Securing rail button to rocket, screw seems too long?

[billdz]

Hello,
A 1010 rail button fell off of my rocket so I need to replace it. I have some spares but, as seen in the attached photo, the screw is quite long, it will go through the body tube and protrude inside. I'm concerned the screw may snag the shock cord or chute. Is this a valid concern? If yes, how to fix? Cut the screw shorter?
Thanks,
b

 

[Art Upton]

Yes that screw with a point can snag recovery items. I've cut a few down, but now just get the right length screw without a point.

Edit: I assume you do not have an old school hardware store still left in town with drawers and drawers of almost every screw known to man do you? I'm lucky we still have an old Pro Hardware and lumber still here.

 

[Rocketholic]

Depending on how thick your body tube is, go ahead and cut/grind it down. If you're inserting it into the hole that is already there it shouldn't be a problem unless the tube is thin and the hole is big.

I wasn't terribly convinced thin-ish body tubes would do a good job of holding the buttons on my rockets. I took an old body tube that I had to cut off at/through a coupler and cut some small pieces around 3/4" on a side and laminated them together. This small stack of 2-3 curved, cut/laminated, pieces got glued inside the body tube where the rail button was to go. Then drilled a small pilot hole and used the screw to make its own threads through the cardboard hard-spot. Trimmed/ground the tip off the screw and no issues whatsoever.
The whole assembly is maybe 3/16" thick not including the body tube so there's no real weight gain or obtrusive bulge on the inside.

You can laminate pretty much any cardboard pieces and bend them to your will. Cereal boxes and Cheeze-it boxes are great sources! LOL

You may need to come up with some creative ways to get down inside a finished rocket though. I used a 1/4 x 1/4" long wooden stick with a pin jammed though the end to lightly hold one of mine while threading down the tube. A thin layer of epoxy on it will adhere it to the tube and the pin will easily release with a little wiggle.

 

[Wrightme43]

You can use a file or a sander to shorten screws as well.

I use @Onebadhawk method with t-nuts upside down epoxied in, and mounded smoothed epoxy so nothing can snag.

Ted is a sharp cat.

 

[Dave S.]

Instead of those pointy wood screws I use machine screws with Lab Rat Rail button nuts. I have a bunch of machine screws of the right diameter and a flat head and a variety of different lengths. I can always use one that doesn’t stick out inside the tube for anything to catch on.

https://www.labratrocketry.com/rail-button-nuts

 

[sriegel]

Put a T-nut inside the tube and screw into that. It's a rock solid mounting and the nut backing is flat enough not to be any real issue inside the tube.

You can run a line from outside the tube through the hole in the tube and then out the tube front. Feed the T-nut onto the line, tie a knot behind the nut, and pull it down the tube to seat through the tube wall. Tack with CA. Pull the string back out the front of the tube. Screw on the rail button.

 

[John Kemker]

Well nuts.

Well, nuts.

 

[Bruiser]

I am finding this a little funny. Not too long ago someone posted about the rail buttons Estes is now selling are lacking nuts. There were so many replies saying just to epoxy the screw in and it will hold. Now here's this thread and peeps are saying to use t-nuts.

Personally I like to use Dubro blind nuts but they are kinda hard to come by without a local hobby shop. Amazon is lacking the correct size every time I've looked.

Apogee and someone else sells rail buttons that come with t-nuts. The buttons are sized so that the barrel of the t-nut actually fits inside the rail button. That does make a nice, clean install.

-Bob

 

[dmaaero]

Blind nuts with blue Loctite gets my vote.

 

[Art Upton]

I am finding this a little funny. Not too long ago someone posted about the rail buttons Estes is now selling are lacking nuts. There were so many replies saying just to epoxy the screw in and it will hold. Now here's this thread and peeps are saying to use t-nuts.

Personally I like to use Dubro blind nuts but they are kinda hard to come by without a local hobby shop. Amazon is lacking the correct size every time I've looked.

Apogee and someone else sells rail buttons that come with t-nuts. The buttons are sized so that the barrel of the t-nut actually fits inside the rail button. That does make a nice, clean install.

-Bob

I do not use nuts on the inside. They hold fine in the body epoxied if the pilot hole is slightly smaller then the screw.
On 5-7" large rockets I put them into the centering ring.

 

[billdz]

Thanks for the replies, I'll figure it out somehow