idea you are doing with the tubes for the shoulder and base of the cone. Since I am working from a roll of paper and other raw materials it is just easier for me to do the cone as one piece. I have to agree with you about the epoxy holding better than anything else on the foam. I find that by heating a hole into the middle just about the full length of the cone and then hotglueing in my dowel i am 100% on them turning out pretty nice. I did one today that actually required no filler of any kind. I painted it with glue to protect it from the primer and shot it. It looks great, it went on my new D/E rocket.

Ben, I would glue the layers with epoxy for those sized cones. Rather than screing it to your face place make a friction plate. Put a piece of 3/4" plywood on the face place. Turn it on your lathe to clena it up and find the exact center. Now drill your new wood plate in the exact center to accept the dowel you put in the cone. If you have a ball bearing tail stock bring it right up to the foam so it pushes it onto the plywood face. If you don't have enough grab you can spray mount the foam to the plywood face or put a piece of sticky backed sand paper on it. (I have tought turning techniques) That is how I will do it when I am done building my new lathe. Smaller cones are just easier to do with the dowel in a drill chuck though.

I have been getting a very nice finish by using 220 sandpaper as my final turning step. The cone in the post,"new bird" was done this way.

OH, be careful with the spray adhesives, some may eat the foam, 77 is okay

 

[Frank Broughton]

Thank for the tips SPONGE! Your nose cones look great.

 

[Micromeister]

Originally posted by slackdaddy
Micro,
I may try a 4" (BT101) cone, for a lite-weight project.
I have never glassed anything, except My 70 Javelin headliner backer !

Others have posted that epoxy without glass cloth is to fragile,
How would You wrap a cone with glass cloth? spiral wind it ?
Brush on the epoxy, then wrap the cloth into the wet epoxy ?

Any tips or idea's are welcome

Slack

I learned from a couple of the US internat team guy's, these folk make all their 30 and 40mm models with a single wrap of 1/4oz/yd fibreglass and a layer of super thin mylar. The nose cones are usually foam with a single "fitted" wrap of the same glass. Now heres someplace I really NEED a photo but I don't have one of one of these guys laying up a cone
Might I suggest you contacting Mark P. at Venus Rocketry, I believe it's www.venusrocketry.com He's really an expert on laying up model bodies and nose cones.
I'll try to explain the process anyway; the foam nosecone is brush coated with a thin layer of 30 minute epoxy, than a pre-cut glass shape is rolled onto the cone. Use rubber gloves, pressing the glass into the epoxy with a rolling motion of the finger in one direction as you lay on the glass turning the cone in the precess. If you want a bullet-proof cone use two layers These tube bodies, transitions and cones are incrredably strong, flexable....And a colossal pain in the back side to lay up!
The model shown below IS all Fibreglass ,with foam cone and mylar on the body layer. Wish I could be more help but laying up fibreglass isn't one of my best techniques

 

[stevem]

my first foam rocket

I used fiberglass cloth and West Systems epoxy to coat this foam rocket. Used a combination of hot-wire foam cutting and turning to shape the foam glue-up.

here's another foam project that I did not use any glass on. Just epoxy over foam. So far it has worked fine with 2 flights on it but if i were to do it again i would use glass cloth

and if you do foam you have to check out this site - look in the Construction link Team Vatsaas

 

[sandman]

Put a layer of cloth and epoxy over the foam and if it's thick enough, say 2 layers of 6 oz cloth and enough epoxy to hide the weave. Then you can safely remove all of the foam.

Gus and my Pad abort models used 0.5 oz cloth and epoxy.

https://www.rocketryforum.com/showthread.php?s=&threadid=25121&highlight=Pad+Abort

When we removed the foam. An extreamly light shell is left.

 

[plasticpaul]

I need to thank SPONGE !!! I did a cone with some of the methods he describes and man did it come out nice. It is going on my new bird and it looks perfect. We flew some of the new rockets this week with the foam cones and they flew so well I did my first upscale. My son and I did a wild looking rocket so I did an upscal and did a similar one only double sized. I wanted a long thin nose cone for it and i did the rectangles with the dado for the dowel and it worked like a champ !! Pics will be up later.

 

[SPONGE]

I'm so glad to hear that work well for you! Now, up with the pics

 

[metalwizard]

a few post back there was talk of foam crumbling, the difference between the two foams is... one is styrofoam, and one type is polystyrene... one is the type that is in little "balls" the other is more of one solid piece.

when your looking for it at your local hardware store (not home depot or the likes, but a building supply store) , ask for "core foam" this should get you what your looking for.

sorry for a duplicate if someone addressed this.

and heres a pic of me turning my prototype on the lathe. it was a first attempt, i found that stacking the foam (like suggested in the beggining of the thread) works fora smoother finish

 

[metalwizard]

and heres glassing my second attempt (with the foam stacked the right way)

 

[sandman]

Yes, it's EXTREAMLY messy!

I use a dust extractor. A large squirrel cage fan with a 4" hose. It helps...but it's still messy!

But a fun messy!

 

[metalwizard]

the dowel idea seems cool for smaller stuff i made a full plywood frame for my attempts, very strong, and easy to chalk up on the lathe....and stroger in a rough landing. plus it tells me exactly how much foam to turn of to be the exact shape i'm looking for!

 

[ben]

I think I might try te wood frame ides. what is a good frame thicknees (.e 1/4" ply 1/8"?? ) I have both I could make the base 1/4" and everytihng else 1/8"

thanx, ben

 

[metalwizard]

ben, depends, the one in the pic was a 10"+ diam casule, and recovery was from above the capsule so i made it thick and heavy, I used 3/16" for the 'cross pieces' and 1/4 for the round bulkheads.. i could have gone even smaller if needed. for a smaller cone i'll bet 1/8th would be fine, its reall strong.

heresanother pic showing how the recovery was attached to the capsule and escape tower.

 

[plasticpaul]

I posted tghis in another post but it really fits very well with this discussion. As MetalWizard, pointed out the origianl way I posted of stacking gives a better finished product than running your glue lines along the axis. I did one last night with my glue lines along the axis and it came out pretty good but the other method gives a much nicer finished product. I got less blow out and a much more round NC.