Launch Rail Questions

So, based off some recent advice, I am now going to outfit my 29mm MMT rockets with both lugs and rails buttons. I'm considering doing the same with my 24mm MMT rockets. As I am not afraid to invest in my hobby, I'm considering doing them in varying sizes. I've seen images on here of what looked like 3 sizes of buttons. Where can I find more info on rails and buttons and where is an inexpensive place to purchase them?

The 24mm MMTs will have 3/16 lugs and medium buttons. The 29mm MMTs will have 1/4 lugs and probably the larger buttons.

As far as rail buttons go, there isn't really a need for anything larger than a 1010 rail button until your rockets get really big. The rails that everyone uses are the 1010 series from 80/20. They come in various lengths and have 4 slotted sections so you can rotate it when one side gets dirty and clean the whole thing at once. Check out the reviews.

Amazon link: https://www.amazon.com/dp/B001F0F112/?tag=skimlinks_replacement-20

Concerning the buttons, I like Giant Leap's site. It shows you a variety of types of rail guides. I'm a particular fan of the conformal rail guides.

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

Those should give you a place to learn about them like you wanted.

There are a couple threads here about smaller rails...railbuttons.com is offering smaller buttons ("Mini" and "Micro") that will work on MPR and LPR rockets. Here is a summary comparison of those rails to the 1010 HeavyLight mentioned...

here is one of those threads https://www.rocketryforum.com/showthread.php?63585-Interest-in-mini-railbuttons

Ok. What buttons would you recommend for the Estes PSII? We are building the entire fleet. All 11 rockets. We are also building them to be 29/40-120 compatible. Going to use a spacer block so they will remain BP compatible also. I'm pretty sure the club is going to use the 1010 rails. Seems they are what most everyone uses. The giant leap airfoil buttons look very interesting, just not sure they reduce enough drag to justify the cost.

Also, I see they are threaded. Are you supposed to put nuts on the back or just screw them to the BT with epoxy?

I would certainly use the standard buttons available through a number of sources. I typically buy from rail-buttons.com. If you are really looking to reduce drag, then look into flyaway guides. There is information on this on Apogee's. Then again, I doubt most people will notice the drag.

Standard 1-piece 1010 buttons will work perfectly on any Estes Pro Series II rocket and allow you to fly from the 1010 rails at your club launch.

https://rail-buttons.com/1010delrin.html

This method works great on fully constructed "paper tube" rockets. The nice thing about this method is it does not require any additional nuts or other hardware. You don't need to drill into a centering ring etc.

To mount standard (1010) rail buttons on a paper tube rocket:

Step 1 - adjust the fit of one-piece rail buttons.
Wrap a sheet of sandpaper around the airframe, and use the curvature of the airframe to lightly sand a slight concave shape on one end of each rail button. This helps the button fit the tube better and gives some tooth for the epoxy. Only a slight adjustment is needed, try not to over-do it.

Step 2 - thread some holes in the airframe.
Drill holes using a 7/64" drill bit or a #36 drill bit if you have one.
A little sanding to clean up the holes on the outside of the rocket.
A drop of thin CA to harden up the edges of the hole.
Use a #6-32 tap to put threads in the hole.

Step 3 - Intall the buttons.
Cheap 5-minute epoxy works fine. No need to use expensive stuff or the kind that takes forever to set-up.
"Butter" the sanded end of the rail button with a tiny bit of epoxy.
A tiny bit of epoxy in/around the airframe hole and a tiny bit on the exposed threads of the screw.
As you screw in the rail button, you should see a bit of epoxy oose out from between the button and air frame. Tighten the screw gently till "snug" being carefull not to overdo it and strip the threads.

I have never lost a rail button with this method on both "thin" paper tubes (BT60 and BT 80) and "heavy-wall" paper tubes like Estes Pro Series II or LOC tubes - and motors up to "H" power.

Very nice. I'm ordering the 1010 low drag buttons. I'm also looking at ordering a rail and the mini buttons for my 24mm E rockets. I figure it'll be a good low end experience for my boys and wife. Get them ready for true MPR.

Ordering retainer ring sets and all. My wife is going to build the E motor SL3 Magician as soon as I get the Kevlar shock cord and rail buttons.

On my PSII Leviathan, I bought the "aftermarket" rail buttons that have pointed screws instead of machine screws. Soaked the screw and tube in CA glue, and poked/threaded in the button. The CA hardens the tube as well as gluing the screw in.

Been holding up for several launches with no sign of fatigue.