Cardboard vs Fiberglass for minimum diameter

Hey guys,

I was wondering if anyone uses cardboard for md rockets. Ive only seen carbon fiber or fiberglass so far, never cardboard. Whats the reason for this? I assume it is due to the fact that minimum diameter rockets go higher, faster and more stresses are exerted on it (also the heat if its supersonic). Carbon fiber and fiberglass can handle this but i doubt cardboard can. Any reason besides this?

Thanks, Littlemisterbig

littlemisterbig said:

Hey guys,

I was wondering if anyone uses cardboard for md rockets. Ive only seen carbon fiber or fiberglass so far, never cardboard. Whats the reason for this? I assume it is due to the fact that minimum diameter rockets go higher, faster and more stresses are exerted on it (also the heat if its supersonic). Carbon fiber and fiberglass can handle this but i doubt cardboard can. Any reason besides this?

Thanks, Littlemisterbig

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How fast do you an on going??

Im not asking this for myself, i ask this because ive never really seen cardboard md rockets.

littlemisterbig said:

Im not asking this for myself, i ask this because ive never really seen cardboard md rockets.

Click to expand...

lots of people make them. many are paper,blue tube, phenolic and anything else you can think of. Many times people use carbon and fiberglass she it is not entirely necessary. for example besides its strength many people use carbon for it's gorgeous look.

Many cases carbon fiber or fiber glass is not needed but because of strong marketing and Internet furums it is used.

M

I think durability is the main reason for carbon and filament wound glass.

Granted they are really strong, so if you are going to really push it the cd or glass wound tubes are likely the way to go. I do think a lot of this tubes are thicker and heavier than they need to be though.


Mark Koelsch
Sent from my iPhone using Rocketry Forum

There is a difference between cardboard and phenolic. Both have their pro's and con's, but it all depends on design and how fast you are going.

I believe there was a video of an LOC kit going past Mach 1. It was a cardboard tube with no reinforcements. It survived the flight with no issue. I will have to look for it.


Alexander Solis

TRA - Level 1
Mariah 54 - CTI RedLightning- I-100 - 6,345 Feet

LOC cardboard is good for a bit past Mach. My Nuke Pro Maxx has been to M1.3 completely unglassed. The PML Cirrus is a 38mm Phenolic min diameter. There have been plenty of Blue Tube minimum diameter builds. The real question is what diameter. I wouldn't build anything past 38mm in paper myself.

grouch said:

LOC cardboard is good for a bit past Mach. My Nuke Pro Maxx has been to M1.3 completely unglassed. The PML Cirrus is a 38mm Phenolic min diameter. There have been plenty of Blue Tube minimum diameter builds. The real question is what diameter. I wouldn't build anything past 38mm in paper myself.

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Thickness varies as well. 29 and 38 are pretty stout. 54 is beefy. 75 is ok but getting comparably thinner. 3.9 is like tissue paper.

SinfulDarkLord said:

There is a difference between cardboard and phenolic. Both have their pro's and con's, but it all depends on design and how fast you are going.

I believe there was a video of an LOC kit going past Mach 1. It was a cardboard tube with no reinforcements. It survived the flight with no issue. I will have to look for it.


Alexander Solis

TRA - Level 1
Mariah 54 - CTI RedLightning- I-100 - 6,345 Feet

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Not my video but I did that myself. Rocket survived fine. Next launch it was Bonged- landed in water and was trashed. Built a new one that I classed and it survived much longer.


Mark Koelsch
Sent from my iPhone using Rocketry Forum

I have used Giant Leap Magnaframe in 38mm and 2.56 diameters up to Mach 1.3. I flew my scratch built to just under 16,000 ft in a 2.56inch rocket near minimum diameter on a 54mm CTI K-490 (five grain). I also flew a K-780 in it with some wind effect, which reduced the altitude. I am nervous about a bigger motor, as I have some stress cracks in the body tube. Don't know if they're from flight or landings. It's not as durable as fiberglass, or so it appears.

I used the Magnaframe to minimize weight. Magnaframe seems tougher than paper. I have used blue tube in 38mm too.