bolt retainers for body tube

[burnout]

What do you guys use in the body tube to retain a bolt on a 2" body tube(the coupler to be precise)?
I want to attach a removable section of my rocket. I also want a retainer for my nosecone which I suspect would be a different but similar setup. I could glue a nut on the inside of the tube but I'm guessing there is something better I haven't thought of. If there are some suggestions I would appreciate it. Thanks.

 

[cwbullet]

There are many methods.

1) Use plastic rivots:
View attachment 112775

2) PEM nuts inserted


3) I use weld nut epoxied into place.


I am sure you come up with 100s more.

 

[qquake2k]

There are also well nuts:

https://www.mcmaster.com/#well-nuts/=l2pjfx

Or can you epoxy pieces of plywood inside and use sheet metal or wood screws?

 

[cwbullet]

Well nuts work well if you need to add them after the rocket is built.

 

[UncleVanya]

There are also well nuts:

https://www.mcmaster.com/#well-nuts/=l2pjfx

Or can you epoxy pieces of plywood inside and use sheet metal or wood screws?

Well nuts work well if you need to add them after the rocket is built.

I think they work for attaching something like a rail button - but I don't see this working for a slip on / slip off section - the top of the well buton sits on top of the material it is inserted into - and removing it from the hole after expansion is not simple - I have a rocket that I screwed up switching to rail buttons - the interchangable mount is captive of the lower rail button but I cannot get the well nut out anymore after letting it sit.

 

[cwbullet]

I see your point, but the do work. They are absolutely not ideal for section attachment or av bays.

 

[kandsrockets]

I epoxy t-nuts on the inside and use button head screws to attach the parts together.

 

[cwbullet]

I epoxy t-nuts on the inside and use button head screws to attach the parts together.
View attachment 113108

Either I use T nuts or Weld nuts epoxied in place.

 

[rstaff3]

I like the rivets shown above the best (got mine from Giant Leap). On even smallish MPR rockets, however, I've merely used any old screws. Cap screws look the coolest IMO but are most draggy. I drill the holes and treat them with thin CA. The only times they've shown a bit of wear is in a landing event that caused a bit of wear elsewhere on the rocket!

 

[awseiger]

I've used the rivets and I honestly dislike them. Too many little parts to use that are expensive to replace.

Use the T-nuts or welding nuts, and then use pan head screws. That way, you can buy buckets of the screws and if you loose one... Oh well!

For smaller rockets, my Dad and I have had some success using nylon nuts epoxied in place, using nylon screws as the retainer. Super light, and perfectly strong for a 2in rocket.
To do this, get metal screws that fit inside the nylon nuts, and dip the metal screws in some kind of light oil. Then, secure the nut against where it should go with the metal screw and apply epoxy. When the epoxy cures, the metal screw should come right out and the nylon one will happily go in it's place. A good coating of oil on the metal screw is important here.

 

[burnout]

Thanks for the ideas.

 

[cwbullet]

It truely is all about preference. The one benefit of the rivets in a fiberglass rocket is that the rivet should break before the tube ins crash.

 

[rstaff3]

My feeble mind thought cardboard when I replied earlier. CA not required for fiberglass.