5" to 4.5" transition?

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billdz

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Lots of rocket shops sell balsa and plastic transition pieces for smaller rockets, but I'm not seeing transitions for large rockets. I'm looking for a 5" to 4.5" transition, anyone know where I could buy one or how to homebrew one?
Thanks,
Bill
 
PR use to advertise a 6" to 4". Mad cow has a 5.5" to 3" for their 2 stage kit. I guessing your best bet would either modify a NC or scratch build one.
 
I turned one from basswood on my lathe a few years back for a project. Not very difficult. If you don't have the ability to do it yourself, go to the local Woodcraft store and ask them if they know anyone willing to turn it for you. Should cost maybe $100 including time and materials.
 
You could easily 3D print one, assuming it doesn't have to be structural. I could print one for you and pass it off to someone at URRG's September launch.
Thanks for the replies. I don't have a 3D printer or a lathe. What would it cost to have one printed? Is it strong enough to work with a large fiberglass rocket?
 
You could easily 3D print one, assuming it doesn't have to be structural. I could print one for you and pass it off to someone at URRG's September launch.
I 3D print centering rings, then use them as a template to make plywood ones on a router table with a pattern bit.
 
I am not sure what the cost would be for a printing service to print one, but the cost of the filament would be a few bucks at most.

Whether it is strong enough depends on your design and requirements. If the transition is mostly form vs. function, and the load is transferred to centering rings between the tube sizes, then a 3D solution is likely a realistic long term solution.

Do you have an OR or RS of your design? I can easily create the 3D file to print the transition. As I said in my previous post I can also print it for you, assuming it meets your needs, and pass it off to someone at the September URRG launch, or ship it to you if that doesn't work.
Thanks for the replies. I don't have a 3D printer or a lathe. What would it cost to have one printed? Is it strong enough to work with a large fiberglass rocket?
 
If it needs to be structural, how about using a 3D print as the form for a fiberglass part? This is outside my limited areas of experience, so someone who knows would have to say if it's a good idea.
 
Bill,

Do you have a TinkerCAD account? If not sign up here https://www.tinkercad.com/join and I will create the drawing and share it with you.

We can work on it collaboratively, and when you are satisfied that it meets your needs, I will print it off and get it over to you.

I also use Fusion360, however, if you are not familiar with CAD, then TinkerCAD is likely the easiest to navigate, plus it saves the files in a native 3D printing format. Besides a project like this is well suited for TinerCAD.
 
Thanks much, I just signed up for a TinkerCAD account. Hopefully I'll be able to follow your drawing, although I have no experience with 3D printing.

The thought of a transition came to mind because I have the remnants of a 4.5" rocket (nose cone) and a 5" rocket (bottom section). I was thinking I could combine them into a single working rocket. Whether the transition goes near the top or the bottom would depend on whether I can get a better deal by purchase or trade on a section of 5" or 4.5" fiberglass for the airframe (transition near the bottom if 4.5", transition near the top if 5").

I like Thorfire's drawing, the only possible issue is that the centering rings would be quite thin, less than 0.5", and I would not be able to make them myself, I don't have any machine tools.
jart base and 4.5 NC.jpg
 
Bill,

Do you have a TinkerCAD account? If not sign up here https://www.tinkercad.com/join and I will create the drawing and share it with you.

We can work on it collaboratively, and when you are satisfied that it meets your needs, I will print it off and get it over to you.

I also use Fusion360, however, if you are not familiar with CAD, then TinkerCAD is likely the easiest to navigate, plus it saves the files in a native 3D printing format. Besides a project like this is well suited for TinerCAD.

I just signed up for TinkerCAD what do you need in order to share the drawing? I'd love to look at it
 
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