Best way to retrofit rockets with rail buttons?

What is the best way to retrofit already made rockets with rail buttons? I have a 4inch diameter bird that I'd like to put buttons on but cant access the tube due to the motor mount already being in place.

Thank you!

Drill a hole. Fill hole with epoxy. Screw in rail button. Fly.

I e done this skipping the epoxy minutes before flight (oops, don't ask why ).

That depends a bit on the type of rocket. How long & heavy is it? What size motor tube is in there?

On some rockets you can attach the buttons with rubber-insulated rivet nuts, also known as well nuts. Others may require more buildup of material so you can screw the button in. If the centering rings are wood you may be able to screw a button into the side of a centering ring.

Of course, I will mention that 98mm fly-away rail guides will be available very soon, but again the appropriateness of that depends on the rocket.

To elaborate, get the rail buttons that come with pointy screws, not machine screws. Depending on what the tube is made of, you may be better served using CA glue than epoxy. I did this with my Leviathan, G-Force, Sumo, and MDRM.

DizWolf said:

Drill a hole. Fill hole with epoxy. Screw in rail button. Fly.

I e done this skipping the epoxy minutes before flight (oops, don't ask why ).

Click to expand...

This is what I do. Rest it rail button side down while the epoxy is curing. All good.

wfcook said:

That depends a bit on the type of rocket. How long & heavy is it? What size motor tube is in there?

On some rockets you can attach the buttons with rubber-insulated rivet nuts, also known as well nuts. Others may require more buildup of material so you can screw the button in. If the centering rings are wood you may be able to screw a button into the side of a centering ring.

Of course, I will mention that 98mm fly-away rail guides will be available very soon, but again the appropriateness of that depends on the rocket.

Click to expand...

It's an aerotech Gforce. 60 inches and four inch diameter with 29mm motor mount

Just like mine. Get screw-in rail buttons. Screw them in, back them out. Add CA to the hole; wait for it to dry. Add some CA to the screw and screw them back in. Done.

RalPh8 said:

It's an aerotech Gforce. 60 inches and four inch diameter with 29mm motor mount

Click to expand...

Here's how I handled it on my Aerotech Arreaux. Aerotech provides an interesting opportunity due to the style of their launch lugs (I assume the G-Force uses the same ones)

Mr Rocket said:

View attachment 287401

Click to expand...

Brilliant!

Glue these on.

Mr Rocket said:

Here's how I handled it on my Aerotech Arreaux. Aerotech provides an interesting opportunity due to the style of their launch lugs (I assume the G-Force uses the same ones)

View attachment 287401

Click to expand...

Man! Wish I had thought of that!

RalPh8 said:

What is the best way to retrofit already made rockets with rail buttons? I have a 4inch diameter bird that I'd like to put buttons on but cant access the tube due to the motor mount already being in place.

Thank you!

Click to expand...

Conformal rail guides are awesome:

https://giantleaprocketry.com/products/components_launch_systems.aspx

Look up wellnuts: https://www.ebay.com/sch/i.html?_fr...2.A0.H0.Xwellnuts.TRS0&_nkw=wellnuts&_sacat=0

or jacknuts: https://www.ebay.com/sch/i.html?_od...C0.H0.XJack+nuts.TRS0&_nkw=Jack+nuts&_sacat=0

Yeah, only good for glass birds and not minimum diameter projects.

This is for button mounting of course and there is a little bit of a standoff but if you need a higher standoff use a longer screw with a spacer.

You can melt a button off the rocket but it wll not wrench out especially with a jacknut. Kurt

ksaves2 said:

Look up wellnuts: https://www.ebay.com/sch/i.html?_fr...2.A0.H0.Xwellnuts.TRS0&_nkw=wellnuts&_sacat=0

or jacknuts: https://www.ebay.com/sch/i.html?_od...C0.H0.XJack+nuts.TRS0&_nkw=Jack+nuts&_sacat=0

Yeah, only good for glass birds and not minimum diameter projects.

This is for button mounting of course and there is a little bit of a standoff but if you need a higher standoff use a longer screw with a spacer.

You can melt a button off the rocket but it wll not wrench out especially with a jacknut. Kurt

Click to expand...

Actually well nuts work just fine with fiberboard airframes. You need to drill a 5/16" hole in your airframe for buttons using 8-32 screws, a 3/8" diameter hole for buttons using 10-32 screws, or a 1/2" diameter hole for buttons using 1/4-20 screws. The simply insert the well nut into the hole from outside the rocket and screw in the rail button. The bottom of the well nut will be pulled up against the inside of the airframe to strongly hold the unit to the airframe as shown in the drawing below. The best part is that you can remove the whole assembly by simply unscrewing the rail button and lifting the well nut out of the hole. Just make sure you order the proper well nut for the thickness of your airframe. For the ones below from Mamaster.com, the shorter ones are what you want for most rockets.

Rubber-Insulated Rivet Nuts










Your fastener sets the insert as you screw it into thin and brittle materials — no special tools needed.
Rubber-insulated brass nuts, also known as well nuts, seal out moisture and reduce vibration.
For technical drawings and 3-D models, click on a part number.