Casting Resin Nose Cones

[1tree]

I am curious if anyone here has tried casting nosecones from plastic resin. In looking through information on casting it would seem very doable. But there might be something I am missing like this would make very heavy nosecones or something. Then again, it would eliminate any need to fill a nosecone with clay right?

For that matter, I would think someone might be able to cast their fins and/or fin cans.

 

[chadrog]

The 38mm cones now in Wildman kits are resin cast, with 29mm and 54mm on the way. A fellow up here is making them, they're very nice - just a bit heavy. So yes, it's very doable, and the cones are awesome! Here's a 29mm Vonkarmen prototype I was able to schmooze from Tim.

 

[Eric1]

I cast my plastic nosecones. I would not recommend fins or a fin can.
Material is to pliable after casting.

 

[TheTellurian]

Hi. I've cast probably over a hundred or so using 2 part polyurathane resins in polyurathane and silicone molds. There is a learning curve to it which means lots of mistakes and it is expensive to buy the resins themselves. I would not recomend it for one off projects and such, it being much less expensive to have a custom NC made by one of the guys specializing in that. I'll tell you what I do know if you want to go ahead.


Richard

 

[Gary Byrum]

I use the Alumilite brand at HL and honestly, the silicone rubber molds can get pricy when you cast stuff like I do. I was so fed up with the Estes Sat V fins & fairings that I didn't mind spending the buck on something I knew would be stronger, have more adhesion area and all in one unit. I figured that somewhere down the road some interest might evolve and I could sell sets of them. Unlike the very thin vacuformed parts that come in the kit, mine fairings are 1/8" thick and hollow inside and the fins are solid. I just made a new mold that went way better than my first mold did and I'm very pleased with the results.

 

[GregGleason]

There is a tutorial on resin nose cone casting on YORF:

https://www.oldrocketforum.com/showthread.php?t=5843

Greg

 

[Buzzard]

Sirius Rocketry sells the Moldin' Oldies resin cones and Saturn V parts. Most of their cones are replicas of out of production Estes and Centuri cones.

www.siriusrocketry.com

Look under "parts, tools, and more".

Chas

 

[sodmeister]

I use the Alumilite brand at HL and honestly, the silicone rubber molds can get pricy when you cast stuff like I do. I was so fed up with the Estes Sat V fins & fairings that I didn't mind spending the buck on something I knew would be stronger, have more adhesion area and all in one unit. I figured that somewhere down the road some interest might evolve and I could sell sets of them. Unlike the very thin vacuformed parts that come in the kit, mine fairings are 1/8" thick and hollow inside and the fins are solid. I just made a new mold that went way better than my first mold did and I'm very pleased with the results.

Very very nice Gary !!

You have been busy.

Paul t

 

[Gary Byrum]

Very very nice Gary !!

You have been busy.

Paul t

Thanks Paul. You know those little issue areas we discussed in the ones you got? Those are history. The exterior of these fin/fairings is up to par now.

 

[1tree]

Thank you all for the information. About how much resin does a typical nosecone (say for a BT60) use?

 

[Gary Byrum]

Thank you all for the information. About how much resin does a typical nosecone (say for a BT60) use?

A solid NC of any kind will always be heavier when cast. Unless you learn how to cast a hollow object, they will weigh a great lot more. Casting a hollow NC would be more work than it's worth. Better to invest in a lathe.

 

[GregGleason]

Thank you all for the information. About how much resin does a typical nosecone (say for a BT60) use?

That would be hard to know without answering a few questions:

1. The nose cone type (e.g., ogive, cone, parabola)
2. The nose cone length/diameter ratio (e.g., 5:1, 3:1)
3. Solid or hollow
4. The density of the resin (full resin, lofted with micro-balloons, or full resin shell w/ lofted core)

Once you supply those bits of information, you can estimate the weight.

My "wet finger to the wind" gross estimate is that a hollow resin nose cone will be 2 to 3 times the weight of a comparable solid core, balsa nose cone.

Check the link to show how you can make a hollow nose cone with relative ease:

https://www.oldrocketforum.com/showpost.php?p=76894&postcount=30
​

Greg

 

[krusty]

I've cast a bunch of smaller nose cones etc.


(the 'master' part is on the left - turned from delrin rod)

To work out how much resin you need, fill your mold with water and then pour out and measure.

Depending on the resin you use, you will mix in a ratio. So you'll need to do a little math to work out how much of each part to give you the correct final volume.

I always mix a little more than I need because some will always stick to the inside of the mixing cup!

Krusty

 

[Kruegon]

I once saw a tutorial in passing about casting hollow parts.

It involved using a 3 spindle gyroscope setup. Caused the resin to be coated over the inside of the mold. They came out looking the same as blown molded nose cones.

No info on quality by comparison, but I'd like to learn how to do it. I'd love to cast the parts of my Maxi HoJo before I build it.

Any suggestions on how to cast these parts the easiest way?

 

[rharshberger]

I once saw a tutorial in passing about casting hollow parts.

It involved using a 3 spindle gyroscope setup. Caused the resin to be coated over the inside of the mold. They came out looking the same as blown molded nose cones.

No info on quality by comparison, but I'd like to learn how to do it. I'd love to cast the parts of my Maxi HoJo before I build it.

Any suggestions on how to cast these parts the easiest way?

Check out John Boren's website he has a homebuilt roto-molding machine, or just PM JumpJet here on TRF. Resin cast parts can be heavy, for their size.

 

[Pat_B]

For smaller nose cones, you can just rotate the mold by hand to make them hollow. Our kids made about 10 of them for their TARC team and they came out great. The process is indeed expensive- especially the RTV rubber. I think they used about $50 worth of RTV for their mold and another $100 or so testing out different resins to get the results they wanted. Ultimately, they ended up with nice nose cones that didn't dent like the balsa wood ones, and that allows for more consistent flights.