Rail Button Installation

I've tried installing rail buttons into the centering rings but I didn't get the holes perfectly perpendicular to the body tube so when I attached the buttons they were angled in different directions. I don't have a drill press and fixture to go with it, so I'm not sure how I would ever install them straight. So, since that didn't work out so well I'm going to try wellnuts instead. I'm hoping I don't have the same problem if the holes are not exactly perpendicular. Will I have the same problem with the wellnuts? Any tips on getting the buttons in the correct orientation if I try to attach to centering rings again?

Thanks,
Chris

Hi Chris. I use well nuts and haven't had any problem with alignment. I do check with a straight edge, though. Good luck on your next try.

I use sheetmetal/wood screws. For fiberglass and other hard tube I predrill a hole with a hand drill. For paper tube you can just screw it right in. Remember to leave the button loose enough to spin.

karlbaum said:

I use sheetmetal/wood screws. For fiberglass and other hard tube I predrill a hole with a hand drill. For paper tube you can just screw it right in. Remember to leave the button loose enough to spin.

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Why do you want the button to spin? I've always tightend the screw enough that the buttons won't spin. The only issue I've ever had with buttons was when I've had them slightly loose and the button would spin. I tried it on one rocket and it hung for a moment on a joint in a 3 piece Blacksky rail. Same rocket and same rail but with the buttons tight and it flew fine.

I think some folks leave them loose so they don't develop a wear pattern. I personally keep them tight - they're cheap, and I don't like loose parts on my rockets until they land...

On one piece buttons, I make them snug. On the 3-piece nylon ones from railbuttons.com, I keep them loose. I relate why I started in a moment, but it seems that this lets rockets slide easier when the rails are all cruddy. On a clean rail, these don't wear badly, but they can when the rail is not smooth.

Having the 3-piece buttons loose also helps if the buttons are not aligned evenly with the body tube. On an installation in your rocket shop, this shouldn't be an issue. But it may be for field installations (retrofits, fixes, etc). I build a lot of odd stuff and had built a big posterboard/foamboard rocket. I put the buttons in chunks of wood but the hardpoints for the wood pieces weren't so hard themselves. When I fixed it on the field, it was binding on my rail a bit. I found that when I loosened the buttons, it sled freely.

Just food for thought.

When buttons are able to spin they roll on the rail instead of dragging on the rail. And we all know that drag is a bad thing for rockets. Also they don't last very long when they wear down.