Suggestions for securing coupler to payload tube with very thick FG.

[Bat-mite]

Up till now, I have secured my coupler to the payload tube using these or similar (Grainger, McMaster, Zoro, Amazon).

I drilled my Formula 200 with five 1/4" holes, dropped the coupler into payload tube, and tried to stick in a rivet. Woops. The material thickness is 0.29 inches, which greatly exceeds the 0.217-inch maximum for these rivets.

For the life of me, I can't find longer ones anywhere! And I have looked at other kinds of push-in rivets, but none of them seems like a good alternative.

I guess I could use weld nuts and screws, but that is more of a pain than pushing in a rivets.

Any suggestions, or does anyone know where I can get snap-in rivets with a 1/4" shaft and longer shank?

 

[Banzai88]

Was linking to McMaster, but their biggest in that size is .217 thickness. Dang.

It's fiberglass. I'd switch over to Pem nuts and fasteners.

https://www.mcmaster.com/#catalog/122/3229/=14gt7ge

 

[Bat-mite]

Think I'm going to go with these: https://www.mcmaster.com/#98001a120/=14gtvyl

 

[Onebadhawk]

John,
I'll agree that the build is more time consuming
to epoxy a steel nut ( pem, weld, or tee ) in place on the inside of the coupler tube...
But after that's done I don't think the steel screws are more difficult....
I've switched and wouldn't go back to plastic rivets again. ..

Teddy

 

[Tonimus]

Get in there with a large drill bit and drill the backside until it is only 0.217" thick. Or a dremel with a sanding drum.

 

[fyrwrxz]

Up till now, I have secured my coupler to the payload tube using these or similar (Grainger, McMaster, Zoro, Amazon).

I drilled my Formula 200 with five 1/4" holes, dropped the coupler into payload tube, and tried to stick in a rivet. Woops. The material thickness is 0.29 inches, which greatly exceeds the 0.217-inch maximum for these rivets.

For the life of me, I can't find longer ones anywhere! And I have looked at other kinds of push-in rivets, but none of them seems like a good alternative.

I guess I could use weld nuts and screws, but that is more of a pain than pushing in a rivets.

Any suggestions, or does anyone know where I can get snap-in rivets with a 1/4" shaft and longer shank?

Bat- Pm me your addy-I may have a solution. No- you can't order these as I found them in an electronics salvage recycling place. They get crap from local shops when they switch product lines. San Diego used to be a big aerospace hub, so you can find all kinds of interesting garbage to re-purpose.

 

[Bat-mite]

Get in there with a large drill bit and drill the backside until it is only 0.217" thick. Or a dremel with a sanding drum.

Not sure what that does to the structural integrity during ejection charge ignition. Doesn't seem worth the risk.

 

[Bat-mite]

Bat- Pm me your addy-I may have a solution. No- you can't order these as I found them in an electronics salvage recycling place. They get crap from local shops when they switch product lines. San Diego used to be a big aerospace hub, so you can find all kinds of interesting garbage to re-purpose.

Thanks. That is very kind of you. But I am going with weld nuts and screws. Ordered yesterday from McMaster and they are already on the UPS truck for delivery today! :jaw:

 

[fyrwrxz]

Thanks. That is very kind of you. But I am going with weld nuts and screws. Ordered yesterday from McMaster and they are already on the UPS truck for delivery today! :jaw:

It's all good , brother. Yours for the asking, anytime.